sysdeps/unix/sysv/linux/hppa/nptl/unwind-forcedunwind.c

   1 /* Copyright (C) 2003, 2005, 2006, 2009 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 not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <dlfcn.h>
  21 #include <stdio.h>
  22 #include <unwind.h>
  23 #include <pthreadP.h>
  24 #include <sysdep.h>
  25
  26 static void *libgcc_s_handle;
  27 static void (*libgcc_s_resume) (struct _Unwind_Exception *exc);
  28 static _Unwind_Reason_Code (*libgcc_s_personality)
  29   (int, _Unwind_Action, _Unwind_Exception_Class, struct _Unwind_Exception *,
  30    struct _Unwind_Context *);
  31 static _Unwind_Reason_Code (*libgcc_s_forcedunwind)
  32   (struct _Unwind_Exception *, _Unwind_Stop_Fn, void *);
  33 static _Unwind_Word (*libgcc_s_getcfa) (struct _Unwind_Context *);
  34
  35 #define LIBGCC_S_SO "libgcc_s.so.4"
  36
  37 void
  38 __attribute_noinline__
  39 pthread_cancel_init (void)
  40 {
  41   void *resume;
  42   void *personality;
  43   void *forcedunwind;
  44   void *getcfa;
  45   void *handle;
  46
  47   if (__builtin_expect (libgcc_s_handle != NULL, 1))
  48     {
  49       /* Force gcc to reload all values.  */
  50       asm volatile ("" ::: "memory");
  51       return;
  52     }
  53
  54   handle = __libc_dlopen (LIBGCC_S_SO);
  55
  56   if (handle == NULL
  57       || (resume = __libc_dlsym (handle, "_Unwind_Resume")) == NULL
  58       || (personality = __libc_dlsym (handle, "__gcc_personality_v0")) == NULL
  59       || (forcedunwind = __libc_dlsym (handle, "_Unwind_ForcedUnwind"))
  60          == NULL
  61       || (getcfa = __libc_dlsym (handle, "_Unwind_GetCFA")) == NULL
  62 #ifdef ARCH_CANCEL_INIT
  63       || ARCH_CANCEL_INIT (handle)
  64 #endif
  65       )
  66     __libc_fatal (LIBGCC_S_SO " must be installed for pthread_cancel to work\n");
  67
  68   PTR_MANGLE (resume);
  69   libgcc_s_resume = resume;
  70   PTR_MANGLE (personality);
  71   libgcc_s_personality = personality;
  72   PTR_MANGLE (forcedunwind);
  73   libgcc_s_forcedunwind = forcedunwind;
  74   PTR_MANGLE (getcfa);
  75   libgcc_s_getcfa = getcfa;
  76   /* Make sure libgcc_s_handle is written last.  Otherwise,
  77      pthread_cancel_init might return early even when the pointer the
  78      caller is interested in is not initialized yet.  */
  79   atomic_write_barrier ();
  80   libgcc_s_handle = handle;
  81 }
  82
  83 void
  84 __libc_freeres_fn_section
  85 __unwind_freeres (void)
  86 {
  87   void *handle = libgcc_s_handle;
  88   if (handle != NULL)
  89     {
  90       libgcc_s_handle = NULL;
  91       __libc_dlclose (handle);
  92     }
  93 }
  94
  95 void
  96 _Unwind_Resume (struct _Unwind_Exception *exc)
  97 {
  98   if (__builtin_expect (libgcc_s_handle == NULL, 0))
  99     pthread_cancel_init ();
 100
 101   void (*resume) (struct _Unwind_Exception *exc) = libgcc_s_resume;
 102   PTR_DEMANGLE (resume);
 103   resume (exc);
 104 }
 105
 106 _Unwind_Reason_Code
 107 __gcc_personality_v0 (int version, _Unwind_Action actions,
 108                       _Unwind_Exception_Class exception_class,
 109                       struct _Unwind_Exception *ue_header,
 110                       struct _Unwind_Context *context)
 111 {
 112   if (__builtin_expect (libgcc_s_handle == NULL, 0))
 113     pthread_cancel_init ();
 114
 115   _Unwind_Reason_Code (*personality)
 116     (int, _Unwind_Action, _Unwind_Exception_Class, struct _Unwind_Exception *,
 117      struct _Unwind_Context *) = libgcc_s_personality;
 118   PTR_DEMANGLE (personality);
 119   return personality (version, actions, exception_class, ue_header, context);
 120 }
 121
 122 _Unwind_Reason_Code
 123 _Unwind_ForcedUnwind (struct _Unwind_Exception *exc, _Unwind_Stop_Fn stop,
 124                       void *stop_argument)
 125 {
 126   if (__builtin_expect (libgcc_s_handle == NULL, 0))
 127     pthread_cancel_init ();
 128
 129   _Unwind_Reason_Code (*forcedunwind)
 130     (struct _Unwind_Exception *, _Unwind_Stop_Fn, void *)
 131     = libgcc_s_forcedunwind;
 132   PTR_DEMANGLE (forcedunwind);
 133   return forcedunwind (exc, stop, stop_argument);
 134 }
 135
 136 _Unwind_Word
 137 _Unwind_GetCFA (struct _Unwind_Context *context)
 138 {
 139   if (__builtin_expect (libgcc_s_handle == NULL, 0))
 140     pthread_cancel_init ();
 141
 142   _Unwind_Word (*getcfa) (struct _Unwind_Context *) = libgcc_s_getcfa;
 143   PTR_DEMANGLE (getcfa);
 144   return getcfa (context);
 145 }