From: Peter Zijlstra <peterz@infradead.org>
To: linux-kernel@vger.kernel.org
Cc: linux-tip-commits@vger.kernel.org,
Kan Liang <kan.liang@linux.intel.com>,
x86@kernel.org
Subject: Re: [tip: perf/core] perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task
Date: Fri, 16 Apr 2021 18:45:39 +0200 [thread overview]
Message-ID: <YHm/M4za2LpRYePw@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <161858530850.29796.5870405530830102241.tip-bot2@tip-bot2>
On Fri, Apr 16, 2021 at 03:01:48PM -0000, tip-bot2 for Kan Liang wrote:
> @@ -2331,6 +2367,9 @@ static void x86_pmu_event_unmapped(struct perf_event *event, struct mm_struct *m
> if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))
> return;
>
> + if (x86_pmu.sched_task && event->hw.target)
> + perf_sched_cb_dec(event->ctx->pmu);
> +
> if (atomic_dec_and_test(&mm->context.perf_rdpmc_allowed))
> on_each_cpu_mask(mm_cpumask(mm), cr4_update_pce, NULL, 1);
> }
'perf test' on a kernel with CONFIG_DEBUG_PREEMPT=y gives:
[ 244.439538] BUG: using smp_processor_id() in preemptible [00000000] code: perf/1771
[ 244.448144] caller is perf_sched_cb_dec+0xa/0x70
[ 244.453314] CPU: 28 PID: 1771 Comm: perf Not tainted 5.12.0-rc3-00026-gb04c0cddff6d #595
[ 244.462347] Hardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013
[ 244.473804] Call Trace:
[ 244.476535] dump_stack+0x6d/0x89
[ 244.480237] check_preemption_disabled+0xc8/0xd0
[ 244.485394] perf_sched_cb_dec+0xa/0x70
[ 244.489677] x86_pmu_event_unmapped+0x35/0x60
[ 244.494541] perf_mmap_close+0x76/0x580
[ 244.498833] remove_vma+0x31/0x70
[ 244.502535] __do_munmap+0x2e8/0x4e0
[ 244.506531] __vm_munmap+0x7e/0x120
[ 244.510429] __x64_sys_munmap+0x28/0x30
[ 244.514712] do_syscall_64+0x33/0x80
[ 244.518701] entry_SYSCALL_64_after_hwframe+0x44/0xae
Obviously I tested that after I pushed it out :/
next prev parent reply other threads:[~2021-04-16 16:45 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-14 14:36 [PATCH V4 1/2] perf/x86: Move cpuc->running into P4 specific code kan.liang
2021-04-14 14:36 ` [PATCH V4 2/2] perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task kan.liang
2021-04-16 15:01 ` [tip: perf/core] " tip-bot2 for Kan Liang
2021-04-16 16:45 ` Peter Zijlstra [this message]
2021-04-16 19:50 ` Liang, Kan
2021-04-16 15:01 ` [tip: perf/core] perf/x86: Move cpuc->running into P4 specific code tip-bot2 for Kan Liang
2021-06-14 17:59 [RESEND PATCH V8] perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task kan.liang
2021-06-18 8:46 ` [tip: perf/core] " tip-bot2 for Kan Liang
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