perf/UAPI: Clearly mark __PERF_SAMPLE_CALLCHAIN_EARLY as internal use

Vince noted that commit:

  6cbc304f2f36 ("perf/x86/intel: Fix unwind errors from PEBS entries (mk-II)")

'leaked' __PERF_SAMPLE_CALLCHAIN_EARLY into the UAPI namespace. And
while sys_perf_event_open() will error out if you try to use it, it is
exposed.

Clearly mark it for internal use only to avoid any confusion.

Requested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index eeb787b1c53c..f35eb72739c0 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -144,7 +144,7 @@ enum perf_event_sample_format {
 
         PERF_SAMPLE_MAX = 1U << 20,             /* non-ABI */
 
-        __PERF_SAMPLE_CALLCHAIN_EARLY           = 1ULL << 63,
+        __PERF_SAMPLE_CALLCHAIN_EARLY           = 1ULL << 63, /* non-ABI; internal use */
 };
 
 /*