| /* Error handling for runtime dynamic linker. |
| Copyright (C) 1995-2014 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 Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <libintl.h> |
| #include <setjmp.h> |
| #include <stdbool.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <ldsodefs.h> |
| |
| /* This structure communicates state between _dl_catch_error and |
| _dl_signal_error. */ |
| struct catch |
| { |
| const char **objname; /* Object/File name. */ |
| const char **errstring; /* Error detail filled in here. */ |
| bool *malloced; /* Nonzero if the string is malloced |
| by the libc malloc. */ |
| volatile int *errcode; /* Return value of _dl_signal_error. */ |
| 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. The _dl_error_catch_tsd function pointer is reset by the thread |
| library so that it returns the address of a thread-local variable. */ |
| |
| |
| /* This message we return as a last resort. We define the string in a |
| variable since we have to avoid freeing it and so have to enable |
| a pointer comparison. See below and in dlfcn/dlerror.c. */ |
| static const char _dl_out_of_memory[] = "out of memory"; |
| |
| |
| /* This points to a function which is called when an continuable 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; |
| |
| #ifdef _LIBC_REENTRANT |
| # define CATCH_HOOK (*(struct catch **) (*GL(dl_error_catch_tsd)) ()) |
| #else |
| static struct catch *catch_hook; |
| # define CATCH_HOOK catch_hook |
| #endif |
| |
| void |
| internal_function |
| _dl_signal_error (int errcode, const char *objname, const char *occation, |
| const char *errstring) |
| { |
| struct catch *lcatch; |
| |
| if (! errstring) |
| errstring = N_("DYNAMIC LINKER BUG!!!"); |
| |
| lcatch = CATCH_HOOK; |
| if (objname == NULL) |
| objname = ""; |
| 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. The object name is always a string constant. */ |
| size_t len_objname = strlen (objname) + 1; |
| size_t len_errstring = strlen (errstring) + 1; |
| |
| char *errstring_copy = malloc (len_objname + len_errstring); |
| if (errstring_copy != NULL) |
| { |
| /* Make a copy of the object file name and the error string. */ |
| *lcatch->objname = memcpy (__mempcpy (errstring_copy, |
| errstring, len_errstring), |
| objname, len_objname); |
| *lcatch->errstring = errstring_copy; |
| |
| /* If the main executable is relocated it means the libc's malloc |
| is used. */ |
| bool malloced = true; |
| #ifdef SHARED |
| malloced = (GL(dl_ns)[LM_ID_BASE]._ns_loaded != NULL |
| && (GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_relocated != 0)); |
| #endif |
| *lcatch->malloced = malloced; |
| } |
| else |
| { |
| /* This is better than nothing. */ |
| *lcatch->objname = ""; |
| *lcatch->errstring = _dl_out_of_memory; |
| *lcatch->malloced = false; |
| } |
| |
| *lcatch->errcode = errcode; |
| |
| /* We do not restore the signal mask because none was saved. */ |
| __longjmp (lcatch->env[0].__jmpbuf, 1); |
| } |
| else |
| { |
| /* Lossage while resolving the program's own symbols is always fatal. */ |
| char buffer[1024]; |
| _dl_fatal_printf ("%s: %s: %s%s%s%s%s\n", |
| RTLD_PROGNAME, |
| occation ?: N_("error while loading shared libraries"), |
| objname, *objname ? ": " : "", |
| errstring, errcode ? ": " : "", |
| (errcode |
| ? __strerror_r (errcode, buffer, sizeof buffer) |
| : "")); |
| } |
| } |
| |
| |
| void |
| internal_function |
| _dl_signal_cerror (int errcode, const char *objname, const char *occation, |
| const char *errstring) |
| { |
| if (__builtin_expect (GLRO(dl_debug_mask) |
| & ~(DL_DEBUG_STATISTICS|DL_DEBUG_PRELINK), 0)) |
| _dl_debug_printf ("%s: error: %s: %s (%s)\n", objname, occation, |
| errstring, receiver ? "continued" : "fatal"); |
| |
| 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 |
| _dl_signal_error (errcode, objname, occation, errstring); |
| } |
| |
| |
| int |
| internal_function |
| _dl_catch_error (const char **objname, const char **errstring, |
| bool *mallocedp, void (*operate) (void *), void *args) |
| { |
| /* We need not handle `receiver' since setting a `catch' is handled |
| before it. */ |
| |
| /* Only this needs to be marked volatile, because it is the only local |
| variable that gets changed between the setjmp invocation and the |
| longjmp call. All others are just set here (before setjmp) and read |
| in _dl_signal_error (before longjmp). */ |
| volatile int errcode; |
| |
| struct catch c; |
| /* Don't use an initializer since we don't need to clear C.env. */ |
| c.objname = objname; |
| c.errstring = errstring; |
| c.malloced = mallocedp; |
| c.errcode = &errcode; |
| |
| struct catch **const catchp = &CATCH_HOOK; |
| struct catch *const old = *catchp; |
| *catchp = &c; |
| |
| /* Do not save the signal mask. */ |
| if (__builtin_expect (__sigsetjmp (c.env, 0), 0) == 0) |
| { |
| (*operate) (args); |
| *catchp = old; |
| *objname = NULL; |
| *errstring = NULL; |
| *mallocedp = false; |
| return 0; |
| } |
| |
| /* We get here only if we longjmp'd out of OPERATE. _dl_signal_error has |
| already stored values into *OBJNAME, *ERRSTRING, and *MALLOCEDP. */ |
| *catchp = old; |
| return errcode; |
| } |
| |
| |
| void |
| internal_function |
| _dl_receive_error (receiver_fct fct, void (*operate) (void *), void *args) |
| { |
| struct catch **const catchp = &CATCH_HOOK; |
| struct catch *old_catch; |
| receiver_fct old_receiver; |
| |
| old_catch = *catchp; |
| old_receiver = receiver; |
| |
| /* Set the new values. */ |
| *catchp = NULL; |
| receiver = fct; |
| |
| (*operate) (args); |
| |
| *catchp = old_catch; |
| receiver = old_receiver; |
| } |