On Wed, Dec 09, 2020 at 08:58:28AM +0800, Jin Yao wrote:
> When unpacking the event which is from dynamic pmu, the array
> output[OUTPUT_TYPE_MAX] may be overrun. For example, type number of
> SKL uncore_imc is 10, but OUTPUT_TYPE_MAX is 7 now (OUTPUT_TYPE_MAX =
> PERF_TYPE_MAX + 1).
>
> /* In builtin-script.c */
> process_event()
> {
> unsigned int type = output_type(attr->type);
>
> if (output[type].fields == 0)
> return;
> }
>
> output[10] is overrun.
>
> Create a type OUTPUT_TYPE_OTHER for dynamic pmu events, then
> output_type(attr->type) will return OUTPUT_TYPE_OTHER here.
>
> Note that if PERF_TYPE_MAX ever changed, then there would be a conflict
> between old perf.data files that had a dynamicaliy allocated PMU number
> that would then be the same as a fixed PERF_TYPE.
>
> Example:
>
> perf record --switch-events -C 0 -e
> "{cpu-clock,uncore_imc/data_reads/,uncore_imc/data_writes/}:SD" -a -- sleep 1
> perf script
>
> Before:
> swapper 0 [000] 1479253.987551: 277766
> cpu-clock: ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
> swapper 0 [000] 1479253.987797: 246709
> cpu-clock: ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
> swapper 0 [000] 1479253.988127: 329883
> cpu-clock: ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
> swapper 0 [000] 1479253.988273: 146393
> cpu-clock: ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
> swapper 0 [000] 1479253.988523: 249977
> cpu-clock: ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
> swapper 0 [000] 1479253.988877: 354090
> cpu-clock: ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
> swapper 0 [000] 1479253.989023: 145940
> cpu-clock: ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
> swapper 0 [000] 1479253.989383: 359856
> cpu-clock: ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
> swapper 0 [000] 1479253.989523: 140082
> cpu-clock: ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
>
> After:
> swapper 0 [000] 1397040.402011: 272384
> cpu-clock: ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
> swapper 0 [000] 1397040.402011: 5396
> uncore_imc/data_reads/:
> swapper 0 [000] 1397040.402011: 967
> uncore_imc/data_writes/:
> swapper 0 [000] 1397040.402259: 249153
> cpu-clock: ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
> swapper 0 [000] 1397040.402259: 7231
> uncore_imc/data_reads/:
> swapper 0 [000] 1397040.402259: 1297
> uncore_imc/data_writes/:
> swapper 0 [000] 1397040.402508: 249108
> cpu-clock: ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
> swapper 0 [000] 1397040.402508: 5333
> uncore_imc/data_reads/:
> swapper 0 [000] 1397040.402508: 1008
> uncore_imc/data_writes/:
>
> Signed-off-by: Jin Yao <yao....@linux.intel.com>
> ---
> v2:
> Remove Fixes tag because this issue has always been here, not caused by
> 1405720d4f26 ("perf script: Add 'synth' event type for synthesized events").
> No functional change in v2.
Acked-by: Jiri Olsa <jo...@redhat.com>
thanks,
jirka
