linux-kernel - [PATCH 3/4] perf: Check the supported CPU of an event

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1623869734-133974-4-git-send-email-kan.liang@linux.intel.com>
Date:   Wed, 16 Jun 2021 11:55:33 -0700
From:   kan.liang@...ux.intel.com
To:     peterz@...radead.org, mingo@...hat.com,
        linux-kernel@...r.kernel.org
Cc:     acme@...nel.org, mark.rutland@....com, ak@...ux.intel.com,
        alexander.shishkin@...ux.intel.com, namhyung@...nel.org,
        jolsa@...hat.com, Kan Liang <kan.liang@...ux.intel.com>
Subject: [PATCH 3/4] perf: Check the supported CPU of an event

From: Kan Liang <kan.liang@...ux.intel.com>

All architectures, which support the filter_match callback, check
whether an event is schedulable on the current CPU. Since the
supported_cpus is moved to struct pmu, the check can be done in the
generic code. The filter_match callback can be avoided for some
architecture, e.g., x86.

Signed-off-by: Kan Liang <kan.liang@...ux.intel.com>
---
 kernel/events/core.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index b172f54..7140f40 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2225,9 +2225,19 @@ static bool is_orphaned_event(struct perf_event *event)
 	return event->state == PERF_EVENT_STATE_DEAD;
 }
 
+static __always_inline bool pmu_can_sched_on_this_cpu(struct pmu *pmu)
+{
+	return cpumask_empty(&pmu->supported_cpus) ||
+	       cpumask_test_cpu(smp_processor_id(), &pmu->supported_cpus);
+}
+
 static inline int __pmu_filter_match(struct perf_event *event)
 {
 	struct pmu *pmu = event->pmu;
+
+	if (!pmu_can_sched_on_this_cpu(pmu))
+		return 0;
+
 	return pmu->filter_match ? pmu->filter_match(event) : 1;
 }
 
@@ -3825,7 +3835,7 @@ static inline void perf_event_context_update_hybrid(struct perf_event_context *c
 {
 	struct pmu *pmu = ctx->pmu;
 
-	if (cpumask_empty(&pmu->supported_cpus) || cpumask_test_cpu(smp_processor_id(), &pmu->supported_cpus))
+	if (pmu_can_sched_on_this_cpu(pmu))
 		return;
 
 	rcu_read_lock();
-- 
2.7.4