perf evsel: Mark the event as supported when retrying an open

Opening a group with perf record on a machine with perf_event_paranoid >
1 and no CAP_PERFMON fails the first perf_event_open() with EACCES, after
which evsel__open_cpu() clears evsel->supported; evsel__fallback() then
adds exclude_kernel and record__open() retries, and the retry succeeds
with supported left false.  get_group_fd() treats unsupported events as
ungroupable, so the retry opens the group members without their leader:

  sys_perf_event_open: pid 12345 cpu 0 group_fd -1
  FAILED '.../test-record-group-sampling1' - group failure

which fails the group subtests of "perf test 82", the Perf attribute
expectations test, when it is run as a regular user, while it passes as
root or with CAP_PERFMON, where the first open doesn't fail.

commit 2cc7aa995ce9 ("perf stat: Refactor retry/skip/fatal error handling")
dropped the pos->supported = true that record__open() did after a
successful open and moved the resets into the stat code only, while
saying "When an event is tried the supported is set to true again".  Do
that in evsel__open_cpu(), which every open entry point funnels through,
so that a retry describes its own try instead of the previous failure.

Fixes: 2cc7aa995ce9ecd8 ("perf stat: Refactor retry/skip/fatal error handling")
Reviewed-by: Ian Rogers <irogers@google.com>
Tested-by: Ian Rogers <irogers@google.com>
Cc: Ian Rogers <irogers@google.com>
Assisted-by: LLM
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

0 files changed, 0 insertions, 0 deletions