[PATCH] mm/kasan: fix kasan_check_read() compiler warning

From: Arnd Bergmann
Date: Tue Jul 09 2019 - 14:37:13 EST


The kasan_check_read() is marked 'inline', which usually includes
the 'always_inline' attribute. In some configuration, gcc decides that
it cannot inline this, causing a build failure:

In file included from include/linux/compiler.h:257,
from arch/x86/include/asm/current.h:5,
from include/linux/sched.h:12,
from include/linux/ratelimit.h:6,
from fs/dcache.c:18:
include/linux/compiler.h: In function 'read_word_at_a_time':
include/linux/kasan-checks.h:31:20: error: inlining failed in call to always_inline 'kasan_check_read': function attribute mismatch
static inline bool kasan_check_read(const volatile void *p, unsigned int size)
^~~~~~~~~~~~~~~~
In file included from arch/x86/include/asm/current.h:5,
from include/linux/sched.h:12,
from include/linux/ratelimit.h:6,
from fs/dcache.c:18:
include/linux/compiler.h:280:2: note: called from here
kasan_check_read(addr, 1);
^~~~~~~~~~~~~~~~~~~~~~~~~

While I have no idea why it does this, but changing the call to the
internal __kasan_check_read() fixes the issue.

Fixes: dc55b51f312c ("mm/kasan: introduce __kasan_check_{read,write}")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
include/linux/compiler.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index f0fd5636fddb..22909500ba1d 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -277,7 +277,7 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
static __no_kasan_or_inline
unsigned long read_word_at_a_time(const void *addr)
{
- kasan_check_read(addr, 1);
+ __kasan_check_read(addr, 1);
return *(unsigned long *)addr;
}

--
2.20.0