elf/dl-error.c

   1 /* Error handling for runtime dynamic linker.
   2 Copyright (C) 1995, 1996 Free Software Foundation, Inc.
   3 This file is part of the GNU C Library.
   4
   5 The GNU C Library is free software; you can redistribute it and/or
   6 modify it under the terms of the GNU Library General Public License as
   7 published by the Free Software Foundation; either version 2 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 Library General Public License for more details.
  14
  15 You should have received a copy of the GNU Library General Public
  16 License along with the GNU C Library; see the file COPYING.LIB.  If
  17 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  18 Cambridge, MA 02139, USA.  */
  19
  20 #include <stddef.h>
  21 #include <link.h>
  22 #include <setjmp.h>
  23 #include <string.h>
  24
  25 /* This structure communicates state between _dl_catch_error and
  26    _dl_signal_error.  */
  27 struct catch
  28   {
  29     const char *errstring, *objname; /* Error detail filled in here.  */
  30     jmp_buf env;                /* longjmp here on error.  */
  31   };
  32
  33 /* This points to such a structure during a call to _dl_catch_error.
  34    During implicit startup and run-time work for needed shared libraries,
  35    this is null.  */
  36 static struct catch *catch;
  37
  38
  39 void
  40 _dl_signal_error (int errcode,
  41                   const char *objname,
  42                   const char *errstring)
  43 {
  44   if (! errstring)
  45     errstring = "DYNAMIC LINKER BUG!!!";
  46
  47   if (catch)
  48     {
  49       /* We are inside _dl_catch_error.  Return to it.  */
  50       catch->errstring = errstring;
  51       catch->objname = objname;
  52       longjmp (catch->env, errcode ?: -1);
  53     }
  54   else
  55     {
  56       /* Lossage while resolving the program's own symbols is always fatal.  */
  57       extern char **_dl_argv;   /* Set in rtld.c at startup.  */
  58       _dl_sysdep_fatal (_dl_argv[0] ?: "<program name unknown>",
  59                         ": error in loading shared libraries\n",
  60                         objname ?: "", objname ? ": " : "",
  61                         errstring, errcode ? ": " : "",
  62                         errcode ? strerror (errcode) : "", "\n", NULL);
  63     }
  64 }
  65
  66 int
  67 _dl_catch_error (const char **errstring,
  68                  const char **objname,
  69                  void (*operate) (void))
  70 {
  71   int errcode;
  72   struct catch c = { errstring: NULL, objname: NULL };
  73
  74   errcode = setjmp (c.env);
  75   if (errcode == 0)
  76     {
  77       catch = &c;
  78       (*operate) ();
  79       catch = NULL;
  80       *errstring = *objname = NULL;
  81       return 0;
  82     }
  83
  84   /* We get here only if we longjmp'd out of OPERATE.  */
  85   *errstring = c.errstring;
  86   *objname = c.objname;
  87   return errcode == -1 ? 0 : errcode;
  88 }