[PATCH] libbpf: avoid inline hint definition from 'linux/stddef.h'

Linux headers might pull 'linux/stddef.h' which defines
'__always_inline' as the following:

   #ifndef __always_inline
   #define __always_inline __inline__
   #endif

This becomes an issue if the program picks up the 'linux/stddef.h'
definition as the macro now just hints inline to clang.

This change now enforces the proper definition for BPF programs
regardless of the include order.

Signed-off-by: Pedro Tammela <redacted>
---
 tools/lib/bpf/bpf_helpers.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index ae6c975e0b87..5fa483c0b508 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h

@@ -29,9 +29,12 @@
  */
 #define SEC(NAME) __attribute__((section(NAME), used))
 
-#ifndef __always_inline
+/*
+ * Avoid 'linux/stddef.h' definition of '__always_inline'.
+ */
+#undef __always_inline
 #define __always_inline inline __attribute__((always_inline))
-#endif
+
 #ifndef __noinline
 #define __noinline __attribute__((noinline))
 #endif

-- 
2.25.1