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| author | Daniel Borkmann <dborkman@redhat.com> | 2015-01-06 00:27:45 +0100 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2015-01-08 11:46:19 +0100 |
| commit | 8155330aad477c5b1337895a6922df76817f0874 (patch) | |
| tree | c71de980f54183c5472fe62357b6276c56d3152a /lib/string.c | |
| parent | crypto: qat - Fix incorrect uses of memzero_explicit (diff) | |
| download | linux-8155330aad477c5b1337895a6922df76817f0874.tar.xz linux-8155330aad477c5b1337895a6922df76817f0874.zip | |
lib: memzero_explicit: add comment for its usage
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 <dborkman@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'lib/string.c')
| -rw-r--r-- | lib/string.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/lib/string.c b/lib/string.c index 10063300b830..d984ec4fd3b7 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. */ |