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| author | Stephane Eranian <eranian@google.com> | 2013-03-15 17:26:07 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-20 23:58:52 +0400 |
| commit | 87a42f27adef5e88b8907edbc168de1380e7129e (patch) | |
| tree | d448849712974ea959023897839e5f85efbcbe81 | |
| parent | 5e44eef46e81bf6e159b44fa893cf7dd47a88f53 (diff) | |
| download | linux-87a42f27adef5e88b8907edbc168de1380e7129e.tar.xz | |
perf,x86: fix kernel crash with PEBS/BTS after suspend/resume
commit 1d9d8639c063caf6efc2447f5f26aa637f844ff6 upstream.
This patch fixes a kernel crash when using precise sampling (PEBS)
after a suspend/resume. Turns out the CPU notifier code is not invoked
on CPU0 (BP). Therefore, the DS_AREA (used by PEBS) is not restored properly
by the kernel and keeps it power-on/resume value of 0 causing any PEBS
measurement to crash when running on CPU0.
The workaround is to add a hook in the actual resume code to restore
the DS Area MSR value. It is invoked for all CPUS. So for all but CPU0,
the DS_AREA will be restored twice but this is harmless.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <shuah.khan@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event_intel_ds.c | 8 | ||||
| -rw-r--r-- | arch/x86/power/cpu.c | 2 | ||||
| -rw-r--r-- | include/linux/perf_event.h | 2 |
3 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c index d812fe2d02be..cf82ee55ef4b 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c @@ -754,6 +754,14 @@ static void intel_ds_init(void) } } +void perf_restore_debug_store(void) +{ + if (!x86_pmu.bts && !x86_pmu.pebs) + return; + + init_debug_store_on_cpu(smp_processor_id()); +} + #else /* CONFIG_CPU_SUP_INTEL */ static void reserve_ds_buffers(void) diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index 87bb35e34ef1..0ea8bd233def 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -10,6 +10,7 @@ #include <linux/suspend.h> #include <linux/smp.h> +#include <linux/perf_event.h> #include <asm/pgtable.h> #include <asm/proto.h> @@ -224,6 +225,7 @@ static void __restore_processor_state(struct saved_context *ctxt) do_fpu_end(); mtrr_bp_restore(); + perf_restore_debug_store(); } /* Needed by apm.c */ diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index effadd668aca..038ad4af336e 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1153,6 +1153,7 @@ extern void perf_swevent_put_recursion_context(int rctx); extern void perf_event_enable(struct perf_event *event); extern void perf_event_disable(struct perf_event *event); extern void perf_event_task_tick(void); +extern void perf_restore_debug_store(void); #else static inline void perf_event_task_sched_in(struct task_struct *task) { } @@ -1187,6 +1188,7 @@ static inline void perf_swevent_put_recursion_context(int rctx) { } static inline void perf_event_enable(struct perf_event *event) { } static inline void perf_event_disable(struct perf_event *event) { } static inline void perf_event_task_tick(void) { } +static inline void perf_restore_debug_store(void) { } #endif #define perf_output_put(handle, x) perf_output_copy((handle), &(x), sizeof(x)) |