linuxthreads/ptlongjmp.c

   1 /* Linuxthreads - a simple clone()-based implementation of Posix        */
   2 /* threads for Linux.                                                   */
   3 /* Copyright (C) 1998 Xavier Leroy (Xavier.Leroy@inria.fr)              */
   4 /*                                                                      */
   5 /* This program is free software; you can redistribute it and/or        */
   6 /* modify it under the terms of the GNU Library General Public License  */
   7 /* as published by the Free Software Foundation; either version 2       */
   8 /* of the License, or (at your option) any later version.               */
   9 /*                                                                      */
  10 /* This program 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        */
  13 /* GNU Library General Public License for more details.                 */
  14
  15 /* Redefine siglongjmp and longjmp so that they interact correctly
  16    with cleanup handlers */
  17
  18 #include <setjmp.h>
  19 #include "pthread.h"
  20 #include "internals.h"
  21 #include <stackinfo.h>
  22
  23 /* These functions are not declared anywhere since they shouldn't be
  24    used at another place but here.  */
  25 extern void __libc_siglongjmp (sigjmp_buf env, int val)
  26      __attribute__ ((noreturn));
  27 extern void __libc_longjmp (sigjmp_buf env, int val)
  28      __attribute__ ((noreturn));
  29
  30
  31 static void pthread_cleanup_upto(__jmp_buf target)
  32 {
  33   pthread_descr self = thread_self();
  34   struct _pthread_cleanup_buffer * c;
  35   char *currentframe = CURRENT_STACK_FRAME;
  36
  37   for (c = THREAD_GETMEM(self, p_cleanup);
  38        c != NULL && _JMPBUF_UNWINDS(target, c);
  39        c = c->__prev)
  40     {
  41 #if _STACK_GROWS_DOWN
  42       if ((char *) c <= currentframe)
  43         {
  44           c = NULL;
  45           break;
  46         }
  47 #elif _STACK_GROWS_UP
  48       if ((char *) c >= currentframe)
  49         {
  50           c = NULL;
  51           break;
  52         }
  53 #else
  54 # error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP"
  55 #endif
  56       c->__routine(c->__arg);
  57     }
  58   THREAD_SETMEM(self, p_cleanup, c);
  59   if (THREAD_GETMEM(self, p_in_sighandler)
  60       && _JMPBUF_UNWINDS(target, THREAD_GETMEM(self, p_in_sighandler)))
  61     THREAD_SETMEM(self, p_in_sighandler, NULL);
  62 }
  63
  64 void siglongjmp(sigjmp_buf env, int val)
  65 {
  66   pthread_cleanup_upto(env->__jmpbuf);
  67   __libc_siglongjmp(env, val);
  68 }
  69
  70 void longjmp(jmp_buf env, int val)
  71 {
  72   pthread_cleanup_upto(env->__jmpbuf);
  73   __libc_longjmp(env, val);
  74 }