[PATCH v3 0/3] powerpc: fix preempt_count imbalances in perf and kexec paths

[Aboorva Devarajan <aboorvad@linux.ibm.com>]

Hi all,

This patch series fixes some minor preempt_count bookkeeping issues in
arch/powerpc/ found during a preemption leak audit prompted by the
lazy/full preemption model changes. These are get_cpu/put_cpu and
get_cpu_var/put_cpu_var pairing errors that leave preempt_count
incorrectly elevated or underflowed.

v2 -> v3:
 - Patches 2 and 3: use raw_smp_processor_id() instead of
   smp_processor_id(). Both paths run with interrupts
   disabled, so the plain accessor is sufficient.

v2: https://lore.kernel.org/all/20260603062743.1152253-1-aboorvad@linux.ibm.com/

v1: https://lore.kernel.org/all/20260518050855.1147242-1-aboorvad@linux.ibm.com/

Testing:
 - Patches 2 and 3: kexec boot-tested on PowerNV (powernv_defconfig)
   and pseries (pseries_defconfig).
 - Patch 1: compile-tested only (ppc64e_defconfig + CONFIG_FSL_EMB_PERFMON);
   no e500/fsl_emb hardware to runtime-test.

Please let me know your comments.

Thanks,
Aboorva

Aboorva Devarajan (3):
  powerpc/perf: fix preempt count underflow in fsl_emb_pmu_del
  powerpc/powernv: fix preempt count leak in
    pnv_kexec_wait_secondaries_down
  powerpc/kexec: fix double get_cpu() imbalance in kexec_prepare_cpus

 arch/powerpc/kexec/core_64.c           | 4 +---
 arch/powerpc/perf/core-fsl-emb.c       | 3 ++-
 arch/powerpc/platforms/powernv/setup.c | 3 ++-
 3 files changed, 5 insertions(+), 5 deletions(-)


base-commit: 03da3bc22934393e1dcc63ed3c50457b6d7e345e
-- 
2.54.0