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| author | melifaro <melifaro@FreeBSD.org> | 2014-10-09 15:35:28 +0000 |
|---|---|---|
| committer | melifaro <melifaro@FreeBSD.org> | 2014-10-09 15:35:28 +0000 |
| commit | d23efba7dd470e247cbcacf9ec6cf642d02d5b8c (patch) | |
| tree | 6d2822f6a5ff6c5c487b859a557d076b53b03c46 /lib/libc/string/bzero.3 | |
| parent | cab1d703b61e2216f130c6d1a23ca70b2b322386 (diff) | |
| parent | c47600c4ec062b8225ac1d48197a2a1de778760d (diff) | |
| download | FreeBSD-src-d23efba7dd470e247cbcacf9ec6cf642d02d5b8c.zip FreeBSD-src-d23efba7dd470e247cbcacf9ec6cf642d02d5b8c.tar.gz | |
Sync to HEAD@r272825.
Diffstat (limited to 'lib/libc/string/bzero.3')
| -rw-r--r-- | lib/libc/string/bzero.3 | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/lib/libc/string/bzero.3 b/lib/libc/string/bzero.3 index 029644a..5af1bcf 100644 --- a/lib/libc/string/bzero.3 +++ b/lib/libc/string/bzero.3 @@ -31,11 +31,12 @@ .\" @(#)bzero.3 8.1 (Berkeley) 6/4/93 .\" $FreeBSD$ .\" -.Dd June 4, 1993 +.Dd October 6, 2014 .Dt BZERO 3 .Os .Sh NAME -.Nm bzero +.Nm bzero , +.Nm explicit_bzero .Nd write zeroes to a byte string .Sh LIBRARY .Lb libc @@ -43,6 +44,8 @@ .In strings.h .Ft void .Fn bzero "void *b" "size_t len" +.Ft void +.Fn explicit_bzero "void *b" "size_t len" .Sh DESCRIPTION The .Fn bzero @@ -56,6 +59,12 @@ If is zero, .Fn bzero does nothing. +.Pp +The +.Fn explicit_bzero +variant behaves the same, but will not be removed by a compiler's dead store +optimization pass, making it useful for clearing sensitive memory such as a +password. .Sh SEE ALSO .Xr memset 3 , .Xr swab 3 @@ -72,3 +81,10 @@ before it was moved to for .St -p1003.1-2001 compliance. +.Pp +The +.Fn explicit_bzero +function first appeared in +.Ox 5.5 +and +.Fx 11.0 . |
