From: Andrew Murray andrew.murray@arm.com
mainline inclusion from mainline-v5.1-rc1 commit cc6795aeffea0a80d0baf9ad31ba926a6c42cef5 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I47H3V CVE: NA
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commit cc6795aeffea0a80d0baf9ad31ba926a6c42cef5 upstream.
Many PMU drivers do not have the capability to exclude counting events that occur in specific contexts such as idle, kernel, guest, etc. These drivers indicate this by returning an error in their event_init upon testing the events attribute flags. This approach is error prone and often inconsistent.
Let's instead allow PMU drivers to advertise their inability to exclude based on context via a new capability: PERF_PMU_CAP_NO_EXCLUDE. This allows the perf core to reject requests for exclusion events where there is no support in the PMU.
Signed-off-by: Andrew Murray andrew.murray@arm.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Cc: Arnaldo Carvalho de Melo acme@kernel.org Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Borislav Petkov bp@alien8.de Cc: Ivan Kokshaysky ink@jurassic.park.msu.ru Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Mark Rutland mark.rutland@arm.com Cc: Matt Turner mattst88@gmail.com Cc: Michael Ellerman mpe@ellerman.id.au Cc: Paul Mackerras paulus@samba.org Cc: Peter Zijlstra peterz@infradead.org Cc: Richard Henderson rth@twiddle.net Cc: Russell King linux@armlinux.org.uk Cc: Sascha Hauer s.hauer@pengutronix.de Cc: Shawn Guo shawnguo@kernel.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Will Deacon will.deacon@arm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linuxppc-dev@lists.ozlabs.org Cc: robin.murphy@arm.com Cc: suzuki.poulose@arm.com Link: https://lkml.kernel.org/r/1547128414-50693-4-git-send-email-andrew.murray@ar... Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Shen, Xiaochen xiaochen.shen@intel.com Signed-off-by: Jackie Liu liuyun01@kylinos.cn Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Yang Jihong yangjihong1@huawei.com Reviewed-by: Xie XiuQi xiexiuqi@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- include/linux/perf_event.h | 1 + kernel/events/core.c | 9 +++++++++ 2 files changed, 10 insertions(+)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index fbdde119b1cc..78c77a91c3b6 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -243,6 +243,7 @@ struct perf_event; #define PERF_PMU_CAP_EXCLUSIVE 0x10 #define PERF_PMU_CAP_ITRACE 0x20 #define PERF_PMU_CAP_HETEROGENEOUS_CPUS 0x40 +#define PERF_PMU_CAP_NO_EXCLUDE 0x80
/** * struct pmu - generic performance monitoring unit diff --git a/kernel/events/core.c b/kernel/events/core.c index f6da9e11693d..728186f7b5df 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9880,6 +9880,15 @@ static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) if (ctx) perf_event_ctx_unlock(event->group_leader, ctx);
+ if (!ret) { + if (pmu->capabilities & PERF_PMU_CAP_NO_EXCLUDE && + event_has_any_exclude_flag(event)) { + if (event->destroy) + event->destroy(event); + ret = -EINVAL; + } + } + if (ret) module_put(pmu->module);