Skip to contentSkip to conversation

Performance events changes for v6.19

GIT PULL Merged Ingo Molnar 3 participants 3 messages Dec 1, 2025 – Mar 9

lore
Share & tools
lore

Ingo Molnar

author
#0 lore raw

Linus,

Please pull the latest perf/core Git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-core-2025-12-01

# HEAD: 9929dffce5ed7e2988e0274f4db98035508b16d9 perf/x86/intel: Fix and clean up intel_pmu_drain_arch_pebs() type use

Performance events changes for v6.19:

Callchain support:

- Add support for deferred user-space stack unwinding for perf, enabled on x86. (Peter Zijlstra, Steven Rostedt)

- unwind_user/x86: Enable frame pointer unwinding on x86 (Josh Poimboeuf)

x86 PMU support and infrastructure:

- x86/insn: Simplify for_each_insn_prefix() (Peter Zijlstra)

- x86/insn,uprobes,alternative: Unify insn_is_nop() (Peter Zijlstra)

Intel PMU driver:

- Large series to prepare for and implement architectural PEBS support for Intel platforms such as Clearwater Forest (CWF) and Panther Lake (PTL). (Dapeng Mi, Kan Liang)

- Check dynamic constraints (Kan Liang)

- Optimize PEBS extended config (Peter Zijlstra)

- cstates: Remove PC3 support from LunarLake (Zhang Rui)

- cstates: Add Pantherlake support (Zhang Rui)

- cstates: Clearwater Forest support (Zide Chen)

AMD PMU driver:

- x86/amd: Check event before enable to avoid GPF (George Kennedy)

Fixes and cleanups:

- task_work: Fix NMI race condition (Peter Zijlstra)

- perf/x86: Fix NULL event access and potential PEBS record loss (Dapeng Mi)

- Misc other fixes and cleanups.
(Dapeng Mi, Ingo Molnar, Peter Zijlstra)

Thanks,

Ingo

------------------>
Dapeng Mi (12):
perf/x86: Remove redundant is_x86_event() prototype perf/x86: Fix NULL event access and potential PEBS record loss perf/x86/intel: Replace x86_pmu.drain_pebs calling with static call perf/x86/intel: Correct large PEBS flag check perf/x86/intel: Initialize architectural PEBS perf/x86/intel/ds: Factor out PEBS record processing code to functions perf/x86/intel/ds: Factor out PEBS group processing code to functions perf/x86/intel: Process arch-PEBS records or record fragments perf/x86/intel: Allocate arch-PEBS buffer and initialize PEBS_BASE MSR perf/x86/intel: Update dyn_constraint base on PEBS event precise level perf/x86/intel: Setup PEBS data configuration and enable legacy groups perf/x86/intel: Add counter group support for arch-PEBS

George Kennedy (1):
perf/x86/amd: Check event before enable to avoid GPF

Ingo Molnar (1):
perf/x86/intel: Fix and clean up intel_pmu_drain_arch_pebs() type use

Josh Poimboeuf (1):
unwind_user/x86: Enable frame pointer unwinding on x86

Kan Liang (1):
perf/x86/intel: Add a check for dynamic constraints

Peter Zijlstra (19):
x86/insn,uprobes,alternative: Unify insn_is_nop() x86/insn: Simplify for_each_insn_prefix()
task_work: Fix NMI race condition
unwind: Shorten lines
unwind: Add required include files
unwind: Simplify unwind_reset_info()
unwind: Add comment to unwind_deferred_task_exit()
unwind: Fix unwind_deferred_request() vs NMI
unwind: Clarify calling context
unwind: Simplify unwind_user_faultable()
unwind: Make unwind_task_info::unwind_mask consistent
unwind: Simplify unwind_user_next_fp() alignment check
unwind: Implement compat fp unwind unwind_user/x86: Teach FP unwind about start of function
perf: Support deferred user unwind unwind_user/x86: Fix arch=um build entry,unwind/deferred: Fix unwind_reset_info() placement perf/x86/intel: Check PEBS dyn_constraints perf/x86/intel: Optimize PEBS extended config

Zhang Rui (2):
perf/x86/intel/cstate: Remove PC3 support from LunarLake perf/x86/intel/cstate: Add Pantherlake support

Zide Chen (1):
perf/x86/intel/cstate: Add Clearwater Forest support

 arch/x86/Kconfig                         |   1 +
 arch/x86/boot/compressed/sev-handle-vc.c |   3 +-
 arch/x86/events/amd/core.c               |   7 +-
 arch/x86/events/core.c                   |  66 +---
 arch/x86/events/intel/core.c             | 444 +++++++++++++++++++++--
 arch/x86/events/intel/cstate.c           |  18 +-
 arch/x86/events/intel/ds.c               | 601 +++++++++++++++++++++++++------
 arch/x86/events/perf_event.h             |  41 ++-
 arch/x86/include/asm/insn-eval.h         |   2 +
 arch/x86/include/asm/insn.h              |   5 +-
 arch/x86/include/asm/intel_ds.h          |  10 +-
 arch/x86/include/asm/msr-index.h         |  20 +
 arch/x86/include/asm/perf_event.h        | 116 +++++-
 arch/x86/include/asm/unwind_user.h       |  41 +++
 arch/x86/include/asm/uprobes.h           |   9 +
 arch/x86/kernel/alternative.c            |  20 +-
 arch/x86/kernel/kprobes/core.c           |   3 +-
 arch/x86/kernel/uprobes.c                |  70 ++--
 arch/x86/lib/insn-eval.c                 | 151 +++++++-
 include/linux/irq-entry-common.h         |   2 +-
 include/linux/perf_event.h               |   2 +-
 include/linux/unwind_deferred.h          |  52 ++-
 include/linux/unwind_deferred_types.h    |  18 +-
 include/linux/unwind_user_types.h        |   2 +
 include/uapi/linux/perf_event.h          |  21 +-
 kernel/bpf/stackmap.c                    |   4 +-
 kernel/events/callchain.c                |  14 +-
 kernel/events/core.c                     |  78 +++-
 kernel/exit.c                            |   7 +-
 kernel/task_work.c                       |   8 +-
 kernel/unwind/deferred.c                 |  44 ++-
 kernel/unwind/user.c                     |  59 ++-
 tools/arch/x86/include/asm/insn.h        |   5 +-
 tools/include/uapi/linux/perf_event.h    |  21 +-
 34 files changed, 1627 insertions(+), 338 deletions(-)
 create mode 100644 arch/x86/include/asm/unwind_user.h
#2 lore raw
In reply to Ingo Molnar
Quoted 28 lines · Ingo Molnar

Linus,

Please pull the latest perf/core Git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-core-2025-12-01

# HEAD: 9929dffce5ed7e2988e0274f4db98035508b16d9 perf/x86/intel: Fix and clean up intel_pmu_drain_arch_pebs() type use

Performance events changes for v6.19:

Callchain support:

- Add support for deferred user-space stack unwinding for perf, enabled on x86. (Peter Zijlstra, Steven Rostedt)

- unwind_user/x86: Enable frame pointer unwinding on x86 (Josh Poimboeuf)

x86 PMU support and infrastructure:

- x86/insn: Simplify for_each_insn_prefix() (Peter Zijlstra)

- x86/insn,uprobes,alternative: Unify insn_is_nop() (Peter Zijlstra)

Intel PMU driver:

Quoted 7 lines

- Large series to prepare for and implement architectural PEBS support for Intel platforms such as Clearwater Forest (CWF) and Panther Lake (PTL). (Dapeng Mi, Kan Liang)

- Check dynamic constraints (Kan Liang)

- Optimize PEBS extended config (Peter Zijlstra)

I'm not seeing this patch on the mailing list, so I'm asking here. An AI review flagged this change and the condition it describes sounds unlikely but possible:

Quoted 5 lines
(quoted diff) +0 -1
@@ -8171,8 +8169,13 @@
 if (!is_hybrid() && boot_cpu_has(X86_FEATURE_ARCH_PERFMON_EXT))
 update_pmu_cap(NULL);
 
- if (x86_pmu.arch_pebs)

Review line 8181

Quoted 10 lines
(quoted diff) +6 -0
+ if (x86_pmu.arch_pebs) {
+ static_call_update(intel_pmu_disable_event_ext,
+    intel_pmu_disable_event_ext);
+ static_call_update(intel_pmu_enable_event_ext,
+    intel_pmu_enable_event_ext);
 pr_cont("Architectural PEBS, ");
+ }
 
 intel_pmu_check_counters_mask(&x86_pmu.cntr_mask64,
       &x86_pmu.fixed_cntr_mask64,

Does this code expose us to a #GP on hybrid platforms if the CPUID check fails? For hybrid processors, update_pmu_cap() is deferred to init_hybrid_pmu(), which runs after intel_pmu_init() sets up the static calls. If update_pmu_cap() encounters an inconsistent CPUID and clears x86_pmu.arch_pebs, the static calls remain patched. This will cause intel_pmu_enable_event_ext() to execute on precise events and access MSR_IA32_PEBS_INDEX, potentially crashing the kernel.

Thanks,
Ian

Quoted 117 lines

- cstates: Remove PC3 support from LunarLake (Zhang Rui)

- cstates: Add Pantherlake support (Zhang Rui)

- cstates: Clearwater Forest support (Zide Chen)

AMD PMU driver:

- x86/amd: Check event before enable to avoid GPF (George Kennedy)

Fixes and cleanups:

- task_work: Fix NMI race condition (Peter Zijlstra)

- perf/x86: Fix NULL event access and potential PEBS record loss (Dapeng Mi)

- Misc other fixes and cleanups.
(Dapeng Mi, Ingo Molnar, Peter Zijlstra)

Thanks,

Ingo

------------------>
Dapeng Mi (12):
perf/x86: Remove redundant is_x86_event() prototype perf/x86: Fix NULL event access and potential PEBS record loss perf/x86/intel: Replace x86_pmu.drain_pebs calling with static call perf/x86/intel: Correct large PEBS flag check perf/x86/intel: Initialize architectural PEBS perf/x86/intel/ds: Factor out PEBS record processing code to functions perf/x86/intel/ds: Factor out PEBS group processing code to functions perf/x86/intel: Process arch-PEBS records or record fragments perf/x86/intel: Allocate arch-PEBS buffer and initialize PEBS_BASE MSR perf/x86/intel: Update dyn_constraint base on PEBS event precise level perf/x86/intel: Setup PEBS data configuration and enable legacy groups perf/x86/intel: Add counter group support for arch-PEBS

George Kennedy (1):
perf/x86/amd: Check event before enable to avoid GPF

Ingo Molnar (1):
perf/x86/intel: Fix and clean up intel_pmu_drain_arch_pebs() type use

Josh Poimboeuf (1):
unwind_user/x86: Enable frame pointer unwinding on x86

Kan Liang (1):
perf/x86/intel: Add a check for dynamic constraints

Peter Zijlstra (19):
x86/insn,uprobes,alternative: Unify insn_is_nop() x86/insn: Simplify for_each_insn_prefix()
task_work: Fix NMI race condition
unwind: Shorten lines
unwind: Add required include files
unwind: Simplify unwind_reset_info()
unwind: Add comment to unwind_deferred_task_exit()
unwind: Fix unwind_deferred_request() vs NMI
unwind: Clarify calling context
unwind: Simplify unwind_user_faultable()
unwind: Make unwind_task_info::unwind_mask consistent
unwind: Simplify unwind_user_next_fp() alignment check
unwind: Implement compat fp unwind unwind_user/x86: Teach FP unwind about start of function
perf: Support deferred user unwind unwind_user/x86: Fix arch=um build entry,unwind/deferred: Fix unwind_reset_info() placement perf/x86/intel: Check PEBS dyn_constraints perf/x86/intel: Optimize PEBS extended config

Zhang Rui (2):
perf/x86/intel/cstate: Remove PC3 support from LunarLake perf/x86/intel/cstate: Add Pantherlake support

Zide Chen (1):
perf/x86/intel/cstate: Add Clearwater Forest support

 arch/x86/Kconfig                         |   1 +
 arch/x86/boot/compressed/sev-handle-vc.c |   3 +-
 arch/x86/events/amd/core.c               |   7 +-
 arch/x86/events/core.c                   |  66 +---
 arch/x86/events/intel/core.c             | 444 +++++++++++++++++++++--
 arch/x86/events/intel/cstate.c           |  18 +-
 arch/x86/events/intel/ds.c               | 601 +++++++++++++++++++++++++------
 arch/x86/events/perf_event.h             |  41 ++-
 arch/x86/include/asm/insn-eval.h         |   2 +
 arch/x86/include/asm/insn.h              |   5 +-
 arch/x86/include/asm/intel_ds.h          |  10 +-
 arch/x86/include/asm/msr-index.h         |  20 +
 arch/x86/include/asm/perf_event.h        | 116 +++++-
 arch/x86/include/asm/unwind_user.h       |  41 +++
 arch/x86/include/asm/uprobes.h           |   9 +
 arch/x86/kernel/alternative.c            |  20 +-
 arch/x86/kernel/kprobes/core.c           |   3 +-
 arch/x86/kernel/uprobes.c                |  70 ++--
 arch/x86/lib/insn-eval.c                 | 151 +++++++-
 include/linux/irq-entry-common.h         |   2 +-
 include/linux/perf_event.h               |   2 +-
 include/linux/unwind_deferred.h          |  52 ++-
 include/linux/unwind_deferred_types.h    |  18 +-
 include/linux/unwind_user_types.h        |   2 +
 include/uapi/linux/perf_event.h          |  21 +-
 kernel/bpf/stackmap.c                    |   4 +-
 kernel/events/callchain.c                |  14 +-
 kernel/events/core.c                     |  78 +++-
 kernel/exit.c                            |   7 +-
 kernel/task_work.c                       |   8 +-
 kernel/unwind/deferred.c                 |  44 ++-
 kernel/unwind/user.c                     |  59 ++-
 tools/arch/x86/include/asm/insn.h        |   5 +-
 tools/include/uapi/linux/perf_event.h    |  21 +-
 34 files changed, 1627 insertions(+), 338 deletions(-)
 create mode 100644 arch/x86/include/asm/unwind_user.h