diff options
| author | Li RongQing <lirongqing@baidu.com> | 2025-03-06 13:11:02 +0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-03-06 22:42:26 +0100 |
| commit | 7a310c644cf571fbdb1d447a1dc39cf048634589 (patch) | |
| tree | cbb30b31daebb68a368dd3b3a5d2d094f19de2e0 | |
| parent | fa6192adc32f4fdfe5b74edd5b210e12afd6ecc0 (diff) | |
perf/x86/intel/bts: Check if bts_ctx is allocated when calling BTS functions
bts_ctx might not be allocated, for example if the CPU has X86_FEATURE_PTI,
but intel_bts_disable/enable_local() and intel_bts_interrupt() are called
unconditionally from intel_pmu_handle_irq() and crash on bts_ctx.
So check if bts_ctx is allocated when calling BTS functions.
Fixes: 3acfcefa795c ("perf/x86/intel/bts: Allocate bts_ctx only if necessary")
Reported-by: Jiri Olsa <olsajiri@gmail.com>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250306051102.2642-1-lirongqing@baidu.com
| -rw-r--r-- | arch/x86/events/intel/bts.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/arch/x86/events/intel/bts.c b/arch/x86/events/intel/bts.c index 953868da82fb..39a987d5eb6e 100644 --- a/arch/x86/events/intel/bts.c +++ b/arch/x86/events/intel/bts.c @@ -338,9 +338,14 @@ static void bts_event_stop(struct perf_event *event, int flags) void intel_bts_enable_local(void) { - struct bts_ctx *bts = this_cpu_ptr(bts_ctx); - int state = READ_ONCE(bts->state); + struct bts_ctx *bts; + int state; + if (!bts_ctx) + return; + + bts = this_cpu_ptr(bts_ctx); + state = READ_ONCE(bts->state); /* * Here we transition from INACTIVE to ACTIVE; * if we instead are STOPPED from the interrupt handler, @@ -358,7 +363,12 @@ void intel_bts_enable_local(void) void intel_bts_disable_local(void) { - struct bts_ctx *bts = this_cpu_ptr(bts_ctx); + struct bts_ctx *bts; + + if (!bts_ctx) + return; + + bts = this_cpu_ptr(bts_ctx); /* * Here we transition from ACTIVE to INACTIVE; @@ -450,12 +460,17 @@ bts_buffer_reset(struct bts_buffer *buf, struct perf_output_handle *handle) int intel_bts_interrupt(void) { struct debug_store *ds = this_cpu_ptr(&cpu_hw_events)->ds; - struct bts_ctx *bts = this_cpu_ptr(bts_ctx); - struct perf_event *event = bts->handle.event; + struct bts_ctx *bts; + struct perf_event *event; struct bts_buffer *buf; s64 old_head; int err = -ENOSPC, handled = 0; + if (!bts_ctx) + return 0; + + bts = this_cpu_ptr(bts_ctx); + event = bts->handle.event; /* * The only surefire way of knowing if this NMI is ours is by checking * the write ptr against the PMI threshold. |