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/* Error handling for runtime dynamic linker.
Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <stddef.h>
#include <link.h>
#include <setjmp.h>
#include <stdlib.h>
#include <string.h>
/* This structure communicates state between _dl_catch_error and
_dl_signal_error. */
struct catch
{
char *errstring; /* Error detail filled in here. */
const char *objname;
jmp_buf env; /* longjmp here on error. */
};
/* This points to such a structure during a call to _dl_catch_error.
During implicit startup and run-time work for needed shared libraries,
this is null. */
static struct catch *catch;
/* This points to a function which is called when an error is
received. Unlike the handling of `catch' this function may return.
The arguments will be the `errstring' and `objname'. */
static receiver_fct receiver;
void
_dl_signal_error (int errcode,
const char *objname,
const char *errstring)
{
if (! errstring)
errstring = "DYNAMIC LINKER BUG!!!";
if (catch)
{
/* We are inside _dl_catch_error. Return to it. We have to
duplicate the error string since it might be allocated on the
stack. */
size_t len = strlen (errstring) + 1;
catch->errstring = malloc (len);
if (catch->errstring != NULL)
memcpy (catch->errstring, errstring, len);
catch->objname = objname;
longjmp (catch->env, errcode ?: -1);
}
else if (receiver)
{
/* We are inside _dl_receive_error. Call the user supplied
handler and resume the work. The receiver will still be
installed. */
(*receiver) (errcode, objname, errstring);
}
else
{
/* Lossage while resolving the program's own symbols is always fatal. */
extern char **_dl_argv; /* Set in rtld.c at startup. */
_dl_sysdep_fatal (_dl_argv[0] ?: "<program name unknown>",
": error in loading shared libraries",
objname ?: "", objname ? ": " : "",
errstring, errcode ? ": " : "",
errcode ? strerror (errcode) : "", "\n", NULL);
}
}
int
_dl_catch_error (char **errstring,
const char **objname,
void (*operate) (void *),
void *args)
{
int errcode;
struct catch *old, c;
/* We need not handle `receiver' since setting a `catch' is handled
before it. */
/* Some systems (.e.g, SPARC) handle constructors to local variables
inefficient. So we initialize `c' by hand. */
c.errstring = NULL;
c.objname = NULL;
old = catch;
errcode = setjmp (c.env);
if (errcode == 0)
{
catch = &c;
(*operate) (args);
catch = old;
*errstring = NULL;
*objname = NULL;
return 0;
}
/* We get here only if we longjmp'd out of OPERATE. */
catch = old;
*errstring = c.errstring;
*objname = c.objname;
return errcode == -1 ? 0 : errcode;
}
void
_dl_receive_error (receiver_fct fct, void (*operate) (void *), void *args)
{
struct catch *old_catch;
receiver_fct old_receiver;
old_catch = catch;
old_receiver = receiver;
/* Set the new values. */
catch = NULL;
receiver = fct;
(*operate) (args);
catch = old_catch;
receiver = old_receiver;
}
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