Messages in this thread | | | Subject | Re: [PATCH] perf/core: Fix perf_sample_data not properly initialized for different swevents in perf_tp_event() | From | Yang Jihong <> | Date | Wed, 19 Apr 2023 09:47:04 +0800 |
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Hello,
On 2023/4/18 18:25, Peter Zijlstra wrote: > On Tue, Apr 18, 2023 at 09:35:23AM +0800, Yang Jihong wrote: > >>> I'm thinking perhaps those flags that update ->dyn_size are the problem? >>> At the same time, Should you not also then clear dyn_size? > >> Yes, according to the code, dyn_size should also be cleared. >> Maybe we need to change it to the following, which would be more >> appropriate? >> >> --- a/kernel/events/core.c >> +++ b/kernel/events/core.c >> @@ -10144,14 +10144,14 @@ void perf_tp_event(u16 event_type, u64 count, void >> *record, int entry_size, >> }, >> }; >> >> - perf_sample_data_init(&data, 0, 0); >> - perf_sample_save_raw_data(&data, &raw); >> - >> perf_trace_buf_update(record, event_type); >> >> hlist_for_each_entry_rcu(event, head, hlist_entry) { >> - if (perf_tp_event_match(event, &data, regs)) >> + if (perf_tp_event_match(event, &data, regs)) { >> + perf_sample_data_init(&data, 0, 0); >> + perf_sample_save_raw_data(&data, &raw); >> perf_swevent_event(event, count, &data, regs); >> + } >> } > > That is certainly the safe option. I just went through the list and > while there's certainly a number of options we'll recompute for naught, > most of them are indeed either dyn_size or event specific :/ > > So yeah, please send the above as v2. > OK, will send v2 according to above fix solution.
Thanks, Yang.
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