diff options
Diffstat (limited to 'lib/explicit_bzero.c')
-rw-r--r-- | lib/explicit_bzero.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/lib/explicit_bzero.c b/lib/explicit_bzero.c index feea4446c06..f50ed0875d7 100644 --- a/lib/explicit_bzero.c +++ b/lib/explicit_bzero.c @@ -54,11 +54,21 @@ explicit_bzero (void *s, size_t len) explicit_memset (s, '\0', len); #elif HAVE_MEMSET_S (void) memset_s (s, len, '\0', len); -#else +#elif defined __GNUC__ && !defined __clang__ memset (s, '\0', len); -# if defined __GNUC__ && !defined __clang__ /* Compiler barrier. */ asm volatile ("" ::: "memory"); -# endif +#elif defined __clang__ + memset (s, '\0', len); + /* Compiler barrier. */ + /* With asm ("" ::: "memory") LLVM analyzes uses of 's' and finds that the + whole thing is dead and eliminates it. Use 'g' to work around this + problem. See <https://bugs.llvm.org/show_bug.cgi?id=15495#c11>. */ + __asm__ volatile ("" : : "g"(s) : "memory"); +#else + /* Invoke memset through a volatile function pointer. This defeats compiler + optimizations. */ + void * (* const volatile volatile_memset) (void *, int, size_t) = memset; + (void) volatile_memset (s, '\0', len); #endif } |