nptl/pt-longjmp.c

   1 /* ABI compatibility for 'longjmp' and 'siglongjmp' symbols in libpthread ABI.
   2    Copyright (C) 2002-2016 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 static __typeof (longjmp) *
  36 __attribute__ ((used))
  37 longjmp_resolve (void)
  38 {
  39   return &__libc_longjmp;
  40 }
  41
  42 #  ifdef HAVE_ASM_SET_DIRECTIVE
  43 #   define DEFINE_LONGJMP(name) \
  44   asm (".set " #name ", longjmp_resolve\n" \
  45        ".globl " #name "\n" \
  46        ".type " #name ", %gnu_indirect_function");
  47 #  else
  48 #   define DEFINE_LONGJMP(name) \
  49   asm (#name " = longjmp_resolve\n" \
  50        ".globl " #name "\n" \
  51        ".type " #name ", %gnu_indirect_function");
  52 #  endif
  53
  54 # else  /* !HAVE_IFUNC */
  55
  56 static void __attribute__ ((noreturn, used))
  57 longjmp_compat (jmp_buf env, int val)
  58 {
  59   __libc_longjmp (env, val);
  60 }
  61
  62 # define DEFINE_LONGJMP(name) strong_alias (longjmp_compat, name)
  63
  64 # endif  /* HAVE_IFUNC */
  65
  66 DEFINE_LONGJMP (longjmp_ifunc)
  67 compat_symbol (libpthread, longjmp_ifunc, longjmp, GLIBC_2_0);
  68
  69 DEFINE_LONGJMP (siglongjmp_ifunc)
  70 compat_symbol (libpthread, siglongjmp_ifunc, siglongjmp, GLIBC_2_0);
  71
  72 #endif