| From c067f122e4e80d71d46ee4717b930ecde1f099ef Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Wed, 28 Apr 2021 20:09:13 +0800 |
| Subject: perf jit: Let convert_timestamp() to be backwards-compatible |
| |
| 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 baf64ea74e10..4a24b855d3ce 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 055bab7a92b3..64d8f9ba8c03 100644 |
| --- a/tools/perf/util/jitdump.c |
| +++ b/tools/perf/util/jitdump.c |
| @@ -369,21 +369,31 @@ jit_inject_event(struct jit_buf_desc *jd, union perf_event *event) |
| |
| 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); |
| } |
| -- |
| 2.30.2 |
| |