from
gradm_adm.c- Code: Select all
static void ipc_sig(int sig)
{
signal(sig, SIG_IGN);
return;
}
void start_grlearn(char *logfile)
{
pid_t pid;
signal(SIGUSR1, ipc_sig);
pid = fork();
if (!pid) {
execl(GRLEARN_PATH, GRLEARN_PATH, logfile, NULL);
exit(EXIT_FAILURE);
} else if (pid > 0) {
pause(); // wait for child to send us SIGUSR1
}
return;
}
If SIGUSR1 will be recieved by gradm from grlearn before
pause() called, gradm will lockup and wait forever. Here is some strace -r for gradm, PID 16806
- Code: Select all
0.000048 open("/etc/grsec/pw", O_RDONLY) = 4
0.000035 read(4, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 112) = 112
0.000053 rt_sigaction(SIGUSR1, {0x8054230, [USR1], SA_RESTART}, {SIG_DFL}, 8) = 0
0.000166 clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0xa648d708) = 16807
0.000019 --- SIGUSR1 (User defined signal 1) @ 0 (0) ---
0.000023 --- SIGCHLD (Child exited) @ 0 (0) ---
0.000020 rt_sigaction(SIGUSR1, {SIG_IGN}, {0x8054230, [USR1], SA_RESTART}, 8) = 0
0.000046 sigreturn() = ? (mask now [])
0.000061 pause() = ? ERESTARTNOHAND (To be restarted)
0.000084 --- SIGINT (Interrupt) @ 0 (0) ---
0.000017 pause() = ? ERESTARTNOHAND (To be restarted)
10.971357 --- SIGTERM (Terminated) @ 0 (0) ---
0.000023 pause() = ? ERESTARTNOHAND (To be restarted)
3.328117 --- SIGTERM (Terminated) @ 0 (0) ---
0.000023 pause(
and for 2-nd grlearn
- Code: Select all
0.000397 stat64("/etc/grsec/.grlearn.pid", {st_mode=S_IFREG|0600, st_size=4, ...}) = 0
0.000134 open("/etc/grsec/.grlearn.pid", O_RDONLY) = 8
0.000056 read(8, "\220A\0\0", 4) = 4
0.000042 close(8) = 0
0.000034 unlink("/etc/grsec/.grlearn.pid") = 0
0.000093 readlink("/proc/16784/exe", 0xb691de50, 4095) = -1 ENOENT (No such file or directory)
0.000062 open("/etc/grsec/.grlearn.pid", O_WRONLY|O_CREAT|O_EXCL, 0600) = 8
0.000055 write(8, "\250A\0\0", 4) = 4
0.000048 close(8) = 0
0.000033 kill(16806, SIGUSR1) = 0
0.000029 close(0) = 0
0.000025 close(1) = 0
0.000025 close(2) = 0
0.000031 poll([{fd=6, events=POLLIN}], 1, -1) = ? ERESTART_RESTARTBLOCK (To be restarted)
14.497522 --- SIGINT (Interrupt) @ 0 (0) ---
0.000011 restart_syscall(<... resuming interrupted call ...>
SIGINT and SIGTERM are my Ctrl+C in console and kill from another console.
