init/main.c: Fix potential static_command_line memory overflow

We allocate memory of size 'xlen + strlen(boot_command_line) + 1' for
static_command_line, but the strings copied into static_command_line are
extra_command_line and command_line, rather than extra_command_line and
boot_command_line.

When strlen(command_line) > strlen(boot_command_line), static_command_line
will overflow.

This patch just recovers strlen(command_line) which was miss-consolidated
with strlen(boot_command_line) in the commit f5c7310ac73e ("init/main: add
checks for the return value of memblock_alloc*()")

Link: https://lore.kernel.org/all/20240412081733.35925-2-ytcoode@gmail.com/

Fixes: f5c7310ac73e ("init/main: add checks for the return value of memblock_alloc*()")
Cc: stable@vger.kernel.org
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

fs/proc: Skip bootloader comment if no embedded kernel parameters

If the "bootconfig" kernel command-line argument was specified or if
the kernel was built with CONFIG_BOOT_CONFIG_FORCE, but if there are
no embedded kernel parameter, omit the "# Parameters from bootloader:"
comment from the /proc/bootconfig file. This will cause automation
to fall back to the /proc/cmdline file, which will be identical to the
comment in this no-embedded-kernel-parameters case.

Link: https://lore.kernel.org/all/20240409044358.1156477-2-paulmck@kernel.org/

Fixes: 8b8ce6c75430 ("fs/proc: remove redundant comments from /proc/bootconfig")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: stable@vger.kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

modules: wait do_free_init correctly

The synchronization here is to ensure the ordering of freeing of a module
init so that it happens before W+X checking. It is worth noting it is not
that the freeing was not happening, it is just that our sanity checkers
raced against the permission checkers which assume init memory is already
gone.

Commit 1a7b7d922081 ("modules: Use vmalloc special flag") moved calling
do_free_init() into a global workqueue instead of relying on it being
called through call_rcu(..., do_free_init), which used to allowed us call
do_free_init() asynchronously after the end of a subsequent grace period.
The move to a global workqueue broke the gaurantees for code which needed
to be sure the do_free_init() would complete with rcu_barrier(). To fix
this callers which used to rely on rcu_barrier() must now instead use
flush_work(&init_free_wq).

Without this fix, we still could encounter false positive reports in W+X
checking since the rcu_barrier() here can not ensure the ordering now.

Even worse, the rcu_barrier() can introduce significant delay. Eric
Chanudet reported that the rcu_barrier introduces ~0.1s delay on a
PREEMPT_RT kernel.

[ 0.291444] Freeing unused kernel memory: 5568K
[ 0.402442] Run /sbin/init as init process

With this fix, the above delay can be eliminated.

Link: https://lkml.kernel.org/r/20240227023546.2490667-1-changbin.du@huawei.com
Fixes: 1a7b7d922081 ("modules: Use vmalloc special flag")
Signed-off-by: Changbin Du <changbin.du@huawei.com>
Tested-by: Eric Chanudet <echanude@redhat.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Xiaoyi Su <suxiaoyi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

init: remove obsolete arch_call_rest_init() wrapper

Since commit 3570ee046c46b5dc ("s390/smp: keep the original lowcore for
CPU 0"), there is no longer any architecture that needs to override
arch_call_rest_init().

Remove the weak wrapper around rest_init(), call rest_init() directly, and
make rest_init() static.

Link: https://lkml.kernel.org/r/aa10868bfb176eef4abb8bb4a710b85330792694.1706106183.git.geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arm64, powerpc, riscv, s390, x86: ptdump: refactor CONFIG_DEBUG_WX

All architectures using the core ptdump functionality also implement
CONFIG_DEBUG_WX, and they all do it more or less the same way, with a
function called debug_checkwx() that is called by mark_rodata_ro(), which
is a substitute to ptdump_check_wx() when CONFIG_DEBUG_WX is set and a
no-op otherwise.

Refactor by centrally defining debug_checkwx() in linux/ptdump.h and call
debug_checkwx() immediately after calling mark_rodata_ro() instead of
calling it at the end of every mark_rodata_ro().

On x86_32, mark_rodata_ro() first checks __supported_pte_mask has _PAGE_NX
before calling debug_checkwx(). Now the check is inside the callee
ptdump_walk_pgd_level_checkwx().

On powerpc_64, mark_rodata_ro() bails out early before calling
ptdump_check_wx() when the MMU doesn't have KERNEL_RO feature. The check
is now also done in ptdump_check_wx() as it is called outside
mark_rodata_ro().

Link: https://lkml.kernel.org/r/a59b102d7964261d31ead0316a9f18628e4e7a8e.1706610398.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg KH <greg@kroah.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Phong Tran <tranmanphong@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Steven Price <steven.price@arm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

init: Declare rodata_enabled and mark_rodata_ro() at all time

Declaring rodata_enabled and mark_rodata_ro() at all time
helps removing related #ifdefery in C files.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

smp: Consolidate smp_prepare_boot_cpu()

There is no point in having seven architectures implementing the same empty
stub.

Provide a weak function in the init code and remove the stubs.

This also allows to utilize the function on UP which is required to
sanitize the per CPU handling on X86 UP.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240304005104.567671691@linutronix.de

pidfd: add pidfs

This moves pidfds from the anonymous inode infrastructure to a tiny
pseudo filesystem. This has been on my todo for quite a while as it will
unblock further work that we weren't able to do simply because of the
very justified limitations of anonymous inodes. Moving pidfds to a tiny
pseudo filesystem allows:

* statx() on pidfds becomes useful for the first time.
* pidfds can be compared simply via statx() and then comparing inode
numbers.
* pidfds have unique inode numbers for the system lifetime.
* struct pid is now stashed in inode->i_private instead of
file->private_data. This means it is now possible to introduce
concepts that operate on a process once all file descriptors have been
closed. A concrete example is kill-on-last-close.
* file->private_data is freed up for per-file options for pidfds.
* Each struct pid will refer to a different inode but the same struct
pid will refer to the same inode if it's opened multiple times. In
contrast to now where each struct pid refers to the same inode. Even
if we were to move to anon_inode_create_getfile() which creates new
inodes we'd still be associating the same struct pid with multiple
different inodes.

The tiny pseudo filesystem is not visible anywhere in userspace exactly
like e.g., pipefs and sockfs. There's no lookup, there's no complex
inode operations, nothing. Dentries and inodes are always deleted when
the last pidfd is closed.

We allocate a new inode for each struct pid and we reuse that inode for
all pidfds. We use iget_locked() to find that inode again based on the
inode number which isn't recycled. We allocate a new dentry for each
pidfd that uses the same inode. That is similar to anonymous inodes
which reuse the same inode for thousands of dentries. For pidfds we're
talking way less than that. There usually won't be a lot of concurrent
openers of the same struct pid. They can probably often be counted on
two hands. I know that systemd does use separate pidfd for the same
struct pid for various complex process tracking issues. So I think with
that things actually become way simpler. Especially because we don't
have to care about lookup. Dentries and inodes continue to be always
deleted.

The code is entirely optional and fairly small. If it's not selected we
fallback to anonymous inodes. Heavily inspired by nsfs which uses a
similar stashing mechanism just for namespaces.

Link: https://lore.kernel.org/r/20240213-vfs-pidfd_fs-v1-2-f863f58cfce1@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

smp: Provide 'setup_max_cpus' definition on UP too

This was already defined locally by init/main.c, but let's make
it generic, as arch/x86/kernel/cpu/topology.c is going to make
use of it to have more uniform code.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

async: Use a dedicated unbound workqueue with raised min_active

Async can schedule a number of interdependent work items. However, since
5797b1c18919 ("workqueue: Implement system-wide nr_active enforcement for
unbound workqueues"), unbound workqueues have separate min_active which sets
the number of interdependent work items that can be handled. This default
value is 8 which isn't sufficient for async and can lead to stalls during
resume from suspend in some cases.

Let's use a dedicated unbound workqueue with raised min_active.

Link: http://lkml.kernel.org/r/708a65cc-79ec-44a6-8454-a93d0f3114c3@samsung.com
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

proc: sysctl: prevent aliased sysctls from getting passed to init

The code that checks for unknown boot options is unaware of the sysctl
alias facility, which maps bootparams to sysctl values. If a user sets
an old value that has a valid alias, a message about an invalid
parameter will be printed during boot, and the parameter will get passed
to init. Fix by checking for the existence of aliased parameters in the
unknown boot parameter code. If an alias exists, don't return an error
or pass the value to init.

Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Cc: stable@vger.kernel.org
Fixes: 0a477e1ae21b ("kernel/sysctl: support handling command line aliases")
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

workqueue: Initialize unbound CPU pods later in the boot

During boot, to initialize unbound CPU pods, wq_pod_init() was called from
workqueue_init(). This is early enough for NUMA nodes to be set up but
before SMP is brought up and CPU topology information is populated.

Workqueue is in the process of improving CPU locality for unbound workqueues
and will need access to topology information during pod init. This adds a
new init function workqueue_init_topology() which is called after CPU
topology information is available and replaces wq_pod_init().

As unbound CPU pods are now initialized after workqueues are activated, we
need to revisit the workqueues to apply the pod configuration. Workqueues
which are created before workqueue_init_topology() are set up so that they
always use the default worker pool. After pods are set up in
workqueue_init_topology(), wq_update_pod() is called on all existing
workqueues to update the pool associations accordingly.

Note that wq_update_pod_attrs_buf allocation is moved to
workqueue_init_early(). This isn't necessary right now but enables further
generalization of pod handling in the future.

This patch changes the initialization sequence but the end result should be
the same.

Signed-off-by: Tejun Heo <tj@kernel.org>

init, x86: Move mem_encrypt_init() into arch_cpu_finalize_init()

Invoke the X86ism mem_encrypt_init() from X86 arch_cpu_finalize_init() and
remove the weak fallback from the core code.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224545.670360645@linutronix.de

init: Invoke arch_cpu_finalize_init() earlier

X86 is reworking the boot process so that initializations which are not
required during early boot can be moved into the late boot process and out
of the fragile and restricted initial boot phase.

arch_cpu_finalize_init() is the obvious place to do such initializations,
but arch_cpu_finalize_init() is invoked too late in start_kernel() e.g. for
initializing the FPU completely. fork_init() requires that the FPU is
initialized as the size of task_struct on X86 depends on the size of the
required FPU register buffer.

Fortunately none of the init calls between calibrate_delay() and
arch_cpu_finalize_init() is relevant for the functionality of
arch_cpu_finalize_init().

Invoke it right after calibrate_delay() where everything which is relevant
for arch_cpu_finalize_init() has been set up already.

No functional change intended.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Link: https://lore.kernel.org/r/20230613224545.612182854@linutronix.de

init: Remove check_bugs() leftovers

Everything is converted over to arch_cpu_finalize_init(). Remove the
check_bugs() leftovers including the empty stubs in asm-generic, alpha,
parisc, powerpc and xtensa.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Link: https://lore.kernel.org/r/20230613224545.553215951@linutronix.de

init: Provide arch_cpu_finalize_init()

check_bugs() has become a dumping ground for all sorts of activities to
finalize the CPU initialization before running the rest of the init code.

Most are empty, a few do actual bug checks, some do alternative patching
and some cobble a CPU advertisement string together....

Aside of that the current implementation requires duplicated function
declaration and mostly empty header files for them.

Provide a new function arch_cpu_finalize_init(). Provide a generic
declaration if CONFIG_ARCH_HAS_CPU_FINALIZE_INIT is selected and a stub
inline otherwise.

This requires a temporary #ifdef in start_kernel() which will be removed
along with check_bugs() once the architectures are converted over.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224544.957805717@linutronix.de

init: consolidate prototypes in linux/init.h

The init/main.c file contains some extern declarations for functions
defined in architecture code, and it defines some other functions that are
called from architecture code with a custom prototype. Both of those
result in warnings with 'make W=1':

init/calibrate.c:261:37: error: no previous prototype for 'calibrate_delay_is_known' [-Werror=missing-prototypes]
init/main.c:790:20: error: no previous prototype for 'mem_encrypt_init' [-Werror=missing-prototypes]
init/main.c:792:20: error: no previous prototype for 'poking_init' [-Werror=missing-prototypes]
arch/arm64/kernel/irq.c:122:13: error: no previous prototype for 'init_IRQ' [-Werror=missing-prototypes]
arch/arm64/kernel/time.c:55:13: error: no previous prototype for 'time_init' [-Werror=missing-prototypes]
arch/x86/kernel/process.c:935:13: error: no previous prototype for 'arch_post_acpi_subsys_init' [-Werror=missing-prototypes]
init/calibrate.c:261:37: error: no previous prototype for 'calibrate_delay_is_known' [-Werror=missing-prototypes]
kernel/fork.c:991:20: error: no previous prototype for 'arch_task_cache_init' [-Werror=missing-prototypes]

Add prototypes for all of these in include/linux/init.h or another
appropriate header, and remove the duplicate declarations from
architecture specific code.

[sfr@canb.auug.org.au: declare time_init_early()]
Link: https://lkml.kernel.org/r/20230519124311.5167221c@canb.auug.org.au
Link: https://lkml.kernel.org/r/20230517131102.934196-12-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

start_kernel: Omit prevent_tail_call_optimization() for newer toolchains

prevent_tail_call_optimization() was added in
commit a9a3ed1eff36 ("x86: Fix early boot crash on gcc-10, third try")
to work around stack canaries getting inserted into functions that would
initialize the stack canary in the first place.

Now that we have no_stack_protector function attribute (gcc-11+,
clang-7+) and use it on start_kernel(), remove the call to
prevent_tail_call_optimization() such that we may one day remove it
outright.

Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20230412-no_stackp-v2-2-116f9fe4bbe7@google.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

start_kernel: Add __no_stack_protector function attribute

Back during the discussion of
commit a9a3ed1eff36 ("x86: Fix early boot crash on gcc-10, third try")
we discussed the need for a function attribute to control the omission
of stack protectors on a per-function basis; at the time Clang had
support for no_stack_protector but GCC did not. This was fixed in
gcc-11. Now that the function attribute is available, let's start using
it.

Callers of boot_init_stack_canary need to use this function attribute
unless they're compiled with -fno-stack-protector, otherwise the canary
stored in the stack slot of the caller will differ upon the call to
boot_init_stack_canary. This will lead to a call to __stack_chk_fail()
then panic.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94722
Link: https://lore.kernel.org/all/20200316130414.GC12561@hirez.programming.kicks-ass.net/
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20230412-no_stackp-v2-1-116f9fe4bbe7@google.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

Signed-off-by: ndesaulniers@google.com <ndesaulniers@google.com>

init: Mark start_kernel() __noreturn

Now that arch_call_rest_init() is __noreturn, mark its caller
start_kernel() __noreturn.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/7069acf026a195f26a88061227fba5a3b0337b9a.1681342859.git.jpoimboe@kernel.org

init: Mark [arch_call_]rest_init() __noreturn

In preparation for improving objtool's handling of weak noreturn
functions, mark start_kernel(), arch_call_rest_init(), and rest_init()
__noreturn.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/7194ed8a989a85b98d92e62df660f4a90435a723.1681342859.git.jpoimboe@kernel.org

init,mm: fold late call to page_ext_init() to page_alloc_init_late()

When deferred initialization of struct pages is enabled, page_ext_init()
must be called after all the deferred initialization is done, but there is
no point to keep it a separate call from kernel_init_freeable() right
after page_alloc_init_late().

Fold the call to page_ext_init() into page_alloc_init_late() and localize
deferred_struct_pages variable.

Link: https://lkml.kernel.org/r/20230321170513.2401534-11-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

init,mm: move mm_init() to mm/mm_init.c and rename it to mm_core_init()

Make mm_init() a part of mm/ codebase. mm_core_init() better describes
what the function does and does not clash with mm_init() in kernel/fork.c

Link: https://lkml.kernel.org/r/20230321170513.2401534-8-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

init: fold build_all_zonelists() and page_alloc_init_cpuhp() to mm_init()

Both build_all_zonelists() and page_alloc_init_cpuhp() must be called
after SMP setup is complete but before the page allocator is set up.

Still, they both are a part of memory management initialization, so move
them to mm_init().

Link: https://lkml.kernel.org/r/20230321170513.2401534-7-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/page_alloc: rename page_alloc_init() to page_alloc_init_cpuhp()

The page_alloc_init() name is really misleading because all this function
does is sets up CPU hotplug callbacks for the page allocator.

Rename it to page_alloc_init_cpuhp() so that name will reflect what the
function does.

Link: https://lkml.kernel.org/r/20230321170513.2401534-6-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

init: Call mem_encrypt_init() after Hyper-V hypercall init is done

Full Hyper-V initialization, including support for hypercalls, is done
as an apic_post_init callback via late_time_init(). mem_encrypt_init()
needs to make hypercalls when it marks swiotlb memory as decrypted.
But mem_encrypt_init() is currently called a few lines before
late_time_init(), so the hypercalls don't work.

Fix this by moving mem_encrypt_init() after late_time_init() and
related clock initializations. The intervening initializations don't
do any I/O that requires the swiotlb, so moving mem_encrypt_init()
slightly later has no impact.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/1678329614-3482-6-git-send-email-mikelley@microsoft.com

kernel: Allow a kernel thread's name to be set in copy_process

This patch allows kernel users to pass in the thread name so it can be
set during creation instead of having to use set_task_comm after the
thread is created.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

bootconfig: Change message if no bootconfig with CONFIG_BOOT_CONFIG_FORCE=y

Change no bootconfig data error message if user do not specify 'bootconfig'
option but CONFIG_BOOT_CONFIG_FORCE=y.
With CONFIG_BOOT_CONFIG_FORCE=y, the kernel proceeds bootconfig check even
if user does not specify 'bootconfig' option. So the current error message
is confusing. Let's show just an information message to notice skipping
the bootconfig in that case.

Link: https://lore.kernel.org/all/167754610254.318944.16848412476667893329.stgit@devnote2/

Fixes: b743852ccc1d ("Allow forcing unconditional bootconfig processing")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/all/CAMuHMdV9jJvE2y8gY5V_CxidUikCf5515QMZHzTA3rRGEOj6=w@mail.gmail.com/
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>

Allow forcing unconditional bootconfig processing

The BOOT_CONFIG family of Kconfig options allows a bootconfig file
containing kernel boot parameters to be embedded into an initrd or into
the kernel itself. This can be extremely useful when deploying kernels
in cases where some of the boot parameters depend on the kernel version
rather than on the server hardware, firmware, or workload.

Unfortunately, the "bootconfig" kernel parameter must be specified in
order to cause the kernel to look for the embedded bootconfig file,
and it clearly does not help to embed this "bootconfig" kernel parameter
into that file.

Therefore, provide a new BOOT_CONFIG_FORCE Kconfig option that causes the
kernel to act as if the "bootconfig" kernel parameter had been specified.
In other words, kernels built with CONFIG_BOOT_CONFIG_FORCE=y will look
for the embedded bootconfig file even when the "bootconfig" kernel
parameter is omitted. This permits kernel-version-dependent kernel
boot parameters to be embedded into the kernel image without the need to
(for example) update large numbers of boot loaders.

Link: https://lore.kernel.org/all/20230105005838.GA1772817@paulmck-ThinkPad-P17-Gen-1/

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <linux-doc@vger.kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

mm/page_ext: init page_ext early if there are no deferred struct pages

page_ext must be initialized after all struct pages are initialized.
Therefore, page_ext is initialized after page_alloc_init_late(), and can
optionally be initialized earlier via early_page_ext kernel parameter
which as a side effect also disables deferred struct pages.

Allow to automatically init page_ext early when there are no deferred
struct pages in order to be able to use page_ext during kernel boot and
track for example page allocations early.

[pasha.tatashin@soleen.com: fix build with CONFIG_PAGE_EXTENSION=n]
Link: https://lkml.kernel.org/r/20230118155251.2522985-1-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20230117204617.1553748-1-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Charan Teja Kalla <quic_charante@quicinc.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Li Zhe <lizhe.67@bytedance.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

x86/mm: Initialize text poking earlier

Move poking_init() up a bunch; specifically move it right after
mm_init() which is right before ftrace_init().

This will allow simplifying ftrace text poking which currently has
a bunch of exceptions for early boot.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221025201057.881703081@infradead.org

mm: Move mm_cachep initialization to mm_init()

In order to allow using mm_alloc() much earlier, move initializing
mm_cachep into mm_init().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221025201057.751153381@infradead.org

proc: give /proc/cmdline size

Most /proc files don't have length (in fstat sense). This leads to
inefficiencies when reading such files with APIs commonly found in modern
programming languages. They open file, then fstat descriptor, get st_size
== 0 and either assume file is empty or start reading without knowing
target size.

cat(1) does OK because it uses large enough buffer by default. But naive
programs copy-pasted from SO aren't:

let mut f = std::fs::File::open("/proc/cmdline").unwrap();
let mut buf: Vec<u8> = Vec::new();
f.read_to_end(&mut buf).unwrap();

will result in

openat(AT_FDCWD, "/proc/cmdline", O_RDONLY|O_CLOEXEC) = 3
statx(0, NULL, AT_STATX_SYNC_AS_STAT, STATX_ALL, NULL) = -1 EFAULT (Bad address)
statx(3, "", AT_STATX_SYNC_AS_STAT|AT_EMPTY_PATH, STATX_ALL, {stx_mask=STATX_BASIC_STATS|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0444, stx_size=0, ...}) = 0
lseek(3, 0, SEEK_CUR) = 0
read(3, "BOOT_IMAGE=(hd3,gpt2)/vmlinuz-5.", 32) = 32
read(3, "19.6-100.fc35.x86_64 root=/dev/m", 32) = 32
read(3, "apper/fedora_localhost--live-roo"..., 64) = 64
read(3, "ocalhost--live-swap rd.lvm.lv=fe"..., 128) = 116
read(3, "", 12)

open/stat is OK, lseek looks silly but there are 3 unnecessary reads
because Rust starts with 32 bytes per Vec<u8> and grows from there.

In case of /proc/cmdline, the length is known precisely.

Make variables readonly while I'm at it.

P.S.: I tried to scp /proc/cpuinfo today and got empty file
but this is separate story.

Link: https://lkml.kernel.org/r/YxoywlbM73JJN3r+@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

init/main.c: remove unnecessary (void*) conversions

The void pointer object can be directly assigned to different structure
objects, it does not need to be cast.

Link: https://lkml.kernel.org/r/20220928014539.11046-1-zhoujie@nfschina.com
Signed-off-by: Zhou jie <zhoujie@nfschina.com>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

init: move from strlcpy with unused retval to strscpy

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Link: https://lkml.kernel.org/r/20220818210200.8203-1-wsa+renesas@sang-engineering.com
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

init: kmsan: call KMSAN initialization routines

kmsan_init_shadow() scans the mappings created at boot time and creates
metadata pages for those mappings.

When the memblock allocator returns pages to pagealloc, we reserve 2/3 of
those pages and use them as metadata for the remaining 1/3. Once KMSAN
starts, every page allocated by pagealloc has its associated shadow and
origin pages.

kmsan_initialize() initializes the bookkeeping for init_task and enables
KMSAN.

Link: https://lkml.kernel.org/r/20220915150417.722975-18-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

random: split initialization into early step and later step

The full RNG initialization relies on some timestamps, made possible
with initialization functions like time_init() and timekeeping_init().
However, these are only available rather late in initialization.
Meanwhile, other things, such as memory allocator functions, make use of
the RNG much earlier.

So split RNG initialization into two phases. We can provide arch
randomness very early on, and then later, after timekeeping and such are
available, initialize the rest.

This ensures that, for example, slabs are properly randomized if RDRAND
is available. Without this, CONFIG_SLAB_FREELIST_RANDOM=y loses a degree
of its security, because its random seed is potentially deterministic,
since it hasn't yet incorporated RDRAND. It also makes it possible to
use a better seed in kfence, which currently relies on only the cycle
counter.

Another positive consequence is that on systems with RDRAND, running
with CONFIG_WARN_ALL_UNSEEDED_RANDOM=y results in no warnings at all.

One subtle side effect of this change is that on systems with no RDRAND,
RDTSC is now only queried by random_init() once, committing the moment
of the function call, instead of multiple times as before. This is
intentional, as the multiple RDTSCs in a loop before weren't
accomplishing very much, with jitter being better provided by
try_to_generate_entropy(). Plus, filling blocks with RDTSC is still
being done in extract_entropy(), which is necessarily called before
random bytes are served anyway.

Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Maple Tree: add new data structure

Patch series "Introducing the Maple Tree"

The maple tree is an RCU-safe range based B-tree designed to use modern
processor cache efficiently. There are a number of places in the kernel
that a non-overlapping range-based tree would be beneficial, especially
one with a simple interface. If you use an rbtree with other data
structures to improve performance or an interval tree to track
non-overlapping ranges, then this is for you.

The tree has a branching factor of 10 for non-leaf nodes and 16 for leaf
nodes. With the increased branching factor, it is significantly shorter
than the rbtree so it has fewer cache misses. The removal of the linked
list between subsequent entries also reduces the cache misses and the need
to pull in the previous and next VMA during many tree alterations.

The first user that is covered in this patch set is the vm_area_struct,
where three data structures are replaced by the maple tree: the augmented
rbtree, the vma cache, and the linked list of VMAs in the mm_struct. The
long term goal is to reduce or remove the mmap_lock contention.

The plan is to get to the point where we use the maple tree in RCU mode.
Readers will not block for writers. A single write operation will be
allowed at a time. A reader re-walks if stale data is encountered. VMAs
would be RCU enabled and this mode would be entered once multiple tasks
are using the mm_struct.

Davidlor said

: Yes I like the maple tree, and at this stage I don't think we can ask for
: more from this series wrt the MM - albeit there seems to still be some
: folks reporting breakage. Fundamentally I see Liam's work to (re)move
: complexity out of the MM (not to say that the actual maple tree is not
: complex) by consolidating the three complimentary data structures very
: much worth it considering performance does not take a hit. This was very
: much a turn off with the range locking approach, which worst case scenario
: incurred in prohibitive overhead. Also as Liam and Matthew have
: mentioned, RCU opens up a lot of nice performance opportunities, and in
: addition academia[1] has shown outstanding scalability of address spaces
: with the foundation of replacing the locked rbtree with RCU aware trees.

A similar work has been discovered in the academic press

https://pdos.csail.mit.edu/papers/rcuvm:asplos12.pdf

Sheer coincidence. We designed our tree with the intention of solving the
hardest problem first. Upon settling on a b-tree variant and a rough
outline, we researched ranged based b-trees and RCU b-trees and did find
that article. So it was nice to find reassurances that we were on the
right path, but our design choice of using ranges made that paper unusable
for us.

This patch (of 70):

The maple tree is an RCU-safe range based B-tree designed to use modern
processor cache efficiently. There are a number of places in the kernel
that a non-overlapping range-based tree would be beneficial, especially
one with a simple interface. If you use an rbtree with other data
structures to improve performance or an interval tree to track
non-overlapping ranges, then this is for you.

The tree has a branching factor of 10 for non-leaf nodes and 16 for leaf
nodes. With the increased branching factor, it is significantly shorter
than the rbtree so it has fewer cache misses. The removal of the linked
list between subsequent entries also reduces the cache misses and the need
to pull in the previous and next VMA during many tree alterations.

The first user that is covered in this patch set is the vm_area_struct,
where three data structures are replaced by the maple tree: the augmented
rbtree, the vma cache, and the linked list of VMAs in the mm_struct. The
long term goal is to reduce or remove the mmap_lock contention.

The plan is to get to the point where we use the maple tree in RCU mode.
Readers will not block for writers. A single write operation will be
allowed at a time. A reader re-walks if stale data is encountered. VMAs
would be RCU enabled and this mode would be entered once multiple tasks
are using the mm_struct.

There is additional BUG_ON() calls added within the tree, most of which
are in debug code. These will be replaced with a WARN_ON() call in the
future. There is also additional BUG_ON() calls within the code which
will also be reduced in number at a later date. These exist to catch
things such as out-of-range accesses which would crash anyways.

Link: https://lkml.kernel.org/r/20220906194824.2110408-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20220906194824.2110408-2-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: David Howells <dhowells@redhat.com>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

page_ext: introduce boot parameter 'early_page_ext'

In commit 2f1ee0913ce5 ("Revert "mm: use early_pfn_to_nid in
page_ext_init""), we call page_ext_init() after page_alloc_init_late() to
avoid some panic problem. It seems that we cannot track early page
allocations in current kernel even if page structure has been initialized
early.

This patch introduces a new boot parameter 'early_page_ext' to resolve
this problem. If we pass it to the kernel, page_ext_init() will be moved
up and the feature 'deferred initialization of struct pages' will be
disabled to initialize the page allocator early and prevent the panic
problem above. It can help us to catch early page allocations. This is
useful especially when we find that the free memory value is not the same
right after different kernel booting.

[akpm@linux-foundation.org: fix section issue by removing __meminitdata]
Link: https://lkml.kernel.org/r/20220825102714.669-1-lizhe.67@bytedance.com
Signed-off-by: Li Zhe <lizhe.67@bytedance.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arm64: fix rodata=full

On arm64, "rodata=full" has been suppored (but not documented) since
commit:

c55191e96caa9d78 ("arm64: mm: apply r/o permissions of VM areas to its linear alias as well")

As it's necessary to determine the rodata configuration early during
boot, arm64 has an early_param() handler for this, whereas init/main.c
has a __setup() handler which is run later.

Unfortunately, this split meant that since commit:

f9a40b0890658330 ("init/main.c: return 1 from handled __setup() functions")

... passing "rodata=full" would result in a spurious warning from the
__setup() handler (though RO permissions would be configured
appropriately).

Further, "rodata=full" has been broken since commit:

0d6ea3ac94ca77c5 ("lib/kstrtox.c: add "false"/"true" support to kstrtobool()")

... which caused strtobool() to parse "full" as false (in addition to
many other values not documented for the "rodata=" kernel parameter.

This patch fixes this breakage by:

* Moving the core parameter parser to an __early_param(), such that it
is available early.

* Adding an (optional) arch hook which arm64 can use to parse "full".

* Updating the documentation to mention that "full" is valid for arm64.

* Having the core parameter parser handle "on" and "off" explicitly,
such that any undocumented values (e.g. typos such as "ful") are
reported as errors rather than being silently accepted.

Note that __setup() and early_param() have opposite conventions for
their return values, where __setup() uses 1 to indicate a parameter was
handled and early_param() uses 0 to indicate a parameter was handled.

Fixes: f9a40b089065 ("init/main.c: return 1 from handled __setup() functions")
Fixes: 0d6ea3ac94ca ("lib/kstrtox.c: add "false"/"true" support to kstrtobool()")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jagdish Gediya <jvgediya@linux.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220817154022.3974645-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

stack: Declare {randomize_,}kstack_offset to fix Sparse warnings

Fix the following Sparse warnings that got noticed when the PPC-dev
patchwork was checking another patch (see the link below):

init/main.c:862:1: warning: symbol 'randomize_kstack_offset' was not declared. Should it be static?
init/main.c:864:1: warning: symbol 'kstack_offset' was not declared. Should it be static?

Which in fact are triggered on all architectures that have
HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET support (for instances x86, arm64
etc).

Link: https://lore.kernel.org/lkml/e7b0d68b-914d-7283-827c-101988923929@huawei.com/T/#m49b2d4490121445ce4bf7653500aba59eefcb67f
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Fixes: 39218ff4c625 ("stack: Optionally randomize kernel stack offset each syscall")
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220629060423.2515693-1-gongruiqi1@huawei.com

kthread: Don't allocate kthread_struct for init and umh

If kthread_is_per_cpu runs concurrently with free_kthread_struct the
kthread_struct that was just freed may be read from.

This bug was introduced by commit 40966e316f86 ("kthread: Ensure
struct kthread is present for all kthreads"). When kthread_struct
started to be allocated for all tasks that have PF_KTHREAD set. This
in turn required the kthread_struct to be freed in kernel_execve and
violated the assumption that kthread_struct will have the same
lifetime as the task.

Looking a bit deeper this only applies to callers of kernel_execve
which is just the init process and the user mode helper processes.
These processes really don't want to be kernel threads but are for
historical reasons. Mostly that copy_thread does not know how to take
a kernel mode function to the process with for processes without
PF_KTHREAD or PF_IO_WORKER set.

Solve this by not allocating kthread_struct for the init process and
the user mode helper processes.

This is done by adding a kthread member to struct kernel_clone_args.
Setting kthread in fork_idle and kernel_thread. Adding
user_mode_thread that works like kernel_thread except it does not set
kthread. In fork only allocating the kthread_struct if .kthread is set.

I have looked at kernel/kthread.c and since commit 40966e316f86
("kthread: Ensure struct kthread is present for all kthreads") there
have been no assumptions added that to_kthread or __to_kthread will
not return NULL.

There are a few callers of to_kthread or __to_kthread that assume a
non-NULL struct kthread pointer will be returned. These functions are
kthread_data(), kthread_parmme(), kthread_exit(), kthread(),
kthread_park(), kthread_unpark(), kthread_stop(). All of those functions
can reasonably expected to be called when it is know that a task is a
kthread so that assumption seems reasonable.

Cc: stable@vger.kernel.org
Fixes: 40966e316f86 ("kthread: Ensure struct kthread is present for all kthreads")
Reported-by: Максим Кутявин <maximkabox13@gmail.com>
Link: https://lkml.kernel.org/r/20220506141512.516114-1-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

bootconfig: Support embedding a bootconfig file in kernel

This allows kernel developer to embed a default bootconfig file in
the kernel instead of embedding it in the initrd. This will be good
for who are using the kernel without initrd, or who needs a default
bootconfigs.
This needs to set two kconfigs: CONFIG_BOOT_CONFIG_EMBED=y and set
the file path to CONFIG_BOOT_CONFIG_EMBED_FILE.

Note that you still need 'bootconfig' command line option to load the
embedded bootconfig. Also if you boot using an initrd with a different
bootconfig, the kernel will use the bootconfig in the initrd, instead
of the default bootconfig.

Link: https://lkml.kernel.org/r/164921227943.1090670.14035119557571329218.stgit@devnote2

Cc: Padmanabha Srinivasaiah <treasure4paddy@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

bootconfig: Check the checksum before removing the bootconfig from initrd

Check the bootconfig's checksum before removing the bootconfig data
from initrd to avoid modifying initrd by mistake.
This will also simplifies the get_boot_config_from_initrd() interface.

Link: https://lkml.kernel.org/r/164921226891.1090670.16955839243639298134.stgit@devnote2

Cc: Padmanabha Srinivasaiah <treasure4paddy@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

random: handle latent entropy and command line from random_init()

Currently, start_kernel() adds latent entropy and the command line to
the entropy bool *after* the RNG has been initialized, deferring when
it's actually used by things like stack canaries until the next time
the pool is seeded. This surely is not intended.

Rather than splitting up which entropy gets added where and when between
start_kernel() and random_init(), just do everything in random_init(),
which should eliminate these kinds of bugs in the future.

While we're at it, rename the awkwardly titled "rand_initialize()" to
the more standard "random_init()" nomenclature.

Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

init: call time_init() before rand_initialize()

Currently time_init() is called after rand_initialize(), but
rand_initialize() makes use of the timer on various platforms, and
sometimes this timer needs to be initialized by time_init() first. In
order for random_get_entropy() to not return zero during early boot when
it's potentially used as an entropy source, reverse the order of these
two calls. The block doing random initialization was right before
time_init() before, so changing the order shouldn't have any complicated
effects.

Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

init/main.c: return 1 from handled __setup() functions

initcall_blacklist() should return 1 to indicate that it handled its
cmdline arguments.

set_debug_rodata() should return 1 to indicate that it handled its
cmdline arguments. Print a warning if the option string is invalid.

This prevents these strings from being added to the 'init' program's
environment as they are not init arguments/parameters.

Link: https://lkml.kernel.org/r/20220221050901.23985-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init: use ktime_us_delta() to make initcall_debug log more precise

Use ktime_us_delta() to make the initcall_debug log more precise than
right shifting the result of ktime_to_ns() by 10 bits.

Link: https://lkml.kernel.org/r/20220209053350.15771-1-mark-pk.tsai@mediatek.com
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Tested-by: Andrew Halaney <ahalaney@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: YJ Chiang <yj.chiang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net: initialize init_net earlier

While testing a patch that will follow later
("net: add netns refcount tracker to struct nsproxy")
I found that devtmpfs_init() was called before init_net
was initialized.

This is a bug, because devtmpfs_setup() calls
ksys_unshare(CLONE_NEWNS);

This has the effect of increasing init_net refcount,
which will be later overwritten to 1, as part of setup_net(&init_net)

We had too many prior patches [1] trying to work around the root cause.

Really, make sure init_net is in BSS section, and that net_ns_init()
is called earlier at boot time.

Note that another patch ("vfs: add netns refcount tracker
to struct fs_context") also will need net_ns_init() being called
before vfs_caches_init()

As a bonus, this patch saves around 4KB in .data section.

[1]

f8c46cb39079 ("netns: do not call pernet ops for not yet set up init_net namespace")
b5082df8019a ("net: Initialise init_net.count to 1")
734b65417b24 ("net: Statically initialize init_net.dev_base_head")

v2: fixed a build error reported by kernel build bots (CONFIG_NET=n)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

stack: Introduce CONFIG_RANDOMIZE_KSTACK_OFFSET

The randomize_kstack_offset feature is unconditionally compiled in when
the architecture supports it.

To add constraints on compiler versions, we require a dedicated Kconfig
variable. Therefore, introduce RANDOMIZE_KSTACK_OFFSET.

Furthermore, this option is now also configurable by EXPERT kernels:
while the feature is supposed to have zero performance overhead when
disabled, due to its use of static branches, there are few cases where
giving a distribution the option to disable the feature entirely makes
sense. For example, in very resource constrained environments, which
would never enable the feature to begin with, in which case the
additional kernel code size increase would be redundant.

Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220131090521.1947110-1-elver@google.com

lib/stackdepot: allow optional init and stack_table allocation by kvmalloc()

Currently, enabling CONFIG_STACKDEPOT means its stack_table will be
allocated from memblock, even if stack depot ends up not actually used.
The default size of stack_table is 4MB on 32-bit, 8MB on 64-bit.

This is fine for use-cases such as KASAN which is also a config option
and has overhead on its own. But it's an issue for functionality that
has to be actually enabled on boot (page_owner) or depends on hardware
(GPU drivers) and thus the memory might be wasted. This was raised as
an issue [1] when attempting to add stackdepot support for SLUB's debug
object tracking functionality. It's common to build kernels with
CONFIG_SLUB_DEBUG and enable slub_debug on boot only when needed, or
create only specific kmem caches with debugging for testing purposes.

It would thus be more efficient if stackdepot's table was allocated only
when actually going to be used. This patch thus makes the allocation
(and whole stack_depot_init() call) optional:

- Add a CONFIG_STACKDEPOT_ALWAYS_INIT flag to keep using the current
well-defined point of allocation as part of mem_init(). Make
CONFIG_KASAN select this flag.

- Other users have to call stack_depot_init() as part of their own init
when it's determined that stack depot will actually be used. This may
depend on both config and runtime conditions. Convert current users
which are page_owner and several in the DRM subsystem. Same will be
done for SLUB later.

- Because the init might now be called after the boot-time memblock
allocation has given all memory to the buddy allocator, change
stack_depot_init() to allocate stack_table with kvmalloc() when
memblock is no longer available. Also handle allocation failure by
disabling stackdepot (could have theoretically happened even with
memblock allocation previously), and don't unnecessarily align the
memblock allocation to its own size anymore.

[1] https://lore.kernel.org/all/CAMuHMdW=eoVzM1Re5FVoEN87nKfiLmM2+Ah7eNu2KXEhCvbZyA@mail.gmail.com/

Link: https://lkml.kernel.org/r/20211013073005.11351-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com> # stackdepot
Cc: Marco Elver <elver@google.com>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Oliver Glitta <glittao@gmail.com>
Cc: Imran Khan <imran.f.khan@oracle.com>
From: Colin Ian King <colin.king@canonical.com>
Subject: lib/stackdepot: fix spelling mistake and grammar in pr_err message

There is a spelling mistake of the work allocation so fix this and
re-phrase the message to make it easier to read.

Link: https://lkml.kernel.org/r/20211015104159.11282-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
From: Vlastimil Babka <vbabka@suse.cz>
Subject: lib/stackdepot: allow optional init and stack_table allocation by kvmalloc() - fixup

On FLATMEM, we call page_ext_init_flatmem_late() just before
kmem_cache_init() which means stack_depot_init() (called by page owner
init) will not recognize properly it should use kvmalloc() and not
memblock_alloc(). memblock_alloc() will also not issue a warning and
return a block memory that can be invalid and cause kernel page fault when
saving stacks, as reported by the kernel test robot [1].

Fix this by moving page_ext_init_flatmem_late() below kmem_cache_init() so
that slab_is_available() is true during stack_depot_init(). SPARSEMEM
doesn't have this issue, as it doesn't do page_ext_init_flatmem_late(),
but a different page_ext_init() even later in the boot process.

Thanks to Mike Rapoport for pointing out the FLATMEM init ordering issue.

While at it, also actually resolve a checkpatch warning in stack_depot_init()
from DRM CI, which was supposed to be in the original patch already.

[1] https://lore.kernel.org/all/20211014085450.GC18719@xsang-OptiPlex-9020/

Link: https://lkml.kernel.org/r/6abd9213-19a9-6d58-cedc-2414386d2d81@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: kernel test robot <oliver.sang@intel.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
From: Vlastimil Babka <vbabka@suse.cz>
Subject: lib/stackdepot: allow optional init and stack_table allocation by kvmalloc() - fixup3

Due to cd06ab2fd48f ("drm/locking: add backtrace for locking contended
locks without backoff") landing recently to -next adding a new stack depot
user in drivers/gpu/drm/drm_modeset_lock.c we need to add an appropriate
call to stack_depot_init() there as well.

Link: https://lkml.kernel.org/r/2a692365-cfa1-64f2-34e0-8aa5674dce5e@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Marco Elver <elver@google.com>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Oliver Glitta <glittao@gmail.com>
Cc: Imran Khan <imran.f.khan@oracle.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
From: Vlastimil Babka <vbabka@suse.cz>
Subject: lib/stackdepot: allow optional init and stack_table allocation by kvmalloc() - fixup4

Due to 4e66934eaadc ("lib: add reference counting tracking
infrastructure") landing recently to net-next adding a new stack depot
user in lib/ref_tracker.c we need to add an appropriate call to
stack_depot_init() there as well.

Link: https://lkml.kernel.org/r/45c1b738-1a2f-5b5f-2f6d-86fab206d01c@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Slab <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init: make unknown command line param message clearer

The prior message is confusing users, which is the exact opposite of the
goal. If the message is being seen, one of the following situations is
happening:

1. the param is misspelled
2. the param is not valid due to the kernel configuration
3. the param is intended for init but isn't after the '--'
delineator on the command line

To make that more clear to the user, explicitly mention "kernel command
line" and also note that the params are still passed to user space to
avoid causing any alarm over params intended for init.

Link: https://lkml.kernel.org/r/20211013223502.96756-1-ahalaney@redhat.com
Fixes: 86d1919a4fb0 ("init: print out unknown kernel parameters")
Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memblock: use memblock_free for freeing virtual pointers

Rename memblock_free_ptr() to memblock_free() and use memblock_free()
when freeing a virtual pointer so that memblock_free() will be a
counterpart of memblock_alloc()

The callers are updated with the below semantic patch and manual
addition of (void *) casting to pointers that are represented by
unsigned long variables.

@@
identifier vaddr;
expression size;
@@
(
- memblock_phys_free(__pa(vaddr), size);
+ memblock_free(vaddr, size);
|
- memblock_free_ptr(vaddr, size);
+ memblock_free(vaddr, size);
)

[sfr@canb.auug.org.au: fixup]
Link: https://lkml.kernel.org/r/20211018192940.3d1d532f@canb.auug.org.au

Link: https://lkml.kernel.org/r/20210930185031.18648-7-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Juergen Gross <jgross@suse.com>
Cc: Shahab Vahedi <Shahab.Vahedi@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: create a new system state and fix core_kernel_text()

core_kernel_text() considers that until system_state in at least
SYSTEM_RUNNING, init memory is valid.

But init memory is freed a few lines before setting SYSTEM_RUNNING, so
we have a small period of time when core_kernel_text() is wrong.

Create an intermediate system state called SYSTEM_FREEING_INIT that is
set before starting freeing init memory, and use it in
core_kernel_text() to report init memory invalid earlier.

Link: https://lkml.kernel.org/r/9ecfdee7dd4d741d172cb93ff1d87f1c58127c9a.1633001016.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

block: move elevator.h to block/

Except for the features passed to blk_queue_required_elevator_features,
elevator.h is only needed internally to the block layer. Move the
ELEVATOR_F_* definitions to blkdev.h, and the move elevator.h to
block/, dropping all the spurious includes outside of that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-13-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

bootconfig: Rename xbc_destroy_all() to xbc_exit()

Avoid using this noisy name and use more calm one.
This is just a name change. No functional change.

Link: https://lkml.kernel.org/r/163187295918.2366983.5231840238429996027.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: Add xbc_get_info() for the node information

Add xbc_get_info() API which allows user to get the
number of used xbc_nodes and the size of bootconfig
data. This is also useful for checking the bootconfig
is initialized or not.

Link: https://lkml.kernel.org/r/163177340877.682366.4360676589783197627.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: Allocate xbc_data inside xbc_init()

Allocate 'xbc_data' in the xbc_init() so that it does
not need to care about the ownership of the copied
data.

Link: https://lkml.kernel.org/r/163177339986.682366.898762699429769117.stgit@devnote2

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: init: Fix memblock leak in xbc_make_cmdline()

Free unused memblock in a error case to fix memblock leak
in xbc_make_cmdline().

Link: https://lkml.kernel.org/r/163177339181.682366.8713781325929549256.stgit@devnote2

Fixes: 51887d03aca1 ("bootconfig: init: Allow admin to use bootconfig for kernel command line")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

init: Revert accidental changes to print irqs_disabled()

Commit f8ade8dddb16 ("xsurf100: drop include of lib8390.c") accidentally
changed init/main.c. Revert that part.

Fixes: f8ade8dddb16 ("xsurf100: drop include of lib8390.c")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memblock: introduce saner 'memblock_free_ptr()' interface

The boot-time allocation interface for memblock is a mess, with
'memblock_alloc()' returning a virtual pointer, but then you are
supposed to free it with 'memblock_free()' that takes a _physical_
address.

Not only is that all kinds of strange and illogical, but it actually
causes bugs, when people then use it like a normal allocation function,
and it fails spectacularly on a NULL pointer:

https://lore.kernel.org/all/20210912140820.GD25450@xsang-OptiPlex-9020/

or just random memory corruption if the debug checks don't catch it:

https://lore.kernel.org/all/61ab2d0c-3313-aaab-514c-e15b7aa054a0@suse.cz/

I really don't want to apply patches that treat the symptoms, when the
fundamental cause is this horribly confusing interface.

I started out looking at just automating a sane replacement sequence,
but because of this mix or virtual and physical addresses, and because
people have used the "__pa()" macro that can take either a regular
kernel pointer, or just the raw "unsigned long" address, it's all quite
messy.

So this just introduces a new saner interface for freeing a virtual
address that was allocated using 'memblock_alloc()', and that was kept
as a regular kernel pointer. And then it converts a couple of users
that are obvious and easy to test, including the 'xbc_nodes' case in
lib/bootconfig.c that caused problems.

Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: 40caa127f3c7 ("init: bootconfig: Remove all bootconfig data when the init memory is removed")
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/bootconfig: Reorder init parameter from bootconfig and cmdline

Reorder the init parameters from bootconfig and kernel cmdline
so that the kernel cmdline always be the last part of the
parameters as below.

" -- "[bootconfig init params][cmdline init params]

This change will help us to prevent that bootconfig init params
overwrite the init params which user gives in the command line.

Link: https://lkml.kernel.org/r/163077085675.222577.5665176468023636160.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

init: bootconfig: Remove all bootconfig data when the init memory is removed

Since the bootconfig is used only in the init functions,
it doesn't need to keep the data after boot. Free it when
the init memory is removed.

Link: https://lkml.kernel.org/r/163077084958.222577.5924961258513004428.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

trap: cleanup trap_init()

There are some empty trap_init() definitions in different ARCHs, Introduce
a new weak trap_init() function to clean them up.

Link: https://lkml.kernel.org/r/20210812123602.76356-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [arm32]
Acked-by: Vineet Gupta [arc]
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <palmerdabbelt@google.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init: move usermodehelper_enable() to populate_rootfs()

Currently, usermodehelper is enabled right before PID1 starts going
through the initcalls. However, any call of a usermodehelper from a
pure_, core_, postcore_, arch_, subsys_ or fs_ initcall is futile, as
there is no filesystem contents yet.

Up until commit e7cb072eb988 ("init/initramfs.c: do unpacking
asynchronously"), such calls, whether via some request_module(), a
legacy uevent "/sbin/hotplug" notification or something else, would
just fail silently with (presumably) -ENOENT from
kernel_execve(). However, that commit introduced the
wait_for_initramfs() synchronization hook which must be called from
the usermodehelper exec path right before the kernel_execve, in order
that request_module() et al done from *after* rootfs_initcall()
time (i.e. device_ and late_ initcalls) would continue to find a
populated initramfs as they used to.

Any call of wait_for_initramfs() done before the unpacking has been
scheduled (i.e. before rootfs_initcall time) must just return
immediately [and let the caller find an empty file system] in order
not to deadlock the machine. I mistakenly thought, and my limited
testing confirmed, that there were no such calls, so I added a
pr_warn_once() in wait_for_initramfs(). It turns out that one can
indeed hit request_module() as well as kobject_uevent_env() during
those early init calls, leading to a user-visible warning in the
kernel log emitted consistently for certain configurations.

We could just remove the pr_warn_once(), but I think it's better to
postpone enabling the usermodehelper framework until there is at least
some chance of finding the executable. That is also a little more
efficient in that a lot of work done in umh.c will be elided. However,
it does change the error seen by those early callers from -ENOENT to
-EBUSY, so there is a risk of a regression if any caller care about
the exact error value.

Link: https://lkml.kernel.org/r/20210728134638.329060-1-linux@rasmusvillemoes.dk
Fixes: e7cb072eb988 ("init/initramfs.c: do unpacking asynchronously")
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reported-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reported-by: Bruno Goncalves <bgoncalv@redhat.com>
Reported-by: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

xsurf100: drop include of lib8390.c

Now that ax88796.c exports the ax_NS8390_reinit() symbol, we can
include 8390.h instead of lib8390.c, avoiding duplication of that
function and killing a few compile warnings in the bargain.

Fixes: 861928f4e60e826c ("net-next: New ax88796 platform
driver for Amiga X-Surf 100 Zorro board (m68k)")

Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

init: Suppress wrong warning for bootconfig cmdline parameter

Since the 'bootconfig' command line parameter is handled before
parsing the command line, it doesn't use early_param(). But in
this case, kernel shows a wrong warning message about it.

[ 0.013714] Kernel command line: ro console=ttyS0 bootconfig console=tty0
[ 0.013741] Unknown command line parameters: bootconfig

To suppress this message, add a dummy handler for 'bootconfig'.

Link: https://lkml.kernel.org/r/162812945097.77369.1849780946468010448.stgit@devnote2

Fixes: 86d1919a4fb0 ("init: print out unknown kernel parameters")
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

buildid: stash away kernels build ID on init

Parse the kernel's build ID at initialization so that other code can print
a hex format string representation of the running kernel's build ID. This
will be used in the kdump and dump_stack code so that developers can
easily locate the vmlinux debug symbols for a crash/stacktrace.

[swboyd@chromium.org: fix implicit declaration of init_vmlinux_build_id()]
Link: https://lkml.kernel.org/r/CAE-0n51UjTbay8N9FXAyE7_aR2+ePrQnKSRJ0gbmRsXtcLBVaw@mail.gmail.com

Link: https://lkml.kernel.org/r/20210511003845.2429846-4-swboyd@chromium.org
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Evan Green <evgreen@chromium.org>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

srcu: Initialize SRCU after timers

Once srcu_init() is called, the SRCU core will make use of delayed
workqueues, which rely on timers. However init_timers() is called
several steps after rcu_init(). This means that a call_srcu() after
rcu_init() but before init_timers() would find itself within a dangerously
uninitialized timer core.

This commit therefore creates a separate call to srcu_init() after
init_timer() completes, which ensures that we stay in early SRCU mode
until timers are safe(r).

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

bootconfig: Share the checksum function with tools

Move the checksum calculation function into the header for sharing it
with tools/bootconfig.

Link: https://lkml.kernel.org/r/162262197470.264090.16325743685807878807.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

init: print out unknown kernel parameters

It is easy to foobar setting a kernel parameter on the command line
without realizing it, there's not much output that you can use to assess
what the kernel did with that parameter by default.

Make it a little more explicit which parameters on the command line
_looked_ like a valid parameter for the kernel, but did not match anything
and ultimately got tossed to init. This is very similar to the unknown
parameter message received when loading a module.

This assumes the parameters are processed in a normal fashion, some
parameters (dyndbg= for example) don't register their parameter with the
rest of the kernel's parameters, and therefore always show up in this list
(and are also given to init - like the rest of this list).

Another example is BOOT_IMAGE= is highlighted as an offender, which it
technically is, but is passed by LILO and GRUB so most systems will see
that complaint.

An example output where "foobared" and "unrecognized" are intentionally
invalid parameters:

Kernel command line: BOOT_IMAGE=/boot/vmlinuz-5.12-dirty debug log_buf_len=4M foobared unrecognized=foo
Unknown command line parameters: foobared BOOT_IMAGE=/boot/vmlinuz-5.12-dirty unrecognized=foo

Link: https://lkml.kernel.org/r/20210511211009.42259-1-ahalaney@redhat.com
Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Suggested-by: Borislav Petkov <bp@suse.de>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sched,init: Fix DEBUG_PREEMPT vs early boot

Extend 8fb12156b8db ("init: Pin init task to the boot CPU, initially")
to cover the new PF_NO_SETAFFINITY requirement.

While there, move wait_for_completion(&kthreadd_done) into kernel_init()
to make it absolutely clear it is the very first thing done by the init
thread.

Fixes: 570a752b7a9b ("lib/smp_processor_id: Use is_percpu_thread() instead of nr_cpus_allowed")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/YLS4mbKUrA3Gnb4t@hirez.programming.kicks-ass.net

sched/core: Initialize the idle task with preemption disabled

As pointed out by commit

de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread")

init_idle() can and will be invoked more than once on the same idle
task. At boot time, it is invoked for the boot CPU thread by
sched_init(). Then smp_init() creates the threads for all the secondary
CPUs and invokes init_idle() on them.

As the hotplug machinery brings the secondaries to life, it will issue
calls to idle_thread_get(), which itself invokes init_idle() yet again.
In this case it's invoked twice more per secondary: at _cpu_up(), and at
bringup_cpu().

Given smp_init() already initializes the idle tasks for all *possible*
CPUs, no further initialization should be required. Now, removing
init_idle() from idle_thread_get() exposes some interesting expectations
with regards to the idle task's preempt_count: the secondary startup always
issues a preempt_disable(), requiring some reset of the preempt count to 0
between hot-unplug and hotplug, which is currently served by
idle_thread_get() -> idle_init().

Given the idle task is supposed to have preemption disabled once and never
see it re-enabled, it seems that what we actually want is to initialize its
preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove
init_idle() from idle_thread_get().

Secondary startups were patched via coccinelle:

@begone@
@@

-preempt_disable();
...
cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com

pid: take a reference when initializing `cad_pid`

During boot, kernel_init_freeable() initializes `cad_pid` to the init
task's struct pid. Later on, we may change `cad_pid` via a sysctl, and
when this happens proc_do_cad_pid() will increment the refcount on the
new pid via get_pid(), and will decrement the refcount on the old pid
via put_pid(). As we never called get_pid() when we initialized
`cad_pid`, we decrement a reference we never incremented, can therefore
free the init task's struct pid early. As there can be dangling
references to the struct pid, we can later encounter a use-after-free
(e.g. when delivering signals).

This was spotted when fuzzing v5.13-rc3 with Syzkaller, but seems to
have been around since the conversion of `cad_pid` to struct pid in
commit 9ec52099e4b8 ("[PATCH] replace cad_pid by a struct pid") from the
pre-KASAN stone age of v2.6.19.

Fix this by getting a reference to the init task's struct pid when we
assign it to `cad_pid`.

Full KASAN splat below.

==================================================================
BUG: KASAN: use-after-free in ns_of_pid include/linux/pid.h:153 [inline]
BUG: KASAN: use-after-free in task_active_pid_ns+0xc0/0xc8 kernel/pid.c:509
Read of size 4 at addr ffff23794dda0004 by task syz-executor.0/273

CPU: 1 PID: 273 Comm: syz-executor.0 Not tainted 5.12.0-00001-g9aef892b2d15 #1
Hardware name: linux,dummy-virt (DT)
Call trace:
ns_of_pid include/linux/pid.h:153 [inline]
task_active_pid_ns+0xc0/0xc8 kernel/pid.c:509
do_notify_parent+0x308/0xe60 kernel/signal.c:1950
exit_notify kernel/exit.c:682 [inline]
do_exit+0x2334/0x2bd0 kernel/exit.c:845
do_group_exit+0x108/0x2c8 kernel/exit.c:922
get_signal+0x4e4/0x2a88 kernel/signal.c:2781
do_signal arch/arm64/kernel/signal.c:882 [inline]
do_notify_resume+0x300/0x970 arch/arm64/kernel/signal.c:936
work_pending+0xc/0x2dc

Allocated by task 0:
slab_post_alloc_hook+0x50/0x5c0 mm/slab.h:516
slab_alloc_node mm/slub.c:2907 [inline]
slab_alloc mm/slub.c:2915 [inline]
kmem_cache_alloc+0x1f4/0x4c0 mm/slub.c:2920
alloc_pid+0xdc/0xc00 kernel/pid.c:180
copy_process+0x2794/0x5e18 kernel/fork.c:2129
kernel_clone+0x194/0x13c8 kernel/fork.c:2500
kernel_thread+0xd4/0x110 kernel/fork.c:2552
rest_init+0x44/0x4a0 init/main.c:687
arch_call_rest_init+0x1c/0x28
start_kernel+0x520/0x554 init/main.c:1064
0x0

Freed by task 270:
slab_free_hook mm/slub.c:1562 [inline]
slab_free_freelist_hook+0x98/0x260 mm/slub.c:1600
slab_free mm/slub.c:3161 [inline]
kmem_cache_free+0x224/0x8e0 mm/slub.c:3177
put_pid.part.4+0xe0/0x1a8 kernel/pid.c:114
put_pid+0x30/0x48 kernel/pid.c:109
proc_do_cad_pid+0x190/0x1b0 kernel/sysctl.c:1401
proc_sys_call_handler+0x338/0x4b0 fs/proc/proc_sysctl.c:591
proc_sys_write+0x34/0x48 fs/proc/proc_sysctl.c:617
call_write_iter include/linux/fs.h:1977 [inline]
new_sync_write+0x3ac/0x510 fs/read_write.c:518
vfs_write fs/read_write.c:605 [inline]
vfs_write+0x9c4/0x1018 fs/read_write.c:585
ksys_write+0x124/0x240 fs/read_write.c:658
__do_sys_write fs/read_write.c:670 [inline]
__se_sys_write fs/read_write.c:667 [inline]
__arm64_sys_write+0x78/0xb0 fs/read_write.c:667
__invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:49 [inline]
el0_svc_common.constprop.1+0x16c/0x388 arch/arm64/kernel/syscall.c:129
do_el0_svc+0xf8/0x150 arch/arm64/kernel/syscall.c:168
el0_svc+0x28/0x38 arch/arm64/kernel/entry-common.c:416
el0_sync_handler+0x134/0x180 arch/arm64/kernel/entry-common.c:432
el0_sync+0x154/0x180 arch/arm64/kernel/entry.S:701

The buggy address belongs to the object at ffff23794dda0000
which belongs to the cache pid of size 224
The buggy address is located 4 bytes inside of
224-byte region [ffff23794dda0000, ffff23794dda00e0)
The buggy address belongs to the page:
page:(____ptrval____) refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4dda0
head:(____ptrval____) order:1 compound_mapcount:0
flags: 0x3fffc0000010200(slab|head)
raw: 03fffc0000010200 dead000000000100 dead000000000122 ffff23794d40d080
raw: 0000000000000000 0000000000190019 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff23794dd9ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff23794dd9ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff23794dda0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff23794dda0080: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
ffff23794dda0100: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
==================================================================

Link: https://lkml.kernel.org/r/20210524172230.38715-1-mark.rutland@arm.com
Fixes: 9ec52099e4b8678a ("[PATCH] replace cad_pid by a struct pid")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Christian Brauner <christian@brauner.io>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/initramfs.c: do unpacking asynchronously

Patch series "background initramfs unpacking, and CONFIG_MODPROBE_PATH", v3.

These two patches are independent, but better-together.

The second is a rather trivial patch that simply allows the developer to
change "/sbin/modprobe" to something else - e.g. the empty string, so
that all request_module() during early boot return -ENOENT early, without
even spawning a usermode helper, needlessly synchronizing with the
initramfs unpacking.

The first patch delegates decompressing the initramfs to a worker thread,
allowing do_initcalls() in main.c to proceed to the device_ and late_
initcalls without waiting for that decompression (and populating of
rootfs) to finish. Obviously, some of those later calls may rely on the
initramfs being available, so I've added synchronization points in the
firmware loader and usermodehelper paths - there might be other places
that would need this, but so far no one has been able to think of any
places I have missed.

There's not much to win if most of the functionality needed during boot is
only available as modules. But systems with a custom-made .config and
initramfs can boot faster, partly due to utilizing more than one cpu
earlier, partly by avoiding known-futile modprobe calls (which would still
trigger synchronization with the initramfs unpacking, thus eliminating
most of the first benefit).

This patch (of 2):

Most of the boot process doesn't actually need anything from the
initramfs, until of course PID1 is to be executed. So instead of doing
the decompressing and populating of the initramfs synchronously in
populate_rootfs() itself, push that off to a worker thread.

This is primarily motivated by an embedded ppc target, where unpacking
even the rather modest sized initramfs takes 0.6 seconds, which is long
enough that the external watchdog becomes unhappy that it doesn't get
attention soon enough. By doing the initramfs decompression in a worker
thread, we get to do the device_initcalls and hence start petting the
watchdog much sooner.

Normal desktops might benefit as well. On my mostly stock Ubuntu kernel,
my initramfs is a 26M xz-compressed blob, decompressing to around 126M.
That takes almost two seconds:

[ 0.201454] Trying to unpack rootfs image as initramfs...
[ 1.976633] Freeing initrd memory: 29416K

Before this patch, these lines occur consecutively in dmesg. With this
patch, the timestamps on these two lines is roughly the same as above, but
with 172 lines inbetween - so more than one cpu has been kept busy doing
work that would otherwise only happen after the populate_rootfs()
finished.

Should one of the initcalls done after rootfs_initcall time (i.e., device_
and late_ initcalls) need something from the initramfs (say, a kernel
module or a firmware blob), it will simply wait for the initramfs
unpacking to be done before proceeding, which should in theory make this
completely safe.

But if some driver pokes around in the filesystem directly and not via one
of the official kernel interfaces (i.e. request_firmware*(),
call_usermodehelper*) that theory may not hold - also, I certainly might
have missed a spot when sprinkling wait_for_initramfs(). So there is an
escape hatch in the form of an initramfs_async= command line parameter.

Link: https://lkml.kernel.org/r/20210313212528.2956377-1-linux@rasmusvillemoes.dk
Link: https://lkml.kernel.org/r/20210313212528.2956377-2-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bootconfig: Update prototype of setup_boot_config()

Parameter "cmdline" has no use, drop it.

Link: https://lkml.kernel.org/r/20210311085213.27680-1-jojing64@gmail.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Cao jin <jojing64@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

mm: move mem_init_print_info() into mm_init()

mem_init_print_info() is called in mem_init() on each architecture, and
pass NULL argument, so using void argument and move it into mm_init().

Link: https://lkml.kernel.org/r/20210317015210.33641-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86]
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> [powerpc]
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Anatoly Pugachev <matorola@gmail.com> [sparc64]
Acked-by: Russell King <rmk+kernel@armlinux.org.uk> [arm]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Guo Ren <guoren@kernel.org>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: HUGE_VMAP arch support cleanup

This changes the awkward approach where architectures provide init
functions to determine which levels they can provide large mappings for,
to one where the arch is queried for each call.

This removes code and indirection, and allows constant-folding of dead
code for unsupported levels.

This also adds a prot argument to the arch query. This is unused
currently but could help with some architectures (e.g., some powerpc
processors can't map uncacheable memory with large pages).

Link: https://lkml.kernel.org/r/20210317062402.533919-7-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Ding Tianhong <dingtianhong@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

stack: Optionally randomize kernel stack offset each syscall

This provides the ability for architectures to enable kernel stack base
address offset randomization. This feature is controlled by the boot
param "randomize_kstack_offset=on/off", with its default value set by
CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT.

This feature is based on the original idea from the last public release
of PaX's RANDKSTACK feature: https://pax.grsecurity.net/docs/randkstack.txt
All the credit for the original idea goes to the PaX team. Note that
the design and implementation of this upstream randomize_kstack_offset
feature differs greatly from the RANDKSTACK feature (see below).

Reasoning for the feature:

This feature aims to make harder the various stack-based attacks that
rely on deterministic stack structure. We have had many such attacks in
past (just to name few):

https://jon.oberheide.org/files/infiltrate12-thestackisback.pdf
https://jon.oberheide.org/files/stackjacking-infiltrate11.pdf
https://googleprojectzero.blogspot.com/2016/06/exploiting-recursion-in-linux-kernel_20.html

As Linux kernel stack protections have been constantly improving
(vmap-based stack allocation with guard pages, removal of thread_info,
STACKLEAK), attackers have had to find new ways for their exploits
to work. They have done so, continuing to rely on the kernel's stack
determinism, in situations where VMAP_STACK and THREAD_INFO_IN_TASK_STRUCT
were not relevant. For example, the following recent attacks would have
been hampered if the stack offset was non-deterministic between syscalls:

https://repositorio-aberto.up.pt/bitstream/10216/125357/2/374717.pdf
(page 70: targeting the pt_regs copy with linear stack overflow)

https://a13xp0p0v.github.io/2020/02/15/CVE-2019-18683.html
(leaked stack address from one syscall as a target during next syscall)

The main idea is that since the stack offset is randomized on each system
call, it is harder for an attack to reliably land in any particular place
on the thread stack, even with address exposures, as the stack base will
change on the next syscall. Also, since randomization is performed after
placing pt_regs, the ptrace-based approach[1] to discover the randomized
offset during a long-running syscall should not be possible.

Design description:

During most of the kernel's execution, it runs on the "thread stack",
which is pretty deterministic in its structure: it is fixed in size,
and on every entry from userspace to kernel on a syscall the thread
stack starts construction from an address fetched from the per-cpu
cpu_current_top_of_stack variable. The first element to be pushed to the
thread stack is the pt_regs struct that stores all required CPU registers
and syscall parameters. Finally the specific syscall function is called,
with the stack being used as the kernel executes the resulting request.

The goal of randomize_kstack_offset feature is to add a random offset
after the pt_regs has been pushed to the stack and before the rest of the
thread stack is used during the syscall processing, and to change it every
time a process issues a syscall. The source of randomness is currently
architecture-defined (but x86 is using the low byte of rdtsc()). Future
improvements for different entropy sources is possible, but out of scope
for this patch. Further more, to add more unpredictability, new offsets
are chosen at the end of syscalls (the timing of which should be less
easy to measure from userspace than at syscall entry time), and stored
in a per-CPU variable, so that the life of the value does not stay
explicitly tied to a single task.

As suggested by Andy Lutomirski, the offset is added using alloca()
and an empty asm() statement with an output constraint, since it avoids
changes to assembly syscall entry code, to the unwinder, and provides
correct stack alignment as defined by the compiler.

In order to make this available by default with zero performance impact
for those that don't want it, it is boot-time selectable with static
branches. This way, if the overhead is not wanted, it can just be
left turned off with no performance impact.

The generated assembly for x86_64 with GCC looks like this:

...
ffffffff81003977: 65 8b 05 02 ea 00 7f mov %gs:0x7f00ea02(%rip),%eax
# 12380 <kstack_offset>
ffffffff8100397e: 25 ff 03 00 00 and $0x3ff,%eax
ffffffff81003983: 48 83 c0 0f add $0xf,%rax
ffffffff81003987: 25 f8 07 00 00 and $0x7f8,%eax
ffffffff8100398c: 48 29 c4 sub %rax,%rsp
ffffffff8100398f: 48 8d 44 24 0f lea 0xf(%rsp),%rax
ffffffff81003994: 48 83 e0 f0 and $0xfffffffffffffff0,%rax
...

As a result of the above stack alignment, this patch introduces about
5 bits of randomness after pt_regs is spilled to the thread stack on
x86_64, and 6 bits on x86_32 (since its has 1 fewer bit required for
stack alignment). The amount of entropy could be adjusted based on how
much of the stack space we wish to trade for security.

My measure of syscall performance overhead (on x86_64):

lmbench: /usr/lib/lmbench/bin/x86_64-linux-gnu/lat_syscall -N 10000 null
randomize_kstack_offset=y Simple syscall: 0.7082 microseconds
randomize_kstack_offset=n Simple syscall: 0.7016 microseconds

So, roughly 0.9% overhead growth for a no-op syscall, which is very
manageable. And for people that don't want this, it's off by default.

There are two gotchas with using the alloca() trick. First,
compilers that have Stack Clash protection (-fstack-clash-protection)
enabled by default (e.g. Ubuntu[3]) add pagesize stack probes to
any dynamic stack allocations. While the randomization offset is
always less than a page, the resulting assembly would still contain
(unreachable!) probing routines, bloating the resulting assembly. To
avoid this, -fno-stack-clash-protection is unconditionally added to
the kernel Makefile since this is the only dynamic stack allocation in
the kernel (now that VLAs have been removed) and it is provably safe
from Stack Clash style attacks.

The second gotcha with alloca() is a negative interaction with
-fstack-protector*, in that it sees the alloca() as an array allocation,
which triggers the unconditional addition of the stack canary function
pre/post-amble which slows down syscalls regardless of the static
branch. In order to avoid adding this unneeded check and its associated
performance impact, architectures need to carefully remove uses of
-fstack-protector-strong (or -fstack-protector) in the compilation units
that use the add_random_kstack() macro and to audit the resulting stack
mitigation coverage (to make sure no desired coverage disappears). No
change is visible for this on x86 because the stack protector is already
unconditionally disabled for the compilation unit, but the change is
required on arm64. There is, unfortunately, no attribute that can be
used to disable stack protector for specific functions.

Comparison to PaX RANDKSTACK feature:

The RANDKSTACK feature randomizes the location of the stack start
(cpu_current_top_of_stack), i.e. including the location of pt_regs
structure itself on the stack. Initially this patch followed the same
approach, but during the recent discussions[2], it has been determined
to be of a little value since, if ptrace functionality is available for
an attacker, they can use PTRACE_PEEKUSR/PTRACE_POKEUSR to read/write
different offsets in the pt_regs struct, observe the cache behavior of
the pt_regs accesses, and figure out the random stack offset. Another
difference is that the random offset is stored in a per-cpu variable,
rather than having it be per-thread. As a result, these implementations
differ a fair bit in their implementation details and results, though
obviously the intent is similar.

[1] https://lore.kernel.org/kernel-hardening/2236FBA76BA1254E88B949DDB74E612BA4BC57C1@IRSMSX102.ger.corp.intel.com/
[2] https://lore.kernel.org/kernel-hardening/20190329081358.30497-1-elena.reshetova@intel.com/
[3] https://lists.ubuntu.com/archives/ubuntu-devel/2019-June/040741.html

Co-developed-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210401232347.2791257-4-keescook@chromium.org

kgdb: fix to kill breakpoints on initmem after boot

Currently breakpoints in kernel .init.text section are not handled
correctly while allowing to remove them even after corresponding pages
have been freed.

Fix it via killing .init.text section breakpoints just prior to initmem
pages being freed.

Doug: "HW breakpoints aren't handled by this patch but it's probably
not such a big deal".

Link: https://lkml.kernel.org/r/20210224081652.587785-1-sumit.garg@linaro.org
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Suggested-by: Doug Anderson <dianders@chromium.org>
Acked-by: Doug Anderson <dianders@chromium.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: stackdepot: add support to disable stack depot

Add a kernel parameter stack_depot_disable to disable stack depot. So
that stack hash table doesn't consume any memory when stack depot is
disabled.

The use case is CONFIG_PAGE_OWNER without page_owner=on. Without this
patch, stackdepot will consume the memory for the hashtable. By default,
it's 8M which is never trivial.

With this option, in CONFIG_PAGE_OWNER configured system, page_owner=off,
stack_depot_disable in kernel command line, we could save the wasted
memory for the hashtable.

[akpm@linux-foundation.org: fix CONFIG_STACKDEPOT=n build]

Link: https://lkml.kernel.org/r/1611749198-24316-2-git-send-email-vjitta@codeaurora.org
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Yogesh Lal <ylal@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: add Kernel Electric-Fence infrastructure

Patch series "KFENCE: A low-overhead sampling-based memory safety error detector", v7.

This adds the Kernel Electric-Fence (KFENCE) infrastructure. KFENCE is a
low-overhead sampling-based memory safety error detector of heap
use-after-free, invalid-free, and out-of-bounds access errors. This
series enables KFENCE for the x86 and arm64 architectures, and adds
KFENCE hooks to the SLAB and SLUB allocators.

KFENCE is designed to be enabled in production kernels, and has near
zero performance overhead. Compared to KASAN, KFENCE trades performance
for precision. The main motivation behind KFENCE's design, is that with
enough total uptime KFENCE will detect bugs in code paths not typically
exercised by non-production test workloads. One way to quickly achieve a
large enough total uptime is when the tool is deployed across a large
fleet of machines.

KFENCE objects each reside on a dedicated page, at either the left or
right page boundaries. The pages to the left and right of the object
page are "guard pages", whose attributes are changed to a protected
state, and cause page faults on any attempted access to them. Such page
faults are then intercepted by KFENCE, which handles the fault
gracefully by reporting a memory access error.

Guarded allocations are set up based on a sample interval (can be set
via kfence.sample_interval). After expiration of the sample interval,
the next allocation through the main allocator (SLAB or SLUB) returns a
guarded allocation from the KFENCE object pool. At this point, the timer
is reset, and the next allocation is set up after the expiration of the
interval.

To enable/disable a KFENCE allocation through the main allocator's
fast-path without overhead, KFENCE relies on static branches via the
static keys infrastructure. The static branch is toggled to redirect the
allocation to KFENCE.

The KFENCE memory pool is of fixed size, and if the pool is exhausted no
further KFENCE allocations occur. The default config is conservative
with only 255 objects, resulting in a pool size of 2 MiB (with 4 KiB
pages).

We have verified by running synthetic benchmarks (sysbench I/O,
hackbench) and production server-workload benchmarks that a kernel with
KFENCE (using sample intervals 100-500ms) is performance-neutral
compared to a non-KFENCE baseline kernel.

KFENCE is inspired by GWP-ASan [1], a userspace tool with similar
properties. The name "KFENCE" is a homage to the Electric Fence Malloc
Debugger [2].

For more details, see Documentation/dev-tools/kfence.rst added in the
series -- also viewable here:

https://raw.githubusercontent.com/google/kasan/kfence/Documentation/dev-tools/kfence.rst

[1] http://llvm.org/docs/GwpAsan.html
[2] https://linux.die.net/man/3/efence

This patch (of 9):

This adds the Kernel Electric-Fence (KFENCE) infrastructure. KFENCE is a
low-overhead sampling-based memory safety error detector of heap
use-after-free, invalid-free, and out-of-bounds access errors.

KFENCE is designed to be enabled in production kernels, and has near
zero performance overhead. Compared to KASAN, KFENCE trades performance
for precision. The main motivation behind KFENCE's design, is that with
enough total uptime KFENCE will detect bugs in code paths not typically
exercised by non-production test workloads. One way to quickly achieve a
large enough total uptime is when the tool is deployed across a large
fleet of machines.

KFENCE objects each reside on a dedicated page, at either the left or
right page boundaries. The pages to the left and right of the object
page are "guard pages", whose attributes are changed to a protected
state, and cause page faults on any attempted access to them. Such page
faults are then intercepted by KFENCE, which handles the fault
gracefully by reporting a memory access error. To detect out-of-bounds
writes to memory within the object's page itself, KFENCE also uses
pattern-based redzones. The following figure illustrates the page
layout:

---+-----------+-----------+-----------+-----------+-----------+---
| xxxxxxxxx | O : | xxxxxxxxx | : O | xxxxxxxxx |
| xxxxxxxxx | B : | xxxxxxxxx | : B | xxxxxxxxx |
| x GUARD x | J : RED- | x GUARD x | RED- : J | x GUARD x |
| xxxxxxxxx | E : ZONE | xxxxxxxxx | ZONE : E | xxxxxxxxx |
| xxxxxxxxx | C : | xxxxxxxxx | : C | xxxxxxxxx |
| xxxxxxxxx | T : | xxxxxxxxx | : T | xxxxxxxxx |
---+-----------+-----------+-----------+-----------+-----------+---

Guarded allocations are set up based on a sample interval (can be set
via kfence.sample_interval). After expiration of the sample interval, a
guarded allocation from the KFENCE object pool is returned to the main
allocator (SLAB or SLUB). At this point, the timer is reset, and the
next allocation is set up after the expiration of the interval.

To enable/disable a KFENCE allocation through the main allocator's
fast-path without overhead, KFENCE relies on static branches via the
static keys infrastructure. The static branch is toggled to redirect the
allocation to KFENCE. To date, we have verified by running synthetic
benchmarks (sysbench I/O, hackbench) that a kernel compiled with KFENCE
is performance-neutral compared to the non-KFENCE baseline.

For more details, see Documentation/dev-tools/kfence.rst (added later in
the series).

[elver@google.com: fix parameter description for kfence_object_start()]
Link: https://lkml.kernel.org/r/20201106092149.GA2851373@elver.google.com
[elver@google.com: avoid stalling work queue task without allocations]
Link: https://lkml.kernel.org/r/CADYN=9J0DQhizAGB0-jz4HOBBh+05kMBXb4c0cXMS7Qi5NAJiw@mail.gmail.com
Link: https://lkml.kernel.org/r/20201110135320.3309507-1-elver@google.com
[elver@google.com: fix potential deadlock due to wake_up()]
Link: https://lkml.kernel.org/r/000000000000c0645805b7f982e4@google.com
Link: https://lkml.kernel.org/r/20210104130749.1768991-1-elver@google.com
[elver@google.com: add option to use KFENCE without static keys]
Link: https://lkml.kernel.org/r/20210111091544.3287013-1-elver@google.com
[elver@google.com: add missing copyright and description headers]
Link: https://lkml.kernel.org/r/20210118092159.145934-1-elver@google.com

Link: https://lkml.kernel.org/r/20201103175841.3495947-2-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: SeongJae Park <sjpark@amazon.de>
Co-developed-by: Marco Elver <elver@google.com>
Reviewed-by: Jann Horn <jannh@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Joern Engel <joern@purestorage.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sfi: Remove framework for deprecated firmware

SFI-based platforms are gone. So does this framework.

This removes mention of SFI through the drivers and other code as well.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

init/gcov: allow CONFIG_CONSTRUCTORS on UML to fix module gcov

On ARCH=um, loading a module doesn't result in its constructors getting
called, which breaks module gcov since the debugfs files are never
registered. On the other hand, in-kernel constructors have already been
called by the dynamic linker, so we can't call them again.

Get out of this conundrum by allowing CONFIG_CONSTRUCTORS to be
selected, but avoiding the in-kernel constructor calls.

Also remove the "if !UML" from GCOV selecting CONSTRUCTORS now, since we
really do want CONSTRUCTORS, just not kernel binary ones.

Link: https://lkml.kernel.org/r/20210120172041.c246a2cac2fb.I1358f584b76f1898373adfed77f4462c8705b736@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Revert "init/console: Use ttynull as a fallback when there is no console"

This reverts commit 757055ae8dedf5333af17b3b5b4b70ba9bc9da4e.

The commit caused that ttynull was used as the default console
on several systems[1][2][3]. As a result, the console was
blank even when a better alternative existed.

It happened when there was no console configured
on the command line and ttynull_init() was the first initcall
calling register_console().

Or it happened when /dev/ did not exist when console_on_rootfs()
was called. It was not able to open /dev/console even though
a console driver was registered. It tried to add ttynull console
but it obviously did not help. But ttynull became the preferred
console and was used by /dev/console when it was available later.

The commit tried to fix a historical problem that have been there
for ages. The primary motivation was the commit 3cffa06aeef7ece30f6
("printk/console: Allow to disable console output by using console=""
or console=null"). It provided a clean solution for a workaround
that was widely used and worked only by chance.

This revert causes that the console="" or console=null command line
options will again work only by chance. These options will cause that
a particular console will be preferred and the default (tty) ones
will not get enabled. There will be no console registered at
all. As a result there won't be stdin, stdout, and stderr for
the init process. But it worked exactly this way even before.

The proper solution has to fulfill many conditions:

+ Register ttynull only when explicitly required or as
the ultimate fallback.

+ ttynull should get associated with /dev/console but it must
not become preferred console when used as a fallback.
Especially, it must still be possible to replace it
by a better console later.

Such a change requires clean up of the register_console() code.
Otherwise, it would be even harder to follow. Especially, the use
of has_preferred_console and CON_CONSDEV flag is tricky. The clean
up is risky. The ordering of consoles is not well defined. And
any changes tend to break existing user settings.

Do the revert at the least risky solution for now.

[1] https://lore.kernel.org/linux-kselftest/20201221144302.GR4077@smile.fi.intel.com/
[2] https://lore.kernel.org/lkml/d2a3b3c0-e548-7dd1-730f-59bc5c04e191@synopsys.com/
[3] https://patchwork.ozlabs.org/project/linux-um/patch/20210105120128.10854-1-thomas@m3y3r.de/

Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reported-by: Vineet Gupta <vgupta@synopsys.com>
Reported-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, page_alloc: do not rely on the order of page_poison and init_on_alloc/free parameters

Patch series "cleanup page poisoning", v3.

I have identified a number of issues and opportunities for cleanup with
CONFIG_PAGE_POISON and friends:

- interaction with init_on_alloc and init_on_free parameters depends on
the order of parameters (Patch 1)

- the boot time enabling uses static key, but inefficienty (Patch 2)

- sanity checking is incompatible with hibernation (Patch 3)

- CONFIG_PAGE_POISONING_NO_SANITY can be removed now that we have
init_on_free (Patch 4)

- CONFIG_PAGE_POISONING_ZERO can be most likely removed now that we
have init_on_free (Patch 5)

This patch (of 5):

Enabling page_poison=1 together with init_on_alloc=1 or init_on_free=1
produces a warning in dmesg that page_poison takes precedence. However,
as these warnings are printed in early_param handlers for
init_on_alloc/free, they are not printed if page_poison is enabled later
on the command line (handlers are called in the order of their
parameters), or when init_on_alloc/free is always enabled by the
respective config option - before the page_poison early param handler is
called, it is not considered to be enabled. This is inconsistent.

We can remove the dependency on order by making the init_on_* parameters
only set a boolean variable, and postponing the evaluation after all early
params have been processed. Introduce a new
init_mem_debugging_and_hardening() function for that, and move the related
debug_pagealloc processing there as well.

As a result init_mem_debugging_and_hardening() knows always accurately if
init_on_* and/or page_poison options were enabled. Thus we can also
optimize want_init_on_alloc() and want_init_on_free(). We don't need to
check page_poisoning_enabled() there, we can instead not enable the
init_on_* static keys at all, if page poisoning is enabled. This results
in a simpler and more effective code.

Link: https://lkml.kernel.org/r/20201113104033.22907-1-vbabka@suse.cz
Link: https://lkml.kernel.org/r/20201113104033.22907-2-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Laura Abbott <labbott@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/main: fix broken buffer_init when DEFERRED_STRUCT_PAGE_INIT set

In the booting phase if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set,
we have following callchain:

start_kernel
...
mm_init
mem_init
memblock_free_all
reset_all_zones_managed_pages
free_low_memory_core_early
...
buffer_init
nr_free_buffer_pages
zone->managed_pages
...
rest_init
kernel_init
kernel_init_freeable
page_alloc_init_late
kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
wait_for_completion(&pgdat_init_all_done_comp);
...
files_maxfiles_init

It's clear that buffer_init depends on zone->managed_pages, but it's reset
in reset_all_zones_managed_pages after that pages are readded into
zone->managed_pages, but when buffer_init runs this process is half done
and most of them will finally be added till deferred_init_memmap done. In
large memory couting of nr_free_buffer_pages drifts too much, also
drifting from kernels to kernels on same hardware.

Fix is simple, it delays buffer_init run till deferred_init_memmap all
done.

But as corrected by this patch, max_buffer_heads becomes very large, the
value is roughly as many as 4 times of totalram_pages, formula:
max_buffer_heads = nrpages * (10%) * (PAGE_SIZE / sizeof(struct
buffer_head));

Say in a 64GB memory box we have 16777216 pages, then max_buffer_heads
turns out to be roughly 67,108,864. In common cases, should a buffer_head
be mapped to one page/block(4KB)? So max_buffer_heads never exceeds
totalram_pages. IMO it's likely to make buffer_heads_over_limit bool
value alwasy false, then make codes 'if (buffer_heads_over_limit)' test in
vmscan unnecessary.

So this patch will change the original behavior related to
buffer_heads_over_limit in vmscan since we used a half done value of
zone->managed_pages before, or should we use a smaller factor(<10%) in
previous formula.

akpm: I think this is OK - the max_buffer_heads code is only needed on
highmem machines, to prevent ZONE_NORMAL from being consumed by large
amounts of buffer_heads attached to highmem pagecache. This problem will
not occur on 64-bit machines, so this feature's non-functionality on such
machines is a feature, not a bug.

Link: https://lkml.kernel.org/r/20201123110500.103523-1-linf@wangsu.com
Signed-off-by: Lin Feng <linf@wangsu.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: fix page_owner initializing issue for arm32

Page owner of pages used by page owner itself used is missing on arm32
targets. The reason is dummy_handle and failure_handle is not initialized
correctly. Buddy allocator is used to initialize these two handles.
However, buddy allocator is not ready when page owner calls it. This
change fixed that by initializing page owner after buddy initialization.

The working flow before and after this change are:
original logic:
1. allocated memory for page_ext(using memblock).
2. invoke the init callback of page_ext_ops like page_owner(using buddy
allocator).
3. initialize buddy.

after this change:
1. allocated memory for page_ext(using memblock).
2. initialize buddy.
3. invoke the init callback of page_ext_ops like page_owner(using buddy
allocator).

with the change, failure/dummy_handle can get its correct value and page
owner output for example has the one for page owner itself:

Page allocated via order 2, mask 0x6202c0(GFP_USER|__GFP_NOWARN), pid 1006, ts 67278156558 ns
PFN 543776 type Unmovable Block 531 type Unmovable Flags 0x0()
init_page_owner+0x28/0x2f8
invoke_init_callbacks_flatmem+0x24/0x34
start_kernel+0x33c/0x5d8

Link: https://lkml.kernel.org/r/1603104925-5888-1-git-send-email-zhenhuah@codeaurora.org
Signed-off-by: Zhenhua Huang <zhenhuah@codeaurora.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rcu-tasks: Move RCU-tasks initialization to before early_initcall()

PowerPC testing encountered boot failures due to RCU Tasks not being
fully initialized until core_initcall() time. This commit therefore
initializes RCU Tasks (along with Rude RCU and RCU Tasks Trace) just
before early_initcall() time, thus allowing waiting on RCU Tasks grace
periods from early_initcall() handlers.

Link: https://lore.kernel.org/rcu/87eekfh80a.fsf@dja-thinkpad.axtens.net/
Fixes: 36dadef23fcc ("kprobes: Init kprobes in early_initcall")
Tested-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

bootconfig: Load size and checksum in the footer as le32

Load the size and the checksum fields in the footer as le32
instead of u32. This will allow us to apply bootconfig to the
cross build initrd without caring the endianness.

Link: https://lkml.kernel.org/r/160583934457.547349.10504070298990791074.stgit@devnote2

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

init/console: Use ttynull as a fallback when there is no console

stdin, stdout, and stderr standard I/O stream are created for the init
process. They are not available when there is no console registered
for /dev/console. It might lead to a crash when the init process
tries to use them, see the commit 48021f98130880dd742 ("printk: handle
blank console arguments passed in.").

Normally, ttySX and ttyX consoles are used as a fallback when no consoles
are defined via the command line, device tree, or SPCR. But there
will be no console registered when an invalid console name is configured
or when the configured consoles do not exist on the system.

Users even try to avoid the console intentionally, for example,
by using console="" or console=null. It is used on production
systems where the serial port or terminal are not visible to
users. Pushing messages to these consoles would just unnecessary
slowdown the system.

Make sure that stdin, stdout, stderr, and /dev/console are always
available by a fallback to the existing ttynull driver. It has
been implemented for exactly this purpose but it was used only
when explicitly configured.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20201111135450.11214-2-pmladek@suse.com

bootconfig: Extend the magic check range to the preceding 3 bytes

Since Grub may align the size of initrd to 4 if user pass
initrd from cpio, we have to check the preceding 3 bytes as well.

Link: https://lkml.kernel.org/r/160520205132.303174.4876760192433315429.stgit@devnote2

Cc: stable@vger.kernel.org
Fixes: 85c46b78da58 ("bootconfig: Add bootconfig magic word for indicating bootconfig explicitly")
Reported-by: Chen Yu <yu.chen.surf@gmail.com>
Tested-by: Chen Yu <yu.chen.surf@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

init: main: add KUnit to kernel init

Although we have not seen any actual examples where KUnit doesn't work
because it runs in the late init phase of the kernel, it has been a
concern for some time that this could potentially be an issue in the
future. So, remove KUnit from init calls entirely, instead call directly
from kernel_init() so that KUnit runs after late init.

Co-developed-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

bootconfig: init: make xbc_namebuf static

This eliminates the following sparse warning:

init/main.c:306:6: warning: symbol 'xbc_namebuf' was not declared.
Should it be static?

Link: https://lkml.kernel.org/r/20200915070324.2239473-1-yanaijie@huawei.com

Reported-by: Hulk Robot <hulkci@huawei.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kprobes: tracing/kprobes: Fix to kill kprobes on initmem after boot

Since kprobe_event= cmdline option allows user to put kprobes on the
functions in initmem, kprobe has to make such probes gone after boot.
Currently the probes on the init functions in modules will be handled
by module callback, but the kernel init text isn't handled.
Without this, kprobes may access non-exist text area to disable or
remove it.

Link: https://lkml.kernel.org/r/159972810544.428528.1839307531600646955.stgit@devnote2

Fixes: 970988e19eb0 ("tracing/kprobe: Add kprobe_event= boot parameter")
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: Fix kernel message mentioning CONFIG_BOOT_CONFIG

Fix up one typo: CONFIG_BOOTCONFIG -> CONFIG_BOOT_CONFIG

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

kasan, arm64: don't instrument functions that enable kasan

This patch prepares Software Tag-Based KASAN for stack tagging support.

With stack tagging enabled, KASAN tags stack variable in each function in
its prologue. In start_kernel() stack variables get tagged before KASAN
is enabled via setup_arch()->kasan_init(). As the result the tags for
start_kernel()'s stack variables end up in the temporary shadow memory.
Later when KASAN gets enabled, switched to normal shadow, and starts
checking tags, this leads to false-positive reports, as proper tags are
missing in normal shadow.

Disable KASAN instrumentation for start_kernel(). Also disable it for
arm64's setup_arch() as a precaution (it doesn't have any stack variables
right now).

[andreyknvl@google.com: reorder attributes for start_kernel()]
Link: http://lkml.kernel.org/r/26fb6165a17abcf61222eda5184c030fb6b133d1.1596544734.git.andreyknvl@google.com

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Elena Petrova <lenaptr@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Walter Wu <walter-zh.wu@mediatek.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Link: http://lkml.kernel.org/r/55d432671a92e931ab8234b03dc36b14d4c21bfb.1596199677.git.andreyknvl@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init: add an init_dup helper

Add a simple helper to grab a reference to a file and install it at
the next available fd, and switch the early init code over to it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

bootconfig: Fix to find the initargs correctly

Since the parse_args() stops parsing at '--', bootconfig_params()
will never get the '--' as param and initargs_found never be true.
In the result, if we pass some init arguments via the bootconfig,
those are always appended to the kernel command line with '--'
even if the kernel command line already has '--'.

To fix this correctly, check the return value of parse_args()
and set initargs_found true if the return value is not an error
but a valid address.

Link: https://lkml.kernel.org/r/159650953285.270383.14822353843556363851.stgit@devnote2

Fixes: f61872bb58a1 ("bootconfig: Use parse_args() to find bootconfig and '--'")
Cc: stable@vger.kernel.org
Reported-by: Arvind Sankar <nivedita@alum.mit.edu>
Suggested-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

init: add an init_eaccess helper

Add a simple helper to check if a file exists based on kernel space file
name and switch the early init code over to it. Note that this
theoretically changes behavior as it always is based on the effective
permissions. But during early init that doesn't make a difference.

Signed-off-by: Christoph Hellwig <hch@lst.de>

init: mark console_on_rootfs as __init

This helper is only used for the early init code.

Signed-off-by: Christoph Hellwig <hch@lst.de>

init: initialize ramdisk_execute_command at compile time

Set ramdisk_execute_command to "/init" at compile time. The command
line can still override it, but this saves a few instructions and
removes a NULL check.

Signed-off-by: Christoph Hellwig <hch@lst.de>

init: open code setting up stdin/stdout/stderr

Don't rely on the implicit set_fs(KERNEL_DS) for ksys_open to work, but
instead open a struct file for /dev/console and then install it as FD
0/1/2 manually.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>

exec: Implement kernel_execve

To allow the kernel not to play games with set_fs to call exec
implement kernel_execve. The function kernel_execve takes pointers
into kernel memory and copies the values pointed to onto the new
userspace stack.

The calls with arguments from kernel space of do_execve are replaced
with calls to kernel_execve.

The calls do_execve and do_execveat are made static as there are now
no callers outside of exec.

The comments that mention do_execve are updated to refer to
kernel_execve or execve depending on the circumstances. In addition
to correcting the comments, this makes it easy to grep for do_execve
and verify it is not used.

Inspired-by: https://lkml.kernel.org/r/20200627072704.2447163-1-hch@lst.de
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/87wo365ikj.fsf@x220.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

security: allow using Clang's zero initialization for stack variables

In addition to -ftrivial-auto-var-init=pattern (used by
CONFIG_INIT_STACK_ALL now) Clang also supports zero initialization for
locals enabled by -ftrivial-auto-var-init=zero. The future of this flag
is still being debated (see https://bugs.llvm.org/show_bug.cgi?id=45497).
Right now it is guarded by another flag,
-enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang,
which means it may not be supported by future Clang releases. Another
possible resolution is that -ftrivial-auto-var-init=zero will persist
(as certain users have already started depending on it), but the name
of the guard flag will change.

In the meantime, zero initialization has proven itself as a good
production mitigation measure against uninitialized locals. Unlike pattern
initialization, which has a higher chance of triggering existing bugs,
zero initialization provides safe defaults for strings, pointers, indexes,
and sizes. On the other hand, pattern initialization remains safer for
return values. Chrome OS and Android are moving to using zero
initialization for production builds.

Performance-wise, the difference between pattern and zero initialization
is usually negligible, although the generated code for zero
initialization is more compact.

This patch renames CONFIG_INIT_STACK_ALL to CONFIG_INIT_STACK_ALL_PATTERN
and introduces another config option, CONFIG_INIT_STACK_ALL_ZERO, that
enables zero initialization for locals if the corresponding flags are
supported by Clang.

Cc: Kees Cook <keescook@chromium.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alexander Potapenko <glider@google.com>
Link: https://lore.kernel.org/r/20200616083435.223038-1-glider@google.com
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

kernel/sysctl: support setting sysctl parameters from kernel command line

Patch series "support setting sysctl parameters from kernel command line", v3.

This series adds support for something that seems like many people
always wanted but nobody added it yet, so here's the ability to set
sysctl parameters via kernel command line options in the form of
sysctl.vm.something=1

The important part is Patch 1. The second, not so important part is an
attempt to clean up legacy one-off parameters that do the same thing as
a sysctl. I don't want to remove them completely for compatibility
reasons, but with generic sysctl support the idea is to remove the
one-off param handlers and treat the parameters as aliases for the
sysctl variants.

I have identified several parameters that mention sysctl counterparts in
Documentation/admin-guide/kernel-parameters.txt but there might be more.
The conversion also has varying level of success:

- numa_zonelist_order is converted in Patch 2 together with adding the
necessary infrastructure. It's easy as it doesn't really do anything
but warn on deprecated value these days.

- hung_task_panic is converted in Patch 3, but there's a downside that
now it only accepts 0 and 1, while previously it was any integer
value

- nmi_watchdog maps to two sysctls nmi_watchdog and hardlockup_panic,
so there's no straighforward conversion possible

- traceoff_on_warning is a flag without value and it would be required
to handle that somehow in the conversion infractructure, which seems
pointless for a single flag

This patch (of 5):

A recently proposed patch to add vm_swappiness command line parameter in
addition to existing sysctl [1] made me wonder why we don't have a
general support for passing sysctl parameters via command line.

Googling found only somebody else wondering the same [2], but I haven't
found any prior discussion with reasons why not to do this.

Settings the vm_swappiness issue aside (the underlying issue might be
solved in a different way), quick search of kernel-parameters.txt shows
there are already some that exist as both sysctl and kernel parameter -
hung_task_panic, nmi_watchdog, numa_zonelist_order, traceoff_on_warning.

A general mechanism would remove the need to add more of those one-offs
and might be handy in situations where configuration by e.g.
/etc/sysctl.d/ is impractical.

Hence, this patch adds a new parse_args() pass that looks for parameters
prefixed by 'sysctl.' and tries to interpret them as writes to the
corresponding sys/ files using an temporary in-kernel procfs mount.
This mechanism was suggested by Eric W. Biederman [3], as it handles
all dynamically registered sysctl tables, even though we don't handle
modular sysctls. Errors due to e.g. invalid parameter name or value
are reported in the kernel log.

The processing is hooked right before the init process is loaded, as
some handlers might be more complicated than simple setters and might
need some subsystems to be initialized. At the moment the init process
can be started and eventually execute a process writing to /proc/sys/
then it should be also fine to do that from the kernel.

Sysctls registered later on module load time are not set by this
mechanism - it's expected that in such scenarios, setting sysctl values
from userspace is practical enough.

[1] https://lore.kernel.org/r/BL0PR02MB560167492CA4094C91589930E9FC0@BL0PR02MB5601.namprd02.prod.outlook.com/
[2] https://unix.stackexchange.com/questions/558802/how-to-set-sysctl-using-kernel-command-line-parameter
[3] https://lore.kernel.org/r/87bloj2skm.fsf@x220.int.ebiederm.org/

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Link: http://lkml.kernel.org/r/20200427180433.7029-1-vbabka@suse.cz
Link: http://lkml.kernel.org/r/20200427180433.7029-2-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init: allow distribution configuration of default init

Some init systems (eg. systemd) have init at their own paths, for
example, /usr/lib/systemd/systemd. A compatibility symlink to one of the
hardcoded init paths is provided by another package, usually named
something like systemd-sysvcompat or similar.

Currently distro maintainers who are hands-off on the bootloader are more
or less required to include those compatibility links as part of their
base distribution, because it's hard to migrate away from them since
there's a risk some users will not get the message to set init= on the
kernel command line appropriately.

Moreover, for distributions where the init system is something the
distribution itself is opinionated about (eg. Arch, which has systemd in
the required `base` package), we could usually reasonably configure this
ahead of time when building the distribution kernel. However, we
currently simply don't have any way to configure the kernel to do this.
Here's an example discussion where removing sysvcompat was discussed by
distro maintainers[0].

This patch adds a new Kconfig tunable, CONFIG_DEFAULT_INIT, which if set
is tried before the hardcoded fallback list. So the order of precedence
is now thus:

1. init= on command line (on failure: panic)
2. CONFIG_DEFAULT_INIT (on failure: try #3)
3. Hardcoded fallback list (on failure: panic)

This new config parameter will allow distribution maintainers to move away
from these compatibility links safely, without having to worry that their
users might not have the right init=.

There are also two other benefits of this over having the distribution
maintain a symlink:

1. One of the value propositions over simply having distributions
maintain a /sbin/init symlink via a package is that it also frees
distributions which have a preferred default, but not mandatory, init
system from having their package manager fight with their users for
control of /{s,}bin/init. Instead, the distribution simply makes
their preference known in CONFIG_DEFAULT_INIT, and if the user
installs another init system and uninstalls the default one they can
still make use of /{s,}bin/init and friends for their own uses. This
makes more cases Just Work(tm) without the user having to perform
extra configuration via init=.

2. Since before this we don't know which path the distribution actually
_intends_ to serve init from, we don't pr_err if it is simply
missing, and usually will just silently put the user in a /bin/sh
shell. Now that the distribution can make a declaration of intent, we
can be more vocal when this init system fails to launch for any
reason, even if it's simply because no file exists at that location,
speeding up the palaver of init/mount dependency/etc debugging a bit.

[0]: https://lists.archlinux.org/pipermail/arch-dev-public/2019-January/029435.html

Signed-off-by: Chris Down <chris@chrisdown.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: http://lkml.kernel.org/r/20200522160234.GA1487022@chrisdown.name
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

padata: initialize earlier

padata will soon initialize the system's struct pages in parallel, so it
needs to be ready by page_alloc_init_late().

The error return from padata_driver_init() triggers an initcall warning,
so add a warning to padata_init() to avoid silent failure.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Josh Triplett <josh@joshtriplett.org>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Robert Elliott <elliott@hpe.com>
Cc: Shile Zhang <shile.zhang@linux.alibaba.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Link: http://lkml.kernel.org/r/20200527173608.2885243-3-daniel.m.jordan@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

x86: Fix early boot crash on gcc-10, third try

... or the odyssey of trying to disable the stack protector for the
function which generates the stack canary value.

The whole story started with Sergei reporting a boot crash with a kernel
built with gcc-10:

Kernel panic — not syncing: stack-protector: Kernel stack is corrupted in: start_secondary
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc5—00235—gfffb08b37df9 #139
Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./H77M—D3H, BIOS F12 11/14/2013
Call Trace:
dump_stack
panic
? start_secondary
__stack_chk_fail
start_secondary
secondary_startup_64
-—-[ end Kernel panic — not syncing: stack—protector: Kernel stack is corrupted in: start_secondary

This happens because gcc-10 tail-call optimizes the last function call
in start_secondary() - cpu_startup_entry() - and thus emits a stack
canary check which fails because the canary value changes after the
boot_init_stack_canary() call.

To fix that, the initial attempt was to mark the one function which
generates the stack canary with:

__attribute__((optimize("-fno-stack-protector"))) ... start_secondary(void *unused)

however, using the optimize attribute doesn't work cumulatively
as the attribute does not add to but rather replaces previously
supplied optimization options - roughly all -fxxx options.

The key one among them being -fno-omit-frame-pointer and thus leading to
not present frame pointer - frame pointer which the kernel needs.

The next attempt to prevent compilers from tail-call optimizing
the last function call cpu_startup_entry(), shy of carving out
start_secondary() into a separate compilation unit and building it with
-fno-stack-protector, was to add an empty asm("").

This current solution was short and sweet, and reportedly, is supported
by both compilers but we didn't get very far this time: future (LTO?)
optimization passes could potentially eliminate this, which leads us
to the third attempt: having an actual memory barrier there which the
compiler cannot ignore or move around etc.

That should hold for a long time, but hey we said that about the other
two solutions too so...

Reported-by: Sergei Trofimovich <slyfox@gentoo.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Kalle Valo <kvalo@codeaurora.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200314164451.346497-1-slyfox@gentoo.org

bootconfig: Fix to prevent warning message if no bootconfig option

Commit de462e5f1071 ("bootconfig: Fix to remove bootconfig
data from initrd while boot") causes a cosmetic regression
on dmesg, which warns "no bootconfig data" message without
bootconfig cmdline option.

Fix setup_boot_config() by moving no bootconfig check after
commandline option check.

Link: http://lkml.kernel.org/r/9b1ba335-071d-c983-89a4-2677b522dcc8@molgen.mpg.de
Link: http://lkml.kernel.org/r/158916116468.21787.14558782332170588206.stgit@devnote2

Fixes: de462e5f1071 ("bootconfig: Fix to remove bootconfig data from initrd while boot")
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: Fix to remove bootconfig data from initrd while boot

If there is a bootconfig data in the tail of initrd/initramfs,
initrd image sanity check caused an error while decompression
stage as follows.

[ 0.883882] Unpacking initramfs...
[ 2.696429] Initramfs unpacking failed: invalid magic at start of compressed archive

This error will be ignored if CONFIG_BLK_DEV_RAM=n,
but CONFIG_BLK_DEV_RAM=y the kernel failed to mount rootfs
and causes a panic.

To fix this issue, shrink down the initrd_end for removing
tailing bootconfig data while boot the kernel.

Link: http://lkml.kernel.org/r/158788401014.24243.17424755854115077915.stgit@devnote2

Cc: Borislav Petkov <bp@alien8.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Fixes: 7684b8582c24 ("bootconfig: Load boot config from the tail of initrd")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

printk: queue wake_up_klogd irq_work only if per-CPU areas are ready

printk_deferred(), similarly to printk_safe/printk_nmi, does not
immediately attempt to print a new message on the consoles, avoiding
calls into non-reentrant kernel paths, e.g. scheduler or timekeeping,
which potentially can deadlock the system.

Those printk() flavors, instead, rely on per-CPU flush irq_work to print
messages from safer contexts. For same reasons (recursive scheduler or
timekeeping calls) printk() uses per-CPU irq_work in order to wake up
user space syslog/kmsg readers.

However, only printk_safe/printk_nmi do make sure that per-CPU areas
have been initialised and that it's safe to modify per-CPU irq_work.
This means that, for instance, should printk_deferred() be invoked "too
early", that is before per-CPU areas are initialised, printk_deferred()
will perform illegal per-CPU access.

Lech Perczak [0] reports that after commit 1b710b1b10ef ("char/random:
silence a lockdep splat with printk()") user-space syslog/kmsg readers
are not able to read new kernel messages.

The reason is printk_deferred() being called too early (as was pointed
out by Petr and John).

Fix printk_deferred() and do not queue per-CPU irq_work before per-CPU
areas are initialized.

Link: https://lore.kernel.org/lkml/aa0732c6-5c4e-8a8b-a1c1-75ebe3dca05b@camlintechnologies.com/
Reported-by: Lech Perczak <l.perczak@camlintechnologies.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Jann Horn <jannh@google.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/bootconfig: Show line and column in parse error

Show line and column when we got a parse error in bootconfig tool.
Current lib/bootconfig shows the parse error with byte offset, but
that is not human readable.
This makes xbc_init() not showing error message itself but able to
pass the error message and position to caller, so that the caller
can decode it and show the error message with line number and columns.

With this patch, bootconfig tool shows an error with line:column as
below.

$ cat samples/bad-dotword.bconf
# do not start keyword with .
key {
.word = 1
}
$ ./bootconfig -a samples/bad-dotword.bconf initrd
Parse Error: Invalid keyword at 3:3

Link: http://lkml.kernel.org/r/158323469002.10560.4023923847704522760.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: Print array as multiple commands for legacy command line

Print arraied values as multiple same options for legacy
kernel command line. With this rule, if the "kernel.*" and
"init.*" array entries in bootconfig are printed out as
multiple same options, e.g.

kernel {
console = "ttyS0,115200"
console += "tty0"
}

will be correctly converted to

console="ttyS0,115200" console="tty0"

in the kernel command line.

Link: http://lkml.kernel.org/r/158220118213.26565.8163300497009463916.stgit@devnote2

Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: Add bootconfig magic word for indicating bootconfig explicitly

Add bootconfig magic word to the end of bootconfig on initrd
image for indicating explicitly the bootconfig is there.
Also tools/bootconfig treats wrong size or wrong checksum or
parse error as an error, because if there is a bootconfig magic
word, there must be a bootconfig.

The bootconfig magic word is "#BOOTCONFIG\n", 12 bytes word.
Thus the block image of the initrd file with bootconfig is
as follows.

[Initrd][bootconfig][size][csum][#BOOTCONFIG\n]

Link: http://lkml.kernel.org/r/158220112263.26565.3944814205960612841.stgit@devnote2

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: Set CONFIG_BOOT_CONFIG=n by default

Set CONFIG_BOOT_CONFIG=n by default. This also warns
user if CONFIG_BOOT_CONFIG=n but "bootconfig" is given
in the kernel command line.

Link: http://lkml.kernel.org/r/158220111291.26565.9036889083940367969.stgit@devnote2

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: Mark boot_config_checksum() static

In fact, this function is only used in this file, so mark it with 'static'.

Link: http://lkml.kernel.org/r/1581852511-14163-1-git-send-email-hqjagain@gmail.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: Use parse_args() to find bootconfig and '--'

The current implementation does a naive search of "bootconfig" on the kernel
command line. But this could find "bootconfig" that is part of another
option in quotes (although highly unlikely). But it also needs to find '--'
on the kernel command line to know if it should append a '--' or not when a
bootconfig in the initrd file has an "init" section. The check uses the
naive strstr() to find to see if it exists. But this can return a false
positive if it exists in an option and then the "init" section in the initrd
will not be appended properly.

Using parse_args() to find both of these will solve both of these problems.

Link: https://lore.kernel.org/r/202002070954.C18E7F58B@keescook

Fixes: 7495e0926fdf3 ("bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline")
Fixes: 1319916209ce8 ("bootconfig: init: Allow admin to use bootconfig for init command line")
Reported-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: Show the number of nodes on boot message

Show the number of bootconfig nodes on boot message.

Link: http://lkml.kernel.org/r/158091062297.27924.9051634676068550285.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: Use bootconfig instead of boot config

Use "bootconfig" (1 word) instead of "boot config" (2 words)
in the boot message.

Link: http://lkml.kernel.org/r/158091059459.27924.14414336187441539879.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline

As the bootconfig is appended to the initrd it is not as easy to modify as
the kernel command line. If there's some issue with the kernel, and the
developer wants to boot a pristine kernel, it should not be needed to modify
the initrd to remove the bootconfig for a single boot.

As bootconfig is silently added (if the admin does not know where to look
they may not know it's being loaded). It should be explicitly added to the
kernel cmdline. The loading of the bootconfig is only done if "bootconfig"
is on the kernel command line. This will let admins know that the kernel
command line is extended.

Note, after adding printk()s for when the size is too great or the checksum
is wrong, exposed that the current method always looked for the boot config,
and if this size and checksum matched, it would parse it (as if either is
wrong a printk has been added to show this). It's better to only check this
if the boot config is asked to be looked for.

Link: https://lore.kernel.org/r/CAHk-=wjfjO+h6bQzrTf=YCZA53Y3EDyAs3Z4gEsT7icA3u_Psw@mail.gmail.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

init/main.c: fix misleading "This architecture does not have kernel memory protection" message

This message leads to thinking that memory protection is not implemented
for the said architecture, whereas absence of CONFIG_STRICT_KERNEL_RWX
only means that memory protection has not been selected at compile time.

Don't print this message when CONFIG_ARCH_HAS_STRICT_KERNEL_RWX is
selected by the architecture. Instead, print "Kernel memory protection
not selected by kernel config."

Link: http://lkml.kernel.org/r/62477e446d9685459d4f27d193af6ff1bd69d55f.1578557581.git.christophe.leroy@c-s.fr
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/main.c: fix quoted value handling in unknown_bootoption

Patch series "init/main.c: minor cleanup/bugfix of envvar handling", v2.

unknown_bootoption passes unrecognized command line arguments to init as
either environment variables or arguments. Some of the logic in the
function is broken for quoted command line arguments.

When an argument of the form param="value" is processed by parse_args
and passed to unknown_bootoption, the command line has

param\0"value\0

with val pointing to the beginning of value. The helper function
repair_env_string is then used to restore the '=' character that was
removed by parse_args, and strip the quotes off fully. This results in

param=value\0\0

and val ends up pointing to the 'a' instead of the 'v' in value. This
bug was introduced when repair_env_string was refactored into a separate
function, and the decrement of val in repair_env_string became dead
code.

This causes two problems in unknown_bootoption in the two places where
the val pointer is used as a substitute for the length of param:

1. An argument of the form param=".value" is misinterpreted as a
potential module parameter, with the result that it will not be
placed in init's environment.

2. An argument of the form param="value" is checked to see if param is
an existing environment variable that should be overwritten, but the
comparison is off-by-one and compares 'param=v' instead of 'param='
against the existing environment. So passing, for example,
TERM="vt100" on the command line results in init being passed both
TERM=linux and TERM=vt100 in its environment.

Patch 1 adds logging for the arguments and environment passed to init
and is independent of the rest: it can be dropped if this is
unnecessarily verbose.

Patch 2 removes repair_env_string from initcall parameter parsing in
do_initcall_level, as that uses a separate copy of the command line now
and the repairing is no longer necessary.

Patch 3 fixes the bug in unknown_bootoption by recording the length of
param explicitly instead of implying it from val-param.

This patch (of 3):

Commit a99cd1125189 ("init: fix bug where environment vars can't be
passed via boot args") introduced two minor bugs in unknown_bootoption
by factoring out the quoted value handling into a separate function.

When value is quoted, repair_env_string will move the value up 1 byte to
strip the quotes, so val in unknown_bootoption no longer points to the
actual location of the value.

The result is that an argument of the form param=".value" is mistakenly
treated as a potential module parameter and is not placed in init's
environment, and an argument of the form param="value" can result in a
duplicate environment variable: eg TERM="vt100" on the command line will
result in both TERM=linux and TERM=vt100 being placed into init's
environment.

Fix this by recording the length of the param before calling
repair_env_string instead of relying on val.

Link: http://lkml.kernel.org/r/20191212180023.24339-4-nivedita@alum.mit.edu
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/main.c: remove unnecessary repair_env_string in do_initcall_level

Since commit 08746a65c296 ("init: fix in-place parameter modification
regression"), parse_args in do_initcall_level is called on a copy of
saved_command_line. It is unnecessary to call repair_env_string during
this parsing, as this copy is not used for anything later.

Remove the now unnecessary arguments from repair_env_string as well.

Link: http://lkml.kernel.org/r/20191212180023.24339-3-nivedita@alum.mit.edu
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Krzysztof Mazur <krzysiek@podlesie.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/main.c: log arguments and environment passed to init

Extend logging in `run_init_process` to also show the arguments and
environment that we are passing to init.

Link: http://lkml.kernel.org/r/20191212180023.24339-2-nivedita@alum.mit.edu
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, debug_pagealloc: don't rely on static keys too early

Commit 96a2b03f281d ("mm, debug_pagelloc: use static keys to enable
debugging") has introduced a static key to reduce overhead when
debug_pagealloc is compiled in but not enabled. It relied on the
assumption that jump_label_init() is called before parse_early_param()
as in start_kernel(), so when the "debug_pagealloc=on" option is parsed,
it is safe to enable the static key.

However, it turns out multiple architectures call parse_early_param()
earlier from their setup_arch(). x86 also calls jump_label_init() even
earlier, so no issue was found while testing the commit, but same is not
true for e.g. ppc64 and s390 where the kernel would not boot with
debug_pagealloc=on as found by our QA.

To fix this without tricky changes to init code of multiple
architectures, this patch partially reverts the static key conversion
from 96a2b03f281d. Init-time and non-fastpath calls (such as in arch
code) of debug_pagealloc_enabled() will again test a simple bool
variable. Fastpath mm code is converted to a new
debug_pagealloc_enabled_static() variant that relies on the static key,
which is enabled in a well-defined point in mm_init() where it's
guaranteed that jump_label_init() has been called, regardless of
architecture.

[sfr@canb.auug.org.au: export _debug_pagealloc_enabled_early]
Link: http://lkml.kernel.org/r/20200106164944.063ac07b@canb.auug.org.au
Link: http://lkml.kernel.org/r/20191219130612.23171-1-vbabka@suse.cz
Fixes: 96a2b03f281d ("mm, debug_pagelloc: use static keys to enable debugging")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Qian Cai <cai@lca.pw>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bootconfig: init: Allow admin to use bootconfig for init command line

Since the current kernel command line is too short to describe
long and many options for init (e.g. systemd command line options),
this allows admin to use boot config for init command line.

All init command line under "init." keywords will be passed to
init.

For example,

init.systemd {
unified_cgroup_hierarchy = 1
debug_shell
default_timeout_start_sec = 60
}

Link: http://lkml.kernel.org/r/157867229521.17873.654222294326542349.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: init: Allow admin to use bootconfig for kernel command line

Since the current kernel command line is too short to describe
many options which supported by kernel, allow user to use boot
config to setup (add) the command line options.

All kernel parameters under "kernel." keywords will be used
for setting up extra kernel command line.

For example,

kernel {
audit = on
audit_backlog_limit = 256
}

Note that you can not specify some early parameters
(like console etc.) by this method, since it is
loaded after early parameters parsed.

Link: http://lkml.kernel.org/r/157867228333.17873.11962796367032622466.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

init/main.c: Alloc initcall_command_line in do_initcall() and free it

Since initcall_command_line is used as a temporary buffer,
it could be freed after usage. Allocate it in do_initcall()
and free it after used.

Link: http://lkml.kernel.org/r/157867227145.17873.17513760552008505454.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

bootconfig: Load boot config from the tail of initrd

Load the extended boot config data from the tail of initrd
image. If there is an SKC data there, it has
[(u32)size][(u32)checksum] header (in really, this is a
footer) at the end of initrd. If the checksum (simple sum
of bytes) is match, this starts parsing it from there.

Link: http://lkml.kernel.org/r/157867222435.17873.9936667353335606867.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Revert "fs: remove ksys_dup()"

This reverts commit 8243186f0cc7 ("fs: remove ksys_dup()") and the
subsequent fix for it in commit 2d3145f8d280 ("early init: fix error
handling when opening /dev/console").

Trying to use filp_open() and f_dupfd() instead of pseudo-syscalls
caused more trouble than what is worth it: it requires accessing vfs
internals and it turns out there were other bugs in it too.

In particular, the file reference counting was wrong - because unlike
the original "open+2*dup" sequence it used "filp_open+3*f_dupfd" and
thus had an extra leaked file reference.

That in turn then caused odd problems with Androidx86 long after boot
becaue of how the extra reference to the console kept the session active
even after all file descriptors had been closed.

Reported-by: youling 257 <youling257@gmail.com>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

early init: fix error handling when opening /dev/console

The comment says "this should never fail", but it definitely can fail
when you have odd initial boot filesystems, or kernel configurations.

So get the error handling right: filp_open() returns an error pointer.

Reported-by: Jesse Barnes <jsbarnes@google.com>
Reported-by: youling 257 <youling257@gmail.com>
Fixes: 8243186f0cc7 ("fs: remove ksys_dup()")
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

device.h: move 'struct driver' stuff out to device/driver.h

device.h has everything and the kitchen sink when it comes to struct
device things, so split out the struct driver things things to a
separate .h file to make things easier to maintain and manage over time.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20191209193303.1694546-7-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs: remove ksys_dup()

ksys_dup() is used only at one place in the kernel, namely to duplicate
fd 0 of /dev/console to stdout and stderr. The same functionality can be
achieved by using functions already available within the kernel namespace.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

init: unify opening /dev/console as stdin/stdout/stderr

Merge the two instances where /dev/console is opened as
stdin/stdout/stderr.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

kcsan: Add Kernel Concurrency Sanitizer infrastructure

Kernel Concurrency Sanitizer (KCSAN) is a dynamic data-race detector for
kernel space. KCSAN is a sampling watchpoint-based data-race detector.
See the included Documentation/dev-tools/kcsan.rst for more details.

This patch adds basic infrastructure, but does not yet enable KCSAN for
any architecture.

Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

mm: use CPU_BITS_NONE to initialize init_mm.cpu_bitmask

Replace open-coded bitmap array initialization of init_mm.cpu_bitmask with
neat CPU_BITS_NONE macro.

And, since init_mm.cpu_bitmask is statically set to zero, there is no way
to clear it again in start_kernel().

Link: http://lkml.kernel.org/r/1565703815-8584-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: consolidate pgtable_cache_init() and pgd_cache_init()

Both pgtable_cache_init() and pgd_cache_init() are used to initialize kmem
cache for page table allocations on several architectures that do not use
PAGE_SIZE tables for one or more levels of the page table hierarchy.

Most architectures do not implement these functions and use __weak default
NOP implementation of pgd_cache_init(). Since there is no such default
for pgtable_cache_init(), its empty stub is duplicated among most
architectures.

Rename the definitions of pgd_cache_init() to pgtable_cache_init() and
drop empty stubs of pgtable_cache_init().

Link: http://lkml.kernel.org/r/1566457046-22637-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Will Deacon <will@kernel.org> [arm64]
Acked-by: Thomas Gleixner <tglx@linutronix.de> [x86]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: kmemleak: use the memory pool for early allocations

Currently kmemleak uses a static early_log buffer to trace all memory
allocation/freeing before the slab allocator is initialised. Such early
log is replayed during kmemleak_init() to properly initialise the kmemleak
metadata for objects allocated up that point. With a memory pool that
does not rely on the slab allocator, it is possible to skip this early log
entirely.

In order to remove the early logging, consider kmemleak_enabled == 1 by
default while the kmem_cache availability is checked directly on the
object_cache and scan_area_cache variables. The RCU callback is only
invoked after object_cache has been initialised as we wouldn't have any
concurrent list traversal before this.

In order to reduce the number of callbacks before kmemleak is fully
initialised, move the kmemleak_init() call to mm_init().

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: remove WARN_ON(), per Catalin]
Link: http://lkml.kernel.org/r/20190812160642.52134-4-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

security: Support early LSMs

The lockdown module is intended to allow for kernels to be locked down
early in boot - sufficiently early that we don't have the ability to
kmalloc() yet. Add support for early initialisation of some LSMs, and
then add them to the list of names when we do full initialisation later.
Early LSMs are initialised in link order and cannot be overridden via
boot parameters, and cannot make use of kmalloc() (since the allocator
isn't initialised yet).

(Fixed by Stephen Rothwell to include a stub to fix builds when
!CONFIG_SECURITY)

Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: James Morris <jmorris@namei.org>

sched/preempt: Use CONFIG_PREEMPTION where appropriate

CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by
CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same
functionality which today depends on CONFIG_PREEMPT.

Switch the preemption code, scheduler and init task over to use
CONFIG_PREEMPTION.

That's the first step towards RT in that area. The more complex changes are
coming separately.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20190726212124.117528401@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

mm: init: report memory auto-initialization features at boot time

Print the currently enabled stack and heap initialization modes.

Stack initialization is enabled by a config flag, while heap
initialization is configured at boot time with defaults being set in the
config. It's more convenient for the user to have all information about
these hardening measures in one place at boot, so the user can reason
about the expected behavior of the running system.

The possible options for stack are:
- "all" for CONFIG_INIT_STACK_ALL;
- "byref_all" for CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL;
- "byref" for CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF;
- "__user" for CONFIG_GCC_PLUGIN_STRUCTLEAK_USER;
- "off" otherwise.

Depending on the values of init_on_alloc and init_on_free boottime options
we also report "heap alloc" and "heap free" as "on"/"off".

In the init_on_free mode initializing pages at boot time may take a while,
so print a notice about that as well. This depends on how much memory is
installed, the memory bandwidth, etc. On a relatively modern x86 system,
it takes about 0.75s/GB to wipe all memory:

[ 0.418722] mem auto-init: stack:byref_all, heap alloc:off, heap free:on
[ 0.419765] mem auto-init: clearing system memory may take some time...
[ 12.376605] Memory: 16408564K/16776672K available (14339K kernel code, 1397K rwdata, 3756K rodata, 1636K init, 11460K bss, 368108K reserved, 0K cma-reserved)

Link: http://lkml.kernel.org/r/20190617151050.92663-3-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Suggested-by: Kees Cook <keescook@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jann Horn <jannh@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Sandeep Patil <sspatil@android.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Kaiwan N Billimoria <kaiwan@kaiwantech.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mnt_init(): call shmem_init() unconditionally

No point having two call sites (earlier in init_rootfs() from
mnt_init() in case we are going to use shmem-style rootfs,
later from do_basic_setup() unconditionally), along with the
logics in shmem_init() itself to make the second call a no-op...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

treewide: Add SPDX license identifier for missed files

Add SPDX license identifiers to all files which:

- Have no license information of any form

- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

init: free_initmem: poison freed init memory

Various architectures including x86 poison the freed init memory. Do the
same in the generic free_initmem implementation and switch sparc32
architecture that is identical to the generic code over to it now.

Link: http://lkml.kernel.org/r/1550515285-17446-4-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init: provide a generic free_initmem implementation

Patch series "provide a generic free_initmem implementation", v2.

Many architectures implement free_initmem() in exactly the same or very
similar way: they wrap the call to free_initmem_default() with sometimes
different 'poison' parameter.

These patches switch those architectures to use a generic implementation
that does free_initmem_default(POISON_FREE_INITMEM).

This was inspired by Christoph's patches for free_initrd_mem [1] and I
shamelessly copied changelog entries from his patches :)

[1] https://lore.kernel.org/lkml/20190213174621.29297-1-hch@lst.de/

This patch (of 2):

For most architectures free_initmem just a wrapper for the same
free_initmem_default(-1) call. Provide that as a generic implementation
marked __weak.

Link: http://lkml.kernel.org/r/1550515285-17446-2-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

x86/mm: Initialize PGD cache during mm initialization

Poking-mm initialization might require to duplicate the PGD in early
stage. Initialize the PGD cache earlier to prevent boot failures.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 4fc19708b165 ("x86/alternatives: Initialize temporary mm for patching")
Link: http://lkml.kernel.org/r/20190505011124.39692-1-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/alternatives: Initialize temporary mm for patching

To prevent improper use of the PTEs that are used for text patching, the
next patches will use a temporary mm struct. Initailize it by copying
the init mm.

The address that will be used for patching is taken from the lower area
that is usually used for the task memory. Doing so prevents the need to
frequently synchronize the temporary-mm (e.g., when BPF programs are
installed), since different PGDs are used for the task memory.

Finally, randomize the address of the PTEs to harden against exploits
that use these PTEs.

Suggested-by: Andy Lutomirski <luto@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akpm@linux-foundation.org
Cc: ard.biesheuvel@linaro.org
Cc: deneen.t.dock@intel.com
Cc: kernel-hardening@lists.openwall.com
Cc: kristen@linux.intel.com
Cc: linux_dti@icloud.com
Cc: will.deacon@arm.com
Link: https://lkml.kernel.org/r/20190426232303.28381-8-nadav.amit@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

random: move rand_initialize() earlier

Right now rand_initialize() is run as an early_initcall(), but it only
depends on timekeeping_init() (for mixing ktime_get_real() into the
pools). However, the call to boot_init_stack_canary() for stack canary
initialization runs earlier, which triggers a warning at boot:

random: get_random_bytes called from start_kernel+0x357/0x548 with crng_init=0

Instead, this moves rand_initialize() to after timekeeping_init(), and moves
canary initialization here as well.

Note that this warning may still remain for machines that do not have
UEFI RNG support (which initializes the RNG pools during setup_arch()),
or for x86 machines without RDRAND (or booting without "random.trust=on"
or CONFIG_RANDOM_TRUST_CPU=y).

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

init: initialize jump labels before command line option parsing

When a module option, or core kernel argument, toggles a static-key it
requires jump labels to be initialized early. While x86, PowerPC, and
ARM64 arrange for jump_label_init() to be called before parse_args(),
ARM does not.

Kernel command line: rdinit=/sbin/init page_alloc.shuffle=1 panic=-1 console=ttyAMA0,115200 page_alloc.shuffle=1
------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at ./include/linux/jump_label.h:303
page_alloc_shuffle+0x12c/0x1ac
static_key_enable(): static key 'page_alloc_shuffle_key+0x0/0x4' used
before call to jump_label_init()
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted
5.1.0-rc4-next-20190410-00003-g3367c36ce744 #1
Hardware name: ARM Integrator/CP (Device Tree)
[<c0011c68>] (unwind_backtrace) from [<c000ec48>] (show_stack+0x10/0x18)
[<c000ec48>] (show_stack) from [<c07e9710>] (dump_stack+0x18/0x24)
[<c07e9710>] (dump_stack) from [<c001bb1c>] (__warn+0xe0/0x108)
[<c001bb1c>] (__warn) from [<c001bb88>] (warn_slowpath_fmt+0x44/0x6c)
[<c001bb88>] (warn_slowpath_fmt) from [<c0b0c4a8>]
(page_alloc_shuffle+0x12c/0x1ac)
[<c0b0c4a8>] (page_alloc_shuffle) from [<c0b0c550>] (shuffle_store+0x28/0x48)
[<c0b0c550>] (shuffle_store) from [<c003e6a0>] (parse_args+0x1f4/0x350)
[<c003e6a0>] (parse_args) from [<c0ac3c00>] (start_kernel+0x1c0/0x488)

Move the fallback call to jump_label_init() to occur before
parse_args().

The redundant calls to jump_label_init() in other archs are left intact
in case they have static key toggling use cases that are even earlier
than option parsing.

Link: http://lkml.kernel.org/r/155544804466.1032396.13418949511615676665.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Guenter Roeck <groeck@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Russell King <rmk@armlinux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively

%pF and %pf are functionally equivalent to %pS and %ps conversion
specifiers. The former are deprecated, therefore switch the current users
to use the preferred variant.

The changes have been produced by the following command:

git grep -l '%p[fF]' | grep -v '^\(tools\|Documentation\)/' | \
while read i; do perl -i -pe 's/%pf/%ps/g; s/%pF/%pS/g;' $i; done

And verifying the result.

Link: http://lkml.kernel.org/r/20190325193229.23390-1-sakari.ailus@linux.intel.com
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: sparclinux@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: xen-devel@lists.xenproject.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: drbd-dev@lists.linbit.com
Cc: linux-block@vger.kernel.org
Cc: linux-mmc@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
Cc: linux-pci@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-btrfs@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: linux-mm@kvack.org
Cc: ceph-devel@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: David Sterba <dsterba@suse.com> (for btrfs)
Acked-by: Mike Rapoport <rppt@linux.ibm.com> (for mm/memblock.c)
Acked-by: Bjorn Helgaas <bhelgaas@google.com> (for drivers/pci)
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

init/main: add checks for the return value of memblock_alloc*()

Add panic() calls if memblock_alloc() returns NULL.

The panic() format duplicates the one used by memblock itself and in
order to avoid explosion with long parameters list replace open coded
allocation size calculations with a local variable.

Link: http://lkml.kernel.org/r/1548057848-15136-18-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Guo Ren <ren_guo@c-sky.com> [c-sky]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Juergen Gross <jgross@suse.com> [Xen]
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Revert "mm: use early_pfn_to_nid in page_ext_init"

This reverts commit fe53ca54270a ("mm: use early_pfn_to_nid in
page_ext_init").

When booting a system with "page_owner=on",

start_kernel
page_ext_init
invoke_init_callbacks
init_section_page_ext
init_page_owner
init_early_allocated_pages
init_zones_in_node
init_pages_in_zone
lookup_page_ext
page_to_nid

The issue here is that page_to_nid() will not work since some page flags
have no node information until later in page_alloc_init_late() due to
DEFERRED_STRUCT_PAGE_INIT. Hence, it could trigger an out-of-bounds
access with an invalid nid.

UBSAN: Undefined behaviour in ./include/linux/mm.h:1104:50
index 7 is out of range for type 'zone [5]'

Also, kernel will panic since flags were poisoned earlier with,

CONFIG_DEBUG_VM_PGFLAGS=y
CONFIG_NODE_NOT_IN_PAGE_FLAGS=n

start_kernel
setup_arch
pagetable_init
paging_init
sparse_init
sparse_init_nid
memblock_alloc_try_nid_raw

It did not handle it well in init_pages_in_zone() which ends up calling
page_to_nid().

page:ffffea0004200000 is uninitialized and poisoned
raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
page_owner info is not active (free page?)
kernel BUG at include/linux/mm.h:990!
RIP: 0010:init_page_owner+0x486/0x520

This means that assumptions behind commit fe53ca54270a ("mm: use
early_pfn_to_nid in page_ext_init") are incomplete. Therefore, revert
the commit for now. A proper way to move the page_owner initialization
to sooner is to hook into memmap initialization.

Link: http://lkml.kernel.org/r/20190115202812.75820-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Michal Hocko <mhocko@kernel.org>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Yang Shi <yang.shi@linaro.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fork: fix some -Wmissing-prototypes warnings

We get a warning when building kernel with W=1:

kernel/fork.c:167:13: warning: no previous prototype for `arch_release_thread_stack' [-Wmissing-prototypes]
kernel/fork.c:779:13: warning: no previous prototype for `fork_init' [-Wmissing-prototypes]

Add the missing declaration in head file to fix this.

Also, remove arch_release_thread_stack() completely because no arch
seems to implement it since bb9d81264 (arch: remove tile port).

Link: http://lkml.kernel.org/r/1542170087-23645-1-git-send-email-wang.yi59@zte.com.cn
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/main.c: make "initcall_level_names[]" const char *

Initcall names should not be changed.

Link: http://lkml.kernel.org/r/20181124091829.GD10969@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

debugobjects: call debug_objects_mem_init eariler

The current value of the early boot static pool size, 1024 is not big
enough for systems with large number of CPUs with timer or/and workqueue
objects selected. As the results, systems have 60+ CPUs with both timer
and workqueue objects enabled could trigger "ODEBUG: Out of memory.
ODEBUG disabled".

Some debug objects are allocated during the early boot. Enabling some
options like timers or workqueue objects may increase the size required
significantly with large number of CPUs. For example,

CONFIG_DEBUG_OBJECTS_TIMERS:
No. CPUs x 2 (worker pool) objects:
start_kernel
workqueue_init_early
init_worker_pool
init_timer_key
debug_object_init

plus No. CPUs objects (CONFIG_HIGH_RES_TIMERS):
sched_init
hrtick_rq_init
hrtimer_init

CONFIG_DEBUG_OBJECTS_WORK:
No. CPUs objects:
vmalloc_init
__init_work

plus No. CPUs x 6 (workqueue) objects:
workqueue_init_early
alloc_workqueue
__alloc_workqueue_key
alloc_and_link_pwqs
init_pwq

Also, plus No. CPUs objects:
perf_event_init
__init_srcu_struct
init_srcu_struct_fields
init_srcu_struct_nodes
__init_work

However, none of the things are actually used or required before
debug_objects_mem_init() is invoked, so just move the call right before
vmalloc_init().

According to tglx, "the reason why the call is at this place in
start_kernel() is historical. It's because back in the days when
debugobjects were added the memory allocator was enabled way later than
today."

Link: http://lkml.kernel.org/r/20181126102407.1836-1-cai@gmx.us
Signed-off-by: Qian Cai <cai@gmx.us>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

x86/efi: Move efi_<reserve/free>_boot_services() to arch/x86

efi_<reserve/free>_boot_services() are x86 specific quirks and as such
should be in asm/efi.h, so move them from linux/efi.h. Also, call
efi_free_boot_services() from __efi_enter_virtual_mode() as it is x86
specific call and ideally shouldn't be part of init/main.c

Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arend van Spriel <arend.vanspriel@broadcom.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Snowberg <eric.snowberg@oracle.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: Julien Thierry <julien.thierry@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: YiFei Zhu <zhuyifei1999@gmail.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181129171230.18699-7-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

main: Replace rcu_barrier_sched() with rcu_barrier()

Now that all RCU flavors have been consolidated, rcu_barrier_sched()
is but a synonym for rcu_barrier(). This commit therefore replaces
the former with the latter.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <linux-mm@kvack.org>

block: remove dead elevator code

This removes a bunch of core and elevator related code. On the core
front, we remove anything related to queue running, draining,
initialization, plugging, and congestions. We also kill anything
related to request allocation, merging, retrieval, and completion.

Remove any checking for single queue IO schedulers, as they no
longer exist. This means we can also delete a bunch of code related
to request issue, adding, completion, etc - and all the SQ related
ops and helpers.

Also kill the load_default_modules(), as all that did was provide
for a way to load the default single queue elevator.

Tested-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

memblock: stop using implicit alignment to SMP_CACHE_BYTES

When a memblock allocation APIs are called with align = 0, the alignment
is implicitly set to SMP_CACHE_BYTES.

Implicit alignment is done deep in the memblock allocator and it can
come as a surprise. Not that such an alignment would be wrong even
when used incorrectly but it is better to be explicit for the sake of
clarity and the prinicple of the least surprise.

Replace all such uses of memblock APIs with the 'align' parameter
explicitly set to SMP_CACHE_BYTES and stop implicit alignment assignment
in the memblock internal allocation functions.

For the case when memblock APIs are used via helper functions, e.g. like
iommu_arena_new_node() in Alpha, the helper functions were detected with
Coccinelle's help and then manually examined and updated where
appropriate.

The direct memblock APIs users were updated using the semantic patch below:

@@
expression size, min_addr, max_addr, nid;
@@
(
|
- memblock_alloc_try_nid_raw(size, 0, min_addr, max_addr, nid)
+ memblock_alloc_try_nid_raw(size, SMP_CACHE_BYTES, min_addr, max_addr,
nid)
|
- memblock_alloc_try_nid_nopanic(size, 0, min_addr, max_addr, nid)
+ memblock_alloc_try_nid_nopanic(size, SMP_CACHE_BYTES, min_addr, max_addr,
nid)
|
- memblock_alloc_try_nid(size, 0, min_addr, max_addr, nid)
+ memblock_alloc_try_nid(size, SMP_CACHE_BYTES, min_addr, max_addr, nid)
|
- memblock_alloc(size, 0)
+ memblock_alloc(size, SMP_CACHE_BYTES)
|
- memblock_alloc_raw(size, 0)
+ memblock_alloc_raw(size, SMP_CACHE_BYTES)
|
- memblock_alloc_from(size, 0, min_addr)
+ memblock_alloc_from(size, SMP_CACHE_BYTES, min_addr)
|
- memblock_alloc_nopanic(size, 0)
+ memblock_alloc_nopanic(size, SMP_CACHE_BYTES)
|
- memblock_alloc_low(size, 0)
+ memblock_alloc_low(size, SMP_CACHE_BYTES)
|
- memblock_alloc_low_nopanic(size, 0)
+ memblock_alloc_low_nopanic(size, SMP_CACHE_BYTES)
|
- memblock_alloc_from_nopanic(size, 0, min_addr)
+ memblock_alloc_from_nopanic(size, SMP_CACHE_BYTES, min_addr)
|
- memblock_alloc_node(size, 0, nid)
+ memblock_alloc_node(size, SMP_CACHE_BYTES, nid)
)

[mhocko@suse.com: changelog update]
[akpm@linux-foundation.org: coding-style fixes]
[rppt@linux.ibm.com: fix missed uses of implicit alignment]
Link: http://lkml.kernel.org/r/20181016133656.GA10925@rapoport-lnx
Link: http://lkml.kernel.org/r/1538687224-17535-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Paul Burton <paul.burton@mips.com> [MIPS]
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: remove include/linux/bootmem.h

Move remaining definitions and declarations from include/linux/bootmem.h
into include/linux/memblock.h and remove the redundant header.

The includes were replaced with the semantic patch below and then
semi-automated removal of duplicated '#include <linux/memblock.h>

@@
@@
- #include <linux/bootmem.h>
+ #include <linux/memblock.h>

[sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h]
Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au
[sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h]
Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au
[sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal]
Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au
Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Serge Semin <fancer.lancer@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memblock: replace alloc_bootmem with memblock_alloc

The alloc_bootmem(size) is a shortcut for allocation of SMP_CACHE_BYTES
aligned memory. When the align parameter of memblock_alloc() is 0, the
alignment is implicitly set to SMP_CACHE_BYTES and thus alloc_bootmem(size)
and memblock_alloc(size, 0) are equivalent.

The conversion is done using the following semantic patch:

@@
expression size;
@@
- alloc_bootmem(size)
+ memblock_alloc(size, 0)

Link: http://lkml.kernel.org/r/1536927045-23536-22-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Serge Semin <fancer.lancer@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memblock: remove _virt from APIs returning virtual address

The conversion is done using

sed -i 's@memblock_virt_alloc@memblock_alloc@g' \
$(git grep -l memblock_virt_alloc)

Link: http://lkml.kernel.org/r/1536927045-23536-8-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Serge Semin <fancer.lancer@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init: add arch_call_rest_init to allow stack switching

With CONFIG_VMAP_STACK=y the kernel stack of all tasks should be
allocated in the vmalloc space. The initial stack used for all
the early init code is in the init_thread_union. To be able to
switch from this early stack to a properly allocated stack
from vmalloc the architecture needs a switch-over point.

Introduce the arch_call_rest_init() function with a weak definition
in init/main.c with the only purpose to call rest_init() from the
end of start_kernel(). The architecture override can then do the
necessary magic to switch to the new vmalloc'ed stack.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

jump_label: Annotate entries that operate on __init code earlier

Jump table entries are mostly read-only, with the exception of the
init and module loader code that defuses entries that point into init
code when the code being referred to is freed.

For robustness, it would be better to move these entries into the
ro_after_init section, but clearing the 'code' member of each jump
table entry referring to init code at module load time races with the
module_enable_ro() call that remaps the ro_after_init section read
only, so we'd like to do it earlier.

So given that whether such an entry refers to init code can be decided
much earlier, we can pull this check forward. Since we may still need
the code entry at this point, let's switch to setting a low bit in the
'key' member just like we do to annotate the default state of a jump
table entry.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jessica Yu <jeyu@kernel.org>
Link: https://lkml.kernel.org/r/20180919065144.25010-8-ard.biesheuvel@linaro.org

init/main.c: log init process file name

Add a log message to `run_init_process()`.

This log message serves two purposes.

1. If the init process is not specified on the Linux Kernel command
line, the user sees, what file was chosen.

2. The time stamps shows exactly, when the Linux kernel handed over
control to the init process.

Link: http://lkml.kernel.org/r/b1fc97fa-4aa9-1904-ddb5-859e78995c41@molgen.mpg.de
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init: allow initcall tables to be emitted using relative references

Allow the initcall tables to be emitted using relative references that
are only half the size on 64-bit architectures and don't require fixups
at runtime on relocatable kernels.

Link: http://lkml.kernel.org/r/20180704083651.24360-5-ard.biesheuvel@linaro.org
Acked-by: James Morris <james.morris@microsoft.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Petr Mladek <pmladek@suse.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init: rename and re-order boot_cpu_state_init()

This is purely a preparatory patch for upcoming changes during the 4.19
merge window.

We have a function called "boot_cpu_state_init()" that isn't really
about the bootup cpu state: that is done much earlier by the similarly
named "boot_cpu_init()" (note lack of "state" in name).

This function initializes some hotplug CPU state, and needs to run after
the percpu data has been properly initialized. It even has a comment to
that effect.

Except it _doesn't_ actually run after the percpu data has been properly
initialized. On x86 it happens to do that, but on at least arm and
arm64, the percpu base pointers are initialized by the arch-specific
'smp_prepare_boot_cpu()' hook, which ran _after_ boot_cpu_state_init().

This had some unexpected results, and in particular we have a patch
pending for the merge window that did the obvious cleanup of using
'this_cpu_write()' in the cpu hotplug init code:

- per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE;
+ this_cpu_write(cpuhp_state.state, CPUHP_ONLINE);

which is obviously the right thing to do. Except because of the
ordering issue, it actually failed miserably and unexpectedly on arm64.

So this just fixes the ordering, and changes the name of the function to
be 'boot_cpu_hotplug_init()' to make it obvious that it's about cpu
hotplug state, because the core CPU state was supposed to have already
been done earlier.

Marked for stable, since the (not yet merged) patch that will show this
problem is marked for stable.

Reported-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage"

Joel Fernandes created a nice patch that cleaned up the duplicate hooks used
by lockdep and irqsoff latency tracer. It made both use tracepoints. But it
caused lockdep to trigger several false positives. We have not figured out
why yet, but removing lockdep from using the trace event hooks and just call
its helper functions directly (like it use to), makes the problem go away.

This is a partial revert of the clean up patch c3bc8fd637a9 ("tracing:
Centralize preemptirq tracepoints and unify their usage") that adds direct
calls for lockdep, but also keeps most of the clean up done to get rid of
the horrible preprocessor if statements.

Link: http://lkml.kernel.org/r/20180806155058.5ee875f4@gandalf.local.home

Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Fixes: c3bc8fd637a9 ("tracing: Centralize preemptirq tracepoints and unify their usage")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Centralize preemptirq tracepoints and unify their usage

This patch detaches the preemptirq tracepoints from the tracers and
keeps it separate.

Advantages:
* Lockdep and irqsoff event can now run in parallel since they no longer
have their own calls.

* This unifies the usecase of adding hooks to an irqsoff and irqson
event, and a preemptoff and preempton event.
3 users of the events exist:
- Lockdep
- irqsoff and preemptoff tracers
- irqs and preempt trace events

The unification cleans up several ifdefs and makes the code in preempt
tracer and irqsoff tracers simpler. It gets rid of all the horrific
ifdeferry around PROVE_LOCKING and makes configuration of the different
users of the tracepoints more easy and understandable. It also gets rid
of the time_* function calls from the lockdep hooks used to call into
the preemptirq tracer which is not needed anymore. The negative delta in
lines of code in this patch is quite large too.

In the patch we introduce a new CONFIG option PREEMPTIRQ_TRACEPOINTS
as a single point for registering probes onto the tracepoints. With
this,
the web of config options for preempt/irq toggle tracepoints and its
users becomes:

PREEMPT_TRACER PREEMPTIRQ_EVENTS IRQSOFF_TRACER PROVE_LOCKING
| | \ | |
\ (selects) / \ \ (selects) /
TRACE_PREEMPT_TOGGLE ----> TRACE_IRQFLAGS
\ /
\ (depends on) /
PREEMPTIRQ_TRACEPOINTS

Other than the performance tests mentioned in the previous patch, I also
ran the locking API test suite. I verified that all tests cases are
passing.

I also injected issues by not registering lockdep probes onto the
tracepoints and I see failures to confirm that the probes are indeed
working.

This series + lockdep probes not registered (just to inject errors):
[ 0.000000] hard-irqs-on + irq-safe-A/21: ok | ok | ok |
[ 0.000000] soft-irqs-on + irq-safe-A/21: ok | ok | ok |
[ 0.000000] sirq-safe-A => hirqs-on/12:FAILED|FAILED| ok |
[ 0.000000] sirq-safe-A => hirqs-on/21:FAILED|FAILED| ok |
[ 0.000000] hard-safe-A + irqs-on/12:FAILED|FAILED| ok |
[ 0.000000] soft-safe-A + irqs-on/12:FAILED|FAILED| ok |
[ 0.000000] hard-safe-A + irqs-on/21:FAILED|FAILED| ok |
[ 0.000000] soft-safe-A + irqs-on/21:FAILED|FAILED| ok |
[ 0.000000] hard-safe-A + unsafe-B #1/123: ok | ok | ok |
[ 0.000000] soft-safe-A + unsafe-B #1/123: ok | ok | ok |

With this series + lockdep probes registered, all locking tests pass:

[ 0.000000] hard-irqs-on + irq-safe-A/21: ok | ok | ok |
[ 0.000000] soft-irqs-on + irq-safe-A/21: ok | ok | ok |
[ 0.000000] sirq-safe-A => hirqs-on/12: ok | ok | ok |
[ 0.000000] sirq-safe-A => hirqs-on/21: ok | ok | ok |
[ 0.000000] hard-safe-A + irqs-on/12: ok | ok | ok |
[ 0.000000] soft-safe-A + irqs-on/12: ok | ok | ok |
[ 0.000000] hard-safe-A + irqs-on/21: ok | ok | ok |
[ 0.000000] soft-safe-A + irqs-on/21: ok | ok | ok |
[ 0.000000] hard-safe-A + unsafe-B #1/123: ok | ok | ok |
[ 0.000000] soft-safe-A + unsafe-B #1/123: ok | ok | ok |

Link: http://lkml.kernel.org/r/20180730222423.196630-4-joel@joelfernandes.org

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

x86/mm/pti: Introduce pti_finalize()

Introduce a new function to finalize the kernel mappings for the userspace
page-table after all ro/nx protections have been applied to the kernel
mappings.

Also move the call to pti_clone_kernel_text() to that function so that it
will run on 32 bit kernels too.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Pavel Machek <pavel@ucw.cz>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: linux-mm@kvack.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Waiman Long <llong@redhat.com>
Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
Cc: joro@8bytes.org
Link: https://lkml.kernel.org/r/1531906876-13451-30-git-send-email-joro@8bytes.org

sched/clock: Enable sched clock early

Allow sched_clock() to be used before schec_clock_init() is called. This
provides a way to get early boot timestamps on machines with unstable
clocks.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: peterz@infradead.org
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180719205545.16512-24-pasha.tatashin@oracle.com

sched/clock: Move sched clock initialization and merge with generic clock

sched_clock_postinit() initializes a generic clock on systems where no
other clock is provided. This function may be called only after
timekeeping_init().

Rename sched_clock_postinit to generic_clock_inti() and call it from
sched_clock_init(). Move the call for sched_clock_init() until after
time_init().

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180719205545.16512-23-pasha.tatashin@oracle.com

init/main.c: include <linux/mem_encrypt.h>

In commit c7753208a94c ("x86, swiotlb: Add memory encryption support") a
call to function `mem_encrypt_init' was added. Include prototype
defined in header <linux/mem_encrypt.h> to prevent a warning reported
during compilation with W=1:

init/main.c:494:20: warning: no previous prototype for `mem_encrypt_init' [-Wmissing-prototypes]

Link: http://lkml.kernel.org/r/20180522195533.31415-1-malat@debian.org
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Gargi Sharma <gs051095@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init: fix false positives in W+X checking

load_module() creates W+X mappings via __vmalloc_node_range() (from
layout_and_allocate()->move_module()->module_alloc()) by using
PAGE_KERNEL_EXEC. These mappings are later cleaned up via
"call_rcu_sched(&freeinit->rcu, do_free_init)" from do_init_module().

This is a problem because call_rcu_sched() queues work, which can be run
after debug_checkwx() is run, resulting in a race condition. If hit,
the race results in a nasty splat about insecure W+X mappings, which
results in a poor user experience as these are not the mappings that
debug_checkwx() is intended to catch.

This issue is observed on multiple arm64 platforms, and has been
artificially triggered on an x86 platform.

Address the race by flushing the queued work before running the
arch-defined mark_rodata_ro() which then calls debug_checkwx().

Link: http://lkml.kernel.org/r/1525103946-29526-1-git-send-email-jhugo@codeaurora.org
Fixes: e1a58320a38d ("x86/mm: Warn on W^X mappings")
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reported-by: Timur Tabi <timur@codeaurora.org>
Reported-by: Jan Glauber <jan.glauber@caviumnetworks.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix typo in comment.

CONFIG_PRREMPT -> CONFIG_PREEMPT

Signed-off-by: Florian La Roche <Florian.LaRoche@googlemail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq_file: allocate seq_file from kmem_cache

For fine-grained debugging and usercopy protection.

Link: http://lkml.kernel.org/r/20180310085027.GA17121@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

uts: create "struct uts_namespace" from kmem_cache

So "struct uts_namespace" can enjoy fine-grained SLAB debugging and
usercopy protection.

I'd prefer shorter name "utsns" but there is "user_namespace" already.

Link: http://lkml.kernel.org/r/20180228215158.GA23146@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init: Have initcall_debug still work without CONFIG_TRACEPOINTS

Add macros around the initcall_debug tracepoint code to have the code to
default back to the old method if CONFIG_TRACEPOINTS is not enabled.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

init, tracing: Have printk come through the trace events for initcall_debug

With trace events set before and after the initcall function calls, instead
of having a separate routine for printing out the initcalls when
initcall_debug is specified on the kernel command line, have the code
register a callback to the tracepoints where the initcall trace events are.

This removes the need for having a separate function to do the initcalls as
the tracepoint callbacks can handle the printk. It also includes other
initcalls that are not called by the do_one_initcall() which includes
console and security initcalls.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

init, tracing: Add initcall trace events

Being able to trace the start and stop of initcalls is useful to see where
the timings are an issue. There is already an "initcall_debug" parameter,
but that can cause a large overhead itself, as the printing of the
information may take longer than the initcall functions.

Adding in a start and finish trace event around the initcall functions, as
well as a trace event that records the level of the initcalls, one can get a
much finer measurement of the times and interactions of the initcalls
themselves, as trace events are much lighter than printk()s.

Suggested-by: Abderrahmane Benbachir <abderrahmane.benbachir@polymtl.ca>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

fs: add ksys_open() wrapper; remove in-kernel calls to sys_open()

Using this wrapper allows us to avoid the in-kernel calls to the
sys_open() syscall. The ksys_ prefix denotes that this function is meant
as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_open().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

fs: add do_faccessat() helper and ksys_access() wrapper; remove in-kernel calls to syscall

Using the fs-internal do_faccessat() helper allows us to get rid of
fs-internal calls to the sys_faccessat() syscall.

Introducing the ksys_access() wrapper allows us to avoid the in-kernel
calls to the sys_access() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_access().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

fs: add ksys_dup{,3}() helper; remove in-kernel calls to sys_dup{,3}()

Using ksys_dup() and ksys_dup3() as helper functions allows us to
avoid the in-kernel calls to the sys_dup() and sys_dup3() syscalls.
The ksys_ prefix denotes that these functions are meant as a drop-in
replacement for the syscalls. In particular, they use the same
calling convention as sys_dup{,3}().

In the near future, the fs-external callers of ksys_dup{,3}() should be
converted to call do_dup2() directly. Then, ksys_dup{,3}() can be moved
within sys_dup{,3}() again.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

init: Fix initcall0 name as it is "pure" not "early"

The early_initcall() functions get assigned to __initcall_start[]. These are
called by do_pre_smp_initcalls(). The initcall_levels[] array starts with
__initcall0_start[], and initcall_levels[] are to match the
initcall_level_names[] array. The first name in that array is "early", but
that is not correct. As pure_initcall() functions get assigned to
__initcall0_start[] array.

Change the first name in initcall_level_names[] array to "pure".

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

jump_label: Disable jump labels in __exit code

With the following commit:

333522447063 ("jump_label: Explicitly disable jump labels in __init code")

... we explicitly disabled jump labels in __init code, so they could be
detected and not warned about in the following commit:

dc1dd184c2f0 ("jump_label: Warn on failed jump_label patching attempt")

In-kernel __exit code has the same issue. It's never used, so it's
freed along with the rest of initmem. But jump label entries in __exit
code aren't explicitly disabled, so we get the following warning when
enabling pr_debug() in __exit code:

can't patch jump_label at dmi_sysfs_exit+0x0/0x2d
WARNING: CPU: 0 PID: 22572 at kernel/jump_label.c:376 __jump_label_update+0x9d/0xb0

Fix the warning by disabling all jump labels in initmem (which includes
both __init and __exit code).

Reported-and-tested-by: Li Wang <liwang@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: dc1dd184c2f0 ("jump_label: Warn on failed jump_label patching attempt")
Link: http://lkml.kernel.org/r/7121e6e595374f06616c505b6e690e275c0054d1.1521483452.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

jump_label: Explicitly disable jump labels in __init code

After initmem has been freed, any jump labels in __init code are
prevented from being written to by the kernel_text_address() check in
__jump_label_update(). However, this check is quite broad. If
kernel_text_address() were to return false for any other reason, the
jump label write would fail silently with no warning.

For jump labels in module init code, entry->code is set to zero to
indicate that the entry is disabled. Do the same thing for core kernel
init code. This makes the behavior more consistent, and will also make
it more straightforward to detect non-init jump label write failures in
the next patch.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/c52825c73f3a174e8398b6898284ec20d4deb126.1519051220.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/pti: Add infrastructure for page table isolation

Add the initial files for kernel page table isolation, with a minimal init
function and the boot time detection for this misfeature.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

init: Invoke init_espfix_bsp() from mm_init()

init_espfix_bsp() needs to be invoked before the page table isolation
initialization. Move it into mm_init() which is the place where pti_init()
will be added.

While at it get rid of the #ifdeffery and provide proper stub functions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

main: kernel_start: move housekeeping_init() before workqueue_init_early()

This is needed in order to allow the unbound workqueue to take
housekeeping cpus into accounty

Signed-off-by: Tal Shorer <tal.shorer@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

pid: remove pidhash

pidhash is no longer required as all the information can be looked up
from idr tree. nr_hashed represented the number of pids that had been
hashed. Since, nr_hashed and PIDNS_HASH_ADDING are no longer relevant,
it has been renamed to pid_allocated and PIDNS_ADDING respectively.

[gs051095@gmail.com: v6]
Link: http://lkml.kernel.org/r/1507760379-21662-3-git-send-email-gs051095@gmail.com
Link: http://lkml.kernel.org/r/1507583624-22146-3-git-send-email-gs051095@gmail.com
Signed-off-by: Gargi Sharma <gs051095@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com> [ia64]
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

pid: replace pid bitmap implementation with IDR API

Patch series "Replacing PID bitmap implementation with IDR API", v4.

This series replaces kernel bitmap implementation of PID allocation with
IDR API. These patches are written to simplify the kernel by replacing
custom code with calls to generic code.

The following are the stats for pid and pid_namespace object files
before and after the replacement. There is a noteworthy change between
the IDR and bitmap implementation.

Before
text data bss dec hex filename
8447 3894 64 12405 3075 kernel/pid.o
After
text data bss dec hex filename
3397 304 0 3701 e75 kernel/pid.o

Before
text data bss dec hex filename
5692 1842 192 7726 1e2e kernel/pid_namespace.o
After
text data bss dec hex filename
2854 216 16 3086 c0e kernel/pid_namespace.o

The following are the stats for ps, pstree and calling readdir on /proc
for 10,000 processes.

ps:
With IDR API With bitmap
real 0m1.479s 0m2.319s
user 0m0.070s 0m0.060s
sys 0m0.289s 0m0.516s

pstree:
With IDR API With bitmap
real 0m1.024s 0m1.794s
user 0m0.348s 0m0.612s
sys 0m0.184s 0m0.264s

proc:
With IDR API With bitmap
real 0m0.059s 0m0.074s
user 0m0.000s 0m0.004s
sys 0m0.016s 0m0.016s

This patch (of 2):

Replace the current bitmap implementation for Process ID allocation.
Functions that are no longer required, for example, free_pidmap(),
alloc_pidmap(), etc. are removed. The rest of the functions are
modified to use the IDR API. The change was made to make the PID
allocation less complex by replacing custom code with calls to generic
API.

[gs051095@gmail.com: v6]
Link: http://lkml.kernel.org/r/1507760379-21662-2-git-send-email-gs051095@gmail.com
[avagin@openvz.org: restore the old behaviour of the ns_last_pid sysctl]
Link: http://lkml.kernel.org/r/20171106183144.16368-1-avagin@openvz.org
Link: http://lkml.kernel.org/r/1507583624-22146-2-git-send-email-gs051095@gmail.com
Signed-off-by: Gargi Sharma <gs051095@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>