From: Leo Yan leo.yan@linaro.org
[ Upstream commit aa616f5a8a2d22a179d5502ebd85045af66fa656 ]
Commit d110162cafc80dad ("perf tsc: Support cap_user_time_short for event TIME_CONV") supports the extended parameters for event TIME_CONV, but it broke the backwards compatibility, so any perf data file with old event format fails to convert timestamp.
This patch introduces a helper event_contains() to check if an event contains a specific member or not. For the backwards-compatibility, if the event size confirms the extended parameters are supported in the event TIME_CONV, then copies these parameters.
Committer notes:
To make this compiler backwards compatible add this patch:
- struct perf_tsc_conversion tc = { 0 }; + struct perf_tsc_conversion tc = { .time_shift = 0, };
Fixes: d110162cafc8 ("perf tsc: Support cap_user_time_short for event TIME_CONV") Signed-off-by: Leo Yan leo.yan@linaro.org Acked-by: Adrian Hunter adrian.hunter@intel.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Gustavo A. R. Silva gustavoars@kernel.org Cc: Ingo Molnar mingo@redhat.com Cc: Jiri Olsa jolsa@redhat.com Cc: Kan Liang kan.liang@linux.intel.com Cc: Mark Rutland mark.rutland@arm.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Steve MacLean Steve.MacLean@Microsoft.com Cc: Yonatan Goldschmidt yonatan.goldschmidt@granulate.io Link: https://lore.kernel.org/r/20210428120915.7123-3-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/lib/perf/include/perf/event.h | 2 ++ tools/perf/util/jitdump.c | 30 +++++++++++++++++++---------- 2 files changed, 22 insertions(+), 10 deletions(-)
diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h index 48583e441d9b..4d0c02ba3f7d 100644 --- a/tools/lib/perf/include/perf/event.h +++ b/tools/lib/perf/include/perf/event.h @@ -8,6 +8,8 @@ #include <linux/bpf.h> #include <sys/types.h> /* pid_t */
+#define event_contains(obj, mem) ((obj).header.size > offsetof(typeof(obj), mem)) + struct perf_record_mmap { struct perf_event_header header; __u32 pid, tid; diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c index 9760d8e7b386..917a9c707371 100644 --- a/tools/perf/util/jitdump.c +++ b/tools/perf/util/jitdump.c @@ -396,21 +396,31 @@ static pid_t jr_entry_tid(struct jit_buf_desc *jd, union jr_entry *jr)
static uint64_t convert_timestamp(struct jit_buf_desc *jd, uint64_t timestamp) { - struct perf_tsc_conversion tc; + struct perf_tsc_conversion tc = { .time_shift = 0, }; + struct perf_record_time_conv *time_conv = &jd->session->time_conv;
if (!jd->use_arch_timestamp) return timestamp;
- tc.time_shift = jd->session->time_conv.time_shift; - tc.time_mult = jd->session->time_conv.time_mult; - tc.time_zero = jd->session->time_conv.time_zero; - tc.time_cycles = jd->session->time_conv.time_cycles; - tc.time_mask = jd->session->time_conv.time_mask; - tc.cap_user_time_zero = jd->session->time_conv.cap_user_time_zero; - tc.cap_user_time_short = jd->session->time_conv.cap_user_time_short; + tc.time_shift = time_conv->time_shift; + tc.time_mult = time_conv->time_mult; + tc.time_zero = time_conv->time_zero;
- if (!tc.cap_user_time_zero) - return 0; + /* + * The event TIME_CONV was extended for the fields from "time_cycles" + * when supported cap_user_time_short, for backward compatibility, + * checks the event size and assigns these extended fields if these + * fields are contained in the event. + */ + if (event_contains(*time_conv, time_cycles)) { + tc.time_cycles = time_conv->time_cycles; + tc.time_mask = time_conv->time_mask; + tc.cap_user_time_zero = time_conv->cap_user_time_zero; + tc.cap_user_time_short = time_conv->cap_user_time_short; + + if (!tc.cap_user_time_zero) + return 0; + }
return tsc_to_perf_time(timestamp, &tc); }