perf tools: Fix the build on the alpine:edge distro

The UAPI file byteorder/little_endian.h uses the __always_inline define
without including the header where it is defined, linux/stddef.h, this
ends up working in all the other distros because that file gets included
seemingly by luck from one of the files included from little_endian.h.

But not on Alpine:edge, that fails for all files where perf_event.h is
included but linux/stddef.h isn't include before that.

Adding the missing linux/stddef.h file where it breaks on Alpine:edge to
fix that, in all other distros, that is just a very small header anyway.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-9r1pifftxvuxms8l7ir73p5l@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index a1a97956136f..d215714f48df 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -5,6 +5,7 @@
 #include <time.h>
 #include <stdbool.h>
 #include <linux/types.h>
+#include <linux/stddef.h>
 #include <linux/perf_event.h>
 
 extern bool test_attr__enabled;