diff options
| author | James Clark <james.clark@linaro.org> | 2024-08-27 15:51:12 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2024-08-30 11:42:24 +0100 |
| commit | 5e9629d0ae977d6f6916d7e519724804e95f0b07 (patch) | |
| tree | 028b0200bf011db01e3ff13e711acdba4b8fe98d | |
| parent | db9e7a83d30821ba50a84e9726099946900abde8 (diff) | |
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>
| -rw-r--r-- | drivers/perf/arm_spe_pmu.c | 9 | ||||
| -rw-r--r-- | include/linux/perf_event.h | 8 | ||||
| -rw-r--r-- | kernel/events/core.c | 9 |
3 files changed, 14 insertions, 12 deletions
diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c index 9100d82bfabc..3569050f9cf3 100644 --- a/drivers/perf/arm_spe_pmu.c +++ b/drivers/perf/arm_spe_pmu.c @@ -41,7 +41,7 @@ /* * Cache if the event is allowed to trace Context information. - * This allows us to perform the check, i.e, perfmon_capable(), + * This allows us to perform the check, i.e, perf_allow_kernel(), * in the context of the event owner, once, during the event_init(). */ #define SPE_PMU_HW_FLAGS_CX 0x00001 @@ -50,7 +50,7 @@ static_assert((PERF_EVENT_FLAG_ARCH & SPE_PMU_HW_FLAGS_CX) == SPE_PMU_HW_FLAGS_C static void set_spe_event_has_cx(struct perf_event *event) { - if (IS_ENABLED(CONFIG_PID_IN_CONTEXTIDR) && perfmon_capable()) + if (IS_ENABLED(CONFIG_PID_IN_CONTEXTIDR) && !perf_allow_kernel(&event->attr)) event->hw.flags |= SPE_PMU_HW_FLAGS_CX; } @@ -745,9 +745,8 @@ static int arm_spe_pmu_event_init(struct perf_event *event) set_spe_event_has_cx(event); reg = arm_spe_event_to_pmscr(event); - if (!perfmon_capable() && - (reg & (PMSCR_EL1_PA | PMSCR_EL1_PCT))) - return -EACCES; + if (reg & (PMSCR_EL1_PA | PMSCR_EL1_PCT)) + return perf_allow_kernel(&event->attr); return 0; } diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 1a8942277dda..e336306b8c08 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1602,13 +1602,7 @@ static inline int perf_is_paranoid(void) return sysctl_perf_event_paranoid > -1; } -static inline int perf_allow_kernel(struct perf_event_attr *attr) -{ - if (sysctl_perf_event_paranoid > 1 && !perfmon_capable()) - return -EACCES; - - return security_perf_event_open(attr, PERF_SECURITY_KERNEL); -} +int perf_allow_kernel(struct perf_event_attr *attr); static inline int perf_allow_cpu(struct perf_event_attr *attr) { diff --git a/kernel/events/core.c b/kernel/events/core.c index aa3450bdc227..ae7d63c0c593 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -13351,6 +13351,15 @@ const struct perf_event_attr *perf_event_attrs(struct perf_event *event) return &event->attr; } +int perf_allow_kernel(struct perf_event_attr *attr) +{ + if (sysctl_perf_event_paranoid > 1 && !perfmon_capable()) + return -EACCES; + + return security_perf_event_open(attr, PERF_SECURITY_KERNEL); +} +EXPORT_SYMBOL_GPL(perf_allow_kernel); + /* * Inherit an event from parent task to child task. * |