main: install crash handler for creating core dumps

[elogind.git] / main.c

diff --git a/main.c b/main.c
index 15ed0f1e2e75af78048037e9bef537d995513778..4aa63cba77310ac27fd56a2476b8703a2fab6ffc 100644 (file)
--- a/main.c
+++ b/main.c
@@ -28,19 +28,83 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <getopt.h>
+#include <signal.h>
 
 #include "manager.h"
 #include "log.h"
 #include "mount-setup.h"
+#include "hostname-setup.h"
+#include "load-fragment.h"
 
 static enum {
         ACTION_RUN,
         ACTION_HELP,
-        ACTION_TEST
+        ACTION_TEST,
+        ACTION_DUMP_CONFIGURATION_ITEMS
 } action = ACTION_RUN;
 
 static char *default_unit = NULL;
 static ManagerRunningAs running_as = _MANAGER_RUNNING_AS_INVALID;
+static bool dump_core = true;
+
+_noreturn static void freeze(void) {
+        for (;;)
+                pause();
+}
+
+_noreturn static void crash(int sig) {
+
+        if (!dump_core)
+                log_error("Caught <%s>, not dumping core.", strsignal(sig));
+        else {
+                pid_t pid;
+
+                log_warning("Caugh <%s>, dumping core.", strsignal(sig));
+
+                if ((pid = fork()) < 0)
+                        log_error("Caught <%s>, cannot dump core: %s", strsignal(sig), strerror(errno));
+
+                else if (pid == 0) {
+                        struct sigaction sa;
+                        struct rlimit rl;
+
+                        /* Enable default signal handler for core dump */
+                        zero(sa);
+                        sa.sa_handler = SIG_DFL;
+                        assert_se(sigaction(sig, &sa, NULL) == 0);
+
+                        /* Don't limit the core dump size */
+                        zero(rl);
+                        rl.rlim_cur = RLIM_INFINITY;
+                        rl.rlim_max = RLIM_INFINITY;
+                        setrlimit(RLIMIT_CORE, &rl);
+
+                        /* Just to be sure... */
+                        assert_se(chdir("/") == 0);
+
+                        /* Raise the signal again */
+                        raise(sig);
+
+                        assert_not_reached("We shouldn't be here...");
+                        _exit(1);
+                }
+        }
+
+        log_error("Freezing execution.");
+        freeze();
+}
+
+static void install_crash_handler(void) {
+        struct sigaction sa;
+
+        zero(sa);
+
+        sa.sa_handler = crash;
+        sa.sa_flags = SA_NODEFER;
+
+        assert_se(sigaction(SIGSEGV, &sa, NULL) == 0);
+        assert_se(sigaction(SIGABRT, &sa, NULL) == 0);
+}
 
 static int set_default_unit(const char *u) {
         char *c;
@@ -70,7 +134,7 @@ static int parse_proc_cmdline_word(const char *word) {
         };
 
         if (startswith(word, "systemd.default="))
-                return set_default_unit(word + 15);
+                return set_default_unit(word + 16);
 
         else if (startswith(word, "systemd.log_target=")) {
 
@@ -136,7 +200,8 @@ static int parse_argv(int argc, char *argv[]) {
                 ARG_LOG_TARGET,
                 ARG_DEFAULT,
                 ARG_RUNNING_AS,
-                ARG_TEST
+                ARG_TEST,
+                ARG_DUMP_CONFIGURATION_ITEMS
         };
 
         static const struct option options[] = {
@@ -146,6 +211,7 @@ static int parse_argv(int argc, char *argv[]) {
                 { "running-as", required_argument, NULL, ARG_RUNNING_AS },
                 { "test",       no_argument,       NULL, ARG_TEST },
                 { "help",       no_argument,       NULL, 'h' },
+                { "dump-configuration-items", no_argument, NULL, ARG_DUMP_CONFIGURATION_ITEMS },
                 { NULL,         0,                 NULL, 0 }
         };
 
@@ -200,6 +266,10 @@ static int parse_argv(int argc, char *argv[]) {
                         action = ACTION_TEST;
                         break;
 
+                case ARG_DUMP_CONFIGURATION_ITEMS:
+                        action = ACTION_DUMP_CONFIGURATION_ITEMS;
+                        break;
+
                 case 'h':
                         action = ACTION_HELP;
                         break;
@@ -218,12 +288,13 @@ static int parse_argv(int argc, char *argv[]) {
 static int help(void) {
 
         printf("%s [options]\n\n"
-               "  -h --help               Show this help\n"
-               "     --default=UNIT       Set default unit\n"
-               "     --log-level=LEVEL    Set log level\n"
-               "     --log-target=TARGET  Set log target (console, syslog, kmsg)\n"
-               "     --running-as=AS      Set running as (init, system, sesstion)\n"
-               "     --test               Determine startup sequence, dump it and exit\n",
+               "  -h --help                      Show this help\n"
+               "     --default=UNIT              Set default unit\n"
+               "     --log-level=LEVEL           Set log level\n"
+               "     --log-target=TARGET         Set log target (console, syslog, kmsg)\n"
+               "     --running-as=AS             Set running as (init, system, session)\n"
+               "     --test                      Determine startup sequence, dump it and exit\n"
+               "     --dump-configuration-items  Dump understood unit configuration items\n",
                __progname);
 
         return 0;
@@ -247,7 +318,8 @@ int main(int argc, char *argv[]) {
 
         /* Mount /proc, /sys and friends, so that /proc/cmdline and
          * /proc/$PID/fd is available. */
-        mount_setup();
+        if (mount_setup() < 0)
+                goto finish;
 
         /* Reset all signal handlers. */
         assert_se(reset_all_signal_handlers() == 0);
@@ -267,10 +339,19 @@ int main(int argc, char *argv[]) {
         if (action == ACTION_HELP) {
                 retval = help();
                 goto finish;
+        } else if (action == ACTION_DUMP_CONFIGURATION_ITEMS) {
+                unit_dump_config_items(stdout);
+                retval = 0;
+                goto finish;
         }
 
         assert_se(action == ACTION_RUN || action == ACTION_TEST);
 
+        /* Set up PATH unless it is already set */
+        setenv("PATH",
+               "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
+               running_as == MANAGER_INIT);
+
         /* Move out of the way, so that we won't block unmounts */
         assert_se(chdir("/")  == 0);
 
@@ -287,8 +368,14 @@ int main(int argc, char *argv[]) {
         log_open_syslog();
         log_open_kmsg();
 
+        install_crash_handler();
+        assert(!"esel");
+
         log_debug("systemd running in %s mode.", manager_running_as_to_string(running_as));
 
+        if (running_as == MANAGER_INIT)
+                hostname_setup();
+
         if ((r = manager_new(running_as, &m)) < 0) {
                 log_error("Failed to allocate manager object: %s", strerror(-r));
                 goto finish;
@@ -303,7 +390,12 @@ int main(int argc, char *argv[]) {
 
         if ((r = manager_load_unit(m, default_unit, &target)) < 0) {
                 log_error("Failed to load default target: %s", strerror(-r));
-                goto finish;
+
+                log_info("Trying to load rescue target...");
+                if ((r = manager_load_unit(m, SPECIAL_RESCUE_TARGET, &target)) < 0) {
+                        log_error("Failed to load rescue target: %s", strerror(-r));
+                        goto finish;
+                }
         }
 
         if (action == ACTION_TEST) {