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main: run crash shell as subprocess, so that we can gdb pid 1

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This commit is contained in:
Lennart Poettering 2010-04-13 20:26:54 +02:00
parent 27563bb44a
commit 6f5e3f3527
1 changed files with 26 additions and 10 deletions
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36
main.c
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@ -59,18 +59,27 @@ _noreturn static void freeze(void) {
pause();
}
static void nop_handler(int sig) {
}
_noreturn static void crash(int sig) {
if (!dump_core)
log_error("Caught <%s>, not dumping core.", strsignal(sig));
else {
struct sigaction sa;
pid_t pid;
/* We want to wait for the core process, hence let's enable SIGCHLD */
zero(sa);
sa.sa_handler = nop_handler;
sa.sa_flags = SA_NOCLDSTOP|SA_RESTART;
assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
if ((pid = fork()) < 0)
log_error("Caught <%s>, cannot fork for core dump: %s", strsignal(sig), strerror(errno));
else if (pid == 0) {
struct sigaction sa;
struct rlimit rl;
/* Enable default signal handler for core dump */
@ -110,21 +119,28 @@ _noreturn static void crash(int sig) {
chvt(crash_chvt);
if (crash_shell) {
sigset_t mask;
struct sigaction sa;
pid_t pid;
log_info("Executing crash shell in 10s...");
sleep(10);
/* Make sure the signal is not delivered inside the
* exec() */
assert_se(sigemptyset(&mask) == 0);
assert_se(sigaddset(&mask, sig) == 0);
assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
/* Let the kernel reap children for us */
zero(sa);
sa.sa_handler = SIG_IGN;
sa.sa_flags = SA_NOCLDSTOP|SA_NOCLDWAIT|SA_RESTART;
assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
ignore_signal(sig);
if ((pid = fork()) < 0)
log_error("Failed to fork off crash shell: %s", strerror(errno));
else if (pid == 0) {
execl("/bin/sh", "/bin/sh", NULL);
execl("/bin/sh", "/bin/sh", NULL);
log_error("execl() failed: %s", strerror(errno));
log_error("execl() failed: %s", strerror(errno));
_exit(1);
}
log_info("Successfully spawned crash shall as pid %llu.", (unsigned long long) pid);
}
log_info("Freezing execution.");