Subject: [PATCH v4 8/9] drivers/perf: open access for CAP_SYS_PERFMON privileged process

From: Alexey Budankov <[email-masked]>
Date: Wed, 18 Dec 2019 12:30:29 +0300

Open access to monitoring for CAP_SYS_PERFMON privileged processes.
For backward compatibility reasons access to the monitoring remains open
for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure
monitoring is discouraged with respect to CAP_SYS_PERFMON capability.

Signed-off-by: Alexey Budankov <[email-masked]>
---
 drivers/perf/arm_spe_pmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c
index 4e4984a55cd1..5dff81bc3324 100644
--- a/drivers/perf/arm_spe_pmu.c
+++ b/drivers/perf/arm_spe_pmu.c
@@ -274,7 +274,7 @@ static u64 arm_spe_event_to_pmscr(struct perf_event *event)
 	if (!attr->exclude_kernel)
 		reg |= BIT(SYS_PMSCR_EL1_E1SPE_SHIFT);
 
-	if (IS_ENABLED(CONFIG_PID_IN_CONTEXTIDR) && capable(CAP_SYS_ADMIN))
+	if (IS_ENABLED(CONFIG_PID_IN_CONTEXTIDR) && perfmon_capable())
 		reg |= BIT(SYS_PMSCR_EL1_CX_SHIFT);
 
 	return reg;
@@ -700,7 +700,7 @@ static int arm_spe_pmu_event_init(struct perf_event *event)
 		return -EOPNOTSUPP;
 
 	reg = arm_spe_event_to_pmscr(event);
-	if (!capable(CAP_SYS_ADMIN) &&
+	if (!perfmon_capable() &&
 	    (reg & (BIT(SYS_PMSCR_EL1_PA_SHIFT) |
 		    BIT(SYS_PMSCR_EL1_CX_SHIFT) |
 		    BIT(SYS_PMSCR_EL1_PCT_SHIFT))))
-- 
2.20.1