From d32624802d0b2105c95f699dd6a887b54cebf197 Mon Sep 17 00:00:00 2001 From: Szabolcs Nagy Date: Wed, 17 Feb 2021 10:15:18 +0000 Subject: malloc: Use mtag_enabled instead of USE_MTAG Use the runtime check where possible: it should not cause slow down in the !USE_MTAG case since then mtag_enabled is constant false, but it allows compiling the tagging logic so it's less likely to break or diverge when developers only test the !USE_MTAG case. Reviewed-by: DJ Delorie --- malloc/hooks.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'malloc/hooks.c') diff --git a/malloc/hooks.c b/malloc/hooks.c index d8e304c..9474e19 100644 --- a/malloc/hooks.c +++ b/malloc/hooks.c @@ -262,11 +262,10 @@ free_check (void *mem, const void *caller) int err = errno; -#ifdef USE_MTAG /* Quickly check that the freed pointer matches the tag for the memory. This gives a useful double-free detection. */ - *(volatile char *)mem; -#endif + if (__glibc_unlikely (mtag_enabled)) + *(volatile char *)mem; __libc_lock_lock (main_arena.mutex); p = mem2chunk_check (mem, NULL); @@ -310,11 +309,10 @@ realloc_check (void *oldmem, size_t bytes, const void *caller) return NULL; } -#ifdef USE_MTAG /* Quickly check that the freed pointer matches the tag for the memory. This gives a useful double-free detection. */ - *(volatile char *)oldmem; -#endif + if (__glibc_unlikely (mtag_enabled)) + *(volatile char *)oldmem; __libc_lock_lock (main_arena.mutex); const mchunkptr oldp = mem2chunk_check (oldmem, &magic_p); -- cgit v1.1