/* Error handling for runtime dynamic linker. Copyright (C) 1995, 1996, 1997, 1998 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 <setjmp.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <elf/ldsodefs.h> #include <bits/libc-tsd.h> /* This structure communicates state between _dl_catch_error and _dl_signal_error. */ struct catch { char *errstring; /* Error detail filled in here. */ jmp_buf env; /* longjmp here on error. */ }; /* Multiple threads at once can use the `_dl_catch_error' function. The calls can come from `_dl_map_object_deps', `_dlerror_run', or from any of the libc functionality which loads dynamic objects (NSS, iconv). Therefore we have to be prepared to save the state in thread-local memory. */ __libc_tsd_define (static, DL_ERROR) #define tsd_getspecific() __libc_tsd_get (DL_ERROR) #define tsd_setspecific(data) __libc_tsd_set (DL_ERROR, (data)) /* 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'. Since this functionality is not used in normal programs (only in ld.so) we do not care about multi-threaded programs here. We keep this as a global variable. */ static receiver_fct receiver; void internal_function _dl_signal_error (int errcode, const char *objname, const char *errstring) { struct catch *lcatch; if (! errstring) errstring = "DYNAMIC LINKER BUG!!!"; lcatch = tsd_getspecific (); if (lcatch != NULL) { /* 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 objname_len = objname ? strlen (objname) + 2 : 0; size_t errstring_len = strlen (errstring) + 1; lcatch->errstring = malloc (objname_len + errstring_len); if (lcatch->errstring != NULL) { if (objname_len > 0) { memcpy (lcatch->errstring, objname, objname_len - 2); memcpy (lcatch->errstring + objname_len - 2, ": ", 2); } memcpy (lcatch->errstring + objname_len, errstring, errstring_len); } longjmp (lcatch->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. */ char buffer[1024]; _dl_sysdep_fatal (_dl_argv[0] ?: "<program name unknown>", ": error in loading shared libraries: ", objname ?: "", objname && *objname ? ": " : "", errstring, errcode ? ": " : "", (errcode ? __strerror_r (errcode, buffer, sizeof buffer) : ""), "\n", NULL); } } int internal_function _dl_catch_error (char **errstring, void (*operate) (void *), void *args) { int errcode; struct catch *volatile old; struct catch 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; old = tsd_getspecific (); errcode = setjmp (c.env); if (errcode == 0) { tsd_setspecific (&c); (*operate) (args); tsd_setspecific (old); *errstring = NULL; return 0; } /* We get here only if we longjmp'd out of OPERATE. */ tsd_setspecific (old); *errstring = c.errstring; return errcode == -1 ? 0 : errcode; } void internal_function _dl_receive_error (receiver_fct fct, void (*operate) (void *), void *args) { struct catch *old_catch; receiver_fct old_receiver; old_catch = tsd_getspecific (); old_receiver = receiver; /* Set the new values. */ tsd_setspecific (NULL); receiver = fct; (*operate) (args); tsd_setspecific (old_catch); receiver = old_receiver; }