[Patch v4 0/8] perf/x86: Miscellaneous PMU bug fixes

[Dapeng Mi <dapeng1.mi@linux.intel.com>]

This series groups several independent PMU fixes to simplify review and
backporting.

Changes:
v3 -> v4:
- Patch 5/8: Move intel_pmu_arch_lbr_init() before
  intel_pmu_check_event_constraints_all() which depends on
  PMU_FL_BR_CNTR flag which is initialized in intel_pmu_arch_lbr_init()
  (Sashiko).
- Refine change log, remove markdown format (Peter).

v2 -> v3:
- Patch 2/8: Directly update PERF_EVENT_FLAG_USER_READ_CNT according to
  rdpmc user disable state (Peter).
- Patch 3/8: Only keep x86_lbr_type check for the detection of hardware
  branch type decoding (Peter).
- Patch 4/8: Switch from_plm and to_plm variables order and refine
  comments (Peter).
- Patch 5/8: Move intel_pmu_arch_lbr_init() after model-specfic PMU
  initialization to avoid extra kmem cache destroy (Peter).
- Patch 6/8: Improve change log to add more details (Peter).

v1 -> v2:
- Fallback to software branch type decoding if hardware decoding is not
  suppprted (Sashiko patch 4/9).
- Drop kernel IP for PERF_SAMPLE_IP if exclude_kernel attribute is
  required (Sashiko, patch 8/9).
- Add kernel access check when kernel callchains are requested
  (Sashiko, patch 9/9)
- Address Zide and Thomas's comments.
- Collect Reviewed-bys.

Patch layout:
- Patch 1/8: Fix anythread_deprecated being overwritten issue. 
- Patch 2/8: Fix the issue that cap_user_rdpmc is not updated correctly.
- Patch 3/8: Fallback to software branch type decoding if no hardware
  decoding.
- Patch 4/8: Fix the kernel address leakage issue in LBR stack.
- Patch 5/8: Fix the issue that the return value of
  intel_pmu_init_hybrid() is not valiated correctly.
- Patch 6/8: Fix a "unchecked MSR access error" on PEBS_ENABLE MSR.
- Patch 7/8: Prevent a theoretical kernel register data leak in sampling.
- Patch 8/8: Add kernel access check when kernel callchains are
  requested. 

History:
v3: https://lore.kernel.org/all/20260612090114.3188886-1-dapeng1.mi@linux.intel.com/
v2: https://lore.kernel.org/all/20260609050222.2458129-1-dapeng1.mi@linux.intel.com/
v1: https://lore.kernel.org/all/20260605011136.2043393-1-dapeng1.mi@linux.intel.com/


Dapeng Mi (8):
  perf/x86/intel: Remove anythread_deprecated bit from perf_capabilities
  perf/x86/intel: Keep cap_user_rdpmc in sync with RDPMC user-disable
    state
  perf/x86/intel: Fallback to sw branch type decoding if no hw decoding
  perf/x86/intel: Fix kernel address leakages in LBR stack
  perf/x86/intel: Validate the return value of intel_pmu_init_hybrid()
  perf/x86/intel: Drop fixed-counter PEBS constraints for baseline PEBS
  perf/core: Fix kernel register info leak via hardware skid
  perf/core: Check kernel access when kernel callchains are requested

 arch/x86/events/core.c       |  3 +-
 arch/x86/events/intel/core.c | 60 +++++++++++++++++++++---------------
 arch/x86/events/intel/ds.c   | 13 --------
 arch/x86/events/intel/lbr.c  | 14 ++++++---
 arch/x86/events/perf_event.h |  4 +--
 kernel/events/core.c         | 41 +++++++++++++++++++-----
 6 files changed, 83 insertions(+), 52 deletions(-)


base-commit: 67d27727854def4a7e2b386429941f5c4741ccc4
-- 
2.34.1