sysdeps/unix/sysv/linux/aarch64/pt-vfork.c

   1 /* vfork ABI-compatibility entry points for libpthread.
   2    Copyright (C) 2014-2017 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <shlib-compat.h>
  20
  21 /* libpthread used to have its own vfork implementation that differed
  22    from libc's only in having a pointless micro-optimization.  There
  23    is no longer any use to having a separate copy in libpthread, but
  24    the historical ABI requires it.  For static linking, there is no
  25    need to provide anything here--the libc version will be linked in.
  26    For shared library ABI compatibility, there must be __vfork and
  27    vfork symbols in libpthread.so.  */
  28
  29 #if HAVE_IFUNC
  30 # include <nptl/pt-vfork.c>
  31 #elif (SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20) \
  32        || SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20))
  33
  34 /* Thankfully, on AArch64 we can rely on the compiler generating
  35    a tail call here.  */
  36
  37 extern void __libc_vfork (void);
  38
  39 void
  40 vfork_compat (void)
  41 {
  42   __libc_vfork ();
  43 }
  44
  45 # if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20)
  46 compat_symbol (libpthread, vfork_compat, vfork, GLIBC_2_0);
  47 # endif
  48
  49 # if SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20)
  50 strong_alias (vfork_compat, vfork_compat2)
  51 compat_symbol (libpthread, vfork_compat2, __vfork, GLIBC_2_1_2);
  52 # endif
  53
  54 #endif