[PATCH 6.12 0771/1102] perf/core: Check sample_type in perf_sample_save_callchain
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COLD19d
REVIEWED: 2 (2M)
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2026-09-17 18:46:28
Also in:
linux-patches
Subsystem:
performance events subsystem, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds, Thomas Gleixner, Borislav Petkov, Dave Hansen
2 review trailers (2 from subsystem maintainers).
6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yabin Cui <redacted> [ Upstream commit f226805bc5f60adf03783d8e4cbfe303ccecd64e ] Check sample_type in perf_sample_save_callchain() to prevent saving callchain data when it isn't required. Suggested-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Yabin Cui <redacted> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20240515193610.2350456-3-yabinc@google.com (local) Stable-dep-of: 88aa1223bfff ("perf/x86/intel: Correct pt_regs->flags update for PEBS path") Signed-off-by: Sasha Levin <sashal@kernel.org> --- arch/x86/events/amd/ibs.c | 3 +-- arch/x86/events/intel/ds.c | 6 ++---- include/linux/perf_event.h | 5 +++++ 3 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index d34ee6f04f18f..1022d1dcbe447 100644
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c@@ -1138,8 +1138,7 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs) * recorded as part of interrupt regs. Thus we need to use rip from * interrupt regs while unwinding call stack. */ - if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) - perf_sample_save_callchain(&data, event, iregs); + perf_sample_save_callchain(&data, event, iregs); throttle = perf_event_overflow(event, &data, ®s); out:
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index d9e37ae5181f7..8a25b56a91dcf 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c@@ -1771,8 +1771,7 @@ static void setup_pebs_fixed_sample_data(struct perf_event *event, * previous PMI context or an (I)RET happened between the record and * PMI. */ - if (sample_type & PERF_SAMPLE_CALLCHAIN) - perf_sample_save_callchain(data, event, iregs); + perf_sample_save_callchain(data, event, iregs); /* * We use the interrupt regs as a base because the PEBS record does not
@@ -1939,8 +1938,7 @@ static void setup_pebs_adaptive_sample_data(struct perf_event *event, * previous PMI context or an (I)RET happened between the record and * PMI. */ - if (sample_type & PERF_SAMPLE_CALLCHAIN) - perf_sample_save_callchain(data, event, iregs); + perf_sample_save_callchain(data, event, iregs); *regs = *iregs; /* The ip in basic is EventingIP */
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 79994d079e505..e0af9788e656e 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h@@ -1286,6 +1286,11 @@ static inline void perf_sample_save_callchain(struct perf_sample_data *data, { int size = 1; + if (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)) + return; + if (WARN_ON_ONCE(data->sample_flags & PERF_SAMPLE_CALLCHAIN)) + return; + data->callchain = perf_callchain(event, regs); size += data->callchain->nr;
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2.53.0