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| H A D | cloexec.c | diff 48536c9195ae8c2a00fd8f400bac72ab613feaab Tue Feb 24 12:20:59 CET 2015 Adrian Hunter <adrian.hunter@intel.com> perf tools: Fix probing for PERF_FLAG_FD_CLOEXEC flag
Commit f6edb53c4993ffe92ce521fb449d1c146cea6ec2 converted the probe to
a CPU wide event first (pid == -1). For kernels that do not support
the PERF_FLAG_FD_CLOEXEC flag the probe fails with EINVAL. Since this
errno is not handled pid is not reset to 0 and the subsequent use of
pid = -1 as an argument brings in an additional failure path if
perf_event_paranoid > 0:
$ perf record -- sleep 1
perf_event_open(..., 0) failed unexpectedly with error 13 (Permission denied)
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.007 MB /tmp/perf.data (11 samples) ]
Also, ensure the fd of the confirmation check is closed and comment why
pid = -1 is used.
Needs to go to 3.18 stable tree as well.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Based-on-patch-by: David Ahern <david.ahern@oracle.com>
Acked-by: David Ahern <david.ahern@oracle.com>
Cc: David Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/r/54EC610C.8000403@intel.com
Cc: stable@vger.kernel.org # v3.18+
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff f6edb53c4993ffe92ce521fb449d1c146cea6ec2 Tue Aug 12 17:04:31 CEST 2014 Adrian Hunter <adrian.hunter@intel.com> perf tools: Prefer to use a cpu-wide event for probing CLOEXEC
When doing a system-wide trace with Intel PT, the jump label set up as a
result of probing CLOEXEC gets reset while the trace is running. That
causes an Intel PT decoding error because the object code (obtained from
/proc/kcore) does not match the running code at that point. While we
can't expect there never to be jump label changes, we can avoid cases
that the perf tool itself creates.
The problem is avoided by first trying a cpu-wide event (pid = -1) for
probing the PERF_FLAG_FD_CLOEXEC flag and falling back to an event for
the current process (pid = 0).
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1407855871-15024-5-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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