From: Nathan Chancellor natechancellor@gmail.com
[ Upstream commit b0d14fc43d39203ae025f20ef4d5d25d9ccf4be1 ]
Clang warns:
mm/kmemleak.c:1955:28: warning: array comparison always evaluates to a constant [-Wtautological-compare] if (__start_ro_after_init < _sdata || __end_ro_after_init > _edata) ^ mm/kmemleak.c:1955:60: warning: array comparison always evaluates to a constant [-Wtautological-compare] if (__start_ro_after_init < _sdata || __end_ro_after_init > _edata)
These are not true arrays, they are linker defined symbols, which are just addresses. Using the address of operator silences the warning and does not change the resulting assembly with either clang/ld.lld or gcc/ld (tested with diff + objdump -Dr).
Suggested-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Nathan Chancellor natechancellor@gmail.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Acked-by: Catalin Marinas catalin.marinas@arm.com Link: https://github.com/ClangBuiltLinux/linux/issues/895 Link: http://lkml.kernel.org/r/20200220051551.44000-1-natechancellor@gmail.com Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- mm/kmemleak.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index d779181bed4d8..706f705c2e0a4 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -2030,7 +2030,7 @@ void __init kmemleak_init(void) create_object((unsigned long)__bss_start, __bss_stop - __bss_start, KMEMLEAK_GREY, GFP_ATOMIC); /* only register .data..ro_after_init if not within .data */ - if (__start_ro_after_init < _sdata || __end_ro_after_init > _edata) + if (&__start_ro_after_init < &_sdata || &__end_ro_after_init > &_edata) create_object((unsigned long)__start_ro_after_init, __end_ro_after_init - __start_ro_after_init, KMEMLEAK_GREY, GFP_ATOMIC);