diff options
Diffstat (limited to 'src/lib/utils')
| -rw-r--r-- | src/lib/utils/zero_mem.cpp | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/src/lib/utils/zero_mem.cpp b/src/lib/utils/zero_mem.cpp index 371c434ca..df195048a 100644 --- a/src/lib/utils/zero_mem.cpp +++ b/src/lib/utils/zero_mem.cpp @@ -18,6 +18,13 @@ void zero_mem(void* ptr, size_t n) #if defined(BOTAN_TARGET_OS_HAS_RTLSECUREZEROMEMORY) ::RtlSecureZeroMemory(ptr, n); #elif defined(BOTAN_USE_VOLATILE_MEMSET_FOR_ZERO) && (BOTAN_USE_VOLATILE_MEMSET_FOR_ZERO == 1) + /* + Call memset through a static volatile pointer, which the compiler + should not elide. This construct should be safe in conforming + compilers, but who knows. I did confirm that on x86-64 GCC 6.1 and + Clang 3.8 both create code that saves the memset address in the + data segment and uncondtionally loads and jumps to that address. + */ static void* (*const volatile memset_ptr)(void*, int, size_t) = std::memset; (memset_ptr)(ptr, 0, n); #else |