-/* Error handling for runtime dynamic linker.
- Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
+/* Error handling for runtime dynamic linker, full version.
+ Copyright (C) 1995-2019 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.
+ 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
- Library General Public License for more details.
+ Lesser 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. */
+ 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 <setjmp.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <elf/ldsodefs.h>
-#include <bits/libc-lock.h>
+/* This implementation lives in libc.so because it uses thread-local
+ data, which is not available in ld.so. It interposes the version
+ in dl-error-minimal.c after ld.so bootstrap.
-/* 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. */
- };
+ The signal/catch mechanism is used by the audit framework, which
+ means that even in ld.so, not all errors are fatal. */
-/* 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. `catch' will only be used for the non-threaded case.
-
- Please note the horrible kludge we have to use to check for the
- thread functions to be defined. The problem is that while running
- ld.so standalone (i.e., before the relocation with the available
- libc symbols) we do not have a real handling of undefined weak symbols.
- All symbols are relocated, regardless of the availability. They are
- relocated relative to the load address of the dynamic linker. Adding
- this start address to zero (the value in the GOT for undefined symbols)
- leads to an address which is the load address of ld.so. Once we have
- relocated with the libc values the value is NULL if the function is
- not available. Our "solution" is to regard NULL and the ld.so load
- address as indicators for unavailable weak symbols. */
-static struct catch *catch;
-
-#ifdef PIC
-# define tsd_setspecific(data) \
- if (__libc_internal_tsd_set != (void *) _dl_rtld_map.l_addr \
- && __libc_internal_tsd_set != NULL) \
- __libc_internal_tsd_set (_LIBC_TSD_KEY_DL_ERROR, data); \
- else \
- catch = (data)
-# define tsd_getspecific() \
- (__libc_internal_tsd_set != (void *) _dl_rtld_map.l_addr \
- && __libc_internal_tsd_set != NULL \
- ? (struct catch *) __libc_internal_tsd_get (_LIBC_TSD_KEY_DL_ERROR) \
- : catch)
-#else
-# define tsd_setspecific(data) \
- if (__libc_internal_tsd_set != NULL) \
- __libc_internal_tsd_set (_LIBC_TSD_KEY_DL_ERROR, data); \
- else \
- catch = (data)
-# define tsd_getspecific() \
- (__libc_internal_tsd_set != NULL \
- ? (struct catch *) __libc_internal_tsd_get (_LIBC_TSD_KEY_DL_ERROR) \
- : catch)
-#endif
-
-
-/* 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;
-}
+#define DL_ERROR_BOOTSTRAP 0
+#include "dl-error-skeleton.c"
projects / thirdparty / glibc.git / blobdiff