From 97c4f35cd541baa2f985ff702a5b9f0b8b524a53 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Sat, 10 Apr 2010 21:40:40 +0200
Subject: [PATCH] main: install crash handler for creating core dumps

---
 main.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/main.c b/main.c
index 082ac4bb..4aa63cba 100644
--- a/main.c
+++ b/main.c
@@ -28,6 +28,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <getopt.h>
+#include <signal.h>
 
 #include "manager.h"
 #include "log.h"
@@ -44,6 +45,66 @@ static enum {
 
 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;
@@ -307,6 +368,9 @@ 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)
-- 
2.39.5