diff options
Diffstat (limited to 'debug/segfault.c')
| -rw-r--r-- | debug/segfault.c | 214 |
1 files changed, 0 insertions, 214 deletions
diff --git a/debug/segfault.c b/debug/segfault.c deleted file mode 100644 index f141fff661..0000000000 --- a/debug/segfault.c +++ /dev/null @@ -1,214 +0,0 @@ -/* Catch segmentation faults and print backtrace. - Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004 - Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. - - 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, write to the Free - Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA - 02111-1307 USA. */ - -#include <alloca.h> -#include <ctype.h> -#include <errno.h> -#include <execinfo.h> -#include <fcntl.h> -#include <signal.h> -#include <stdint.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> -#include <stdio-common/_itoa.h> -#include <ldsodefs.h> - -#include <bp-checks.h> - -/* This file defines macros to access the content of the sigcontext element - passed up by the signal handler. */ -#include <sigcontextinfo.h> - -/* Get code to possibly dump the content of all registers. */ -#include <register-dump.h> - -/* We'll use tis a lot. */ -#define WRITE_STRING(s) write (fd, s, strlen (s)) - -/* Name of the output file. */ -static const char *fname; - - -/* We better should not use `strerror' since it can call far too many - other functions which might fail. Do it here ourselves. */ -static void -write_strsignal (int fd, int signal) -{ - if (signal < 0 || signal >= _NSIG || _sys_siglist[signal] == NULL) - { - char buf[30]; - char *ptr = _itoa_word (signal, &buf[sizeof (buf)], 10, 0); - WRITE_STRING ("signal "); - write (fd, buf, &buf[sizeof (buf)] - ptr); - } - else - WRITE_STRING (_sys_siglist[signal]); -} - - -/* This function is called when a segmentation fault is caught. The system - is in an instable state now. This means especially that malloc() might - not work anymore. */ -static void -catch_segfault (int signal, SIGCONTEXT ctx) -{ - int fd, cnt, i; - void **arr; - struct sigaction sa; - uintptr_t pc; - - /* This is the name of the file we are writing to. If none is given - or we cannot write to this file write to stderr. */ - fd = 2; - if (fname != NULL) - { - fd = open (fname, O_TRUNC | O_WRONLY | O_CREAT, 0666); - if (fd == -1) - fd = 2; - } - - WRITE_STRING ("*** "); - write_strsignal (fd, signal); - WRITE_STRING ("\n"); - -#ifdef REGISTER_DUMP - REGISTER_DUMP; -#endif - - WRITE_STRING ("\nBacktrace:\n"); - - /* Get the backtrace. */ - arr = alloca (256 * sizeof (void *)); - cnt = backtrace (arr, 256); - - /* Now try to locate the PC from signal context in the backtrace. - Normally it will be found at arr[2], but it might appear later - if there were some signal handler wrappers. Allow a few bytes - difference to cope with as many arches as possible. */ - pc = (uintptr_t) GET_PC (ctx); - for (i = 0; i < cnt; ++i) - if ((uintptr_t) arr[i] >= pc - 16 && (uintptr_t) arr[i] <= pc + 16) - break; - - /* If we haven't found it, better dump full backtrace even including - the signal handler frames instead of not dumping anything. */ - if (i == cnt) - i = 0; - - /* Now generate nicely formatted output. */ - __backtrace_symbols_fd (arr + i, cnt - i, fd); - -#ifdef HAVE_PROC_SELF - /* Now the link map. */ - int mapfd = open ("/proc/self/maps", O_RDONLY); - if (mapfd != -1) - { - write (fd, "\nMemory map:\n\n", 14); - - char buf[256]; - ssize_t n; - - while ((n = TEMP_FAILURE_RETRY (read (mapfd, buf, sizeof (buf)))) > 0) - TEMP_FAILURE_RETRY (write (fd, buf, n)); - - close (mapfd); - } -#endif - - /* Pass on the signal (so that a core file is produced). */ - sa.sa_handler = SIG_DFL; - sigemptyset (&sa.sa_mask); - sa.sa_flags = 0; - sigaction (signal, &sa, NULL); - raise (signal); -} - - -static void -__attribute__ ((constructor)) -install_handler (void) -{ - struct sigaction sa; - const char *sigs = getenv ("SEGFAULT_SIGNALS"); - const char *name; - - sa.sa_handler = (void *) catch_segfault; - sigemptyset (&sa.sa_mask); - sa.sa_flags = SA_RESTART; - - /* Maybe we are expected to use an alternative stack. */ - if (getenv ("SEGFAULT_USE_ALTSTACK") != 0) - { - void *stack_mem = malloc (2 * SIGSTKSZ); - struct sigaltstack ss; - - if (stack_mem != NULL) - { - ss.ss_sp = stack_mem; - ss.ss_flags = 0; - ss.ss_size = 2 * SIGSTKSZ; - - if (sigaltstack (&ss, NULL) == 0) - sa.sa_flags |= SA_ONSTACK; - } - } - - if (sigs == NULL) - sigaction (SIGSEGV, &sa, NULL); - else if (sigs[0] == '\0') - /* Do not do anything. */ - return; - else - { - const char *where; - int all = __strcasecmp (sigs, "all") == 0; - -#define INSTALL_FOR_SIG(sig, name) \ - where = __strcasestr (sigs, name); \ - if (all || (where != NULL \ - && (where == sigs || !isalnum (where[-1])) \ - && !isalnum (where[sizeof (name) - 1]))) \ - sigaction (sig, &sa, NULL); - - INSTALL_FOR_SIG (SIGSEGV, "segv"); - INSTALL_FOR_SIG (SIGILL, "ill"); -#ifdef SIGBUS - INSTALL_FOR_SIG (SIGBUS, "bus"); -#endif -#ifdef SIGSTKFLT - INSTALL_FOR_SIG (SIGSTKFLT, "stkflt"); -#endif - INSTALL_FOR_SIG (SIGABRT, "abrt"); - INSTALL_FOR_SIG (SIGFPE, "fpe"); - } - - /* Preserve the output file name if there is any given. */ - name = getenv ("SEGFAULT_OUTPUT_NAME"); - if (name != NULL && name[0] != '\0') - { - int ret = access (name, R_OK | W_OK); - - if (ret == 0 || (ret == -1 && errno == ENOENT)) - fname = __strdup (name); - } -} |