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/*
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 <syslog.h>
#include <string>
#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;
}
// taken from kernel
#define COMMAND_LINE_SIZE 2048
static char* get_cmdline(pid_t pid)
{
char path[PATH_MAX];
char cmdline[COMMAND_LINE_SIZE];
snprintf(path, sizeof(path), "/proc/%u/cmdline", (int)pid);
int idx = 0;
int fd = open(path, O_RDONLY);
if (fd >= 0)
{
int len = read(fd, cmdline, sizeof(cmdline) - 1);
close(fd);
if (len > 0)
{
/* In Linux, there is always one trailing NUL byte,
* prevent it from being replaced by space below.
*/
if (cmdline[len - 1] == '\0')
len--;
while (idx < len)
{
unsigned char ch = cmdline[idx];
if (ch == '\0')
{
cmdline[idx++] = ' ';
}
else if (ch >= ' ' && ch <= 0x7e)
{
cmdline[idx++] = ch;
}
else
{
cmdline[idx++] = '?';
}
}
}
}
cmdline[idx] = '\0';
return xstrdup(cmdline);
}
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: <dddir> <pid> <signal> <uid>", 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;
char* cmdline;
executable = get_executable(pid);
cmdline = get_cmdline(pid);
if (executable == NULL || cmdline == NULL)
{
error_msg_and_die("can not get proc info for pid %u", (int)pid);
}
if (strstr(executable, "/abrt"))
{
/* free(executable); - why bother? */
/* free(cmdline); */
error_msg_and_die("pid %u is '%s', not dumping it to avoid abrt recursion",
(int)pid, executable);
}
char path[PATH_MAX];
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, std::string("Process was terminated by signal ") + signal_str);
int len = strlen(path);
snprintf(path + len, sizeof(path) - len, "/"FILENAME_COREDUMP);
int fd;
/* 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 */
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);
}
if (copyfd_eof(STDIN_FILENO, fd) < 0)
{
/* close(fd); - why bother? */
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);
}
/* close(fd); - why bother? */
/* free(executable); */
/* free(cmdline); */
log("saved core dump of pid %u to %s", (int)pid, path);
}
catch (CABRTException& e)
{
error_msg_and_die("%s", e.what().c_str());
}
catch (std::exception& e)
{
error_msg_and_die("%s", e.what());
}
return 0;
}
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