[PATCH] lib: memzero_explicit: add comment for its usage
From: Daniel Borkmann <hidden>
Date: 2015-01-05 23:27:51
Subsystem:
generic string library, library code, the rest · Maintainers:
Kees Cook, Andrew Morton, Linus Torvalds
Lets improve the comment to add a note on when to use memzero_explicit() for those not digging through the git logs. We don't want people to pollute places with memzero_explicit() where it's not really necessary. Reference: https://lkml.org/lkml/2015/1/4/190 Suggested-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Daniel Borkmann <redacted> --- [ Sending to -crypto as it's most relevant here and suggested by Herbert anyway. ] lib/string.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/lib/string.c b/lib/string.c
index 1006330..d984ec4 100644
--- a/lib/string.c
+++ b/lib/string.c@@ -604,6 +604,11 @@ EXPORT_SYMBOL(memset); * @s: Pointer to the start of the area. * @count: The size of the area. * + * Note: usually using memset() is just fine (!), but in cases + * where clearing out _local_ data at the end of a scope is + * necessary, memzero_explicit() should be used instead in + * order to prevent the compiler from optimising away zeroing. + * * memzero_explicit() doesn't need an arch-specific version as * it just invokes the one of memset() implicitly. */
--
1.7.11.7