Merge tag 'selinux-pr-20201214' of git://git./linux/kernel/git/pcmoore/selinux

Pull selinux updates from Paul Moore:
 "While we have a small number of SELinux patches for v5.11, there are a
  few changes worth highlighting:

   - Change the LSM network hooks to pass flowi_common structs instead
     of the parent flowi struct as the LSMs do not currently need the
     full flowi struct and they do not have enough information to use it
     safely (missing information on the address family).

     This patch was discussed both with Herbert Xu (representing team
     netdev) and James Morris (representing team
     LSMs-other-than-SELinux).

   - Fix how we handle errors in inode_doinit_with_dentry() so that we
     attempt to properly label the inode on following lookups instead of
     continuing to treat it as unlabeled.

   - Tweak the kernel logic around allowx, auditallowx, and dontauditx
     SELinux policy statements such that the auditx/dontauditx are
     effective even without the allowx statement.

  Everything passes our test suite"

* tag 'selinux-pr-20201214' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  lsm,selinux: pass flowi_common instead of flowi to the LSM hooks
  selinux: Fix fall-through warnings for Clang
  selinux: drop super_block backpointer from superblock_security_struct
  selinux: fix inode_doinit_with_dentry() LABEL_INVALID error handling
  selinux: allow dontauditx and auditallowx rules to take effect without allowx
  selinux: fix error initialization in inode_doinit_with_dentry()

Merge tag 'audit-pr-20201214' of git://git./linux/kernel/git/pcmoore/audit

Pull audit updates from Paul Moore:
 "A small set of audit patches for v5.11 with four patches in total and
  only one of any real significance.

  Richard's patch to trigger accompanying records causes the kernel to
  emit additional related records when an audit event occurs; helping
  provide some much needed context to events in the audit log. It is
  also worth mentioning that this is a revised patch based on an earlier
  attempt that had to be reverted in the v5.8 time frame.

  Everything passes our test suite, and with no problems reported please
  merge this for v5.11"

* tag 'audit-pr-20201214' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: replace atomic_add_return()
  audit: fix macros warnings
  audit: trigger accompanying records when no rules present
  audit: fix a kernel-doc markup

Merge tag 'printk-for-5.11' of git://git./linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Finally allow parallel writes and reads into/from the lockless
   ringbuffer. But it is not a complete solution. Readers are still
   serialized against each other. And nested writes are still prevented
   by printk_safe per-CPU buffers.

 - Use ttynull as the ultimate fallback for /dev/console.

 - Officially allow disabling console output by using console="" or
   console=null

 - A few code cleanups

* tag 'printk-for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: remove logbuf_lock writer-protection of ringbuffer
  printk: inline log_output(),log_store() in vprintk_store()
  printk: remove obsolete dead assignment
  printk/console: Allow to disable console output by using console="" or console=null
  init/console: Use ttynull as a fallback when there is no console
  printk: ringbuffer: Reference text_data_ring directly in callees.

Merge tag 'fallthrough-fixes-clang-5.11-rc1' of git://git./linux/kernel/git/gustavoars/linux

Pull fallthrough fixes from Gustavo A. R. Silva:
 "Fix many fall-through warnings when building with Clang 12.0.0
  using -Wimplicit-fallthrough.

   - powerpc: boot: include compiler_attributes.h (Nick Desaulniers)

   - Revert "lib: Revert use of fallthrough pseudo-keyword in lib/"
     (Nick Desaulniers)

   - powerpc: fix -Wimplicit-fallthrough (Nick Desaulniers)

   - lib: Fix fall-through warnings for Clang (Gustavo A. R. Silva)"

* tag 'fallthrough-fixes-clang-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
  lib: Fix fall-through warnings for Clang
  powerpc: fix -Wimplicit-fallthrough
  Revert "lib: Revert use of fallthrough pseudo-keyword in lib/"
  powerpc: boot: include compiler_attributes.h

Merge tag 'linux-kselftest-kunit-5.11-rc1' of git://git./linux/kernel/git/shuah/linux-kselftest

Pull Kunit updates from Shuah Khan:

 - documentation update and fix to kunit_tool to parse diagnostic
   messages correctly from David Gow

 - Support for Parameterized Testing and fs/ext4 test updates to use
   KUnit parameterized testing feature from Arpitha Raghunandan

 - Helper to derive file names depending on --build_dir argument from
   Andy Shevchenko

* tag 'linux-kselftest-kunit-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  fs: ext4: Modify inode-test.c to use KUnit parameterized testing feature
  kunit: Support for Parameterized Testing
  kunit: kunit_tool: Correctly parse diagnostic messages
  Documentation: kunit: provide guidance for testing many inputs
  kunit: Introduce get_file_path() helper

Merge tag 'linux-kselftest-next-5.11-rc1' of git://git./linux/kernel/git/shuah/linux-kselftest

Pull Kselftest updates from Shuah Khan:

 - Much needed gpio test Makefile cleanup to various problems with test
   dependencies and build errors from Michael Ellerman

 - Enabling vDSO test on non x86 platforms from Vincenzo Frascino

 - Fix intel_pstate to replace deprecated ftime() usages with
   clock_gettime() from Tommi Rantala

 - cgroup test build fix on older releases from Sachin Sant

 - A couple of spelling mistake fixes

* tag 'linux-kselftest-next-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/cgroup: Fix build on older distros
  selftests/run_kselftest.sh: fix dry-run typo
  tool: selftests: fix spelling typo of 'writting'
  selftests/memfd: Fix implicit declaration warnings
  selftests: intel_pstate: ftime() is deprecated
  selftests/gpio: Add to CLEAN rule rather than overriding
  selftests/gpio: Fix build when source tree is read only
  selftests/gpio: Move include of lib.mk up
  selftests/gpio: Use TEST_GEN_PROGS_EXTENDED
  kselftest: Extend vdso correctness test to clock_gettime64
  kselftest: Move test_vdso to the vDSO test suite
  kselftest: Extend vDSO selftest to clock_getres
  kselftest: Extend vDSO selftest
  kselftest: Enable vDSO test on non x86 platforms

Merge tag 'linux-kselftest-fixes-5.11-rc1' of git://git./linux/kernel/git/shuah/linux-kselftest

Pull Kselftest fixes from Shuah Khan:
 "Build fixes for clone3 and rseq tests"

* tag 'linux-kselftest-fixes-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/clone3: Fix build error
  rseq/selftests: Fix MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ build error under other arch.

Merge tag 'asm-generic-timers-5.11' of git://git./linux/kernel/git/arnd/asm-generic

Pull asm-generic cross-architecture timer cleanup from Arnd Bergmann:
 "This cleans up two ancient timer features that were never completed in
  the past, CONFIG_GENERIC_CLOCKEVENTS and CONFIG_ARCH_USES_GETTIMEOFFSET.

  There was only one user left for the ARCH_USES_GETTIMEOFFSET variant
  of clocksource implementations, the ARM EBSA110 platform. Rather than
  changing to use modern timekeeping, we remove the platform entirely as
  Russell no longer uses his machine and nobody else seems to have one
  any more.

  The conditional code for using arch_gettimeoffset() is removed as a
  result.

  For CONFIG_GENERIC_CLOCKEVENTS, there are still a couple of platforms
  not using clockevent drivers: parisc, ia64, most of m68k, and one Arm
  platform. These all do timer ticks slighly differently, and this gets
  cleaned up to the point they at least all call the same helper
  function.

  Instead of most platforms using 'select GENERIC_CLOCKEVENTS' in
  Kconfig, the polarity is now reversed, with the few remaining ones
  selecting LEGACY_TIMER_TICK instead"

* tag 'asm-generic-timers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  timekeeping: default GENERIC_CLOCKEVENTS to enabled
  timekeeping: remove xtime_update
  m68k: remove timer_interrupt() function
  m68k: change remaining timers to legacy_timer_tick
  m68k: m68328: use legacy_timer_tick()
  m68k: sun3/sun3c: use legacy_timer_tick
  m68k: split heartbeat out of timer function
  m68k: coldfire: use legacy_timer_tick()
  parisc: use legacy_timer_tick
  ARM: rpc: use legacy_timer_tick
  ia64: convert to legacy_timer_tick
  timekeeping: add CONFIG_LEGACY_TIMER_TICK
  timekeeping: remove arch_gettimeoffset
  net: remove am79c961a driver
  ARM: remove ebsa110 platform

Merge tag 'asm-generic-mmu-context-5.11' of git://git./linux/kernel/git/arnd/asm-generic

Pull asm-generic mmu-context cleanup from Arnd Bergmann:
 "This is a cleanup series from Nicholas Piggin, preparing for later
  changes. The asm/mmu_context.h header are generalized and common code
  moved to asm-gneneric/mmu_context.h.

  This saves a bit of code and makes it easier to change in the future"

* tag 'asm-generic-mmu-context-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (25 commits)
  h8300: Fix generic mmu_context build
  m68k: mmu_context: Fix Sun-3 build
  xtensa: use asm-generic/mmu_context.h for no-op implementations
  x86: use asm-generic/mmu_context.h for no-op implementations
  um: use asm-generic/mmu_context.h for no-op implementations
  sparc: use asm-generic/mmu_context.h for no-op implementations
  sh: use asm-generic/mmu_context.h for no-op implementations
  s390: use asm-generic/mmu_context.h for no-op implementations
  riscv: use asm-generic/mmu_context.h for no-op implementations
  powerpc: use asm-generic/mmu_context.h for no-op implementations
  parisc: use asm-generic/mmu_context.h for no-op implementations
  openrisc: use asm-generic/mmu_context.h for no-op implementations
  nios2: use asm-generic/mmu_context.h for no-op implementations
  nds32: use asm-generic/mmu_context.h for no-op implementations
  mips: use asm-generic/mmu_context.h for no-op implementations
  microblaze: use asm-generic/mmu_context.h for no-op implementations
  m68k: use asm-generic/mmu_context.h for no-op implementations
  ia64: use asm-generic/mmu_context.h for no-op implementations
  hexagon: use asm-generic/mmu_context.h for no-op implementations
  csky: use asm-generic/mmu_context.h for no-op implementations
  ...

Merge tag 'asm-generic-cleanup-5.11' of git://git./linux/kernel/git/arnd/asm-generic

Pull asm-generic cleanups from Arnd Bergmann:
 "These are a couple of compiler warning fixes to make 'make W=2' less
  noisy, as well as some fixes to code comments in asm-generic"

* tag 'asm-generic-cleanup-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  syscalls: Fix file comments for syscalls implemented in kernel/sys.c
  ctype.h: remove duplicate isdigit() helper
  qspinlock: use signed temporaries for cmpxchg
  asm-generic: fix ffs -Wshadow warning
  asm-generic: percpu: avoid Wshadow warning
  asm-generic/sembuf: Update architecture related information in comment

Merge branch 'akpm' (patches from Andrew)

Merge yet more updates from Andrew Morton:

 - lots of little subsystems

 - a few post-linux-next MM material. Most of the rest awaits more
   merging of other trees.

Subsystems affected by this series: alpha, procfs, misc, core-kernel,
bitmap, lib, lz4, checkpatch, nilfs, kdump, rapidio, gcov, bfs, relay,
resource, ubsan, reboot, fault-injection, lzo, apparmor, and mm (swap,
memory-hotplug, pagemap, cleanups, and gup).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (86 commits)
  mm: fix some spelling mistakes in comments
  mm: simplify follow_pte{,pmd}
  mm: unexport follow_pte_pmd
  apparmor: remove duplicate macro list_entry_is_head()
  lib/lzo/lzo1x_compress.c: make lzogeneric1x_1_compress() static
  fault-injection: handle EI_ETYPE_TRUE
  reboot: hide from sysfs not applicable settings
  reboot: allow to override reboot type if quirks are found
  reboot: remove cf9_safe from allowed types and rename cf9_force
  reboot: allow to specify reboot mode via sysfs
  reboot: refactor and comment the cpu selection code
  lib/ubsan.c: mark type_check_kinds with static keyword
  kcov: don't instrument with UBSAN
  ubsan: expand tests and reporting
  ubsan: remove UBSAN_MISC in favor of individual options
  ubsan: enable for all*config builds
  ubsan: disable UBSAN_TRAP for all*config
  ubsan: disable object-size sanitizer under GCC
  ubsan: move cc-option tests into Kconfig
  ubsan: remove redundant -Wno-maybe-uninitialized
  ...

mm: fix some spelling mistakes in comments

Fix some spelling mistakes in comments:
udpate ==> update
succesful ==> successful
exmaple ==> example
unneccessary ==> unnecessary
stoping ==> stopping
uknown ==> unknown

Link: https://lkml.kernel.org/r/20201127011747.86005-1-shihaitao1@huawei.com
Signed-off-by: Haitao Shi <shihaitao1@huawei.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: simplify follow_pte{,pmd}

Merge __follow_pte_pmd, follow_pte_pmd and follow_pte into a single
follow_pte function and just pass two additional NULL arguments for the
two previous follow_pte callers.

[sfr@canb.auug.org.au: merge fix for "s390/pci: remove races against pte updates"]
Link: https://lkml.kernel.org/r/20201111221254.7f6a3658@canb.auug.org.au
Link: https://lkml.kernel.org/r/20201029101432.47011-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: unexport follow_pte_pmd

Patch series "simplify follow_pte a bit".

This small series drops the not needed follow_pte_pmd exports, and
simplifies the follow_pte family of functions a bit.

This patch (of 2):

follow_pte_pmd() is only used by the DAX code, which can't be modular.

Link: https://lkml.kernel.org/r/20201029101432.47011-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

apparmor: remove duplicate macro list_entry_is_head()

Strangely I hadn't had noticed the existence of the list_entry_is_head()
in apparmor code when added the same one in the list.h.  Luckily it's
fully identical and didn't break builds.  In any case we don't need a
duplicate anymore, thus remove it from apparmor code.

Link: https://lkml.kernel.org/r/20201208100639.88182-1-andriy.shevchenko@linux.intel.com
Fixes: e130816164e244 ("include/linux/list.h: add a macro to test if entry is pointing to the head")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E . Hallyn " <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/lzo/lzo1x_compress.c: make lzogeneric1x_1_compress() static

Fix the following sparse warning:

  lib/lzo/lzo1x_compress.c:304:5: warning: symbol 'lzogeneric1x_1_compress' was not declared. Should it be static?

Link: https://lkml.kernel.org/r/20201020031415.136874-1-yanaijie@huawei.com
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Dave Rodgman <dave.rodgman@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fault-injection: handle EI_ETYPE_TRUE

Commit af3b854492f351d1 ("mm/page_alloc.c: allow error injection")
introduced EI_ETYPE_TRUE, but did not extend

 * lib/error-inject.c:error_type_string(), and
 * kernel/fail_function.c:adjust_error_retval()

to accommodate for this change.

Handle EI_ETYPE_TRUE in both functions appropriately by
 * returning "TRUE" in error_type_string(),
 * adjusting the return value to true (1) in adjust_error_retval().

Furthermore, simplify the logic of handling EI_ETYPE_NULL in
adjust_error_retval().

Link: https://lkml.kernel.org/r/njB1czX0ZgWPR9h61euHIBb5bEyePw9D4D2m3i5lc9Cl96P8Q1308dTcmsEZW7Vtz3Ifz4do-rOtSfuFTyGoEDYokkK2aUqBePVptzZEWfU=@protonmail.com
Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reboot: hide from sysfs not applicable settings

Not all the reboot settings from both the kernel command line or sysfs
interface are available to all platforms.

Filter out reboot_type and reboot_force which are x86 only, and also
remove reboot_cpu on kernels without SMP support.

This saves some space, and avoid confusing the user with settings which
will have no effect.

Link: https://lkml.kernel.org/r/20201130173717.198952-3-mcroce@linux.microsoft.com
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reboot: allow to override reboot type if quirks are found

Patch series "reboot: sysfs improvements".

Some improvements to the sysfs reboot interface: hide not working settings
and support machines with known reboot quirks.

This patch (of 2):

On some machines a quirk can force a specific reboot type.  Quirks are
found during a DMI scan, the list of machines which need special reboot
handling is defined in reboot_dmi_table.

The kernel command line reboot= option overrides this via a global
variable `reboot_default`, so that the reboot type requested in the
command line is really performed.

This was not true when setting the reboot type via the new sysfs
interface.  Fix this by setting reboot_default upon the first change, like
reboot_setup() does for the command line.

Link: https://lkml.kernel.org/r/20201130173717.198952-1-mcroce@linux.microsoft.com
Link: https://lkml.kernel.org/r/20201130173717.198952-2-mcroce@linux.microsoft.com
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reboot: remove cf9_safe from allowed types and rename cf9_force

BOOT_CF9_SAFE_STR is an internal value used only by the x86 code and it's
not possible to set it from userspace.

Remove it, and rename 'cf9_force' to 'pci', so to make it coherent with
the kernel command line reboot= option.

Tested with this script:

cd /sys/kernel/reboot/

for i in cold warm hard soft gpio; do
echo $i >mode
read j <mode
[ $i = $j ] || echo "mode $i != $j"
done

for i in bios acpi kbd triple efi pci; do
echo $i >type
read j <type
[ $i = $j ] || echo "type $i != $j"
done

for i in $(seq 0 $(nproc --ignore=1)); do
echo $i >cpu
read j <cpu
[ $i = $j ] || echo "cpu $i != $j"
done

for i in 0 1; do
echo $i >force
read j <force
[ $i = $j ] || echo "force $i != $j"
done

Link: https://lkml.kernel.org/r/20201113015900.543923-1-mcroce@linux.microsoft.com
Fixes: eab8da48579d ("reboot: allow to specify reboot mode via sysfs")
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reboot: allow to specify reboot mode via sysfs

The kernel cmdline reboot= option offers some sort of control on how the
reboot is issued.

We don't always know in advance what type of reboot to perform.

Sometimes a warm reboot is preferred to persist certain memory regions
across the reboot.  Others a cold one is needed to apply a future system
update that makes a memory memory model change, like changing the base
page size or resizing a persistent memory region.

Or simply we want to enable reboot_force because we noticed that
something bad happened.

Add handles in sysfs to allow setting these reboot options, so they can
be changed when the system is booted, other than at boot time.

The handlers are under <sysfs>/kernel/reboot, can be read to get the
current configuration and written to alter it.

# cd /sys/kernel/reboot/

# grep . *
cpu:0
force:0
mode:cold
type:acpi

# echo 2 >cpu
# echo yes >force
# echo soft >mode
# echo bios >type

# grep . *
cpu:2
force:1
mode:soft
type:bios

Before setting anything, check for CAP_SYS_BOOT capability, so it's
possible to allow an unpriviledged process to change these settings simply
by relaxing the handles permissions, without opening them to the world.

[natechancellor@gmail.com: fix variable assignments in type_store]
Link: https://lkml.kernel.org/r/20201112035023.974748-1-natechancellor@gmail.com
Link: https://github.com/ClangBuiltLinux/linux/issues/1197
Link: https://lkml.kernel.org/r/20201110202746.9690-1-mcroce@linux.microsoft.com
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reboot: refactor and comment the cpu selection code

Small improvements to the code, without changing the way it works:

 - use a local variable, to avoid a small time lapse where reboot_cpu
   can have an invalid value

 - comment the code which is not easy to understand at a glance

 - merge two identical code blocks into one

 - replace pointer arithmetics with equivalent array syntax

Link: https://lkml.kernel.org/r/20201103214025.116799-4-mcroce@linux.microsoft.com
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Robin Holt <robinmholt@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/ubsan.c: mark type_check_kinds with static keyword

Fix the following sparse warning:

  lib/ubsan.c:20:12: warning: symbol 'type_check_kinds' was not declared. Should it be static?

[akpm@linux-foundation.org: make it `static const char * const' while we're in there]

Link: https://lkml.kernel.org/r/1607602638-79584-1-git-send-email-zou_wei@huawei.com
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kcov: don't instrument with UBSAN

Both KCOV and UBSAN use compiler instrumentation.  If UBSAN detects a bug
in KCOV, it may cause infinite recursion via printk and other common
functions.  We already don't instrument KCOV with KASAN/KCSAN for this
reason, don't instrument it with UBSAN as well.

As a side effect this also resolves the following gcc warning:

conflicting types for built-in function '__sanitizer_cov_trace_switch';
expected 'void(long unsigned int, void *)'
[-Wbuiltin-declaration-mismatch]

It's only reported when kcov.c is compiled with any of the sanitizers
enabled.  Size of the arguments is correct, it's just that gcc uses 'long'
on 64-bit arches and 'long long' on 32-bit arches, while kernel type is
always 'long long'.

Link: https://lkml.kernel.org/r/20201209100152.2492072-1-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Suggested-by: Marco Elver <elver@google.com>
Acked-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ubsan: expand tests and reporting

Expand the UBSAN tests to include some additional UB cases.  Notably the
out-of-bounds enum loading appears not to work.  Also include per-test
reporting, including the relevant CONFIG_UBSAN...  Kconfigs.

Link: https://lkml.kernel.org/r/20201203004437.389959-8-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ubsan: remove UBSAN_MISC in favor of individual options

Make each UBSAN option individually selectable and remove UBSAN_MISC which
no longer has any purpose.  Add help text for each Kconfig, and include a
reference to the Clang sanitizer documentation.  Disable unsigned overflow
by default (not available with GCC and makes x86 unbootable with Clang).
Disable unreachable when objtool is in use (redundant and confuses things:
instrumentation appears at unreachable locations).

Link: https://lkml.kernel.org/r/20201203004437.389959-7-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ubsan: enable for all*config builds

With UBSAN_OBJECT_SIZE disabled for GCC, only UBSAN_ALIGNMENT remained a
noisy UBSAN option.  Disable it for COMPILE_TEST so the rest of UBSAN can
be used for full all*config builds or other large combinations.

[sfr@canb.auug.org.au: add .data..Lubsan_data*/.data..Lubsan_type* sections explicitly]
Link: https://lkml.kernel.org/r/20201208230157.42c42789@canb.auug.org.au
Link: https://lore.kernel.org/lkml/CAHk-=wgXW=YLxGN0QVpp-1w5GDd2pf1W-FqY15poKzoVfik2qA@mail.gmail.com/
Link: https://lkml.kernel.org/r/20201203004437.389959-6-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ubsan: disable UBSAN_TRAP for all*config

Doing all*config builds attempts to build as much as possible. UBSAN_TRAP
effectively short-circuits lib/usban.c, so it should be disabled for
COMPILE_TEST so that the lib/ubsan.c code gets built.

Link: https://lkml.kernel.org/r/20201203004437.389959-5-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ubsan: disable object-size sanitizer under GCC

GCC's -fsanitize=object-size (as part of CONFIG_UBSAN_MISC) greatly
increases stack utilization.  Do not allow this under GCC.

Link: https://lkml.kernel.org/r/20201203004437.389959-4-keescook@chromium.org
Link: https://lore.kernel.org/lkml/CAHk-=wjPasyJrDuwDnpHJS2TuQfExwe=px-SzLeN8GFMAQJPmQ@mail.gmail.com/
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ubsan: move cc-option tests into Kconfig

Instead of doing if/endif blocks with cc-option calls in the UBSAN
Makefile, move all the tests into Kconfig and use the Makefile to collect
the results.

Link: https://lkml.kernel.org/r/20201203004437.389959-3-keescook@chromium.org
Link: https://lore.kernel.org/lkml/CAHk-=wjPasyJrDuwDnpHJS2TuQfExwe=px-SzLeN8GFMAQJPmQ@mail.gmail.com/
Signed-off-by: Kees Cook <keescook@chromium.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ubsan: remove redundant -Wno-maybe-uninitialized

Patch series "Clean up UBSAN Makefile", v2.

This series attempts to address the issues seen with UBSAN's object-size
sanitizer causing problems under GCC.  In the process, the Kconfig and
Makefile are refactored to do all the cc-option calls in the Kconfig.
Additionally start to detangle -Wno-maybe-uninitialized, disable
UBSAN_TRAP under COMPILE_TEST for wider build coverage, and expand the
libusan tests.

This patch (of 7):

In commit 78a5255ffb6a ("Stop the ad-hoc games with
-Wno-maybe-initialized") -Wmaybe-uninitialized was disabled globally, so
keeping the disabling logic here too doesn't make sense.

Link: https://lkml.kernel.org/r/20201203004437.389959-1-keescook@chromium.org
Link: https://lkml.kernel.org/r/20201203004437.389959-2-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/resource.c: fix kernel-doc markups

Kernel-doc markups should use this format:
        identifier - description

While here, fix a kernel-doc tag that was using, instead,
a normal comment block.

[akpm@linux-foundation.org: coding style fixes]

Link: https://lkml.kernel.org/r/c5e38e1070f8dbe2f9607a10b44afe2875bd966c.1605521731.git.mchehab+huawei@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: "Jonathan Corbet" <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

blktrace: make relay callbacks const

Now that relay_open() accepts const callbacks, make relay callbacks
const.

Link: https://lkml.kernel.org/r/7ff5ce0b735901eb4f10e13da2704f1d8c4a2507.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ath9k: make relay callbacks const

Now that relay_open() accepts const callbacks, make relay callbacks
const.

Link: https://lkml.kernel.org/r/7db0286c428f3a478dd7544afef04a3b131f1aa0.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ath11k: make relay callbacks const

Now that relay_open() accepts const callbacks, make relay callbacks
const.

Link: https://lkml.kernel.org/r/44e3d65b71025c462948d0c554061dc7b40ab488.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ath10k: make relay callbacks const

Now that relay_open() accepts const callbacks, make relay callbacks const.

Link: https://lkml.kernel.org/r/85cabc6d4b0d0ca43d4e0fb94897ccd16e3b7930.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm/i915: make relay callbacks const

Now that relay_open() accepts const callbacks, make relay callbacks const.

Link: https://lkml.kernel.org/r/534d089f413db98aa0b94773fa49d5275d0d3c25.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

relay: allow the use of const callback structs

None of the relay users require the use of mutable structs for callbacks,
however the relay code does.  Instead of assigning the default callback
for subbuf_start, add a wrapper to conditionally call the client callback
if available, and fall back to default behaviour otherwise.

This lets all relay users make their struct rchan_callbacks const data.

[jani.nikula@intel.com: cleanups, per Christoph]
Link: https://lkml.kernel.org/r/20201124115412.32402-1-jani.nikula@intel.com
Link: https://lkml.kernel.org/r/cc3ff292e4eb4fdc56bee3d690c7b8e39209cd37.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

relay: make create_buf_file and remove_buf_file callbacks mandatory

All clients provide create_buf_file and remove_buf_file callbacks, and
they're required for relay to make sense.  There is no point in them being
optional.

Also document whether each callback is mandatory/optional.

Link: https://lkml.kernel.org/r/88003c1527386b93036e286e7917f1e33aec84ac.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

relay: require non-NULL callbacks in relay_open()

There are no clients passing NULL callbacks, which makes sense as it
wouldn't even create a file.  Require non-NULL callbacks, and throw away
the handling for NULL callbacks.

Link: https://lkml.kernel.org/r/e40642f3b027d2bb6bc851ddb60e0a61ea51f5f8.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

relay: remove unused buf_mapped and buf_unmapped callbacks

Patch series "relay: cleanup and const callbacks", v2.

None of the relay users require the use of mutable structs for callbacks,
however the relay code does.  Instead of assigning default callbacks when
there is none, add callback wrappers to conditionally call the client
callbacks if available, and fall back to default behaviour (typically
no-op) otherwise.

This lets all relay users make their struct rchan_callbacks const data.

This series starts with a number of cleanups first based on Christoph's
feedback.

This patch (of 9):

No relay client uses the buf_mapped or buf_unmapped callbacks.  Remove
them.  This makes relay's vm_operations_struct close callback a dummy,
remove it as well.

Link: https://lkml.kernel.org/r/cover.1606153547.git.jani.nikula@intel.com
Link: https://lkml.kernel.org/r/c69fff6e0cd485563604240bbfcc028434983bec.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bfs: don't use WARNING: string when it's just info.

Make the printk() [bfs "printf" macro] seem less severe by changing
"WARNING:" to "NOTE:".

<asm-generic/bug.h> warns us about using WARNING or BUG in a format string
other than in WARN() or BUG() family macros.  bfs/inode.c is doing just
that in a normal printk() call, so change the "WARNING" string to be
"NOTE".

Link: https://lkml.kernel.org/r/20201203212634.17278-1-rdunlap@infradead.org
Reported-by: syzbot+3fd34060f26e766536ff@syzkaller.appspotmail.com
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: "Tigran A. Aivazian" <aivazian.tigran@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gcov: fix kernel-doc markup issue

Fix the following kernel-doc issue in gcov:

  kernel/gcov/gcc_4_7.c:238: warning: Function parameter or member 'dst' not described in 'gcov_info_add'
  kernel/gcov/gcc_4_7.c:238: warning: Function parameter or member 'src' not described in 'gcov_info_add'
  kernel/gcov/gcc_4_7.c:238: warning: Excess function parameter 'dest' description in 'gcov_info_add'
  kernel/gcov/gcc_4_7.c:238: warning: Excess function parameter 'source' description in 'gcov_info_add'

Link: https://lkml.kernel.org/r/1605252352-63983-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gcov: remove support for GCC < 4.9

Since commit 0bddd227f3dc ("Documentation: update for gcc 4.9
requirement") the minimum supported version of GCC is gcc-4.9.  It's now
safe to remove this code.

Similar to commit 10415533a906 ("gcov: Remove old GCC 3.4 support") but
that was for GCC 4.8 and this is for GCC 4.9.

Link: https://github.com/ClangBuiltLinux/linux/issues/427
Link: https://lkml.kernel.org/r/20201111030557.2015680-1-ndesaulniers@google.com
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio: remove unused rio_get_asm() and rio_get_device()

The functions rio_get_asm() and rio_get_device() are globally exported
but have almost no users in tree. The only user is rio_init_mports()
which invokes it via rio_init().

rio_init() iterates over every registered device and invokes
rio_fixup_device().  It looks like a fixup function which should perform a
"change" to the device but does nothing.  It has been like this since its
introduction in commit 394b701ce4fbf ("[PATCH] RapidIO support: core
base") which was merged into v2.6.15-rc1.

Remove rio_init() because the performed fixup function
(rio_fixup_device()) does nothing.  Remove rio_get_asm() and
rio_get_device() which have no callers now.

Link: https://lkml.kernel.org/r/20201116170004.420143-1-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kdump: append uts_namespace.name offset to VMCOREINFO

The offset of the field 'init_uts_ns.name' has changed since commit
9a56493f6942 ("uts: Use generic ns_common::count").

Make the offset of the field 'uts_namespace.name' available in VMCOREINFO
because tools like 'crash-utility' and 'makedumpfile' must be able to read
it from crash dumps.

Link: https://lore.kernel.org/r/159644978167.604812.1773586504374412107.stgit@localhost.localdomain
Link: https://lkml.kernel.org/r/20200930102328.396488-1-egorenar@linux.ibm.com
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Acked-by: lijiang <lijiang@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/nilfs2: remove some unused macros to tame gcc

There some macros are unused and cause gcc warning. Remove them.

  fs/nilfs2/segment.c:137:0: warning: macro "nilfs_cnt32_gt" is not used [-Wunused-macros]
  fs/nilfs2/segment.c:144:0: warning: macro "nilfs_cnt32_le" is not used [-Wunused-macros]
  fs/nilfs2/segment.c:143:0: warning: macro "nilfs_cnt32_lt" is not used [-Wunused-macros]

Link: https://lkml.kernel.org/r/1607552733-24292-1-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: add printk_once and printk_ratelimit to prefer pr_<level> warning

Add the _once and _ratelimited variants to the test for
printk(KERN_<LEVEL> that should prefer pr_<level>.

Miscellanea:

o Add comment description for the conversions

[joe@perches.com: fixlet]
Link: https://lkml.kernel.org/r/32260871d4718ba7f48a8e9e07452bb76de300db.camel@perches.comLink:
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: fix TYPO_SPELLING check for words with apostrophe

checkpatch reports a false TYPO_SPELLING warning for some words containing
an apostrophe when run with --codespell option.

A false positive is "doesn't".  Occurrence of the word causes checkpatch
to emit the following warning:

"WARNING: 'doesn'' may be misspelled - perhaps 'doesn't'?"

Modify the regex pattern to be more in line with the codespell default
word matching regex.  This fixes the word capture and avoids the false
warning.

In addition, highlight the misspelled word location by adding a caret
below the word.

[akpm@linux-foundation.org: make matched misspelling more obvious, per Joe]
Link: https://lkml.kernel.org/r/09c24ef1aa2f1c4fe909d76f5426f08780b9d81c.camel@perches.com
Link: https://lkml.kernel.org/r/20201201190729.169733-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Reported-by: Peilin Ye <yepeilin.cs@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: add warning for lines starting with a '#' in commit log

Commit log lines starting with '#' are dropped by git as comments.
Add a check to emit a warning for these lines.

Also add a --fix option to insert a space before the leading '#' in
such lines.

Link: https://lkml.kernel.org/r/20201202205740.127986-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Suggested-by: Peilin Ye <yepeilin.cs@gmail.com>
Tested-by: Peilin Ye <yepeilin.cs@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: add warning for unnecessary use of %h[xudi] and %hh[xudi]

Modifiers %h and %hh should never be used.

Commit cbacb5ab0aa0 ("docs: printk-formats: Stop encouraging use of
unnecessary %h[xudi] and %hh[xudi]") specifies that:

 "Standard integer promotion is already done and %hx and %hhx is useless
  so do not encourage the use of %hh[xudi] or %h[xudi]."

 "The "h" and "hh" things should never be used. The only reason for them
  being used if you have an "int", but you want to print it out as a
  "char" (and honestly, that is a really bad reason, you'd be better off
  just using a proper cast to make the code more obvious)."

Add a new check to emit a warning on finding an unneeded use of %h or
%hh modifier.

Also add a fix option to the check.

Link: https://lore.kernel.org/lkml/4910042649a4f3ab22fac93191b8c1fa0a2e17c3.camel@perches.com/
Link: https://lkml.kernel.org/r/20201128200046.78739-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Suggested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: add fix and improve warning msg for non-standard signature

Currently checkpatch warns for BAD_SIGN_OFF on non-standard signature
styles.

A large number of these warnings occur because of typo mistakes in
signature tags.  An evaluation over v4.13..v5.8 showed that out of 539
warnings due to non-standard signatures, 87 are due to typo mistakes.

Following are the standard signature tags which are often incorrectly
used, along with their individual counts of incorrect use (over
v4.13..v5.8):

Reviewed-by: 42
Signed-off-by: 25
Reported-by: 6
Acked-by: 4
Tested-by: 4
Suggested-by: 4
Provide a fix by calculating levenshtein distance for the signature tag
with all the standard signatures and suggest a fix with a signature, whose
edit distance is less than or equal to 2 with the misspelled signature.

Out of the 86 mispelled signatures fixed with this approach, 85 were found
to be good corrections and 1 was bad correction.

Following was found to be a bad correction:
 Tweeted-by (count: 1) => Tested-by

Link: https://lkml.kernel.org/r/20201128204333.7054-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: add fix option for LOGICAL_CONTINUATIONS

Currently, checkpatch warns if logical continuations are placed at the
start of a line and not at the end of previous line.

E.g., running checkpatch on commit 3485507fc272 ("staging: bcm2835-camera:
Reduce length of enum names") reports:

  CHECK:LOGICAL_CONTINUATIONS: Logical continuations should be on the previous line
  + if (!ret
  +     && camera_port ==

Provide a simple fix by inserting logical operator at the last
non-comment, non-whitespace char of the previous line and removing from
current line, if both the lines are additions(ie start with '+')

Link: https://lkml.kernel.org/r/20201123102818.24364-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: add fix option for ASSIGNMENT_CONTINUATIONS

Currently, checkpatch warns us if an assignment operator is placed at the
start of a line and not at the end of previous line.

E.g., running checkpatch on commit 8195b1396ec8 ("hv_netvsc: fix
deadlock on hotplug") reports:

  CHECK: Assignment operator '=' should be on the previous line
  + struct netvsc_device *nvdev
  + = container_of(w, struct netvsc_device, subchan_work);

Provide a simple fix by appending assignment operator to the previous
line and removing from the current line, if both the lines are additions
(ie start with '+')

Link: https://lkml.kernel.org/r/20201121120407.22942-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: fix unescaped left brace

There is an unescaped left brace in a regex in OPEN_BRACE check.  This
throws a runtime error when checkpatch is run with --fix flag and the
OPEN_BRACE check is executed.

Fix it by escaping the left brace.

Link: https://lkml.kernel.org/r/20201115202928.81955-1-dwaipayanray1@gmail.com
Fixes: 8d1824780f2f ("checkpatch: add --fix option for a couple OPEN_BRACE misuses")
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: avoid COMMIT_LOG_LONG_LINE warning for signature tags

Currently checkpatch warns us for long lines in commits even for signature
tag lines.

Generally these lines exceed the 75-character limit because of:

 1) long names and long email address

 2) some comments on scoped review and acknowledgement, i.e., for a
    dedicated pointer on what was reported by the identity in
    'Reported-by'

 3) some additional comments on CC: stable@vger.org tags

Exclude signature tag lines from this class of warning.

There were 1896 COMMIT_LOG_LONG_LINE warnings in v5.6..v5.8 before this
patch application and 1879 afterwards.

A quick manual check found all the dropped warnings related to signature
tags.

Link: https://lkml.kernel.org/r/20201116083754.10629-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: fix spelling errors and remove repeated word

Delete repeated word in scripts/checkpatch.pl:
  "are are" -> "are"

Fix typos:
  "commments" -> "comments"
  "falsly" -> "falsely"

Link: https://lkml.kernel.org/r/20201113152316.62975-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: improve email parsing

checkpatch doesn't report warnings for many common mistakes in emails.
Some of which are trailing commas and incorrect use of email comments.

At the same time several false positives are reported due to incorrect
handling of mail comments.  The most common of which is due to the
pattern:

<stable@vger.kernel.org> # X.X

Improve email parsing in checkpatch.

Some general email rules are defined:

- Multiple name comments should not be allowed.
- Comments inside address should not be allowed.
- In general comments should be enclosed within parentheses.
  Relaxation is given to comments beginning with #.
- Stable addresses should not begin with a name.
- Comments in stable addresses should begin only
  with a #.

Improvements to parsing:

- Detect and report unexpected content after email.
- Quoted names are excluded from comment parsing.
- Trailing dots, commas or quotes in email are removed during
  formatting. Correspondingly a BAD_SIGN_OFF warning
  is emitted.
- Improperly quoted email like '"name <address>"' are now
  warned about.

In addition, added fixes for all the possible rules.

Link: https://lore.kernel.org/linux-kernel-mentees/6c275d95c3033422addfc256a30e6ae3dd37941d.camel@perches.com/
Link: https://lore.kernel.org/linux-kernel-mentees/20201105200857.GC1333458@kroah.com/
Link: https://lkml.kernel.org/r/20201108100632.75340-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: add __alias and __weak to suggested __attribute__ conversions

Add __alias and __weak to the suggested __attribute__((<foo>))
conversions.

Link: https://lkml.kernel.org/r/7b74137743c58ce0633ec4d575b94e2210e4dbe7.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: add fix option for GERRIT_CHANGE_ID

Currently, whenever a Gerrit Change-Id is present in a commit,
checkpatch.pl warns to remove the Change-Id before submitting the patch.

E.g., running checkpatch on commit adc311a5bbf6 ("iwlwifi: bump FW
API to 53 for 22000 series") reports this error:

  ERROR: Remove Gerrit Change-Id's before submitting upstream
  Change-Id: I5725e46394f3f53c3069723fd513cc53c7df383d

Provide a simple fix option by simply deleting the indicated line.

Link: https://lkml.kernel.org/r/20201030114447.24199-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: update __attribute__((section("name"))) quote removal

commit 33def8498fdd ("treewide: Convert macro and uses of
__section(foo) to __section("foo")") removed the stringification of the
section name and now requires quotes around the named section.

Update checkpatch to not remove any quotes when suggesting conversion
of __attribute__((section("name"))) to __section("name")

Miscellanea:

o Add section to the hash with __section replacement
o Remove separate test for __attribute__((section
o Remove the limitation on converting attributes containing only
  known, possible conversions.  Any unknown attribute types are now
  left as-is and known types are converted and moved before
  __attribute__ and removed from within the __attribute__((list...)).

[joe@perches.com: eliminate the separate test below the possible conversions loop]
Link: https://lkml.kernel.org/r/58e9d55e933dc8fdc6af489f2ad797fa8eb13e44.camel@perches.com
Link: https://lkml.kernel.org/r/c04dd1c810e8d6a68e6a632e3191ae91651c8edf.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: add a fixer for missing newline at eof

Remove the trailing error message from the fixed lines.

Link: https://lkml.kernel.org/r/20201017142546.28988-1-trix@redhat.com
Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: extend attributes check to handle more patterns

It is generally preferred that the macros from
include/linux/compiler_attributes.h are used, unless there is a reason not
to.

checkpatch currently checks __attribute__ for each of packed, aligned,
section, printf, scanf, and weak.  Other declarations in
compiler_attributes.h are not handled.

Add a generic test to check the presence of such attributes.  Some
attributes require more specific handling and are kept separate.

Also add fixes to the generic attributes check to substitute the correct
conversions.

New attributes which are now handled are:

__always_inline__
__assume_aligned__(a, ## __VA_ARGS__)
__cold__
__const__
__copy__(symbol)
__designated_init__
__externally_visible__
__gnu_inline__
__malloc__
__mode__(x)
__no_caller_saved_registers__
__noclone__
__noinline__
__nonstring__
__noreturn__
__pure__
__unused__
__used__

Declarations which contain multiple attributes like
__attribute__((__packed__, __cold__)) are also handled except when proper
conversions for one or more attributes of the list cannot be determined.

Link: https://lore.kernel.org/linux-kernel-mentees/3ec15b41754b01666d94b76ce51b9832c2dd577a.camel@perches.com/
Link: https://lkml.kernel.org/r/20201025193103.23223-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: allow --fix removal of unnecessary break statements

switch/case use of break after a return, goto or break is unnecessary.

There is an existing warning for the return and goto uses, so add
break and a --fix option too.

Link: https://lkml.kernel.org/r/d9ea654104d55f590fb97d252d64a66b23c1a096.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Tom Rix <trix@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: prefer static const declarations

There are about 100,000 uses of 'static const <type>' but about 400 uses
of 'static <type> const' in the kernel where type is not a pointer.

The kernel almost always uses "static const" over "const static" as there
is a compiler warning for that declaration style.

But there is no compiler warning for "static <type> const".

So add a checkpatch warning for the atypical declaration uses of.

const static <type> <foo>
and
static <type> const <foo>

For example:

  $ ./scripts/checkpatch.pl -f --emacs --quiet --nosummary -types=static_const arch/arm/crypto/aes-ce-glue.c
  arch/arm/crypto/aes-ce-glue.c:75: WARNING: Move const after static - use 'static const u8'
  #75: FILE: arch/arm/crypto/aes-ce-glue.c:75:
  + static u8 const rcon[] = {

Link: https://lkml.kernel.org/r/4b863be68e679546b40d50b97a4a806c03056a1c.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: ignore generated CamelCase defines and enum values

Ignore autogenerated CamelCase-like defines and enum values like
DRM_MODE_CONNECTOR_Unknown or ETHTOOL_LINK_MODE_Asym_Pause_BIT.

Link: https://lkml.kernel.org/r/20201022184916.7904-1-l.stelmach@samsung.com
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
Suggested-by: Joe Perches <joe@perches.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: fix false positives in REPEATED_WORD warning

Presence of hexadecimal address or symbol results in false warning
message by checkpatch.pl.

For example, running checkpatch on commit b8ad540dd4e4 ("mptcp: fix
memory leak in mptcp_subflow_create_socket()") results in warning:

  WARNING:REPEATED_WORD: Possible repeated word: 'ff'
      00 00 00 00 00 00 00 00 00 2f 30 0a 81 88 ff ff  ........./0.....

Similarly, the presence of list command output in commit results in
an unnecessary warning.

For example, running checkpatch on commit 899e5ffbf246 ("perf record:
Introduce --switch-output-event") gives:

  WARNING:REPEATED_WORD: Possible repeated word: 'root'
    dr-xr-x---. 12 root root    4096 Apr 27 17:46 ..

Here, it reports 'ff' and 'root' to be repeated, but it is in fact part
of some address or code, where it has to be repeated.

In these cases, the intent of the warning to find stylistic issues in
commit messages is not met and the warning is just completely wrong in
this case.

To avoid these warnings, add an additional regex check for the directory
permission pattern and avoid checking the line for this class of
warning.  Similarly, to avoid hex pattern, check if the word consists of
hex symbols and skip this warning if it is not among the common english
words formed using hex letters.

A quick evaluation on v5.6..v5.8 showed that this fix reduces
REPEATED_WORD warnings by the frequency of 1890.

A quick manual check found all cases are related to hex output or list
command outputs in commit messages.

Link: https://lkml.kernel.org/r/20201024102253.13614-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: add new exception to repeated word check

Recently, commit 4f6ad8aa1eac ("checkpatch: move repeated word test")
moved the repeated word test to check for more file types. But after
this, if checkpatch.pl is run on MAINTAINERS, it generates several
new warnings of the type:

  WARNING: Possible repeated word: 'git'

For example:

  WARNING: Possible repeated word: 'git'
  +T: git git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml.git

So, the pattern "git git://..." is a false positive in this case.

There are several other combinations which may produce a wrong warning
message, such as "@size size", ":Begin begin", etc.

Extend repeated word check to compare the characters before and after
the word matches.

If there is a non whitespace character before the first word or a non
whitespace character excluding punctuation characters after the second
word, then the check is skipped and the warning is avoided.

Also add case insensitive word matching to the repeated word check.

Link: https://lore.kernel.org/linux-kernel-mentees/81b6a0bb2c7b9256361573f7a13201ebcd4876f1.camel@perches.com/
Link: https://lkml.kernel.org/r/20201017162732.152351-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Suggested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Aditya Srivastava <yashsri421@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/lz4: explicitly support in-place decompression

LZ4 final literal copy could be overlapped when doing
in-place decompression, so it's unsafe to just use memcpy()
on an optimized memcpy approach but memmove() instead.

Upstream LZ4 has updated this years ago [1] (and the impact
is non-sensible [2] plus only a few bytes remain), this commit
just synchronizes LZ4 upstream code to the kernel side as well.

It can be observed as EROFS in-place decompression failure
on specific files when X86_FEATURE_ERMS is unsupported,
memcpy() optimization of commit 59daa706fbec ("x86, mem:
Optimize memcpy by avoiding memory false dependece") will
be enabled then.

Currently most modern x86-CPUs support ERMS, these CPUs just
use "rep movsb" approach so no problem at all. However, it can
still be verified with forcely disabling ERMS feature...

arch/x86/lib/memcpy_64.S:
        ALTERNATIVE_2 "jmp memcpy_orig", "", X86_FEATURE_REP_GOOD, \
-                     "jmp memcpy_erms", X86_FEATURE_ERMS
+                     "jmp memcpy_orig", X86_FEATURE_ERMS

We didn't observe any strange on arm64/arm/x86 platform before
since most memcpy() would behave in an increasing address order
("copy upwards" [3]) and it's the correct order of in-place
decompression but it really needs an update to memmove() for sure
considering it's an undefined behavior according to the standard
and some unique optimization already exists in the kernel.

[1] https://github.com/lz4/lz4/commit/33cb8518ac385835cc17be9a770b27b40cd0e15b
[2] https://github.com/lz4/lz4/pull/717#issuecomment-497818921
[3] https://sourceware.org/bugzilla/show_bug.cgi?id=12518

Link: https://lkml.kernel.org/r/20201122030749.2698994-1-hsiangkao@redhat.com
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Nick Terrell <terrelln@fb.com>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Miao Xie <miaoxie@huawei.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Li Guifu <bluce.liguifu@huawei.com>
Cc: Guo Xuenan <guoxuenan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: cleanup kstrto*() usage

Use proper conversion functions.  kstrto*() variants exist for all
standard types.

Link: https://lkml.kernel.org/r/20201122123410.GB92364@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/misc/lkdtm/lkdtm.h: correct wrong filenames in comment

In lkdtm.h, files targeted in comments are named "lkdtm_file.c" while
there are named "file.c" in directory.

Link: https://lkml.kernel.org/r/20201122162451.27551-6-laniel_francis@privacyrequired.com
Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/misc/lkdtm: add new file in LKDTM to test fortified strscpy

This new test ensures that fortified strscpy has the same behavior than
vanilla strscpy (e.g.  returning -E2BIG when src content is truncated).
Finally, it generates a crash at runtime because there is a write overflow
in destination string.

Link: https://lkml.kernel.org/r/20201122162451.27551-5-laniel_francis@privacyrequired.com
Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

string.h: add FORTIFY coverage for strscpy()

The fortified version of strscpy ensures the following before vanilla strscpy
is called:

1. There is no read overflow because we either size is smaller than
   src length or we shrink size to src length by calling fortified
   strnlen.

2. There is no write overflow because we either failed during
   compilation or at runtime by checking that size is smaller than dest
   size.

Link: https://lkml.kernel.org/r/20201122162451.27551-4-laniel_francis@privacyrequired.com
Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lkdtm: tests for FORTIFY_SOURCE

Add code to test both:

 - runtime detection of the overrun of a structure. This covers the
   __builtin_object_size(x, 0) case. This test is called FORTIFY_OBJECT.

 - runtime detection of the overrun of a char array within a structure.
   This covers the __builtin_object_size(x, 1) case which can be used
   for some string functions. This test is called FORTIFY_SUBOBJECT.

Link: https://lkml.kernel.org/r/20201122162451.27551-3-laniel_francis@privacyrequired.com
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: string.h: detect intra-object overflow in fortified string functions

Patch series "Fortify strscpy()", v7.

This patch implements a fortified version of strscpy() enabled by setting
CONFIG_FORTIFY_SOURCE=y.  The new version ensures the following before
calling vanilla strscpy():

1. There is no read overflow because either size is smaller than src
   length or we shrink size to src length by calling fortified strnlen().

2. There is no write overflow because we either failed during
   compilation or at runtime by checking that size is smaller than dest
   size.  Note that, if src and dst size cannot be got, the patch defaults
   to call vanilla strscpy().

The patches adds the following:

1. Implement the fortified version of strscpy().

2. Add a new LKDTM test to ensures the fortified version still returns
   the same value as the vanilla one while panic'ing when there is a write
   overflow.

3. Correct some typos in LKDTM related file.

I based my modifications on top of two patches from Daniel Axtens which
modify calls to __builtin_object_size, in fortified string functions, to
ensure the true size of char * are returned and not the surrounding
structure size.

About performance, I measured the slow down of fortified strscpy(), using
the vanilla one as baseline.  The hardware I used is an Intel i3 2130 CPU
clocked at 3.4 GHz.  I ran "Linux 5.10.0-rc4+ SMP PREEMPT" inside qemu
3.10 with 4 CPU cores.  The following code, called through LKDTM, was used
as a benchmark:

#define TIMES 10000
char *src;
char dst[7];
int i;
ktime_t begin;

src = kstrdup("foobar", GFP_KERNEL);

if (src == NULL)
return;

begin = ktime_get();
for (i = 0; i < TIMES; i++)
strscpy(dst, src, strlen(src));
pr_info("%d fortified strscpy() tooks %lld", TIMES, ktime_get() - begin);

begin = ktime_get();
for (i = 0; i < TIMES; i++)
__real_strscpy(dst, src, strlen(src));
pr_info("%d vanilla strscpy() tooks %lld", TIMES, ktime_get() - begin);

kfree(src);

I called the above code 30 times to compute stats for each version (in ns,
round to int):

| version   | mean    | std    | median  | 95th    |
| --------- | ------- | ------ | ------- | ------- |
| fortified | 245_069 | 54_657 | 216_230 | 331_122 |
| vanilla   | 172_501 | 70_281 | 143_539 | 219_553 |

On average, fortified strscpy() is approximately 1.42 times slower than
vanilla strscpy().  For the 95th percentile, the fortified version is
about 1.50 times slower.

So, clearly the stats are not in favor of fortified strscpy().  But, the
fortified version loops the string twice (one in strnlen() and another in
vanilla strscpy()) while the vanilla one only loops once.  This can
explain why fortified strscpy() is slower than the vanilla one.

This patch (of 5):

When the fortify feature was first introduced in commit 6974f0c4555e
("include/linux/string.h: add the option of fortified string.h
functions"), Daniel Micay observed:

  * It should be possible to optionally use __builtin_object_size(x, 1) for
    some functions (C strings) to detect intra-object overflows (like
    glibc's _FORTIFY_SOURCE=2), but for now this takes the conservative
    approach to avoid likely compatibility issues.

This is a case that often cannot be caught by KASAN. Consider:

struct foo {
    char a[10];
    char b[10];
}

void test() {
    char *msg;
    struct foo foo;

    msg = kmalloc(16, GFP_KERNEL);
    strcpy(msg, "Hello world!!");
    // this copy overwrites foo.b
    strcpy(foo.a, msg);
}

The questionable copy overflows foo.a and writes to foo.b as well.  It
cannot be detected by KASAN.  Currently it is also not detected by
fortify, because strcpy considers __builtin_object_size(x, 0), which
considers the size of the surrounding object (here, struct foo).  However,
if we switch the string functions over to use __builtin_object_size(x, 1),
the compiler will measure the size of the closest surrounding subobject
(here, foo.a), rather than the size of the surrounding object as a whole.
See https://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html for more
info.

Only do this for string functions: we cannot use it on things like memcpy,
memmove, memcmp and memchr_inv due to code like this which purposefully
operates on multiple structure members: (arch/x86/kernel/traps.c)

/*
 * regs->sp points to the failing IRET frame on the
 * ESPFIX64 stack.  Copy it to the entry stack.  This fills
 * in gpregs->ss through gpregs->ip.
 *
 */
memmove(&gpregs->ip, (void *)regs->sp, 5*8);

This change passes an allyesconfig on powerpc and x86, and an x86 kernel
built with it survives running with syz-stress from syzkaller, so it seems
safe so far.

Link: https://lkml.kernel.org/r/20201122162451.27551-1-laniel_francis@privacyrequired.com
Link: https://lkml.kernel.org/r/20201122162451.27551-2-laniel_francis@privacyrequired.com
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/string: remove unnecessary #undefs

A few architecture specific string.h functions used to be implemented in
terms of preprocessor defines to the corresponding compiler builtins.
Since this is no longer the case, remove unused #undefs.

Only memcmp is still defined in terms of builtins for a few arches.

Link: https://github.com/ClangBuiltLinux/linux/issues/428
Link: https://lkml.kernel.org/r/20201120041113.89382-1-ndesaulniers@google.com
Fixes: 5f074f3e192f ("lib/string.c: implement a basic bcmp")
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Alexandru Ardelean <alexandru.ardelean@analog.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ilog2: improve ilog2 for constant arguments

As discussed in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97445 the
const_ilog2 macro generates a lot of code which interferes badly with GCC
inlining heuristics, until it can be proven that the ilog2 argument can or
can't be simplified into a constant.

It can be expressed using __builtin_clzll builtin which is supported by
GCC 3.4 and later and when used only in the __builtin_constant_p guarded
code it ought to always fold back to a constant.  Other compilers support
the same builtin for many years too.

Other option would be to change the const_ilog2 macro, though as the
description says it is meant to be used also in C constant expressions,
and while GCC will fold it to constant with constant argument even in
those, perhaps it is better to avoid using extensions in that case.

[akpm@linux-foundation.org: coding style fixes]

Link: https://lkml.kernel.org/r/20201120125154.GB3040@hirez.programming.kicks-ass.net
Link: https://lkml.kernel.org/r/20201021132718.GB2176@tucnak
Signed-off-by: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/cmdline_kunit: add a new test suite for cmdline API

Test get_option() for a starter which is provided by cmdline.c.

[akpm@linux-foundation.org: fix warning by constifying cmdline_test_values]
[andriy.shevchenko@linux.intel.com: type of expected returned values should be int]
Link: https://lkml.kernel.org/r/20201116104244.15472-1-andriy.shevchenko@linux.intel.com
[andriy.shevchenko@linux.intel.com: provide meaningful MODULE_LICENSE()]
Link: https://lkml.kernel.org/r/20201116104257.15527-1-andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20201112180732.75589-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Vitor Massaru Iha <vitor@massaru.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Cc: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/cmdline: allow NULL to be an output for get_option()

In the future we would like to use get_option() to only validate the
string and parse it separately.  To achieve this, allow NULL to be an
output for get_option().

Link: https://lkml.kernel.org/r/20201112180732.75589-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Vitor Massaru Iha <vitor@massaru.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/cmdline: fix get_option() for strings starting with hyphen

When string doesn't have an integer and starts from hyphen get_option()
may return interesting results.  Fix it to return 0.

The simple_strtoull() is used due to absence of simple_strtoul() in a boot
code on some architectures.

Note, the Fixes tag below is rather for anthropological curiosity.

Link: https://lkml.kernel.org/r/20201112180732.75589-4-andriy.shevchenko@linux.intel.com
Fixes: f68565831e72 ("Import 2.4.0-test2pre3")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Vitor Massaru Iha <vitor@massaru.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/test_lockup.c: minimum fix to get it compiled on PREEMPT_RT

On PREEMPT_RT the locks are quite different so they can't be tested as it
is done below.  The alternative is to test for the waitlock within
rtmutex.

This is the bare minimun to get it compiled.  Problems which exist on
PREEMP_RT:

 - none of the locks (spinlock_t, rwlock_t, mutex_t, rw_semaphore) may
   be acquired with disabled preemption or interrupts.

   If I read the code correct the it is possible to acquire a mutex_t
   with disabled interrupts.

   I don't know how to obtain a lock pointer. Technically they are not
   exported to userland.

 - memory can not be allocated with disabled preemption or interrupts
   even with GFP_ATOMIC.

Link: https://lkml.kernel.org/r/20201028181041.xyeothhkouc3p4md@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/stackdepot.c: use array_size() helper in jhash2()

Use array_size() helper instead of the open-coded version in jhash2().
These sorts of multiplication factors need to be wrapped in array_size().

Also, use the preferred form for passing the size of an object type.

Link: https://lkml.kernel.org/r/cb8a682e4bba4dbddd2bd8aca7f8c02fea89639b.1601565471.git.gustavoars@kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/stackdepot.c: use flex_array_size() helper in memcpy()

Make use of the flex_array_size() helper to calculate the size of a
flexible array member within an enclosing structure.

This helper offers defense-in-depth against potential integer overflows,
while at the same time makes it explicitly clear that we are dealing with
a flexible array member.

Link: https://lkml.kernel.org/r/186e37fe07196ee41a0e562fa8a8cb7a01112ec5.1601565471.git.gustavoars@kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/stackdepot.c: replace one-element array with flexible-array member

Patch series "lib/stackdepot.c: Replace one-element array with flexible-array member".

This series aims to replace a one-element array with a flexible-array
member.  Also, make use of the struct_size(), flexible_array_size() and
array_size() helpers.

This patch (of 3):

There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure.  Kernel code
should always use “flexible array members”[1] for these cases.  The
older style of one-element or zero-length arrays should no longer be
used[2].

Refactor the code according to the use of a flexible-array member in
struct stack_record, instead of a one-element array, and use the
struct_size() helper to calculate the size for the allocation.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://lkml.kernel.org/r/cover.1601565471.git.gustavoars@kernel.org
Link: https://lore.kernel.org/lkml/5f75876b.x9zdN10esiC0qLHV%25lkp@intel.com/
Link: https://lkml.kernel.org/r/2f1e6a17aaa891ad9c58817cf0a10b8ab8894f59.1601565471.git.gustavoars@kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/test_free_pages.c: add basic progress indicators

The test module to check that free_pages() does not leak memory does not
provide any feedback whatsoever its state or progress, but may take some
time on slow machines.  Add the printing of messages upon starting each
phase of the test, and upon completion.

Link: https://lkml.kernel.org/r/20201018140445.20972-1-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bitmap: remove unused function declaration

Link: https://lkml.kernel.org/r/BN7PR11MB26097166B6B46387D8A1ABA4FDE30@BN7PR11MB2609.namprd11.prod.outlook.com
Fixes: 2afe27c718b6 ("lib/bitmap.c: bitmap_[empty,full]: remove code duplication")
Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>
Acked-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/bitmap.h: convert bitmap_empty() / bitmap_full() to return boolean

There is no need to return int type out of boolean expression.

Link: https://lkml.kernel.org/r/20201027180936.20806-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/acct.c: use #elif instead of #end and #elif

Cleanup: use #elif instead of #end and #elif.

Link: https://lkml.kernel.org/r/20201015150736.GA91603@rlk
Signed-off-by: Hui Su <sh_def@163.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>

kernel.h: split out mathematical helpers

kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out
mathematical helpers.

At the same time convert users in header and lib folder to use new
header.  Though for time being include new header back to kernel.h to
avoid twisted indirected includes for existing users.

[sfr@canb.auug.org.au: fix powerpc build]
Link: https://lkml.kernel.org/r/20201029150809.13059608@canb.auug.org.au
Link: https://lkml.kernel.org/r/20201028173212.41768-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

asm-generic: force inlining of get_order() to work around gcc10 poor decision

When building mpc885_ads_defconfig with gcc 10.1,
the function get_order() appears 50 times in vmlinux:

  [linux]# ppc-linux-objdump -x vmlinux | grep get_order | wc -l
  50

  [linux]# size vmlinux
     text    data     bss     dec     hex filename
  3842620  675624  135160 4653404  47015c vmlinux

In the old days, marking a function 'static inline' was forcing GCC to
inline, but since commit ac7c3e4ff401 ("compiler: enable
CONFIG_OPTIMIZE_INLINING forcibly") GCC may decide to not inline a
function.

It looks like GCC 10 is taking poor decisions on this.

get_order() compiles into the following tiny function, occupying 20
bytes of text.

  0000007c <get_order>:
    7c:   38 63 ff ff     addi    r3,r3,-1
    80:   54 63 a3 3e     rlwinm  r3,r3,20,12,31
    84:   7c 63 00 34     cntlzw  r3,r3
    88:   20 63 00 20     subfic  r3,r3,32
    8c:   4e 80 00 20     blr

By forcing get_order() to be __always_inline, the size of text is
reduced by 1940 bytes, that is almost twice the space occupied by
50 times get_order()

  [linux-powerpc]# size vmlinux
     text    data     bss     dec     hex filename
  3840680  675588  135176 4651444  46f9b4 vmlinux

Link: https://lkml.kernel.org/r/96c6172d619c51acc5c1c4884b80785c59af4102.1602949927.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/proc: make pde_get() return nothing

We don't need pde_get()'s return value, so make pde_get() return nothing

Link: https://lkml.kernel.org/r/20201211061944.GA2387571@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

proc: fix lookup in /proc/net subdirectories after setns(2)

Commit 1fde6f21d90f ("proc: fix /proc/net/* after setns(2)") only forced
revalidation of regular files under /proc/net/

However, /proc/net/ is unusual in the sense of /proc/net/foo handlers
take netns pointer from parent directory which is old netns.

Steps to reproduce:

(void)open("/proc/net/sctp/snmp", O_RDONLY);
unshare(CLONE_NEWNET);

int fd = open("/proc/net/sctp/snmp", O_RDONLY);
read(fd, &c, 1);

Read will read wrong data from original netns.

Patch forces lookup on every directory under /proc/net .

Link: https://lkml.kernel.org/r/20201205160916.GA109739@localhost.localdomain
Fixes: 1da4d377f943 ("proc: revalidate misc dentries")
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reported-by: "Rantala, Tommi T. (Nokia - FI/Espoo)" <tommi.t.rantala@nokia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

proc: provide details on indirect branch speculation

Similar to speculation store bypass, show information about the indirect
branch speculation mode of a task in /proc/$pid/status.

For testing/benchmarking, I needed to see whether IB (Indirect Branch)
speculation (see Spectre-v2) is enabled on a task, to see whether an
IBPB instruction should be executed on an address space switch.
Unfortunately, this information isn't available anywhere else and
currently the only way to get it is to hack the kernel to expose it
(like this change).  It also helped expose a bug with conditional IB
speculation on certain CPUs.

Another place this could be useful is to audit the system when using
sanboxing.  With this change, I can confirm that seccomp-enabled
process have IB speculation force disabled as expected when the kernel
command line parameter `spectre_v2_user=seccomp`.

Since there's already a 'Speculation_Store_Bypass' field, I used that
as precedent for adding this one.

[amistry@google.com: remove underscores from field name to workaround documentation issue]
Link: https://lkml.kernel.org/r/20201106131015.v2.1.I7782b0cedb705384a634cfd8898eb7523562da99@changeid
Link: https://lkml.kernel.org/r/20201030172731.1.I7782b0cedb705384a634cfd8898eb7523562da99@changeid
Signed-off-by: Anand K Mistry <amistry@google.com>
Cc: Anthony Steinhauser <asteinhauser@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Anand K Mistry <amistry@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alexey Gladkov <gladkov.alexey@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: NeilBrown <neilb@suse.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>

procfs: delete duplicated words + other fixes

Delete repeated words in fs/proc/.
{the, which}
where "which which" was changed to "with which".

Link: https://lkml.kernel.org/r/20201028191525.13413-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

alpha: replace bogus in_interrupt()

in_interrupt() is true for a variety of things including bottom half
disabled regions.  Deducing hard interrupt context from it is dubious at
best.

Use in_irq() which is true if called in hard interrupt context.  Otherwise
calling irq_exit() would do more harm than good.

Link: https://lkml.kernel.org/r/20201113135832.2202833-1-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Serge Belyshev <belyshev@depni.sinp.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Matt Turner <mattst88@gmail.com>
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>

mm/memory_hotplug: quieting offline operation

On PowerPC, when dymically removing memory from a system we can see in the
console a lot of messages like this:

[  186.575389] Offlined Pages 4096

This message is displayed on each LMB (256MB) removed, which means that we
removing 1TB of memory, this message is displayed 4096 times.

Moving it to DEBUG to not flood the console.

Link: https://lkml.kernel.org/r/20201211150157.91399-1-ldufour@linux.ibm.com
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Scott Cheloha <cheloha@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: fix a race on nr_swap_pages

The scenario on which "Free swap = -4kB" happens in my system, which is caused
by several get_swap_pages racing with each other and show_swap_cache_info
happens simutaniously. No need to add a lock on get_swap_page_of_type as we
remove "Presub/PosAdd" here.

ProcessA ProcessB ProcessC
ngoals = 1 ngoals = 1
avail = nr_swap_pages(1) avail = nr_swap_pages(1)
nr_swap_pages(1) -= ngoals
nr_swap_pages(0) -= ngoals
nr_swap_pages = -1

Link: https://lkml.kernel.org/r/1607050340-4535-1-git-send-email-zhaoyang.huang@unisoc.com
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge branch 'exec-update-lock-for-v5.11' of git://git./linux/kernel/git/ebiederm/user-namespace

Pull exec-update-lock update from Eric Biederman:
 "The key point of this is to transform exec_update_mutex into a
  rw_semaphore so readers can be separated from writers.

  This makes it easier to understand what the holders of the lock are
  doing, and makes it harder to contend or deadlock on the lock.

  The real deadlock fix wound up in perf_event_open"

* 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  exec: Transform exec_update_mutex into a rw_semaphore

Merge branch 'exec-for-v5.11' of git://git./linux/kernel/git/ebiederm/user-namespace

Pull execve updates from Eric Biederman:
 "This set of changes ultimately fixes the interaction of posix file
  lock and exec. Fundamentally most of the change is just moving where
  unshare_files is called during exec, and tweaking the users of
  files_struct so that the count of files_struct is not unnecessarily
  played with.

  Along the way fcheck and related helpers were renamed to more
  accurately reflect what they do.

  There were also many other small changes that fell out, as this is the
  first time in a long time much of this code has been touched.

  Benchmarks haven't turned up any practical issues but Al Viro has
  observed a possibility for a lot of pounding on task_lock. So I have
  some changes in progress to convert put_files_struct to always rcu
  free files_struct. That wasn't ready for the merge window so that will
  have to wait until next time"

* 'exec-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
  exec: Move io_uring_task_cancel after the point of no return
  coredump: Document coredump code exclusively used by cell spufs
  file: Remove get_files_struct
  file: Rename __close_fd_get_file close_fd_get_file
  file: Replace ksys_close with close_fd
  file: Rename __close_fd to close_fd and remove the files parameter
  file: Merge __alloc_fd into alloc_fd
  file: In f_dupfd read RLIMIT_NOFILE once.
  file: Merge __fd_install into fd_install
  proc/fd: In fdinfo seq_show don't use get_files_struct
  bpf/task_iter: In task_file_seq_get_next use task_lookup_next_fd_rcu
  proc/fd: In proc_readfd_common use task_lookup_next_fd_rcu
  file: Implement task_lookup_next_fd_rcu
  kcmp: In get_file_raw_ptr use task_lookup_fd_rcu
  proc/fd: In tid_fd_mode use task_lookup_fd_rcu
  file: Implement task_lookup_fd_rcu
  file: Rename fcheck lookup_fd_rcu
  file: Replace fcheck_files with files_lookup_fd_rcu
  file: Factor files_lookup_fd_locked out of fcheck_files
  file: Rename __fcheck_files to files_lookup_fd_raw
  ...

Merge branch 'signal-for-v5.11' of git://git./linux/kernel/git/ebiederm/user-namespace

Pull signal cleanup from Eric Biederman:
 "Remove a never used HP-UX compatibility from parisc headers and
  consolidating the SA_* flags definitions into a generic header as much
  as possible.

  We only have 32 SA_* flag bits total, so we need to be careful. But as
  this is the first addition in a decade or so I think we are fine for
  the forseeable future"

* 'signal-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal/parisc: Remove parisc specific definition of __ARCH_UAPI_SA_FLAGS