glibc/debug/explicit_bzero_chk.c
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00

44 lines
1.7 KiB
C

/* Generic implementation of __explicit_bzero_chk.
Copyright (C) 1991-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/* This is the generic definition of __explicit_bzero_chk. The
__explicit_bzero_chk symbol is used as the implementation of
explicit_bzero throughout glibc. If this file is overriden by an
architecture, both __explicit_bzero_chk and
__explicit_bzero_chk_internal have to be defined (the latter not as
an IFUNC). */
#include <string.h>
void
__explicit_bzero_chk (void *dst, size_t len, size_t dstlen)
{
/* Inline __memset_chk to avoid a PLT reference to __memset_chk. */
if (__glibc_unlikely (dstlen < len))
__chk_fail ();
memset (dst, '\0', len);
/* Compiler barrier. */
asm volatile ("" ::: "memory");
}
/* libc-internal references use the hidden
__explicit_bzero_chk_internal symbol. This is necessary if
__explicit_bzero_chk is implemented as an IFUNC because some
targets do not support hidden references to IFUNC symbols. */
strong_alias (__explicit_bzero_chk, __explicit_bzero_chk_internal)