The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x b0823d5fbacb1c551d793cbfe7af24e0d1fa45ed # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025062337-conceal-parole-52a4@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b0823d5fbacb1c551d793cbfe7af24e0d1fa45ed Mon Sep 17 00:00:00 2001 From: Kan Liang kan.liang@linux.intel.com Date: Thu, 12 Jun 2025 07:38:18 -0700 Subject: [PATCH] perf/x86/intel: Fix crash in icl_update_topdown_event()
The perf_fuzzer found a hard-lockup crash on a RaptorLake machine:
Oops: general protection fault, maybe for address 0xffff89aeceab400: 0000 CPU: 23 UID: 0 PID: 0 Comm: swapper/23 Tainted: [W]=WARN Hardware name: Dell Inc. Precision 9660/0VJ762 RIP: 0010:native_read_pmc+0x7/0x40 Code: cc e8 8d a9 01 00 48 89 03 5b cd cc cc cc cc 0f 1f ... RSP: 000:fffb03100273de8 EFLAGS: 00010046 .... Call Trace: <TASK> icl_update_topdown_event+0x165/0x190 ? ktime_get+0x38/0xd0 intel_pmu_read_event+0xf9/0x210 __perf_event_read+0xf9/0x210
CPUs 16-23 are E-core CPUs that don't support the perf metrics feature. The icl_update_topdown_event() should not be invoked on these CPUs.
It's a regression of commit:
f9bdf1f95339 ("perf/x86/intel: Avoid disable PMU if !cpuc->enabled in sample read")
The bug introduced by that commit is that the is_topdown_event() function is mistakenly used to replace the is_topdown_count() call to check if the topdown functions for the perf metrics feature should be invoked.
Fix it.
Fixes: f9bdf1f95339 ("perf/x86/intel: Avoid disable PMU if !cpuc->enabled in sample read") Closes: https://lore.kernel.org/lkml/352f0709-f026-cd45-e60c-60dfd97f73f3@maine.edu/ Reported-by: Vince Weaver vincent.weaver@maine.edu Signed-off-by: Kan Liang kan.liang@linux.intel.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Ingo Molnar mingo@kernel.org Tested-by: Vince Weaver vincent.weaver@maine.edu Cc: stable@vger.kernel.org # v6.15+ Link: https://lore.kernel.org/r/20250612143818.2889040-1-kan.liang@linux.intel.com
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 741b229f0718..c2fb729c270e 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -2826,7 +2826,7 @@ static void intel_pmu_read_event(struct perf_event *event) * If the PEBS counters snapshotting is enabled, * the topdown event is available in PEBS records. */ - if (is_topdown_event(event) && !is_pebs_counter_event_group(event)) + if (is_topdown_count(event) && !is_pebs_counter_event_group(event)) static_call(intel_pmu_update_topdown_event)(event, NULL); else intel_pmu_drain_pebs_buffer();