On Wed, Dec 18, 2019 at 12:30:29PM +0300, Alexey Budankov wrote: > > 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 <alexey.budankov@xxxxxxxxxxxxxxx> > --- > 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)))) Acked-by: Will Deacon <will@xxxxxxxxxx> Worth noting that this allows profiling of *physical* addresses used by memory access instructions and so probably has some security implications beyond the usual "but perf is buggy" line of reasoning. Will _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
