perf/core, arch/alpha: Strengthen exclusion checks with PERF_PMU_CAP_NO_EXCLUDE

As the Alpha PMU doesn't support context exclusion let's advertise
the PERF_PMU_CAP_NO_EXCLUDE capability. This ensures that perf will
prevent us from handling events where any exclusion flags are set.
Let's also remove the now unnecessary check for exclusion flags.

This change means that __hw_perf_event_init will now also
indicate that it doesn't support exclude_host and exclude_guest and
will now implicitly return -EINVAL instead of -EPERM. This is likely
more desirable as -EPERM will result in a kernel.perf_event_paranoid
related warning from the perf userspace utility.

Signed-off-by: Andrew Murray <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Russell King <[email protected]>
Cc: Sascha Hauer <[email protected]>
Cc: Shawn Guo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 1 insertions, 6 deletions

diff --git a/arch/alpha/kernel/perf_event.c b/arch/alpha/kernel/perf_event.c
index 5613aa378a83..4341ccf5c0c4 100644
--- a/arch/alpha/kernel/perf_event.c
+++ b/arch/alpha/kernel/perf_event.c
@@ -630,12 +630,6 @@ static int __hw_perf_event_init(struct perf_event *event)
 		return ev;
 	}
 
-	/* The EV67 does not support mode exclusion */
-	if (attr->exclude_kernel || attr->exclude_user
-			|| attr->exclude_hv || attr->exclude_idle) {
-		return -EPERM;
-	}
-
 	/*
 	 * We place the event type in event_base here and leave calculation
 	 * of the codes to programme the PMU for alpha_pmu_enable() because
@@ -771,6 +765,7 @@ static struct pmu pmu = {
 	.start		= alpha_pmu_start,
 	.stop		= alpha_pmu_stop,
 	.read		= alpha_pmu_read,
+	.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
 };