linux-stable.git/arch/s390/kernel/perf_event.c, branch linux-rolling-stable

s390: Remove KMSG_COMPONENT macro

2025-11-24T10:45:21+00:00

The KMSG_COMPONENT macro is a leftover of the s390 specific "kernel
message catalog" which never made it upstream.

Remove the macro in order to get rid of a pointless indirection. Replace
all users with the string it defines. In almost all cases this leads to a
simple replacement like this:

 - #define KMSG_COMPONENT "appldata"
 - #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 + #define pr_fmt(fmt) "appldata: " fmt

Except for some special cases this is just mechanical/scripted work.

Acked-by: Thomas Richter 
Signed-off-by: Heiko Carstens

s390: Remove compat support

2025-11-17T10:10:38+00:00

There shouldn't be any 31 bit code around anymore that matters.
Remove the compat layer support required to run 31 bit code.

Reason for removal is code simplification and reduced test effort.

Note that this comes without any deprecation warnings added to config
options, or kernel messages, since most likely those would be ignored
anyway.

If it turns out there is still a reason to keep the compat layer this
can be reverted at any time in the future.

Reviewed-by: Arnd Bergmann 
Signed-off-by: Heiko Carstens

s390: Remove unnecessary include

2025-06-17T16:18:02+00:00

Remove include  from all files which do not contain an
EXPORT_SYMBOL().

See commit 7d95680d64ac ("scripts/misc-check: check unnecessary #include
 when W=1") for more details.

Acked-by: Alexander Gordeev 
Signed-off-by: Heiko Carstens 
Signed-off-by: Alexander Gordeev

Merge tag 'perf-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2024-11-19T21:34:06+00:00

Pull performance events updates from Ingo Molnar:
 "Uprobes:
    - Add BPF session support (Jiri Olsa)
    - Switch to RCU Tasks Trace flavor for better performance (Andrii
      Nakryiko)
    - Massively increase uretprobe SMP scalability by SRCU-protecting
      the uretprobe lifetime (Andrii Nakryiko)
    - Kill xol_area->slot_count (Oleg Nesterov)

  Core facilities:
    - Implement targeted high-frequency profiling by adding the ability
      for an event to "pause" or "resume" AUX area tracing (Adrian
      Hunter)

  VM profiling/sampling:
    - Correct perf sampling with guest VMs (Colton Lewis)

  New hardware support:
    - x86/intel: Add PMU support for Intel ArrowLake-H CPUs (Dapeng Mi)

  Misc fixes and enhancements:
    - x86/intel/pt: Fix buffer full but size is 0 case (Adrian Hunter)
    - x86/amd: Warn only on new bits set (Breno Leitao)
    - x86/amd/uncore: Avoid a false positive warning about snprintf
      truncation in amd_uncore_umc_ctx_init (Jean Delvare)
    - uprobes: Re-order struct uprobe_task to save some space
      (Christophe JAILLET)
    - x86/rapl: Move the pmu allocation out of CPU hotplug (Kan Liang)
    - x86/rapl: Clean up cpumask and hotplug (Kan Liang)
    - uprobes: Deuglify xol_get_insn_slot/xol_free_insn_slot paths (Oleg
      Nesterov)"

* tag 'perf-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  perf/core: Correct perf sampling with guest VMs
  perf/x86: Refactor misc flag assignments
  perf/powerpc: Use perf_arch_instruction_pointer()
  perf/core: Hoist perf_instruction_pointer() and perf_misc_flags()
  perf/arm: Drop unused functions
  uprobes: Re-order struct uprobe_task to save some space
  perf/x86/amd/uncore: Avoid a false positive warning about snprintf truncation in amd_uncore_umc_ctx_init
  perf/x86/intel: Do not enable large PEBS for events with aux actions or aux sampling
  perf/x86/intel/pt: Add support for pause / resume
  perf/core: Add aux_pause, aux_resume, aux_start_paused
  perf/x86/intel/pt: Fix buffer full but size is 0 case
  uprobes: SRCU-protect uretprobe lifetime (with timeout)
  uprobes: allow put_uprobe() from non-sleepable softirq context
  perf/x86/rapl: Clean up cpumask and hotplug
  perf/x86/rapl: Move the pmu allocation out of CPU hotplug
  uprobe: Add support for session consumer
  uprobe: Add data pointer to consumer handlers
  perf/x86/amd: Warn only on new bits set
  uprobes: fold xol_take_insn_slot() into xol_get_insn_slot()
  uprobes: kill xol_area->slot_count
  ...

perf/core: Hoist perf_instruction_pointer() and perf_misc_flags()

2024-11-14T09:40:01+00:00

For clarity, rename the arch-specific definitions of these functions
to perf_arch_* to denote they are arch-specifc. Define the
generic-named functions in one place where they can call the
arch-specific ones as needed.

Signed-off-by: Colton Lewis 
Signed-off-by: Ingo Molnar 
Reviewed-by: Oliver Upton 
Acked-by: Thomas Richter 
Acked-by: Mark Rutland 
Acked-by: Madhavan Srinivasan 
Acked-by: Kan Liang 
Link: https://lore.kernel.org/r/20241113190156.2145593-3-coltonlewis@google.com

s390/perf_event: Switch over to sysfs_emit()

2024-10-25T14:03:24+00:00

Per Documentation/filesystems/sysfs.rst, sysfs_emit() is preferred over
sprintf for presenting attributes to user space. Convert the left-over
uses in the s390/perf_event code.

Signed-off-by: Mete Durlu 
Reviewed-by: Gerd Bayer 
Reviewed-by: Heiko Carstens 
Signed-off-by: Heiko Carstens

s390/stacktrace: Merge perf_callchain_user() and arch_stack_walk_user()

2024-05-14T11:37:06+00:00

The two functions perf_callchain_user() and arch_stack_walk_user() are
nearly identical. Reduce code duplication and add a common helper which can
be called by both functions.

Fixes: aa44433ac4ee ("s390: add USER_STACKTRACE support")
Reviewed-by: Jens Remus 
Signed-off-by: Heiko Carstens 
Signed-off-by: Alexander Gordeev

s390/perf: implement perf_callchain_user()

2023-11-05T21:34:57+00:00

Daan De Meyer and Neal Gompa reported that s390 does not support perf user
stack unwinding.

This was never implemented since this requires user space to be compiled
with the -mbackchain compile option, which until now no distribution
did. However this is going to change with Fedora. Therefore provide a
perf_callchain_user() implementation.

Note that due to the way s390 sets up stack frames the provided call chains
can contain invalid values. This is especially true for the first stack
frame, where it is not possible to tell if the return address has been
written to the stack already or not.

Reported-by: Daan De Meyer 
Reported-by: Neal Gompa 
Closes: https://lore.kernel.org/all/CAO8sHcn3+_qrnvp0580aK7jN0Wion5F7KYeBAa4MnCY4mqABPA@mail.gmail.com/
Link: https://lore.kernel.org/all/20231030123558.10816-A-hca@linux.ibm.com
Reviewed-by: Neal Gompa 
Acked-by: Ilya Leoshkevich 
Signed-off-by: Heiko Carstens 
Signed-off-by: Vasily Gorbik

s390/stack: add union to reflect kvm stack slot usages

2022-06-01T10:03:17+00:00

Add a union which describes how the empty stack slots are being used
by kvm and perf. This should help to avoid another bug like the one
which was fixed with commit c9bfb460c3e4 ("s390/perf: obtain sie_block
from the right address").

Reviewed-by: Nico Boehr 
Tested-by: Nico Boehr 
Signed-off-by: Heiko Carstens

s390/stack: merge empty stack frame slots

2022-06-01T10:03:17+00:00

Merge empty1 and empty2 arrays within the stack frame to one single
array. This is possible since with commit 42b01a553a56 ("s390: always
use the packed stack layout") the alternative stack frame layout is
gone.

Reviewed-by: Nico Boehr 
Reviewed-by: Alexander Gordeev 
Signed-off-by: Heiko Carstens