drivers/perf: arm_spe: Use perf_allow_kernel() for permissions
authorJames Clark <james.clark@linaro.org>
Tue, 27 Aug 2024 14:51:12 +0000 (15:51 +0100)
committerWill Deacon <will@kernel.org>
Fri, 30 Aug 2024 10:42:24 +0000 (11:42 +0100)
commit5e9629d0ae977d6f6916d7e519724804e95f0b07
tree028b0200bf011db01e3ff13e711acdba4b8fe98d
parentdb9e7a83d30821ba50a84e9726099946900abde8
drivers/perf: arm_spe: Use perf_allow_kernel() for permissions

Use perf_allow_kernel() for 'pa_enable' (physical addresses),
'pct_enable' (physical timestamps) and context IDs. This means that
perf_event_paranoid is now taken into account and LSM hooks can be used,
which is more consistent with other perf_event_open calls. For example
PERF_SAMPLE_PHYS_ADDR uses perf_allow_kernel() rather than just
perfmon_capable().

This also indirectly fixes the following error message which is
misleading because perf_event_paranoid is not taken into account by
perfmon_capable():

  $ perf record -e arm_spe/pa_enable/

  Error:
  Access to performance monitoring and observability operations is
  limited. Consider adjusting /proc/sys/kernel/perf_event_paranoid
  setting ...

Suggested-by: Al Grant <al.grant@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20240827145113.1224604-1-james.clark@linaro.org
Link: https://lore.kernel.org/all/20240807120039.GD37996@noisy.programming.kicks-ass.net/
Signed-off-by: Will Deacon <will@kernel.org>
drivers/perf/arm_spe_pmu.c
include/linux/perf_event.h
kernel/events/core.c