mm: ptdump: have ptdump_check_wx() return bool

Have ptdump_check_wx() return true when the check is successful or false
otherwise.

[akpm@linux-foundation.org: fix a couple of build issues (x86_64 allmodconfig)]
Link: https://lkml.kernel.org/r/7943149fe955458cb7b57cd483bf41a3aad94684.1706610398.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.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>

powerpc,s390: ptdump: define ptdump_check_wx() regardless of CONFIG_DEBUG_WX

Following patch will use ptdump_check_wx() regardless of CONFIG_DEBUG_WX,
so define it at all times on powerpc and s390 just like other
architectures. Though keep the WARN_ON_ONCE() only when CONFIG_DEBUG_WX
is set.

Link: https://lkml.kernel.org/r/07bfb04c7fec58e84413e91d2533581be357a696.1706610398.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.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>

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>

powerpc: Book3S 64-bit outline-only KASAN support

Implement a limited form of KASAN for Book3S 64-bit machines running under
the Radix MMU, supporting only outline mode.

- Enable the compiler instrumentation to check addresses and maintain the
shadow region. (This is the guts of KASAN which we can easily reuse.)

- Require kasan-vmalloc support to handle modules and anything else in
vmalloc space.

- KASAN needs to be able to validate all pointer accesses, but we can't
instrument all kernel addresses - only linear map and vmalloc. On boot,
set up a single page of read-only shadow that marks all iomap and
vmemmap accesses as valid.

- Document KASAN in powerpc docs.

Background
----------

KASAN support on Book3S is a bit tricky to get right:

- It would be good to support inline instrumentation so as to be able to
catch stack issues that cannot be caught with outline mode.

- Inline instrumentation requires a fixed offset.

- Book3S runs code with translations off ("real mode") during boot,
including a lot of generic device-tree parsing code which is used to
determine MMU features.

[ppc64 mm note: The kernel installs a linear mapping at effective
address c000...-c008.... This is a one-to-one mapping with physical
memory from 0000... onward. Because of how memory accesses work on
powerpc 64-bit Book3S, a kernel pointer in the linear map accesses the
same memory both with translations on (accessing as an 'effective
address'), and with translations off (accessing as a 'real
address'). This works in both guests and the hypervisor. For more
details, see s5.7 of Book III of version 3 of the ISA, in particular
the Storage Control Overview, s5.7.3, and s5.7.5 - noting that this
KASAN implementation currently only supports Radix.]

- Some code - most notably a lot of KVM code - also runs with translations
off after boot.

- Therefore any offset has to point to memory that is valid with
translations on or off.

One approach is just to give up on inline instrumentation. This way
boot-time checks can be delayed until after the MMU is set is up, and we
can just not instrument any code that runs with translations off after
booting. Take this approach for now and require outline instrumentation.

Previous attempts allowed inline instrumentation. However, they came with
some unfortunate restrictions: only physically contiguous memory could be
used and it had to be specified at compile time. Maybe we can do better in
the future.

[paulus@ozlabs.org - Rebased onto 5.17. Note that a kernel with
CONFIG_KASAN=y will crash during boot on a machine using HPT
translation because not all the entry points to the generic
KASAN code are protected with a call to kasan_arch_is_ready().]

Originally-by: Balbir Singh <bsingharora@gmail.com> # ppc64 out-of-line radix version
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
[mpe: Update copyright year and comment formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YoTE69OQwiG7z+Gu@cleo

powerpc/mm: Add __init attribute to eligible functions

Some functions defined in 'arch/powerpc/mm' are deserving of an
`__init` macro attribute. These functions are only called by other
initialization functions and therefore should inherit the attribute.
Also, change function declarations in header files to include `__init`.

Signed-off-by: Nick Child <nick.child@ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211216220035.605465-4-nick.child@ibm.com

powerpc/ptdump: Fix display a BAT's size unit

We have wrong units on BAT's sizes (G instead of M, M instead of ...)

---[ Instruction Block Address Translation ]---
0: 0xc0000000-0xc03fffff 0x00000000 4G Kernel x m
1: 0xc0400000-0xc05fffff 0x00400000 2G Kernel x m
2: 0xc0600000-0xc06fffff 0x00600000 1G Kernel x m
3: 0xc0700000-0xc077ffff 0x00700000 512M Kernel x m
4: 0xc0780000-0xc079ffff 0x00780000 128M Kernel x m
5: 0xc07a0000-0xc07bffff 0x007a0000 128M Kernel x m
6: -
7: -

This is because pt_dump_size() expects a size in Kbytes but
bat_show_603() gives the size in bytes.

To avoid risk of confusion, change pt_dump_size() to take bytes.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f16c30f5c9185a63335322cf1a8b22f189d335ef.1637922595.git.christophe.leroy@csgroup.eu

powerpc/ptdump: Fix DEBUG_WX since generic ptdump conversion

In note_prot_wx() we bail out without reporting anything if
CONFIG_PPC_DEBUG_WX is disabled.

But CONFIG_PPC_DEBUG_WX was removed in the conversion to generic ptdump,
we now need to use CONFIG_DEBUG_WX instead.

Fixes: e084728393a5 ("powerpc/ptdump: Convert powerpc to GENERIC_PTDUMP")
Cc: stable@vger.kernel.org # v5.15+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/20211203124112.2912562-1-mpe@ellerman.id.au

powerpc/ptdump: Fix generic ptdump for 64-bit

Since the conversion to generic ptdump we see crashes on 64-bit:

BUG: Unable to handle kernel data access on read at 0xc0eeff7f00000000
Faulting instruction address: 0xc00000000045e5fc
Oops: Kernel access of bad area, sig: 11 [#1]
...
NIP __walk_page_range+0x2bc/0xce0
LR __walk_page_range+0x240/0xce0
Call Trace:
__walk_page_range+0x240/0xce0 (unreliable)
walk_page_range_novma+0x74/0xb0
ptdump_walk_pgd+0x98/0x170
ptdump_check_wx+0x88/0xd0
mark_rodata_ro+0x48/0x80
kernel_init+0x74/0x1a0
ret_from_kernel_thread+0x5c/0x64

What's happening is that have walked off the end of the kernel page
tables, and started dereferencing junk values.

That happens because we initialised the ptdump_range to span all the way
up to 0xffffffffffffffff:

static struct ptdump_range ptdump_range[] __ro_after_init = {
{TASK_SIZE_MAX, ~0UL},

But the kernel page tables don't span that far. So on 64-bit set the end
of the range to be the address immediately past the end of the kernel
page tables, to limit the page table walk to valid addresses.

Fixes: e084728393a5 ("powerpc/ptdump: Convert powerpc to GENERIC_PTDUMP")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210831135151.886620-1-mpe@ellerman.id.au

powerpc/ptdump: Convert powerpc to GENERIC_PTDUMP

This patch converts powerpc to the generic PTDUMP implementation.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/03166d569526be70214fe9370a7bad219d2f41c8.1625762907.git.christophe.leroy@csgroup.eu

powerpc/ptdump: Reduce level numbers by 1 in note_page() and add p4d level

Do the same as commit f8f0d0b6fa20 ("mm: ptdump: reduce level numbers
by 1 in note_page()") and add missing p4d level.

This will align powerpc to the users of generic ptdump.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d76495c574132b197b445a1f133755cca4b912a4.1625762906.git.christophe.leroy@csgroup.eu

powerpc/ptdump: Remove unused 'page_size' parameter

note_page_update_state() doesn't use page_size. Remove it.

Could also be removed to note_page() but as a following patch
will remove all current users of note_page(), just leave it as
is for now.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e2f80d052001155251bfe009c360d0c5d9242c6b.1625762906.git.christophe.leroy@csgroup.eu

powerpc/ptdump: Use DEFINE_SHOW_ATTRIBUTE()

Use DEFINE_SHOW_ATTRIBUTE() instead of open coding
open() and fops.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b864a92693ca8413ef0b19f0c12065c212899b6e.1625762905.git.christophe.leroy@csgroup.eu

powerpc/mm: Properly coalesce pages in ptdump

Commit aaa229529244 ("powerpc/mm: Add physical address to Linux page
table dump") changed range coalescing to only combine ranges that are
both virtually and physically contiguous, in order to avoid erroneous
combination of unrelated mappings in IOREMAP space.

But in the VMALLOC space, mappings almost never have contiguous
physical pages, so the commit mentionned above leads to dumping one
line per page for vmalloc mappings.

Taking into account the vmalloc always leave a gap between two areas,
we never have two mappings dumped as a single combination even if they
have the exact same flags. The only space that may have encountered
such an issue was the early IOREMAP which is not using vmalloc engine.
But previous commits added gaps between early IO mappings, so it is
not an issue anymore.

That commit created some difficulties with KASAN mappings, see
commit cabe8138b23c ("powerpc: dump as a single line areas mapping a
single physical page.") and with huge page, see
commit b00ff6d8c1c3 ("powerpc/ptdump: Properly handle non standard
page size").

So, almost revert commit aaa229529244 to properly coalesce pages
mapped with the same flags as before, only keep the display of the
first physical address of the range, as it can be usefull especially
for IO mappings.

It brings back powerpc at the same level as other architectures and
simplifies the conversion to GENERIC PTDUMP.

With the patch:

---[ kasan shadow mem start ]---
0xf8000000-0xf8ffffff 0x07000000 16M huge rw present dirty accessed
0xf9000000-0xf91fffff 0x01434000 2M r present accessed
0xf9200000-0xf95affff 0x02104000 3776K rw present dirty accessed
0xfef5c000-0xfeffffff 0x01434000 656K r present accessed
---[ kasan shadow mem end ]---

Before:

---[ kasan shadow mem start ]---
0xf8000000-0xf8ffffff 0x07000000 16M huge rw present dirty accessed
0xf9000000-0xf91fffff 0x01434000 16K r present accessed
0xf9200000-0xf9203fff 0x02104000 16K rw present dirty accessed
0xf9204000-0xf9207fff 0x0213c000 16K rw present dirty accessed
0xf9208000-0xf920bfff 0x02174000 16K rw present dirty accessed
0xf920c000-0xf920ffff 0x02188000 16K rw present dirty accessed
0xf9210000-0xf9213fff 0x021dc000 16K rw present dirty accessed
0xf9214000-0xf9217fff 0x02220000 16K rw present dirty accessed
0xf9218000-0xf921bfff 0x023c0000 16K rw present dirty accessed
0xf921c000-0xf921ffff 0x023d4000 16K rw present dirty accessed
0xf9220000-0xf9227fff 0x023ec000 32K rw present dirty accessed
...
0xf93b8000-0xf93e3fff 0x02614000 176K rw present dirty accessed
0xf93e4000-0xf94c3fff 0x027c0000 896K rw present dirty accessed
0xf94c4000-0xf94c7fff 0x0236c000 16K rw present dirty accessed
0xf94c8000-0xf94cbfff 0x041f0000 16K rw present dirty accessed
0xf94cc000-0xf94cffff 0x029c0000 16K rw present dirty accessed
0xf94d0000-0xf94d3fff 0x041ec000 16K rw present dirty accessed
0xf94d4000-0xf94d7fff 0x0407c000 16K rw present dirty accessed
0xf94d8000-0xf94f7fff 0x041c0000 128K rw present dirty accessed
...
0xf95ac000-0xf95affff 0x042b0000 16K rw present dirty accessed
0xfef5c000-0xfeffffff 0x01434000 16K r present accessed
---[ kasan shadow mem end ]---

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c56ce1f5c3c75adc9811b1a5f9c410fa74183a8d.1618828806.git.christophe.leroy@csgroup.eu

mm: remove unneeded includes of <asm/pgalloc.h>

Patch series "mm: cleanup usage of <asm/pgalloc.h>"

Most architectures have very similar versions of pXd_alloc_one() and
pXd_free_one() for intermediate levels of page table. These patches add
generic versions of these functions in <asm-generic/pgalloc.h> and enable
use of the generic functions where appropriate.

In addition, functions declared and defined in <asm/pgalloc.h> headers are
used mostly by core mm and early mm initialization in arch and there is no
actual reason to have the <asm/pgalloc.h> included all over the place.
The first patch in this series removes unneeded includes of
<asm/pgalloc.h>

In the end it didn't work out as neatly as I hoped and moving
pXd_alloc_track() definitions to <asm-generic/pgalloc.h> would require
unnecessary changes to arches that have custom page table allocations, so
I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local
to mm/.

This patch (of 8):

In most cases <asm/pgalloc.h> header is required only for allocations of
page table memory. Most of the .c files that include that header do not
use symbols declared in <asm/pgalloc.h> and do not require that header.

As for the other header files that used to include <asm/pgalloc.h>, it is
possible to move that include into the .c file that actually uses symbols
from <asm/pgalloc.h> and drop the include from the header file.

The process was somewhat automated using

sed -i -E '/[<"]asm\/pgalloc\.h/d' \
$(grep -L -w -f /tmp/xx \
$(git grep -E -l '[<"]asm/pgalloc\.h'))

where /tmp/xx contains all the symbols defined in
arch/*/include/asm/pgalloc.h.

[rppt@linux.ibm.com: fix powerpc warning]

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc/ptdump: Refactor update of pg_state

In note_page(), the pg_state is updated the same way in two places.

Add note_page_update_state() to do it.

Also include the display of boundary markers there as it is missing
"no level" leg, leading to a mismatch when the first two markers
are at the same address and the first displayed area uses that
address.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a284a809f01c705bbaab303b06fda216f147a99a.1593429426.git.christophe.leroy@csgroup.eu

powerpc/ptdump: Refactor update of st->last_pa

st->last_pa is always updated in note_page() so it can
be done outside the if/elseif/else block.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/610d6b1a60ad0bedef865a90153c1110cfaa507e.1593429426.git.christophe.leroy@csgroup.eu

powerpc/32s: Use dedicated segment for modules with STRICT_KERNEL_RWX

When STRICT_KERNEL_RWX is set, we want to set NX bit on vmalloc
segments. But modules require exec.

Use a dedicated segment for modules. There is not much space
above kernel, and we don't waste vmalloc space to do alignment.
Therefore, we take the segment before PAGE_OFFSET for modules.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/eb8faba9148b6cf17c696ba776b4e8ee2f6313bf.1593428200.git.christophe.leroy@csgroup.eu

powerpc/32: Set user/kernel boundary at TASK_SIZE instead of PAGE_OFFSET

User space stops at TASK_SIZE. At the moment, kernel space starts
at PAGE_OFFSET.

In order to use space between TASK_SIZE and PAGE_OFFSET for modules,
make TASK_SIZE the limit between user and kernel space.

Note that fault.c already considers TASK_SIZE as the boundary between
user and kernel space.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b38b52cd8dabbb56fbd6f9219d6f3cdccbb43b44.1593428200.git.christophe.leroy@csgroup.eu

mm: don't include asm/pgtable.h if linux/mm.h is already included

Patch series "mm: consolidate definitions of page table accessors", v2.

The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once. For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.

Most of these definitions are actually identical and typically it boils
down to, e.g.

static inline unsigned long pmd_index(unsigned long address)
{
return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}

static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}

These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.

For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.

These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.

This patch (of 12):

The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the
functions involving page table manipulations, e.g. pte_alloc() and
pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h>
in the files that include <linux/mm.h>.

The include statements in such cases are remove with a simple loop:

for f in $(git grep -l "include <linux/mm.h>") ; do
sed -i -e '/include <asm\/pgtable.h>/ d' $f
done

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
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 Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
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: Mike Rapoport <rppt@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc: add support for folded p4d page tables

Implement primitives necessary for the 4th level folding, add walks of p4d
level where appropriate and replace 5level-fixup.h with pgtable-nop4d.h.

[rppt@linux.ibm.com: powerpc/xmon: drop unused pgdir varialble in show_pte() function]
Link: http://lkml.kernel.org/r/20200519181454.GI1059226@linux.ibm.com
[rppt@linux.ibm.com; build fix]
Link: http://lkml.kernel.org/r/20200423141845.GI13521@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Christophe Leroy <christophe.leroy@c-s.fr> # 8xx and 83xx
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: James Morse <james.morse@arm.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200414153455.21744-9-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc/ptdump: Handle hugepd at PGD level

The 8xx is about to map kernel linear space and IMMR using huge
pages.

In order to display those pages properly, ptdump needs to handle
hugepd tables at PGD level.

For the time being do it only at PGD level. Further patches may
add handling of hugepd tables at lower level for other platforms
when needed in the future.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/630728289158dcfeb06b14d40ed7c4c4e7148cf1.1589866984.git.christophe.leroy@csgroup.eu

powerpc/ptdump: Properly handle non standard page size

In order to properly display information regardless of the page size,
it is necessary to take into account real page size.

Fixes: cabe8138b23c ("powerpc: dump as a single line areas mapping a single physical page.")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a53b2a0ffd042a8d85464bf90d55bc5b970e00a1.1589866984.git.christophe.leroy@csgroup.eu

powerpc/ptdump: Display size of BATs

Display the size of areas mapped with BATs.

For that, the size display for pages is refactorised.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/acf764eee231f0358e66ca9e819f052804055acc.1589866984.git.christophe.leroy@csgroup.eu

powerpc/mm: ptdump: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200209105901.1620958-4-gregkh@linuxfoundation.org

powerpc/ptdump: Fix W+X verification

Verification cannot rely on simple bit checking because on some
platforms PAGE_RW is 0, checking that a page is not W means
checking that PAGE_RO is set instead of checking that PAGE_RW
is not set.

Use pte helpers instead of checking bits.

Fixes: 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0d894839fdbb19070f0e1e4140363be4f2bb62fc.1578989540.git.christophe.leroy@c-s.fr

powerpc/ptdump: don't entirely rebuild kernel when selecting CONFIG_PPC_DEBUG_WX

Selecting CONFIG_PPC_DEBUG_WX only impacts ptdump and pgtable_32/64
init calls. Declaring related functions in asm/pgtable.h implies
rebuilding almost everything.

Move ptdump_check_wx() declaration in mm/mmu_decl.h

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bf34fd9dca61eadf9a134a9f89ebbc162cfd5f86.1578986011.git.christophe.leroy@c-s.fr

powerpc: use the generic dma coherent remap allocator

This switches to using common code for the DMA allocations, including
potential use of the CMA allocator if configured.

Switching to the generic code enables DMA allocations from atomic
context, which is required by the DMA API documentation, and also
adds various other minor features drivers start relying upon. It
also makes sure we have on tested code base for all architectures
that require uncached pte bits for coherent DMA allocations.

Another advantage is that consistent memory allocations now share
the general vmalloc pool instead of needing an explicit careout
from it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Christophe Leroy <christophe.leroy@c-s.fr> # tested on 8xx
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190814132230.31874-2-hch@lst.de

powerpc/ptdump: get out of note_prot_wx() when CONFIG_PPC_DEBUG_WX is not selected.

When CONFIG_PPC_DEBUG_WX, note_prot_wx() is useless.

Get out of it early and inconditionnally in that case,
so that GCC can kick all the code out.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ff6c8f631bd4ce3a10e0cc241eb569816187bc20.1565786091.git.christophe.leroy@c-s.fr

powerpc/ptdump: drop dummy KERN_VIRT_START on PPC32

PPC32 doesn't have KERN_VIRT_START. Make PAGE_OFFSET the
default starting address for the dump, and drop the dummy
definition of KERN_VIRT_START. Only use KERN_VIRT_START for
non radix PPC64.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/334632b1df4775b0ccf3bdc8d6b201d14e3daedd.1565786091.git.christophe.leroy@c-s.fr

powerpc/ptdump: fix walk_pagetables() address mismatch

walk_pagetables() always walk the entire pgdir from address 0
but considers PAGE_OFFSET or KERN_VIRT_START as the starting
address of the walk, resulting in a possible mismatch in the
displayed addresses.

Ex: on PPC32, when KERN_VIRT_START was locally defined as
PAGE_OFFSET, ptdump displayed 0x80000000
instead of 0xc0000000 for the first kernel page,
because 0xc0000000 + 0xc0000000 = 0x80000000

Start the walk at st->start_address instead of starting at 0.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5aa2ac513295f594cce8ddb1c649f61947bd063d.1565786091.git.christophe.leroy@c-s.fr

powerpc/ptdump: Fix addresses display on PPC32

Commit 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot")
wrongly changed KERN_VIRT_START from 0 to PAGE_OFFSET, leading to a
shift in the displayed addresses.

Lets revert that change to resync walk_pagetables()'s addr val and
pgd_t pointer for PPC32.

Fixes: 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/eb4d626514e22f85814830012642329018ef6af9.1565786091.git.christophe.leroy@c-s.fr

powerpc/book3s: Use config independent helpers for page table walk

Even when we have HugeTLB and THP disabled, kernel linear map can still be
mapped with hugepages. This is only an issue with radix translation because hash
MMU doesn't map kernel linear range in linux page table and other kernel
map areas are not mapped using hugepage.

Add config independent helpers and put WARN_ON() when we don't expect things
to be mapped via hugepages.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 of the license

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 315 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

powerpc/mm: Warn if W+X pages found on boot

Implement code to walk all pages and warn if any are found to be both
writable and executable. Depends on STRICT_KERNEL_RWX enabled, and is
behind the DEBUG_WX config option.

This only runs on boot and has no runtime performance implications.

Very heavily influenced (and in some cases copied verbatim) from the
ARM64 code written by Laura Abbott (thanks!), since our ptdump
infrastructure is similar.

Signed-off-by: Russell Currey <ruscur@russell.cc>
[mpe: Fixup build error when disabled]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/mm/ptdump: Wrap seq_printf() to handle NULL pointers

Lovingly borrowed from the arch/arm64 ptdump code.

This doesn't seem to be an issue in practice, but is necessary for my
upcoming commit.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/32: prepare shadow area for KASAN

This patch prepares a shadow area for KASAN.

The shadow area will be at the top of the kernel virtual
memory space above the fixmap area and will occupy one
eighth of the total kernel virtual memory space.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/mm/hash64: Map all the kernel regions in the same 0xc range

This patch maps vmalloc, IO and vmemap regions in the 0xc address range
instead of the current 0xd and 0xf range. This brings the mapping closer
to radix translation mode.

With hash 64K page size each of this region is 512TB whereas with 4K config
we are limited by the max page table range of 64TB and hence there regions
are of 16TB size.

The kernel mapping is now:

On 4K hash

kernel_region_map_size = 16TB
kernel vmalloc start = 0xc000100000000000
kernel IO start = 0xc000200000000000
kernel vmemmap start = 0xc000300000000000

64K hash, 64K radix and 4k radix:

kernel_region_map_size = 512TB
kernel vmalloc start = 0xc008000000000000
kernel IO start = 0xc00a000000000000
kernel vmemmap start = 0xc00c000000000000

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc: Move page table dump files in a dedicated subdirectory

This patch moves the files related to page table dump in a
dedicated subdirectory.

The purpose is to clean a bit arch/powerpc/mm by regrouping
multiple files handling a dedicated function.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Shorten the file names while we're at it]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>