On Wed, Jul 31, 2019 at 04:38:18PM -0400, Qian Cai wrote: > When CONFIG_KASAN_SW_TAGS=n, set_tag() is compiled away. GCC throws a > warning, > > mm/kasan/common.c: In function '__kasan_kmalloc': > mm/kasan/common.c:464:5: warning: variable 'tag' set but not used > [-Wunused-but-set-variable] > u8 tag = 0xff; > ^~~ > > Fix it by making __tag_set() a static inline function. > > Signed-off-by: Qian Cai <[email protected]> > --- > arch/arm64/include/asm/memory.h | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h > index b7ba75809751..9645b1340afe 100644 > --- a/arch/arm64/include/asm/memory.h > +++ b/arch/arm64/include/asm/memory.h > @@ -210,7 +210,11 @@ static inline unsigned long kaslr_offset(void) > #define __tag_reset(addr) untagged_addr(addr) > #define __tag_get(addr) (__u8)((u64)(addr) >> 56) > #else > -#define __tag_set(addr, tag) (addr) > +static inline const void *__tag_set(const void *addr, u8 tag) > +{ > + return addr; > +}
Why doesn't this trigger a warning in page_to_virt(), which passes an unsigned long for the address parameter? Will
