perf record: Fix event fd races

The write call may set errno which is problematic if occurring in a
function also setting errno. Save and restore errno around the write
call.

done_fd may be used after close, clear it as part of the close and check
its validity in the signal handler.

Suggested-by: <[email protected]>
Reviewed-by: Leo Yan <[email protected]>
Signed-off-by: Ian Rogers <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Anand K Mistry <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions