/* CCpp.cpp - the hook for C/C++ crashing program Copyright (C) 2009 Zdenek Prikryl (zprikryl@redhat.com) Copyright (C) 2009 RedHat inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program 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 General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "abrtlib.h" #include "DebugDump.h" #include "ABRTException.h" #include #define FILENAME_EXECUTABLE "executable" #define FILENAME_CMDLINE "cmdline" #define FILENAME_COREDUMP "coredump" #define VAR_RUN_PID_FILE VAR_RUN"/abrt.pid" static char* get_executable(pid_t pid) { char buf[PATH_MAX + 1]; int len; snprintf(buf, sizeof(buf), "/proc/%u/exe", (int)pid); len = readlink(buf, buf, sizeof(buf)-1); if (len >= 0) { buf[len] = '\0'; return xstrdup(buf); } return NULL; } static char *append_escaped(char *start, const char *s) { char hex_char_buf[] = "\\x00"; *start++ = ' '; char *dst = start; const unsigned char *p = (unsigned char *)s; while (1) { const unsigned char *old_p = p; while (*p > ' ' && *p <= 0x7e && *p != '\"' && *p != '\'' && *p != '\\') p++; if (dst == start) { if (p != (unsigned char *)s && *p == '\0') { /* entire word does not need escaping and quoting */ strcpy(dst, s); dst += strlen(s); return dst; } *dst++ = '\''; } strncpy(dst, s, (p - old_p)); dst += (p - old_p); if (*p == '\0') { *dst++ = '\''; *dst = '\0'; return dst; } const char *a; switch (*p) { case '\r': a = "\\r"; break; case '\n': a = "\\n"; break; case '\t': a = "\\t"; break; case '\'': a = "\\\'"; break; case '\"': a = "\\\""; break; case '\\': a = "\\\\"; break; case ' ': a = " "; break; default: hex_char_buf[2] = "0123456789abcdef"[*p >> 4]; hex_char_buf[3] = "0123456789abcdef"[*p & 0xf]; a = hex_char_buf; } strcpy(dst, a); dst += strlen(a); p++; } } // taken from kernel #define COMMAND_LINE_SIZE 2048 static char* get_cmdline(pid_t pid) { char path[sizeof("/proc/%u/cmdline") + sizeof(int)*3]; char cmdline[COMMAND_LINE_SIZE]; char escaped_cmdline[COMMAND_LINE_SIZE*4 + 4]; escaped_cmdline[1] = '\0'; sprintf(path, "/proc/%u/cmdline", (int)pid); int fd = open(path, O_RDONLY); if (fd >= 0) { int len = read(fd, cmdline, sizeof(cmdline) - 1); close(fd); if (len > 0) { cmdline[len] = '\0'; char *src = cmdline; char *dst = escaped_cmdline; while ((src - cmdline) < len) { dst = append_escaped(dst, src); src += strlen(src) + 1; } } } return xstrdup(escaped_cmdline + 1); /* +1 skips extraneous leading space */ } static int daemon_is_ok() { char pid[sizeof(pid_t)*3 + 2]; char path[PATH_MAX]; struct stat buff; int fd = open(VAR_RUN_PID_FILE, O_RDONLY); if (fd < 0) { return 0; } int len = read(fd, pid, sizeof(pid)-1); close(fd); if (len <= 0) return 0; pid[len] = '\0'; *strchrnul(pid, '\n') = '\0'; /* paranoia: we don't want to check /proc//stat or /proc///stat */ if (pid[0] == '\0' || pid[0] == '/') return 0; /* TODO: maybe readlink and check that it is "xxx/abrt"? */ snprintf(path, sizeof(path), "/proc/%s/stat", pid); if (stat(path, &buff) == -1) { return 0; } return 1; } int main(int argc, char** argv) { const char* program_name = argv[0]; if (argc < 4) { error_msg_and_die("Usage: %s: ", program_name); } openlog("abrt", 0, LOG_DAEMON); logmode = LOGMODE_SYSLOG; const char* dddir = argv[1]; pid_t pid = atoi(argv[2]); const char* signal_str = argv[3]; int signal = atoi(argv[3]); uid_t uid = atoi(argv[4]); if (signal != SIGQUIT && signal != SIGILL && signal != SIGABRT && signal != SIGFPE && signal != SIGSEGV ) { /* not an error, exit silently */ return 0; } if (pid <= 0 || uid < 0) { error_msg_and_die("pid '%s' or uid '%s' are bogus", argv[2], argv[4]); } if (!daemon_is_ok()) { /* not an error, exit with exitcode 0 */ log("abrt daemon is not running. If it crashed, " "/proc/sys/kernel/core_pattern contains a stale value, " "consider resetting it to 'core'" ); return 0; } try { char* executable = get_executable(pid); if (executable == NULL) { error_msg_and_die("can't read /proc/%u/exe link", (int)pid); } if (strstr(executable, "/hookCCpp")) { error_msg_and_die("pid %u is '%s', not dumping it to avoid recursion", (int)pid, executable); } char path[PATH_MAX]; if (strstr(executable, "/abrtd")) { /* If abrtd crashes, we don't want to create a _directory_, * since that can make new copy of abrtd to process it, * and maybe crash again... * On the contrary, mere files are ignored by abrtd. */ snprintf(path, sizeof(path), "%s/abrtd-coredump", dddir); int fd = xopen3(path, O_WRONLY | O_CREAT | O_TRUNC, 0644); off_t size = copyfd_eof(STDIN_FILENO, fd); if (size < 0 || close(fd) != 0) { unlink(path); /* copyfd_eof logs the error including errno string, * but it does not log file name */ error_msg_and_die("error saving coredump to %s", path); } log("saved core dump of pid %u to %s (%llu bytes)", (int)pid, path, (long long)size); return 0; } /* rhbz#539551: "abrt going crazy when crashing process is respawned". * Do we want to protect against or ameliorate this? How? Ideas: * (1) nice ourself? * (2) check total size of dump dir, if it overflows, either abort dump * or delete oldest/biggest dumps? [abort would be simpler, * abrtd already does "delete on overflow" thing] * (3) detect parallel dumps in progress and back off * (pause/renice further/??) */ char* cmdline = get_cmdline(pid); /* never NULL */ const char *signame = strsignal(atoi(signal_str)); char *reason = xasprintf("Process was terminated by signal %s (%s)", signal_str, signame ? signame : signal_str); snprintf(path, sizeof(path), "%s/ccpp-%ld-%u", dddir, (long)time(NULL), (int)pid); CDebugDump dd; dd.Create(path, uid); dd.SaveText(FILENAME_ANALYZER, "CCpp"); dd.SaveText(FILENAME_EXECUTABLE, executable); dd.SaveText(FILENAME_CMDLINE, cmdline); dd.SaveText(FILENAME_REASON, reason); int len = strlen(path); snprintf(path + len, sizeof(path) - len, "/"FILENAME_COREDUMP); /* We need coredumps to be readable by all, because * process producing backtraces is run under the same UID * as the crashed process. * Thus 644, not 600 */ int fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644); if (fd < 0) { dd.Delete(); dd.Close(); perror_msg_and_die("can't open '%s'", path); } off_t size = copyfd_eof(STDIN_FILENO, fd); if (size < 0 || close(fd) != 0) { unlink(path); dd.Delete(); dd.Close(); /* copyfd_eof logs the error including errno string, * but it does not log file name */ error_msg_and_die("error saving coredump to %s", path); } /* free(executable); - why bother? */ /* free(cmdline); */ log("saved core dump of pid %u to %s (%llu bytes)", (int)pid, path, (long long)size); return 0; } catch (CABRTException& e) { error_msg_and_die("%s", e.what()); } catch (std::exception& e) { error_msg_and_die("%s", e.what()); } return 0; }