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78 lines
2.8 KiB
C
78 lines
2.8 KiB
C
/* vfork ABI-compatibility entry points for libpthread.
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Copyright (C) 2014-2015 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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#include <unistd.h>
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#include <shlib-compat.h>
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/* libpthread used to have its own vfork implementation that differed
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from libc's only in having a pointless micro-optimization. There
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is no longer any use to having a separate copy in libpthread, but
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the historical ABI requires it. For static linking, there is no
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need to provide anything here--the libc version will be linked in.
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For shared library ABI compatibility, there must be __vfork and
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vfork symbols in libpthread.so; so we define them using IFUNC to
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redirect to the libc function. */
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/* Note! If the architecture doesn't support IFUNC, then we need an
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alternate target-specific mechanism to implement this. So we just
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assume IFUNC here and require that the target override this file
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if necessary.
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If the architecture can assume all supported versions of gcc will
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produce a tail-call to __libc_vfork, consider including the version
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in sysdeps/unix/sysv/linux/aarch64/pt-vfork.c. */
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#if !HAVE_IFUNC
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# error "must write pt-vfork for this machine or get IFUNC support"
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#endif
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#if (SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20) \
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|| SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20))
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extern __typeof (vfork) __libc_vfork; /* Defined in libc. */
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static __typeof (vfork) *
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__attribute__ ((used))
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vfork_resolve (void)
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{
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return &__libc_vfork;
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}
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# ifdef HAVE_ASM_SET_DIRECTIVE
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# define DEFINE_VFORK(name) \
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asm (".set " #name ", vfork_resolve\n" \
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".globl " #name "\n" \
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".type " #name ", %gnu_indirect_function");
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# else
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# define DEFINE_VFORK(name) \
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asm (#name " = vfork_resolve\n" \
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".globl " #name "\n" \
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".type " #name ", %gnu_indirect_function");
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# endif
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#endif
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#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20)
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DEFINE_VFORK (vfork_ifunc)
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compat_symbol (libpthread, vfork_ifunc, vfork, GLIBC_2_0);
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#endif
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#if SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20)
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DEFINE_VFORK (__vfork_ifunc)
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compat_symbol (libpthread, __vfork_ifunc, __vfork, GLIBC_2_1_2);
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#endif
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