nptl/pt-longjmp.c

   1 /* ABI compatibility for 'longjmp' and 'siglongjmp' symbols in libpthread ABI.
   2    Copyright (C) 2002-2017 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <setjmp.h>
  21 #include <shlib-compat.h>
  22
  23 /* libpthread once had its own longjmp (and siglongjmp alias), though there
  24    was no apparent reason for it.  There is no use in having a separate
  25    symbol in libpthread, but the historical ABI requires it.  For static
  26    linking, there is no need to provide anything here--the libc version
  27    will be linked in.  For shared library ABI compatibility, there must be
  28    longjmp and siglongjmp symbols in libpthread.so; so we define them using
  29    IFUNC to redirect to the libc function.  */
  30
  31 #if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22)
  32
  33 # if HAVE_IFUNC
  34
  35 #  undef INIT_ARCH
  36 #  define INIT_ARCH()
  37 #  define DEFINE_LONGJMP(name) libc_ifunc (name, &__libc_longjmp)
  38
  39 extern __typeof(longjmp) longjmp_ifunc;
  40 extern __typeof(siglongjmp) siglongjmp_ifunc;
  41
  42 # else  /* !HAVE_IFUNC */
  43
  44 static void __attribute__ ((noreturn, used))
  45 longjmp_compat (jmp_buf env, int val)
  46 {
  47   __libc_longjmp (env, val);
  48 }
  49
  50 # define DEFINE_LONGJMP(name) strong_alias (longjmp_compat, name)
  51
  52 # endif  /* HAVE_IFUNC */
  53
  54 DEFINE_LONGJMP (longjmp_ifunc)
  55 compat_symbol (libpthread, longjmp_ifunc, longjmp, GLIBC_2_0);
  56
  57 strong_alias (longjmp_ifunc, siglongjmp_ifunc)
  58 compat_symbol (libpthread, siglongjmp_ifunc, siglongjmp, GLIBC_2_0);
  59
  60 #endif