sysdeps/gnu/unwind-resume.c

   1 /* Copyright (C) 2003-2018 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Jakub Jelinek <jakub@redhat.com>.
   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 License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    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; see the file COPYING.LIB.  If
  17    not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include <dlfcn.h>
  20 #include <stdio.h>
  21 #include <unwind.h>
  22 #include <gnu/lib-names.h>
  23 #include <sysdep.h>
  24 #include <unwind-resume.h>
  25
  26
  27 void (*__libgcc_s_resume) (struct _Unwind_Exception *exc)
  28   attribute_hidden __attribute__ ((noreturn));
  29
  30 static _Unwind_Reason_Code (*libgcc_s_personality) PERSONALITY_PROTO;
  31
  32 void attribute_hidden __attribute__ ((cold))
  33 __libgcc_s_init (void)
  34 {
  35   void *resume, *personality;
  36   void *handle;
  37
  38   /* Use RTLD_NOW here for consistency with pthread_cancel_init.
  39      RTLD_NOW will rarely make a difference here because unwinding is
  40      already in progress, so libgcc_s.so has already been loaded if
  41      its unwinder is used.  */
  42   handle = __libc_dlopen_mode (LIBGCC_S_SO, RTLD_NOW | __RTLD_DLOPEN);
  43
  44   if (handle == NULL
  45       || (resume = __libc_dlsym (handle, "_Unwind_Resume")) == NULL
  46       || (personality = __libc_dlsym (handle, "__gcc_personality_v0")) == NULL)
  47     __libc_fatal (LIBGCC_S_SO
  48                   " must be installed for unwinding to work\n");
  49
  50 #ifdef PTR_MANGLE
  51   PTR_MANGLE (resume);
  52 #endif
  53   __libgcc_s_resume = resume;
  54 #ifdef PTR_MANGLE
  55   PTR_MANGLE (personality);
  56 #endif
  57   libgcc_s_personality = personality;
  58 }
  59
  60 #if !HAVE_ARCH_UNWIND_RESUME
  61 void
  62 _Unwind_Resume (struct _Unwind_Exception *exc)
  63 {
  64   if (__glibc_unlikely (__libgcc_s_resume == NULL))
  65     __libgcc_s_init ();
  66
  67   __typeof (__libgcc_s_resume) resume = __libgcc_s_resume;
  68 #ifdef PTR_DEMANGLE
  69   PTR_DEMANGLE (resume);
  70 #endif
  71   (*resume) (exc);
  72 }
  73 #endif
  74
  75 _Unwind_Reason_Code
  76 __gcc_personality_v0 PERSONALITY_PROTO
  77 {
  78   if (__glibc_unlikely (libgcc_s_personality == NULL))
  79     __libgcc_s_init ();
  80
  81   __typeof (libgcc_s_personality) personality = libgcc_s_personality;
  82 #ifdef PTR_DEMANGLE
  83   PTR_DEMANGLE (personality);
  84 #endif
  85   return (*personality) PERSONALITY_ARGS;
  86 }