Add generic support for try_cmpxchg64{,_acquire,_release,_relaxed}
and their falbacks involving cmpxchg64.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220515184205.103089-2-ubizjak@gmail.com

Earlier the PREEMPT_RT patch had a PREEMPT_RT_FULL and PREEMPT_RT_BASE
Kconfig option. The latter was a subset of the functionality that was
enabled with PREEMPT_RT_FULL and was mainly useful for debugging.

During the merging efforts the two Kconfig options were abandoned in the
v5.4.3-rt1 release and since then there is only PREEMPT_RT which enables
the full features set (as PREEMPT_RT_FULL did in earlier releases).

Replace the PREEMPT_RT_FULL reference with PREEMPT_RT.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/r/YnvWUvq1vpqCfCU7@linutronix.de

Queued rwlock was originally named "queue rwlock" which wasn't quite
grammatically correct. However there are still some "queue rwlock"
references in the code. Change those to "queued rwlock" for consistency.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220510192134.434753-1-longman@redhat.com

No more users and there is no desire to grow new ones.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/8735hir0j4.ffs@tglx

Have the trace_contention_*() tracepoints consistently include
adaptive spinning. In order to differentiate between the spinning and
non-spinning states add LCB_F_MUTEX and combine with LCB_F_SPIN.

The consequence is that a mutex contention can now triggler multiple
_begin() tracepoints before triggering an _end().

Additionally, this fixes one path where mutex would trigger _end()
without ever seeing a _begin().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Adding the lock contention tracepoints in various lock function slow
paths.  Note that each arch can define spinlock differently, I only
added it only to the generic qspinlock for now.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Link: https://lkml.kernel.org/r/20220322185709.141236-3-namhyung@kernel.org

This adds two new lock contention tracepoints like below:

 * lock:contention_begin
 * lock:contention_end

The lock:contention_begin takes a flags argument to classify locks.  I
found it useful to identify what kind of locks it's tracing like if
it's spinning or sleeping, reader-writer lock, real-time, and per-cpu.

Move tracepoint definitions into mutex.c so that we can use them
without lockdep.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Link: https://lkml.kernel.org/r/20220322185709.141236-2-namhyung@kernel.org

For writers, the out_nolock path will always attempt to wake up waiters.
This may not be really necessary if the waiter to be removed is not the
first one.

For readers, no attempt to wake up waiter is being made. However, if
the HANDOFF bit is set and the reader to be removed is the first waiter,
the waiter behind it will inherit the HANDOFF bit and for a write lock
waiter waking it up will allow it to spin on the lock to acquire it
faster. So it can be beneficial to do a wakeup in this case.

Add a new rwsem_del_wake_waiter() helper function to do that consistently
for both reader and writer out_nolock paths.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220322152059.2182333-4-longman@redhat.com

In an analysis of a recent vmcore, a reader-owned rwsem was found with
385 readers but no writer in the wait queue. That is kind of unusual
but it may be caused by some race conditions that we have not fully
understood yet. In such a case, all the readers in the wait queue should
join the other reader-owners and acquire the read lock.

In rwsem_down_write_slowpath(), an incoming writer will try to
wake up the front readers under such circumstance. That is not
the case for rwsem_down_read_slowpath(), add a new helper function
rwsem_cond_wake_waiter() to do wakeup and use it in both reader and
writer slowpaths to have a consistent and correct behavior.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220322152059.2182333-3-longman@redhat.com

Since commit d257cc8c ("locking/rwsem: Make handoff bit handling
more consistent"), the handoff bit is always cleared if the wait queue
becomes empty. There is no need to check for RWSEM_FLAG_HANDOFF when
the wait list is known to be empty.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220322152059.2182333-2-longman@redhat.com

While looking into a bug related to the compiler's handling of addresses
of labels, I noticed some uses of _THIS_IP_ seemed unused in lockdep.
Drive by cleanup.

-Wunused-parameter:
kernel/locking/lockdep.c:1383:22: warning: unused parameter 'ip'
kernel/locking/lockdep.c:4246:48: warning: unused parameter 'ip'
kernel/locking/lockdep.c:4844:19: warning: unused parameter 'ip'
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20220314221909.2027027-1-ndesaulniers@google.com

Fix:

  vmlinux.o: warning: objtool: __sev_es_nmi_complete()+0x8b: call to __phys_addr_nodebug() leaves .noinstr.text section
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220324183607.31717-4-bp@alien8.de

In order to fix:

  vmlinux.o: warning: objtool: __sev_es_nmi_complete()+0x4c: call to ghcb_set_sw_exit_code() leaves .noinstr.text section
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220324183607.31717-3-bp@alien8.de

Force-inline two stack helpers to fix the following objtool warnings:

  vmlinux.o: warning: objtool: in_task_stack()+0xc: call to task_stack_page() leaves .noinstr.text section
  vmlinux.o: warning: objtool: in_entry_stack()+0x10: call to cpu_entry_stack() leaves .noinstr.text section
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220324183607.31717-2-bp@alien8.de

Pull more tracing updates from Steven Rostedt:

 - Rename the staging files to give them some meaning. Just
   stage1,stag2,etc, does not show what they are for

 - Check for NULL from allocation in bootconfig

 - Hold event mutex for dyn_event call in user events

 - Mark user events to broken (to work on the API)

 - Remove eBPF updates from user events

 - Remove user events from uapi header to keep it from being installed.

 - Move ftrace_graph_is_dead() into inline as it is called from hot
   paths and also convert it into a static branch.

* tag 'trace-v5.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Move user_events.h temporarily out of include/uapi
  ftrace: Make ftrace_graph_is_dead() a static branch
  tracing: Set user_events to BROKEN
  tracing/user_events: Remove eBPF interfaces
  tracing/user_events: Hold event_mutex during dyn_event_add
  proc: bootconfig: Add null pointer check
  tracing: Rename the staging files for trace_events

Pull clk fix from Stephen Boyd:
 "A single revert to fix a boot regression seen when clk_put() started
  dropping rate range requests. It's best to keep various systems
  booting so we'll kick this out and try again next time"

* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  Revert "clk: Drop the rate range on clk_put()"

Pull x86 fixes from Thomas Gleixner:
 "A set of x86 fixes and updates:

   - Make the prctl() for enabling dynamic XSTATE components correct so
     it adds the newly requested feature to the permission bitmap
     instead of overwriting it. Add a selftest which validates that.

   - Unroll string MMIO for encrypted SEV guests as the hypervisor
     cannot emulate it.

   - Handle supervisor states correctly in the FPU/XSTATE code so it
     takes the feature set of the fpstate buffer into account. The
     feature sets can differ between host and guest buffers. Guest
     buffers do not contain supervisor states. So far this was not an
     issue, but with enabling PASID it needs to be handled in the buffer
     offset calculation and in the permission bitmaps.

   - Avoid a gazillion of repeated CPUID invocations in by caching the
     values early in the FPU/XSTATE code.

   - Enable CONFIG_WERROR in x86 defconfig.

   - Make the X86 defconfigs more useful by adapting them to Y2022
     reality"

* tag 'x86-urgent-2022-04-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu/xstate: Consolidate size calculations
  x86/fpu/xstate: Handle supervisor states in XSTATE permissions
  x86/fpu/xsave: Handle compacted offsets correctly with supervisor states
  x86/fpu: Cache xfeature flags from CPUID
  x86/fpu/xsave: Initialize offset/size cache early
  x86/fpu: Remove unused supervisor only offsets
  x86/fpu: Remove redundant XCOMP_BV initialization
  x86/sev: Unroll string mmio with CC_ATTR_GUEST_UNROLL_STRING_IO
  x86/config: Make the x86 defconfigs a bit more usable
  x86/defconfig: Enable WERROR
  selftests/x86/amx: Update the ARCH_REQ_XCOMP_PERM test
  x86/fpu/xstate: Fix the ARCH_REQ_XCOMP_PERM implementation

Pull RT signal fix from Thomas Gleixner:
 "Revert the RT related signal changes. They need to be reworked and
  generalized"

* tag 'core-urgent-2022-04-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "signal, x86: Delay calling signals in atomic on RT enabled kernels"

Pull more dma-mapping updates from Christoph Hellwig:

 - fix a regression in dma remap handling vs AMD memory encryption (me)

 - finally kill off the legacy PCI DMA API (Christophe JAILLET)

* tag 'dma-mapping-5.18-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: move pgprot_decrypted out of dma_pgprot
  PCI/doc: cleanup references to the legacy PCI DMA API
  PCI: Remove the deprecated "pci-dma-compat.h" API

Pull ARM fixes from Russell King:

 - avoid unnecessary rebuilds for library objects

 - fix return value of __setup handlers

 - fix invalid input check for "crashkernel=" kernel option

 - silence KASAN warnings in unwind_frame

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 9191/1: arm/stacktrace, kasan: Silence KASAN warnings in unwind_frame()
  ARM: 9190/1: kdump: add invalid input check for 'crashkernel=0'
  ARM: 9187/1: JIVE: fix return value of __setup handler
  ARM: 9189/1: decompressor: fix unneeded rebuilds of library objects

This reverts commit 7dabfa2b. There are
multiple reports that this breaks boot on various systems. The common
theme is that orphan clks are having rates set on them when that isn't
expected. Let's revert it out for now so that -rc1 boots.
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reported-by: Tony Lindgren <tony@atomide.com>
Reported-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: https://lore.kernel.org/r/366a0232-bb4a-c357-6aa8-636e398e05eb@samsung.com
Cc: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20220403022818.39572-1-sboyd@kernel.org

Merge tag 'perf-tools-for-v5.18-2022-04-02' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull more perf tools updates from Arnaldo Carvalho de Melo:

 - Avoid SEGV if core.cpus isn't set in 'perf stat'.

 - Stop depending on .git files for building PERF-VERSION-FILE, used in
   'perf --version', fixing some perf tools build scenarios.

 - Convert tracepoint.py example to python3.

 - Update UAPI header copies from the kernel sources: socket,
   mman-common, msr-index, KVM, i915 and cpufeatures.

 - Update copy of libbpf's hashmap.c.

 - Directly return instead of using local ret variable in
   evlist__create_syswide_maps(), found by coccinelle.

* tag 'perf-tools-for-v5.18-2022-04-02' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  perf python: Convert tracepoint.py example to python3
  perf evlist: Directly return instead of using local ret variable
  perf cpumap: More cpu map reuse by merge.
  perf cpumap: Add is_subset function
  perf evlist: Rename cpus to user_requested_cpus
  perf tools: Stop depending on .git files for building PERF-VERSION-FILE
  tools headers cpufeatures: Sync with the kernel sources
  tools headers UAPI: Sync drm/i915_drm.h with the kernel sources
  tools headers UAPI: Sync linux/kvm.h with the kernel sources
  tools kvm headers arm64: Update KVM headers from the kernel sources
  tools arch x86: Sync the msr-index.h copy with the kernel sources
  tools headers UAPI: Sync asm-generic/mman-common.h with the kernel
  perf beauty: Update copy of linux/socket.h with the kernel sources
  perf tools: Update copy of libbpf's hashmap.c
  perf stat: Avoid SEGV if core.cpus isn't set

Merge tag 'kbuild-fixes-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Fix empty $(PYTHON) expansion.

 - Fix UML, which got broken by the attempt to suppress Clang warnings.

 - Fix warning message in modpost.

* tag 'kbuild-fixes-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  modpost: restore the warning message for missing symbol versions
  Revert "um: clang: Strip out -mno-global-merge from USER_CFLAGS"
  kbuild: Remove '-mno-global-merge'
  kbuild: fix empty ${PYTHON} in scripts/link-vmlinux.sh
  kconfig: remove stale comment about removed kconfig_print_symbol()

Pull MIPS fixes from Thomas Bogendoerfer:

 - build fix for gpio

 - fix crc32 build problems

 - check for failed memory allocations

* tag 'mips_5.18_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: crypto: Fix CRC32 code
  MIPS: rb532: move GPIOD definition into C-files
  MIPS: lantiq: check the return value of kzalloc()
  mips: sgi-ip22: add a check for the return of kzalloc()

Pull kvm fixes from Paolo Bonzini:

 - Only do MSR filtering for MSRs accessed by rdmsr/wrmsr

 - Documentation improvements

 - Prevent module exit until all VMs are freed

 - PMU Virtualization fixes

 - Fix for kvm_irq_delivery_to_apic_fast() NULL-pointer dereferences

 - Other miscellaneous bugfixes

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (42 commits)
  KVM: x86: fix sending PV IPI
  KVM: x86/mmu: do compare-and-exchange of gPTE via the user address
  KVM: x86: Remove redundant vm_entry_controls_clearbit() call
  KVM: x86: cleanup enter_rmode()
  KVM: x86: SVM: fix tsc scaling when the host doesn't support it
  kvm: x86: SVM: remove unused defines
  KVM: x86: SVM: move tsc ratio definitions to svm.h
  KVM: x86: SVM: fix avic spec based definitions again
  KVM: MIPS: remove reference to trap&emulate virtualization
  KVM: x86: document limitations of MSR filtering
  KVM: x86: Only do MSR filtering when access MSR by rdmsr/wrmsr
  KVM: x86/emulator: Emulate RDPID only if it is enabled in guest
  KVM: x86/pmu: Fix and isolate TSX-specific performance event logic
  KVM: x86: mmu: trace kvm_mmu_set_spte after the new SPTE was set
  KVM: x86/svm: Clear reserved bits written to PerfEvtSeln MSRs
  KVM: x86: Trace all APICv inhibit changes and capture overall status
  KVM: x86: Add wrappers for setting/clearing APICv inhibits
  KVM: x86: Make APICv inhibit reasons an enum and cleanup naming
  KVM: X86: Handle implicit supervisor access with SMAP
  KVM: X86: Rename variable smap to not_smap in permission_fault()
  ...

This log message was accidentally chopped off.

I was wondering why this happened, but checking the ML log, Mark
precisely followed my suggestion [1].

I just used "..." because I was too lazy to type the sentence fully.
Sorry for the confusion.

[1]: https://lore.kernel.org/all/CAK7LNAR6bXXk9-ZzZYpTqzFqdYbQsZHmiWspu27rtsFxvfRuVA@mail.gmail.com/

Fixes: 4a679593 ("kbuild: modpost: Explicitly warn about unprototyped symbols")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

Pull block driver fix from Jens Axboe:
 "Got two reports on nbd spewing warnings on load now, which is a
  regression from a commit that went into your tree yesterday.

  Revert the problematic change for now"

* tag 'for-5.18/drivers-2022-04-02' of git://git.kernel.dk/linux-block:
  Revert "nbd: fix possible overflow on 'first_minor' in nbd_dev_add()"

Pull pci fix from Bjorn Helgaas:

 - Fix Hyper-V "defined but not used" build issue added during merge
   window (YueHaibing)

* tag 'pci-v5.18-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: hv: Remove unused hv_set_msi_entry_from_desc()

Merge tag 'tag-chrome-platform-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux

Pull chrome platform updates from Benson Leung:
 "cros_ec_typec:

   - Check for EC device - Fix a crash when using the cros_ec_typec
     driver on older hardware not capable of typec commands

   - Make try power role optional

   - Mux configuration reorganization series from Prashant

  cros_ec_debugfs:

   - Fix use after free. Thanks Tzung-bi

  sensorhub:

   - cros_ec_sensorhub fixup - Split trace include file

  misc:

   - Add new mailing list for chrome-platform development:

	chrome-platform@lists.linux.dev

     Now with patchwork!"

* tag 'tag-chrome-platform-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux:
  platform/chrome: cros_ec_debugfs: detach log reader wq from devm
  platform: chrome: Split trace include file
  platform/chrome: cros_ec_typec: Update mux flags during partner removal
  platform/chrome: cros_ec_typec: Configure muxes at start of port update
  platform/chrome: cros_ec_typec: Get mux state inside configure_mux
  platform/chrome: cros_ec_typec: Move mux flag checks
  platform/chrome: cros_ec_typec: Check for EC device
  platform/chrome: cros_ec_typec: Make try power role optional
  MAINTAINERS: platform-chrome: Add new chrome-platform@lists.linux.dev list

This reverts commit 6d35d04a.

Both Gabriel and Borislav report that this commit casues a regression
with nbd:

sysfs: cannot create duplicate filename '/dev/block/43:0'

Revert it before 5.18-rc1 and we'll investigage this separately in
due time.

Link: https://lore.kernel.org/all/YkiJTnFOt9bTv6A2@zn.tnic/Reported-by: Gabriel L. Somlo <somlo@cmu.edu>
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Commit 7ea1a012 ("watch_queue: Free the alloc bitmap when the
watch_queue is torn down") took care of the bitmap, but not the page
array.

  BUG: memory leak
  unreferenced object 0xffff88810d9bc140 (size 32):
  comm "syz-executor335", pid 3603, jiffies 4294946994 (age 12.840s)
  hex dump (first 32 bytes):
    40 a7 40 04 00 ea ff ff 00 00 00 00 00 00 00 00  @.@.............
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
     kmalloc_array include/linux/slab.h:621 [inline]
     kcalloc include/linux/slab.h:652 [inline]
     watch_queue_set_size+0x12f/0x2e0 kernel/watch_queue.c:251
     pipe_ioctl+0x82/0x140 fs/pipe.c:632
     vfs_ioctl fs/ioctl.c:51 [inline]
     __do_sys_ioctl fs/ioctl.c:874 [inline]
     __se_sys_ioctl fs/ioctl.c:860 [inline]
     __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:860
     do_syscall_x64 arch/x86/entry/common.c:50 [inline]

Reported-by: syzbot+25ea042ae28f3888727a@syzkaller.appspotmail.com
Fixes: c73be61c ("pipe: Add general notification queue support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/r/20220322004654.618274-1-eric.dumazet@gmail.com/Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

After being merged, user_events become more visible to a wider audience
that have concerns with the current API.

It is too late to fix this for this release, but instead of a full
revert, just mark it as BROKEN (which prevents it from being selected in
make config).  Then we can work finding a better API.  If that fails,
then it will need to be completely reverted.

To not have the code silently bitrot, still allow building it with
COMPILE_TEST.

And to prevent the uapi header from being installed, then later changed,
and then have an old distro user space see the old version, move the
header file out of the uapi directory.

Surround the include with CONFIG_COMPILE_TEST to the current location,
but when the BROKEN tag is taken off, it will use the uapi directory,
and fail to compile.  This is a good way to remind us to move the header
back.

Link: https://lore.kernel.org/all/20220330155835.5e1f6669@gandalf.local.home
Link: https://lkml.kernel.org/r/20220330201755.29319-1-mathieu.desnoyers@efficios.comSuggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

While user_events API is under development and has been marked for broken
to not let the API become fixed, move the header file out of the uapi
directory. This is to prevent it from being installed, then later changed,
and then have an old distro user space update with a new kernel, where
applications see the user_events being available, but the old header is in
place, and then they get compiled incorrectly.

Also, surround the include with CONFIG_COMPILE_TEST to the current
location, but when the BROKEN tag is taken off, it will use the uapi
directory, and fail to compile. This is a good way to remind us to move
the header back.

Link: https://lore.kernel.org/all/20220330155835.5e1f6669@gandalf.local.home
Link: https://lkml.kernel.org/r/20220330201755.29319-1-mathieu.desnoyers@efficios.com
Link: https://lkml.kernel.org/r/20220401143903.188384f3@gandalf.local.homeSuggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

ftrace_graph_is_dead() is used on hot paths, it just reads a variable
in memory and is not worth suffering function call constraints.

For instance, at entry of prepare_ftrace_return(), inlining it avoids
saving prepare_ftrace_return() parameters to stack and restoring them
after calling ftrace_graph_is_dead().

While at it using a static branch is even more performant and is
rather well adapted considering that the returned value will almost
never change.

Inline ftrace_graph_is_dead() and replace 'kill_ftrace_graph' bool
by a static branch.

The performance improvement is noticeable.

Link: https://lkml.kernel.org/r/e0411a6a0ed3eafff0ad2bc9cd4b0e202b4617df.1648623570.git.christophe.leroy@csgroup.euSigned-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

After being merged, user_events become more visible to a wider audience
that have concerns with the current API. It is too late to fix this for
this release, but instead of a full revert, just mark it as BROKEN (which
prevents it from being selected in make config). Then we can work finding
a better API. If that fails, then it will need to be completely reverted.

Link: https://lore.kernel.org/all/2059213643.196683.1648499088753.JavaMail.zimbra@efficios.com/
Link: https://lkml.kernel.org/r/20220330155835.5e1f6669@gandalf.local.homeSigned-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Remove eBPF interfaces within user_events to ensure they are fully
reviewed.

Link: https://lore.kernel.org/all/20220329165718.GA10381@kbox/
Link: https://lkml.kernel.org/r/20220329173051.10087-1-beaub@linux.microsoft.comSuggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Make sure the event_mutex is properly held during dyn_event_add call.
This is required when adding dynamic events.

Link: https://lkml.kernel.org/r/20220328223225.1992-1-beaub@linux.microsoft.comReported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

kzalloc is a memory allocation function which can return NULL when some
internal memory errors happen. It is safer to add null pointer check.

Link: https://lkml.kernel.org/r/20220329104004.2376879-1-lv.ruyi@zte.com.cn

Cc: stable@vger.kernel.org
Fixes: c1a3c360 ("proc: bootconfig: Add /proc/bootconfig to show boot config list")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Lv Ruyi <lv.ruyi@zte.com.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

When looking for implementation of different phases of the creation of the
TRACE_EVENT() macro, it is pretty useless when all helper macro
redefinitions are in files labeled "stageX_defines.h". Rename them to
state which phase the files are for. For instance, when looking for the
defines that are used to create the event fields, seeing
"stage4_event_fields.h" gives the developer a good idea that the defines
are in that file.
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>