parisc: Use page table locks only if DEBUG_KERNEL is enabled

The usage of page table locks in TLB fault handler is usually
only needed when debugging the kernel. So make this configuration
option dependend on DEBUG_KERNEL.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Fix lightweight spinlock checks to not break futexes

The lightweight spinlock checks verify that a spinlock has either value
0 (spinlock locked) and that not any other bits than in
__ARCH_SPIN_LOCK_UNLOCKED_VAL is set.

This breaks the current LWS code, which writes the address of the lock
into the lock word to unlock it, which was an optimization to save one
assembler instruction.

Fix it by making spinlock_types.h accessible for asm code, change the
LWS spinlock-unlocking code to write __ARCH_SPIN_LOCK_UNLOCKED_VAL into
the lock word, and add some missing lightweight spinlock checks to the
LWS path. Finally, make the spinlock checks dependend on DEBUG_KERNEL.

Noticed-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Tested-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # v6.4+
Fixes: 15e64ef6520e ("parisc: Add lightweight spinlock checks")

parisc: Move TLB_PTLOCK option to Kconfig.debug

Move this debug option to the Kconfig.debug file.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Add lightweight spinlock checks

Add a lightweight spinlock check which uses only two instructions
per spinlock call. It detects if a spinlock has been trashed by
some memory corruption and then halts the kernel. It will not detect
uninitialized spinlocks, for which CONFIG_DEBUG_SPINLOCK needs to
be enabled.

This lightweight spinlock check shouldn't influence runtime, so it's
safe to enable it by default.

The __ARCH_SPIN_LOCK_UNLOCKED_VAL constant has been choosen small enough
to be able to be loaded by one LDI assembler statement.

Signed-off-by: Helge Deller <deller@gmx.de>

tracing: Refactor TRACE_IRQFLAGS_SUPPORT in Kconfig

Make architectures select TRACE_IRQFLAGS_SUPPORT instead of
having many defines.

Link: https://lkml.kernel.org/r/20210731052233.4703-2-masahiroy@kernel.org

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>   #arch/arc
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Kconfig: consolidate the "Kernel hacking" menu

Move the source of lib/Kconfig.debug and arch/$(ARCH)/Kconfig.debug to
the top-level Kconfig. For two architectures that means moving their
arch-specific symbols in that menu into a new arch Kconfig.debug file,
and for a few more creating a dummy file so that we can include it
unconditionally.

Also move the actual 'Kernel hacking' menu to lib/Kconfig.debug, where
it belongs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch: Move CONFIG_DEBUG_RODATA and CONFIG_SET_MODULE_RONX to be common

There are multiple architectures that support CONFIG_DEBUG_RODATA and
CONFIG_SET_MODULE_RONX. These options also now have the ability to be
turned off at runtime. Move these to an architecture independent
location and make these options def_bool y for almost all of those
arches.

Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

parisc: Fix ftrace function tracer

Fix the FTRACE function tracer for 32- and 64-bit kernel.
The former code was horribly broken.

Reimplement most coding in assembly and utilize optimizations, e.g. put
mcount() and ftrace_stub() into one L1 cacheline.

Signed-off-by: Helge Deller <deller@gmx.de>

consolidate per-arch stack overflow debugging options

Original posting:

http://lkml.kernel.org/r/20121214184202.F54094D9@kernel.stglabs.ibm.com

Several architectures have similar stack debugging config options.
They all pretty much do the same thing, some with slightly
differing help text.

This patch changes the architectures to instead enable a Kconfig
boolean, and then use that boolean in the generic Kconfig.debug
to present the actual menu option. This removes a bunch of
duplication and adds consistency across arches.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com> [for tile]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parisc: add kernel stack overflow check

Add the CONFIG_DEBUG_STACKOVERFLOW config option to enable checks to
detect kernel stack overflows.

Stack overflows can not be detected reliable since we do not want to
introduce too much overhead.

Instead, during irq processing in do_cpu_irq_mask() we check kernel
stack usage of the interrupted kernel process. Kernel threads can be
easily detected by checking the value of space register 7 (sr7) which
is zero when running inside the kernel.

Since THREAD_SIZE is 16k and PAGE_SIZE is 4k, reduce the alignment of
the init thread to the lower value (PAGE_SIZE) in the kernel
vmlinux.ld.S linker script.

Signed-off-by: Helge Deller <deller@gmx.de>

Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS

The help text for this config is duplicated across the x86, parisc, and
s390 Kconfig.debug files. Arnd Bergman noted that the help text was
slightly misleading and should be fixed to state that enabling this
option isn't a problem when using pre 4.4 gcc.

To simplify the rewording, consolidate the text into lib/Kconfig.debug
and modify it there to be more explicit about when you should say N to
this config.

Also, make the text a bit more generic by stating that this option
enables compile time checks so we can cover architectures which emit
warnings vs. ones which emit errors. The details of how an
architecture decided to implement the checks isn't as important as the
concept of compile time checking of copy_from_user() calls.

While we're doing this, remove all the copy_from_user_overflow() code
that's duplicated many times and place it into lib/ so that any
architecture supporting this option can get the function for free.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Helge Deller <deller@gmx.de>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parisc: add strict copy size checks (v2)

Add CONFIG_DEBUG_STRICT_USER_COPY_CHECKS, copied from the x86
implementation. Tested with 32 and 64bit kernel.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

alpha/parisc: remove config variable DEBUG_RWLOCK

Remove config variable DEBUG_RWLOCK, since it is not used.

Signed-off-by: Jiri Olsa <olsajiri@gmail.com>
Acked-by: Grant Grundler <grundler@parisc-linux.org>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[PARISC] Add CONFIG_DEBUG_RODATA to protect read-only data

Add the parisc version of the "mark rodata section read only" patches.
Based on code from and Signed-off-by Arjan van de Ven
<arjan@infradead.org>, Ingo Molnar <mingo@elte.hu>, Andi Kleen <ak@muc.de>,
Andrew Morton <akpm@osdl.org>, Linus Torvalds <torvalds@osdl.org>.

Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!