[PATCH 4.4 008/112] compiler.h, kasan: Avoid duplicating __read_once_size_nocheck()

From: Greg Kroah-Hartman
Date: Tue Oct 27 2020 - 14:27:49 EST


From: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>

commit bdb5ac801af3d81d36732c2f640d6a1d3df83826 upstream.

Instead of having two identical __read_once_size_nocheck() functions
with different attributes, consolidate all the difference in new macro
__no_kasan_or_inline and use it. No functional changes.

Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/compiler.h | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)

--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -241,23 +241,21 @@ void __read_once_size(const volatile voi

#ifdef CONFIG_KASAN
/*
- * This function is not 'inline' because __no_sanitize_address confilcts
+ * We can't declare function 'inline' because __no_sanitize_address confilcts
* with inlining. Attempt to inline it may cause a build failure.
* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
* '__maybe_unused' allows us to avoid defined-but-not-used warnings.
*/
-static __no_sanitize_address __maybe_unused
-void __read_once_size_nocheck(const volatile void *p, void *res, int size)
-{
- __READ_ONCE_SIZE;
-}
+# define __no_kasan_or_inline __no_sanitize_address __maybe_unused
#else
-static __always_inline
+# define __no_kasan_or_inline __always_inline
+#endif
+
+static __no_kasan_or_inline
void __read_once_size_nocheck(const volatile void *p, void *res, int size)
{
__READ_ONCE_SIZE;
}
-#endif

static __always_inline void __write_once_size(volatile void *p, void *res, int size)
{