tools headers UAPI: Sync linux/perf_event.h with the kernel sources

To pick the trivial change in:

  ddecd22878601a60 ("perf: uapi: Document perf_event_attr::sig_data truncation on 32 bit architectures")

Just adds a comment.

This silences this perf build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs from latest version at 'include/uapi/linux/perf_event.h'
  diff -u tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h

Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
index 1b65042ab1db8df48b3daa7940756e1d0e132abe..82858b697c05a1d27b6db110a9da3a24bce6ca0b 100644 (file)
--- a/tools/include/uapi/linux/perf_event.h
+++ b/tools/include/uapi/linux/perf_event.h
@@ -465,6 +465,8 @@ struct perf_event_attr {
        /*
         * User provided data if sigtrap=1, passed back to user via
         * siginfo_t::si_perf_data, e.g. to permit user to identify the event.
+        * Note, siginfo_t::si_perf_data is long-sized, and sig_data will be
+        * truncated accordingly on 32 bit architectures.
         */
        __u64   sig_data;
 };