The perf hardlockup detector works by looking at interrupt counts and
seeing if they change from run to run.  The interrupt counts are managed
by the common watchdog code via its watchdog_timer_fn().

Currently the API between the perf detector and the common code is a
function: is_hardlockup().  When the hard lockup detector sees that
function return true then it handles printing out debug info and inducing
a panic if necessary.

Let's change the API a little bit in preparation for the buddy hardlockup
detector.  The buddy hardlockup detector wants to print nearly the same
debug info and have nearly the same panic behavior.  That means we want to
move all that code to the common file.  For now, the code in the common
file will only be there if the perf hardlockup detector is enabled, but
eventually it will be selected by a common config.

Right now, this _just_ moves the code from the perf detector file to the
common file and changes the names.  It doesn't make the changes that the
buddy hardlockup detector will need and doesn't do any style cleanups.  A
future patch will do cleanup to make it more obvious what changed.

With the above, we no longer have any callers of is_hardlockup() outside
of the "watchdog.c" file, so we can remove it from the header, make it
static, and move it to the same "#ifdef" block as our new
watchdog_hardlockup_check().  While doing this, it can be noted that even
if no hardlockup detectors were configured the existing code used to still
have the code for counting/checking "hrtimer_interrupts" even if the perf
hardlockup detector wasn't configured.  We didn't need to do that, so move
all the "hrtimer_interrupts" counting to only be there if the perf
hardlockup detector is configured as well.

This change is expected to be a no-op.

Link: https://lkml.kernel.org/r/20230519101840.v5.8.Id4133d3183e798122dc3b6205e7852601f289071@changeidSigned-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Colin Cross <ccross@android.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: Tzung-Bi Shih <tzungbi@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The code currently in "watchdog_hld.c" is for detecting hardlockups using
perf, as evidenced by the line in the Makefile that only compiles this
file if CONFIG_HARDLOCKUP_DETECTOR_PERF is defined.  Rename the file to
prepare for the buddy hardlockup detector, which doesn't use perf.

It could be argued that the new name makes it less obvious that this is a
hardlockup detector.  While true, it's not hard to remember that the
"perf" detector is always a hardlockup detector and it's nice not to have
names that are too convoluted.

Link: https://lkml.kernel.org/r/20230519101840.v5.7.Ice803cb078d0e15fb2cbf49132f096ee2bd4199d@changeidSigned-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Colin Cross <ccross@android.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: Tzung-Bi Shih <tzungbi@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

In preparation for the buddy hardlockup detector, add comments to
touch_nmi_watchdog() to make it obvious that it touches the configured
hardlockup detector regardless of whether it's backed by an NMI.  Also
note that arch_touch_nmi_watchdog() may not be architecture-specific.

Ideally, we'd like to rename these functions but that is a fairly
disruptive change touching a lot of drivers.  After discussion [1] the
plan is to defer this until a good time.

[1] https://lore.kernel.org/r/ZFy0TX1tfhlH8gxj@alley

[akpm@linux-foundation.org: comment changes, per Petr]
  Link: https://lkml.kernel.org/r/ZGyONWPXpE1DcxA5@alley
Link: https://lkml.kernel.org/r/20230519101840.v5.6.I4e47cbfa1bb2ebbcdb5ca16817aa2887f15dc82c@changeidSigned-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Colin Cross <ccross@android.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: Tzung-Bi Shih <tzungbi@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hardlockup_detector_event_create() should create perf_event on the current
CPU.  Preemption could not get disabled because
perf_event_create_kernel_counter() allocates memory.  Instead, the CPU
locality is achieved by processing the code in a per-CPU bound kthread.

Add a check to prevent mistakes when calling the code in another code
path.

Link: https://lkml.kernel.org/r/20230519101840.v5.5.I654063e53782b11d53e736a8ad4897ffd207406a@changeidSigned-off-by: Pingfan Liu <kernelfans@gmail.com>
Co-developed-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Colin Cross <ccross@android.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: Tzung-Bi Shih <tzungbi@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Nobody cares about the return value of watchdog_nmi_enable(), changing its
prototype to void.

Link: https://lkml.kernel.org/r/20230519101840.v5.4.Ic3a19b592eb1ac4c6f6eade44ffd943e8637b6e5@changeidSigned-off-by: Pingfan Liu <kernelfans@gmail.com>
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Colin Cross <ccross@android.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: Tzung-Bi Shih <tzungbi@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

No reference to WATCHDOG_DEFAULT, remove it.

Link: https://lkml.kernel.org/r/20230519101840.v5.3.I6a729209a1320e0ad212176e250ff945b8f91b2a@changeidSigned-off-by: Pingfan Liu <kernelfans@gmail.com>
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Colin Cross <ccross@android.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: Tzung-Bi Shih <tzungbi@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Currently, in the watchdog_overflow_callback() we first check to see if
the watchdog had been touched and _then_ we handle the workaround for
turbo mode.  This order should be reversed.

Specifically, "touching" the hardlockup detector's watchdog should avoid
lockups being detected for one period that should be roughly the same
regardless of whether we're running turbo or not.  That means that we
should do the extra accounting for turbo _before_ we look at (and clear)
the global indicating that we've been touched.

NOTE: this fix is made based on code inspection.  I am not aware of any
reports where the old code would have generated false positives.  That
being said, this order seems more correct and also makes it easier down
the line to share code with the "buddy" hardlockup detector.

Link: https://lkml.kernel.org/r/20230519101840.v5.2.I843b0d1de3e096ba111a179f3adb16d576bef5c7@changeid
Fixes: 7edaeb68 ("kernel/watchdog: Prevent false positives with turbo modes")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Colin Cross <ccross@android.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: Tzung-Bi Shih <tzungbi@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Patch series "watchdog/hardlockup: Add the buddy hardlockup detector", v5.

This patch series adds the "buddy" hardlockup detector.  In brief, the
buddy hardlockup detector can detect hardlockups without arch-level
support by having CPUs checkup on a "buddy" CPU periodically.

Given the new design of this patch series, testing all combinations is
fairly difficult. I've attempted to make sure that all combinations of
CONFIG_ options are good, but it wouldn't surprise me if I missed
something. I apologize in advance and I'll do my best to fix any
problems that are found.


This patch (of 18):

The real watchdog_update_hrtimer_threshold() is defined in
kernel/watchdog_hld.c.  That file is included if
CONFIG_HARDLOCKUP_DETECTOR_PERF and the function is defined in that file
if CONFIG_HARDLOCKUP_CHECK_TIMESTAMP.

The dummy version of the function in "nmi.h" didn't get that quite right. 
While this doesn't appear to be a huge deal, it's nice to make it
consistent.

It doesn't break builds because CHECK_TIMESTAMP is only defined by x86 so
others don't get a double definition, and x86 uses perf lockup detector,
so it gets the out of line version.

Link: https://lkml.kernel.org/r/20230519101840.v5.18.Ia44852044cdcb074f387e80df6b45e892965d4a1@changeid
Link: https://lkml.kernel.org/r/20230519101840.v5.1.I8cbb2f4fa740528fcfade4f5439b6cdcdd059251@changeid
Fixes: 7edaeb68 ("kernel/watchdog: Prevent false positives with turbo modes")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: Tzung-Bi Shih <tzungbi@chromium.org>
Cc: Will Deacon <will@kernel.org>
Cc: Colin Cross <ccross@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The entry points for the decompressor don't always have a prototype
included in the .c file:

lib/decompress_inflate.c:42:17: error: no previous prototype for '__gunzip' [-Werror=missing-prototypes]
lib/decompress_unxz.c:251:17: error: no previous prototype for 'unxz' [-Werror=missing-prototypes]
lib/decompress_unzstd.c:331:17: error: no previous prototype for 'unzstd' [-Werror=missing-prototypes]

Include the correct headers for unxz and unzstd, and mark the inflate
function above as unconditionally 'static' to avoid these warnings.

Link: https://lkml.kernel.org/r/20230517131936.936840-1-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Booting with the QEMU command line:
"qemu-system-x86_64 -append root=/dev/vda rootfstype=ext4 ..."
will panic if ext4 is not builtin and a request to load the ext4 module
fails.

[    1.729006] VFS: Cannot open root device "vda" or unknown-block(253,0): error -19
[    1.730603] Please append a correct "root=" boot option; here are the available partitions:
[    1.732323] fd00          256000 vda
[    1.732329]  driver: virtio_blk
[    1.734194] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(253,0)
[    1.734771] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.4.0-rc2+ #53
[    1.735194] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-1ubuntu1 04/01/2014
[    1.735772] Call Trace:
[    1.735950]  <TASK>
[    1.736113]  dump_stack_lvl+0x32/0x50
[    1.736367]  panic+0x108/0x310
[    1.736570]  mount_block_root+0x161/0x310
[    1.736849]  ? rdinit_setup+0x40/0x40
[    1.737088]  prepare_namespace+0x10c/0x180
[    1.737393]  kernel_init_freeable+0x354/0x450
[    1.737707]  ? rest_init+0xd0/0xd0
[    1.737945]  kernel_init+0x16/0x130
[    1.738196]  ret_from_fork+0x1f/0x30

As a hint, print all the bdev fstypes which are available.

[akpm@linux-foundation.org: fix spelling in printk message]
Link: https://lkml.kernel.org/r/20230518035321.1672-1-angus.chen@jaguarmicro.comSigned-off-by: Angus Chen <angus.chen@jaguarmicro.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

A number of internal functions in kcov are only called from generated code
and don't technically need a declaration, but 'make W=1' warns about
global symbols without a prototype:

kernel/kcov.c:199:14: error: no previous prototype for '__sanitizer_cov_trace_pc' [-Werror=missing-prototypes]
kernel/kcov.c:264:14: error: no previous prototype for '__sanitizer_cov_trace_cmp1' [-Werror=missing-prototypes]
kernel/kcov.c:270:14: error: no previous prototype for '__sanitizer_cov_trace_cmp2' [-Werror=missing-prototypes]
kernel/kcov.c:276:14: error: no previous prototype for '__sanitizer_cov_trace_cmp4' [-Werror=missing-prototypes]
kernel/kcov.c:282:14: error: no previous prototype for '__sanitizer_cov_trace_cmp8' [-Werror=missing-prototypes]
kernel/kcov.c:288:14: error: no previous prototype for '__sanitizer_cov_trace_const_cmp1' [-Werror=missing-prototypes]
kernel/kcov.c:295:14: error: no previous prototype for '__sanitizer_cov_trace_const_cmp2' [-Werror=missing-prototypes]
kernel/kcov.c:302:14: error: no previous prototype for '__sanitizer_cov_trace_const_cmp4' [-Werror=missing-prototypes]
kernel/kcov.c:309:14: error: no previous prototype for '__sanitizer_cov_trace_const_cmp8' [-Werror=missing-prototypes]
kernel/kcov.c:316:14: error: no previous prototype for '__sanitizer_cov_trace_switch' [-Werror=missing-prototypes]

Adding prototypes for these in a header solves that problem, but now there
is a mismatch between the built-in type and the prototype on 64-bit
architectures because they expect some functions to take a 64-bit
'unsigned long' argument rather than an 'unsigned long long' u64 type:

include/linux/kcov.h:84:6: error: conflicting types for built-in function '__sanitizer_cov_trace_switch'; expected 'void(long long unsigned int,  void *)' [-Werror=builtin-declaration-mismatch]
   84 | void __sanitizer_cov_trace_switch(u64 val, u64 *cases);
      |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

Avoid this as well with a custom type definition.

Link: https://lkml.kernel.org/r/20230517124944.929997-1-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Rong Tao <rongtao@cestc.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The arch_get_vdso_data() function is defined separately on each
architecture, but only called when CONFIG_TIME_NS is set.  If the
definition is a global function, this causes a W=1 warning without
TIME_NS:

arch/x86/entry/vdso/vma.c:35:19: error: no previous prototype for 'arch_get_vdso_data' [-Werror=missing-prototypes]

Move the prototype out of the #ifdef block to reliably turn off that
warning.

Link: https://lkml.kernel.org/r/20230517131102.934196-15-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

There are a few __weak functions in kernel/fork.c, which architectures
can override. If there is no prototype, the compiler warns about them:

kernel/fork.c:164:13: error: no previous prototype for 'arch_release_task_struct' [-Werror=missing-prototypes]
kernel/fork.c:991:20: error: no previous prototype for 'arch_task_cache_init' [-Werror=missing-prototypes]
kernel/fork.c:1086:12: error: no previous prototype for 'arch_dup_task_struct' [-Werror=missing-prototypes]

There are already prototypes in a number of architecture specific headers
that have addressed those warnings before, but it's much better to have
these in a single place so the warning no longer shows up anywhere.

Link: https://lkml.kernel.org/r/20230517131102.934196-14-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

cifs_root_data() is defined in cifs and called from early init code, but
lacks a global prototype:

fs/cifs/cifsroot.c:83:12: error: no previous prototype for 'cifs_root_data'

Move the declaration from do_mounts.c into an appropriate header.

Link: https://lkml.kernel.org/r/20230517131102.934196-13-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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

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

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

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

An extra #include statement is needed to ensure the prototypes for debugfs
interfaces are visible, avoiding this warning:

lib/kunit/debugfs.c:28:6: error: no previous prototype for 'kunit_debugfs_cleanup' [-Werror=missing-prototypes]
lib/kunit/debugfs.c:33:6: error: no previous prototype for 'kunit_debugfs_init' [-Werror=missing-prototypes]
lib/kunit/debugfs.c:102:6: error: no previous prototype for 'kunit_debugfs_create_suite' [-Werror=missing-prototypes]
lib/kunit/debugfs.c:118:6: error: no previous prototype for 'kunit_debugfs_destroy_suite' [-Werror=missing-prototypes]

Link: https://lkml.kernel.org/r/20230517131102.934196-10-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: David Gow <davidgow@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

A few panic() related functions have a global definition but not
declaration, which causes a warning with W=1:

kernel/panic.c:710:6: error: no previous prototype for '__warn_printk' [-Werror=missing-prototypes]
kernel/panic.c:756:24: error: no previous prototype for '__stack_chk_fail' [-Werror=missing-prototypes]
kernel/exit.c:1917:32: error: no previous prototype for 'abort' [-Werror=missing-prototypes]

__warn_printk() is called both as a global function when CONFIG_BUG
is enabled, and as a local function in other configs. The other
two here are called indirectly from generated or assembler code.

Add prototypes for all of these.

Link: https://lkml.kernel.org/r/20230517131102.934196-9-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Building with W=1 shows warnings about two functions that have no
declaration or caller in certain configurations:

kernel/panic.c:688:6: error: no previous prototype for 'warn_slowpath_fmt' [-Werror=missing-prototypes]
kernel/panic.c:710:6: error: no previous prototype for '__warn_printk' [-Werror=missing-prototypes]

Enclose the definition in the same #ifdef check as the declaration.

Link: https://lkml.kernel.org/r/20230517131102.934196-8-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lockevent_read() has a __weak definition and the only caller in
kernel/locking/lock_events.c, plus a strong definition in qspinlock_stat.h
that overrides it, but no other declaration.  This causes a W=1 warning:

kernel/locking/lock_events.c:61:16: error: no previous prototype for 'lockevent_read' [-Werror=missing-prototypes]

Add shared prototype to avoid the warnings.

Link: https://lkml.kernel.org/r/20230517131102.934196-7-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The devmem_is_allowed() function is defined in a file of the same name,
but the declaration is in asm/io.h, which is not included there, causing a
W=1 warning:

lib/devmem_is_allowed.c:20:5: error: no previous prototype for 'devmem_is_allowed' [-Werror=missing-prototypes]

Include the appropriate header to avoid the warning.

Link: https://lkml.kernel.org/r/20230517131102.934196-6-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

There are two definitions of this function, but the second one lacks the
'static' annotation:

mm/sparse.c:704:25: error: no previous prototype for 'populate_section_memmap' [-Werror=missing-prototypes]

Link: https://lkml.kernel.org/r/20230517131102.934196-4-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The __kernel_map_pages() function is mainly used for
CONFIG_DEBUG_PAGEALLOC, but has a number of architecture specific
definitions that may also be used in other configurations, as well as a
global fallback definition for architectures that do not support
DEBUG_PAGEALLOC.

When the option is disabled, any definitions without the prototype cause a
warning:

mm/page_poison.c:102:6: error: no previous prototype for '__kernel_map_pages' [-Werror=missing-prototypes]

The function is a trivial nop here, so just declare it anyway
to avoid the warning.

Link: https://lkml.kernel.org/r/20230517131102.934196-3-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Patch series "mm/init/kernel: missing-prototypes warnings".

These are patches addressing -Wmissing-prototypes warnings in common
kernel code and memory management code files that usually get merged
through the -mm tree.


This patch (of 12):

This function is called whenever CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK or
CONFIG_HAVE_SETUP_PER_CPU_AREA, but only declared when the former is set:

mm/percpu.c:3055:12: error: no previous prototype for 'pcpu_embed_first_chunk' [-Werror=missing-prototypes]

There is no real point in hiding declarations, so just remove
the #ifdef here.

Link: https://lkml.kernel.org/r/20230517131102.934196-1-arnd@kernel.org
Link: https://lkml.kernel.org/r/20230517131102.934196-2-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Before commit 93e72b3c ("squashfs: migrate from ll_rw_block
usage to BIO"), compressed blocks read by squashfs were cached in the page
cache, but that is not the case after that commit.  That has lead to
squashfs having to re-read a lot of sectors from disk/flash.

For example, the first sectors of every metadata block need to be read
twice from the disk.  Once partially to read the length, and a second time
to read the block itself.  Also, in linear reads of large files, the last
sectors of one data block are re-read from disk when reading the next data
block, since the compressed blocks are of variable sizes and not aligned
to device blocks.  This extra I/O results in a degrade in read performance
of, for example, ~16% in one scenario on my ARM platform using squashfs
with dm-verity and NAND.

Since the decompressed data is cached in the page cache or squashfs'
internal metadata and fragment caches, caching _all_ compressed pages
would lead to a lot of double caching and is undesirable.  But make the
code cache any disk blocks which were only partially requested, since
these are the ones likely to include data which is needed by other file
system blocks.  This restores read performance in my test scenario.

The compressed block caching is only applied when the disk block size is
equal to the page size, to avoid having to deal with caching sub-page
reads.

[akpm@linux-foundation.org: fs/squashfs/block.c needs linux/pagemap.h]
[vincent.whitchurch@axis.com: fix page update race]
  Link: https://lkml.kernel.org/r/20230526-squashfs-cache-fixup-v1-1-d54a7fa23e7b@axis.com
[vincent.whitchurch@axis.com: fix page indices]
  Link: https://lkml.kernel.org/r/20230526-squashfs-cache-fixup-v1-2-d54a7fa23e7b@axis.com
[akpm@linux-foundation.org: fix layout, per hch]
Link: https://lkml.kernel.org/r/20230510-squashfs-cache-v4-1-3bd394e1ee71@axis.comSigned-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Squashfs has stopped using buffers heads in 93e72b3c
("squashfs: migrate from ll_rw_block usage to BIO").

Link: https://lkml.kernel.org/r/20230517071622.245151-1-hch@lst.deSigned-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Since commit f1c1a9ee ("fork: Move memcg_charge_kernel_stack()
into CONFIG_VMAP_STACK"), memcg_charge_kernel_stack() has been moved
into CONFIG_VMAP_STACK block, so the CONFIG_VMAP_STACK check can be
removed.

Furthermore, memcg_charge_kernel_stack() is only invoked by
alloc_thread_stack_node() instead of dup_task_struct(). If
memcg_kmem_charge_page() fails, the uncharge process is handled in
memcg_charge_kernel_stack() itself instead of free_thread_stack(),
so remove the incorrect comments.

If memcg_charge_kernel_stack() fails to charge pages used by kernel
stack, only charged pages need to be uncharged. It's unnecessary to
uncharge those pages which memory cgroup pointer is NULL.

[akpm@linux-foundation.org: remove assertion that PAGE_SIZE is a multiple of 1k]
Link: https://lkml.kernel.org/r/20230508064458.32855-1-haifeng.xu@shopee.comSigned-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Add signed intptr_t given that a) it is standard type and b) uintptr_t is
in tree.

Link: https://lkml.kernel.org/r/ed66b9e4-1fb7-45be-9bb9-d4bc291c691f@p183Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

strlcpy() reads the entire source buffer first.  This read may exceed the
destination size limit.  This is both inefficient and can lead to linear
read overflows if a source string is not NUL-terminated [1].  In an effort
to remove strlcpy() completely [2], replace strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Link: https://lkml.kernel.org/r/20230510212457.3491385-1-azeemshaikh38@gmail.comSigned-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Some of the more common spelling mistakes and typos that I've found while
fixing up spelling mistakes in the kernel over the past couple of
releases.

Link: https://lkml.kernel.org/r/20230427102835.83482-1-colin.i.king@gmail.comSigned-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

- `If present` -> `If present,'
- `reuturn` -> `return`
- `function exit safely` -> `function to exit safely`

Link: https://lkml.kernel.org/r/20230502090242.3037194-1-quic_pbaronia@quicinc.comSigned-off-by: Prathu Baronia <quic_pbaronia@quicinc.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Pull x86 cpu fix from Thomas Gleixner:
 "A single fix for x86:

   - Prevent a bogus setting for the number of HT siblings, which is
     caused by the CPUID evaluation trainwreck of X86. That recomputes
     the value for each CPU, so the last CPU "wins". That can cause
     completely bogus sibling values"

* tag 'x86-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/topology: Fix erroneous smp_num_siblings on Intel Hybrid platforms

Pull perf fixes from Thomas Gleixner:
 "A small set of perf fixes:

   - Make the MSR-readout based CHA discovery work around broken
     discovery tables in some SPR firmwares.

   - Prevent saving PEBS configuration which has software bits set that
     cause a crash when restored into the relevant MSR"

* tag 'perf-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/uncore: Correct the number of CHAs on SPR
  perf/x86/intel: Save/restore cpuc->active_pebs_data_cfg when using guest PEBS

Pull unwinder fixes from Thomas Gleixner:
 "A set of unwinder and tooling fixes:

   - Ensure that the stack pointer on x86 is aligned again so that the
     unwinder does not read past the end of the stack

   - Discard .note.gnu.property section which has a pointlessly
     different alignment than the other note sections. That confuses
     tooling of all sorts including readelf, libbpf and pahole"

* tag 'objtool-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/show_trace_log_lvl: Ensure stack pointer is aligned, again
  vmlinux.lds.h: Discard .note.gnu.property section

Pull debugobjects fixes from Thomas Gleixner:
 "Two fixes for debugobjects:

   - Prevent the allocation path from waking up kswapd.

     That's a long standing issue due to the GFP_ATOMIC allocation flag.
     As debug objects can be invoked from pretty much any context waking
     kswapd can end up in arbitrary lock chains versus the waitqueue
     lock

   - Correct the explicit lockdep wait-type violation in
     debug_object_fill_pool()"

* tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  debugobjects: Don't wake up kswapd from fill_pool()
  debugobjects,locking: Annotate debug_object_fill_pool() wait type violation

Pull irq fixes from Thomas Gleixner:
 "A set of fixes for interrupt chip drivers:

   - Prevent loss of state in the MIPS GIC interrupt controller

   - Disable pseudo NMIs on Mediatek based Chromebooks as they have
     firmware issues which cause instantenous chrashes and freezes wen
     pseudo NMIs are used

   - Fix the error handling path in the MBIGEN driver and a defined but
     not used warning in the meson-gpio interrupt chip driver"

* tag 'irq-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/mbigen: Unify the error handling in mbigen_of_create_domain()
  irqchip/meson-gpio: Mark OF related data as maybe unused
  irqchip/mips-gic: Use raw spinlock for gic_lock
  irqchip/mips-gic: Don't touch vl_map if a local interrupt is not routable
  irqchip/gic-v3: Disable pseudo NMIs on Mediatek devices w/ firmware issues
  dt-bindings: interrupt-controller: arm,gic-v3: Add quirk for Mediatek SoCs w/ broken FW

Pull MIPS fixes from Thomas Bogendoerfer:

 - fixes to get alchemy platform back in shape

 - fix for initrd detection

* tag 'mips-fixes_6.4_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  mips: Move initrd_start check after initrd address sanitisation.
  MIPS: Alchemy: fix dbdma2
  MIPS: Restore Au1300 support
  MIPS: unhide PATA_PLATFORM

Pull powerpc fix from Michael Ellerman:

 - Reinstate ARCH_FORCE_MAX_ORDER ranges to fix various breakage

* tag 'powerpc-6.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm: Reinstate ARCH_FORCE_MAX_ORDER ranges

Pull xen fixes from Juergen Gross:

 - a double free fix in the Xen pvcalls backend driver

 - a fix for a regression causing the MSI related sysfs entries to not
   being created in Xen PV guests

 - a fix in the Xen blkfront driver for handling insane input data
   better

* tag 'for-linus-6.4-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/pci/xen: populate MSI sysfs entries
  xen/pvcalls-back: fix double frees with pvcalls_new_active_socket()
  xen/blkfront: Only check REQ_FUA for writes

Pull char/misc fixes from Greg KH:
 "Here are some small driver fixes for 6.4-rc4. They are just two
  different types:

   - binder fixes and reverts for reported problems and regressions in
     the binder "driver".

   - coresight driver fixes for reported problems.

  All of these have been in linux-next for over a week with no reported
  problems"

* tag 'char-misc-6.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  binder: fix UAF of alloc->vma in race with munmap()
  binder: add lockless binder_alloc_(set|get)_vma()
  Revert "android: binder: stop saving a pointer to the VMA"
  Revert "binder_alloc: add missing mmap_lock calls when using the VMA"
  binder: fix UAF caused by faulty buffer cleanup
  coresight: perf: Release Coresight path when alloc trace id failed
  coresight: Fix signedness bug in tmc_etr_buf_insert_barrier_packet()