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| author |   Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> | 2017-11-30 14:03:22 +0530 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2017-12-04 16:03:19 +1100 |
| commit | 5aa04b3eb6fca63d2e9827be656dcadc26d54e11 (patch) | |
| tree | b07e919885c34c47cc2c7b644422a0291922d4ac /arch | |
| parent | Linux 4.15-rc2 (diff) | |
| download | linux-dev-5aa04b3eb6fca63d2e9827be656dcadc26d54e11.tar.xz linux-dev-5aa04b3eb6fca63d2e9827be656dcadc26d54e11.zip | |
powerpc/perf: Fix oops when grouping different pmu events
When user tries to group imc (In-Memory Collections) event with
normal event, (sometime) kernel crashes with following log:
Faulting instruction address: 0x00000000
[link register ] c00000000010ce88 power_check_constraints+0x128/0x980
...
c00000000010e238 power_pmu_event_init+0x268/0x6f0
c0000000002dc60c perf_try_init_event+0xdc/0x1a0
c0000000002dce88 perf_event_alloc+0x7b8/0xac0
c0000000002e92e0 SyS_perf_event_open+0x530/0xda0
c00000000000b004 system_call+0x38/0xe0
'event_base' field of 'struct hw_perf_event' is used as flags for
normal hw events and used as memory address for imc events. While
grouping these two types of events, collect_events() tries to
interpret imc 'event_base' as a flag, which causes a corruption
resulting in a crash.
Consider only those events which belongs to 'perf_hw_context' in
collect_events().
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Reviewed-By: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/perf/core-book3s.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 9e3da168d54c..153812966365 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -1415,7 +1415,7 @@ static int collect_events(struct perf_event *group, int max_count, int n = 0; struct perf_event *event; - if (!is_software_event(group)) { + if (group->pmu->task_ctx_nr == perf_hw_context) { if (n >= max_count) return -1; ctrs[n] = group; @@ -1423,7 +1423,7 @@ static int collect_events(struct perf_event *group, int max_count, events[n++] = group->hw.config; } list_for_each_entry(event, &group->sibling_list, group_entry) { - if (!is_software_event(event) && + if (event->pmu->task_ctx_nr == perf_hw_context && event->state != PERF_EVENT_STATE_OFF) { if (n >= max_count) return -1; |