glibc/sysdeps/x86_64/multiarch/memmove.c
H.J. Lu 5c3e322d3b x86-64: Implement memmove family IFUNC selectors in C
Implement memmove family IFUNC selectors in C.

All internal calls within libc.so can use IFUNC on x86-64 since unlike
x86, x86-64 supports PC-relative addressing to access the GOT entry so
that it can call via PLT without using an extra register.  For libc.a,
we can't use IFUNC for functions which are called before IFUNC has been
initialized.  Use IFUNC internally reduces the icache footprint since
libc.so and other codes in the process use the same implementations.
This patch uses IFUNC for memmove family functions within libc.

	* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
	memmove-sse2-unaligned-erms, memcpy_chk-nonshared,
	mempcpy_chk-nonshared and memmove_chk-nonshared.
	* sysdeps/x86_64/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Add tests for __memmove_chk_erms,
	__memcpy_chk_erms and __mempcpy_chk_erms.  Update comments.
	* sysdeps/x86_64/multiarch/ifunc-memmove.h: New file.
	* sysdeps/x86_64/multiarch/memcpy.c: Likewise.
	* sysdeps/x86_64/multiarch/memcpy_chk-nonshared.S: Likewise.
	* sysdeps/x86_64/multiarch/memcpy_chk.c: Likewise.
	* sysdeps/x86_64/multiarch/memmove-sse2-unaligned-erms.S: Likewise.
	* sysdeps/x86_64/multiarch/memmove.c: Likewise.
	* sysdeps/x86_64/multiarch/memmove_chk-nonshared.S: Likewise.
	* sysdeps/x86_64/multiarch/memmove_chk.c: Likewise.
	* sysdeps/x86_64/multiarch/mempcpy.c: Likewise.
	* sysdeps/x86_64/multiarch/mempcpy_chk-nonshared.S: Likewise.
	* sysdeps/x86_64/multiarch/mempcpy_chk.c: Likewise.
	* sysdeps/x86_64/multiarch/memcpy.S: Removed.
	* sysdeps/x86_64/multiarch/memcpy_chk.S: Likewise.
	* sysdeps/x86_64/multiarch/memmove.S: Likewise.
	* sysdeps/x86_64/multiarch/memmove_chk.S: Likewise.
	* sysdeps/x86_64/multiarch/mempcpy.S: Likewise.
	* sysdeps/x86_64/multiarch/mempcpy_chk.S: Likewise.
	* sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
	(__mempcpy_chk_erms): New function.
	(__memmove_chk_erms): Likewise.
	(__memcpy_chk_erms): New alias.
2017-06-14 12:11:10 -07:00

39 lines
1.3 KiB
C

/* Multiple versions of memmmove.
All versions must be listed in ifunc-impl-list.c.
Copyright (C) 2016-2017 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
<http://www.gnu.org/licenses/>. */
/* Define multiple versions only for the definition in lib and for
DSO. */
#if IS_IN (libc)
# define memmove __redirect_memmove
# include <string.h>
# undef memmove
# define SYMBOL_NAME memmove
# include "ifunc-memmove.h"
libc_ifunc_redirected (__redirect_memmove, __libc_memmove,
IFUNC_SELECTOR ());
strong_alias (__libc_memmove, memmove);
# ifdef SHARED
__hidden_ver1 (__libc_memmove, __GI_memmove, __redirect_memmove)
__attribute__ ((visibility ("hidden")));
# endif
#endif