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93e46f8773
Implement memset 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 memset functions within libc. 2017-06-07 H.J. Lu <hongjiu.lu@intel.com> Erich Elsen <eriche@google.com> * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add memset-sse2-unaligned-erms, and memset_chk-nonshared. * sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Add test for __memset_chk_erms. Update comments. * sysdeps/x86_64/multiarch/ifunc-memset.h: New file. * sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S: Likewise. * sysdeps/x86_64/multiarch/memset.c: Likewise. * sysdeps/x86_64/multiarch/memset_chk-nonshared.S: Likewise. * sysdeps/x86_64/multiarch/memset_chk.c: Likewise. * sysdeps/x86_64/multiarch/memset.S: Removed. * sysdeps/x86_64/multiarch/memset_chk.S: Likewise. * sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S (__memset_chk_erms): New function.
38 lines
1.3 KiB
C
38 lines
1.3 KiB
C
/* Multiple versions of memset.
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All versions must be listed in ifunc-impl-list.c.
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Copyright (C) 2017 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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/* Define multiple versions only for the definition in lib and for
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DSO. In static binaries we need memset before the initialization
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happened. */
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#if IS_IN (libc)
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# define memset __redirect_memset
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# include <string.h>
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# undef memset
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# define SYMBOL_NAME memset
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# include "ifunc-memset.h"
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libc_ifunc_redirected (__redirect_memset, memset, IFUNC_SELECTOR ());
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# ifdef SHARED
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__hidden_ver1 (memset, __GI_memset, __redirect_memset)
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__attribute__ ((visibility ("hidden")));
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# endif
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#endif
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