X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udevd.c;h=0999b5fa756bfc7b553dd413fa9672ca388dc9be;hp=b221692944c74dbc9604fd157852f0c08a98ce00;hb=3bf1efa8ddee3999656b0454734bc6b39fc7c00b;hpb=b3518c16e3c3795a5ff278ef4c71f8e439057d6d

diff --git a/udevd.c b/udevd.c
index b22169294..0999b5fa7 100644
--- a/udevd.c
+++ b/udevd.c
@@ -1,10 +1,7 @@
 /*
- * udevd.c - event listener and serializer
- *
  * Copyright (C) 2004-2006 Kay Sievers <kay.sievers@vrfy.org>
  * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
  *
- *
  *	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 version 2 of the License.
@@ -16,7 +13,7 @@
  *
  *	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.,
- *	675 Mass Ave, Cambridge, MA 02139, USA.
+ *	51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
  */
 
@@ -32,6 +29,7 @@
 #include <fcntl.h>
 #include <syslog.h>
 #include <time.h>
+#include <getopt.h>
 #include <sys/select.h>
 #include <sys/wait.h>
 #include <sys/types.h>
@@ -45,11 +43,15 @@
 #include "udev.h"
 #include "udev_rules.h"
 #include "udevd.h"
+#include "udev_selinux.h"
+
+static int debug_trace;
+static int verbose;
 
 static struct udev_rules rules;
-static int udevd_sock;
-static int uevent_netlink_sock;
-static int inotify_fd;
+static int udevd_sock = -1;
+static int uevent_netlink_sock = -1;
+static int inotify_fd = -1;
 static pid_t sid;
 
 static int signal_pipe[2] = {-1, -1};
@@ -74,10 +76,19 @@ void log_message(int priority, const char *format, ...)
 	if (priority > udev_log_priority)
 		return;
 
-	va_start(args, format);
-	vsyslog(priority, format, args);
-	va_end(args);
+	if (verbose) {
+		printf("[%d] ", (int) getpid());
+		va_start(args, format);
+		vprintf(format, args);
+		va_end(args);
+		printf("\n");
+	} else {
+		va_start(args, format);
+		vsyslog(priority, format, args);
+		va_end(args);
+	}
 }
+
 #endif
 
 static void asmlinkage udev_event_sig_handler(int signum)
@@ -114,11 +125,11 @@ static int udev_event_process(struct udevd_uevent_msg *msg)
 	for (i = 0; msg->envp[i]; i++)
 		putenv(msg->envp[i]);
 
-	udev = udev_device_init();
+	udev = udev_device_init(NULL);
 	if (udev == NULL)
 		return -1;
 	strlcpy(udev->action, msg->action, sizeof(udev->action));
-	sysfs_device_set_values(udev->dev, msg->devpath, msg->subsystem);
+	sysfs_device_set_values(udev->dev, msg->devpath, msg->subsystem, msg->driver);
 	udev->devt = msg->devt;
 
 	retval = udev_device_event(&rules, udev);
@@ -157,45 +168,32 @@ static void export_event_state(struct udevd_uevent_msg *msg, enum event_state st
 {
 	char filename[PATH_SIZE];
 	char filename_failed[PATH_SIZE];
-	char target[PATH_SIZE];
-	size_t start, end, i;
+	size_t start;
 	struct udevd_uevent_msg *loop_msg;
+	int fd;
 
 	/* add location of queue files */
 	strlcpy(filename, udev_root, sizeof(filename));
 	strlcat(filename, "/", sizeof(filename));
-	start = strlcat(filename, EVENT_QUEUE_DIR, sizeof(filename));
-	end = strlcat(filename, msg->devpath, sizeof(filename));
-	if (end > sizeof(filename))
-		end = sizeof(filename);
-
-	/* replace '/' to transform path into a filename */
-	for (i = start+1; i < end; i++)
-		if (filename[i] == '/')
-			filename[i] = PATH_TO_NAME_CHAR;
+	start = strlcat(filename, EVENT_QUEUE_DIR"/", sizeof(filename));
+	strlcat(filename, msg->devpath, sizeof(filename));
+	path_encode(&filename[start], sizeof(filename) - start);
 
 	/* add location of failed files */
 	strlcpy(filename_failed, udev_root, sizeof(filename_failed));
 	strlcat(filename_failed, "/", sizeof(filename_failed));
-	start = strlcat(filename_failed, EVENT_FAILED_DIR, sizeof(filename_failed));
-	end = strlcat(filename_failed, msg->devpath, sizeof(filename_failed));
-	if (end > sizeof(filename_failed))
-		end = sizeof(filename_failed);
-
-	/* replace '/' to transform path into a filename */
-	for (i = start+1; i < end; i++)
-		if (filename_failed[i] == '/')
-			filename_failed[i] = PATH_TO_NAME_CHAR;
+	start = strlcat(filename_failed, EVENT_FAILED_DIR"/", sizeof(filename_failed));
+	strlcat(filename_failed, msg->devpath, sizeof(filename_failed));
+	path_encode(&filename_failed[start], sizeof(filename) - start);
 
 	switch (state) {
 	case EVENT_QUEUED:
 		unlink(filename_failed);
 		delete_path(filename_failed);
-
-		strlcpy(target, sysfs_path, sizeof(target));
-		strlcat(target, msg->devpath, sizeof(target));
 		create_path(filename);
-		symlink(target, filename);
+		fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
+		if (fd > 0)
+			close(fd);
 		return;
 	case EVENT_FINISHED:
 	case EVENT_FAILED:
@@ -299,6 +297,15 @@ static void msg_queue_insert(struct udevd_uevent_msg *msg)
 
 	export_event_state(msg, EVENT_QUEUED);
 
+	/* run one event after the other in debug mode */
+	if (debug_trace) {
+		list_add_tail(&msg->node, &running_list);
+		udev_event_run(msg);
+		waitpid(msg->pid, NULL, 0);
+		msg_queue_delete(msg);
+		return;
+	}
+
 	/* run all events with a timeout set immediately */
 	if (msg->timeout != 0) {
 		list_add_tail(&msg->node, &running_list);
@@ -310,34 +317,70 @@ static void msg_queue_insert(struct udevd_uevent_msg *msg)
 	run_exec_q = 1;
 }
 
-/* runs event and removes event from run queue when finished */
-static int running_processes(void)
+static int mem_size_mb(void)
 {
-	int f;
-	char buf[32768];
-	int len;
-	int running;
-	const char *pos;
+	FILE* f;
+	char buf[4096];
+	long int memsize = -1;
 
-	f = open("/proc/stat", O_RDONLY);
-	if (f == -1)
+	f = fopen("/proc/meminfo", "r");
+	if (f == NULL)
 		return -1;
 
-	len = read(f, buf, sizeof(buf)-1);
-	close(f);
+	while (fgets(buf, sizeof(buf), f) != NULL) {
+		long int value;
 
-	if (len <= 0)
+		if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
+			memsize = value / 1024;
+			break;
+		}
+	}
+
+	fclose(f);
+	return memsize;
+}
+
+static int cpu_count(void)
+{
+	FILE* f;
+	char buf[4096];
+	int count = 0;
+
+	f = fopen("/proc/stat", "r");
+	if (f == NULL)
 		return -1;
-	else
-		buf[len] = '\0';
 
-	pos = strstr(buf, "procs_running ");
-	if (pos == NULL)
+	while (fgets(buf, sizeof(buf), f) != NULL) {
+		if (strncmp(buf, "cpu", 3) == 0 && isdigit(buf[3]))
+			count++;
+	}
+
+	fclose(f);
+	if (count == 0)
 		return -1;
+	return count;
+}
+
+static int running_processes(void)
+{
+	FILE* f;
+	char buf[4096];
+	int running = -1;
 
-	if (sscanf(pos, "procs_running %u", &running) != 1)
+	f = fopen("/proc/stat", "r");
+	if (f == NULL)
 		return -1;
 
+	while (fgets(buf, sizeof(buf), f) != NULL) {
+		int value;
+
+		if (sscanf(buf, "procs_running %u", &value) == 1) {
+			running = value;
+			break;
+		}
+	}
+
+	fclose(f);
 	return running;
 }
 
@@ -430,26 +473,49 @@ static int compare_devpath(const char *running, const char *waiting)
 	return 0;
 }
 
-/* returns still running task for the same device, its parent or its physical device */
-static int running_with_devpath(struct udevd_uevent_msg *msg, int limit)
+/* lookup event for identical, parent, child, or physical device */
+static int devpath_busy(struct udevd_uevent_msg *msg, int limit)
 {
 	struct udevd_uevent_msg *loop_msg;
 	int childs_count = 0;
 
+	/* check exec-queue which may still contain delayed events we depend on */
+	list_for_each_entry(loop_msg, &exec_list, node) {
+		/* skip ourself and all later events */
+		if (loop_msg->seqnum >= msg->seqnum)
+			break;
+
+		/* check identical, parent, or child device event */
+		if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) {
+			dbg("%llu, device event still pending %llu (%s)",
+			    msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
+			return 2;
+		}
+
+		/* check physical device event (special case of parent) */
+		if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0)
+			if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) {
+				dbg("%llu, physical device event still pending %llu (%s)",
+				    msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
+				return 3;
+			}
+	}
+
+	/* check runing-queue for still running events */
 	list_for_each_entry(loop_msg, &running_list, node) {
 		if (limit && childs_count++ > limit) {
-			dbg("%llu, maximum number (%i) of child reached", msg->seqnum, childs_count);
+			dbg("%llu, maximum number (%i) of childs reached", msg->seqnum, childs_count);
 			return 1;
 		}
 
-		/* return running parent/child device event */
+		/* check identical, parent, or child device event */
 		if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) {
-			dbg("%llu, child device event still running %llu (%s)",
+			dbg("%llu, device event still running %llu (%s)",
 			    msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
 			return 2;
 		}
 
-		/* return running physical device event */
+		/* check physical device event (special case of parent) */
 		if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0)
 			if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) {
 				dbg("%llu, physical device event still running %llu (%s)",
@@ -457,11 +523,10 @@ static int running_with_devpath(struct udevd_uevent_msg *msg, int limit)
 				return 3;
 			}
 	}
-
 	return 0;
 }
 
-/* exec queue management routine executes the events and serializes events in the same sequence */
+/* serializes events for the identical and parent and child devices */
 static void msg_queue_manager(void)
 {
 	struct udevd_uevent_msg *loop_msg;
@@ -487,8 +552,8 @@ static void msg_queue_manager(void)
 			}
 		}
 
-		/* don't run two processes for the same devpath and wait for the parent*/
-		if (running_with_devpath(loop_msg, max_childs)) {
+		/* serialize and wait for parent or child events */
+		if (devpath_busy(loop_msg, max_childs) != 0) {
 			dbg("delay seq %llu (%s)", loop_msg->seqnum, loop_msg->devpath);
 			continue;
 		}
@@ -506,8 +571,9 @@ static struct udevd_uevent_msg *get_msg_from_envbuf(const char *buf, int buf_siz
 	int bufpos;
 	int i;
 	struct udevd_uevent_msg *msg;
-	int major = 0;
-	int minor = 0;
+	char *physdevdriver_key = NULL;
+	int maj = 0;
+	int min = 0;
 
 	msg = malloc(sizeof(struct udevd_uevent_msg) + buf_size);
 	if (msg == NULL)
@@ -534,19 +600,30 @@ static struct udevd_uevent_msg *get_msg_from_envbuf(const char *buf, int buf_siz
 			msg->devpath = &key[8];
 		else if (strncmp(key, "SUBSYSTEM=", 10) == 0)
 			msg->subsystem = &key[10];
+		else if (strncmp(key, "DRIVER=", 7) == 0)
+			msg->driver = &key[7];
 		else if (strncmp(key, "SEQNUM=", 7) == 0)
 			msg->seqnum = strtoull(&key[7], NULL, 10);
 		else if (strncmp(key, "PHYSDEVPATH=", 12) == 0)
 			msg->physdevpath = &key[12];
+		else if (strncmp(key, "PHYSDEVDRIVER=", 14) == 0)
+			physdevdriver_key = key;
 		else if (strncmp(key, "MAJOR=", 6) == 0)
-			major = strtoull(&key[6], NULL, 10);
+			maj = strtoull(&key[6], NULL, 10);
 		else if (strncmp(key, "MINOR=", 6) == 0)
-			minor = strtoull(&key[6], NULL, 10);
+			min = strtoull(&key[6], NULL, 10);
 		else if (strncmp(key, "TIMEOUT=", 8) == 0)
 			msg->timeout = strtoull(&key[8], NULL, 10);
 	}
-	msg->devt = makedev(major, minor);
+	msg->devt = makedev(maj, min);
 	msg->envp[i++] = "UDEVD_EVENT=1";
+
+	if (msg->driver == NULL && msg->physdevpath == NULL && physdevdriver_key != NULL) {
+		/* for older kernels DRIVER is empty for a bus device, export PHYSDEVDRIVER as DRIVER */
+		msg->envp[i++] = &physdevdriver_key[7];
+		msg->driver = &physdevdriver_key[14];
+	}
+
 	msg->envp[i] = NULL;
 
 	if (msg->devpath == NULL || msg->action == NULL) {
@@ -568,6 +645,7 @@ static void get_ctrl_msg(void)
 	struct ucred *cred;
 	char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
 	int *intval;
+	char *pos;
 
 	memset(&ctrl_msg, 0x00, sizeof(struct udevd_ctrl_msg));
 	iov.iov_base = &ctrl_msg;
@@ -604,6 +682,21 @@ static void get_ctrl_msg(void)
 	}
 
 	switch (ctrl_msg.type) {
+	case UDEVD_CTRL_ENV:
+		pos = strchr(ctrl_msg.buf, '=');
+		if (pos == NULL) {
+			err("wrong key format '%s'", ctrl_msg.buf);
+			break;
+		}
+		pos[0] = '\0';
+		if (pos[1] == '\0') {
+			info("udevd message (ENV) received, unset '%s'", ctrl_msg.buf);
+			unsetenv(ctrl_msg.buf);
+		} else {
+			info("udevd message (ENV) received, set '%s=%s'", ctrl_msg.buf, &pos[1]);
+			setenv(ctrl_msg.buf, &pos[1], 1);
+		}
+		break;
 	case UDEVD_CTRL_STOP_EXEC_QUEUE:
 		info("udevd message (STOP_EXEC_QUEUE) received");
 		stop_exec_q = 1;
@@ -625,12 +718,17 @@ static void get_ctrl_msg(void)
 		info("udevd message (UDEVD_SET_MAX_CHILDS) received, max_childs=%i", *intval);
 		max_childs = *intval;
 		break;
+	case UDEVD_CTRL_SET_MAX_CHILDS_RUNNING:
+		intval = (int *) ctrl_msg.buf;
+		info("udevd message (UDEVD_SET_MAX_CHILDS_RUNNING) received, max_childs=%i", *intval);
+		max_childs_running = *intval;
+		break;
 	case UDEVD_CTRL_RELOAD_RULES:
 		info("udevd message (RELOAD_RULES) received");
 		reload_config = 1;
 		break;
 	default:
-		dbg("unknown message type");
+		err("unknown control message type");
 	}
 }
 
@@ -746,7 +844,6 @@ static void reap_sigchilds(void)
 static int init_udevd_socket(void)
 {
 	struct sockaddr_un saddr;
-	const int buffersize = 16 * 1024 * 1024;
 	socklen_t addrlen;
 	const int feature_on = 1;
 	int retval;
@@ -763,13 +860,12 @@ static int init_udevd_socket(void)
 		return -1;
 	}
 
-	/* set receive buffersize */
-	setsockopt(udevd_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize));
-
 	/* the bind takes care of ensuring only one copy running */
 	retval = bind(udevd_sock, (struct sockaddr *) &saddr, addrlen);
 	if (retval < 0) {
 		err("bind failed: %s", strerror(errno));
+		close(udevd_sock);
+		udevd_sock = -1;
 		return -1;
 	}
 
@@ -845,67 +941,121 @@ int main(int argc, char *argv[], char *envp[])
 	fd_set readfds;
 	const char *value;
 	int daemonize = 0;
-	int i;
-	int rc = 0;
+	int option;
+	static const struct option options[] = {
+		{ "daemon", 0, NULL, 'd' },
+		{ "debug-trace", 0, NULL, 't' },
+		{ "verbose", 0, NULL, 'v' },
+		{ "help", 0, NULL, 'h' },
+		{ "version", 0, NULL, 'V' },
+		{}
+	};
+	int rc = 1;
 	int maxfd;
 
-	/* redirect std fd's, if the kernel forks us, we don't have them at all */
-	fd = open("/dev/null", O_RDWR);
-	if (fd >= 0) {
-		if (fd != STDIN_FILENO)
-			dup2(fd, STDIN_FILENO);
-		if (fd != STDOUT_FILENO)
-			dup2(fd, STDOUT_FILENO);
-		if (fd != STDERR_FILENO)
-			dup2(fd, STDERR_FILENO);
-		if (fd > STDERR_FILENO)
-			close(fd);
-	}
-
 	logging_init("udevd");
-	if (fd < 0)
-		err("fatal, could not open /dev/null: %s", strerror(errno));
-
 	udev_config_init();
+	selinux_init();
 	dbg("version %s", UDEV_VERSION);
 
+	while (1) {
+		option = getopt_long(argc, argv, "dtvhV", options, NULL);
+		if (option == -1)
+			break;
+
+		switch (option) {
+		case 'd':
+			daemonize = 1;
+			break;
+		case 't':
+			debug_trace = 1;
+			break;
+		case 'v':
+			verbose = 1;
+			if (udev_log_priority < LOG_INFO)
+				udev_log_priority = LOG_INFO;
+			break;
+		case 'h':
+			printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--verbose] [--version]\n");
+			goto exit;
+		case 'V':
+			printf("%s\n", UDEV_VERSION);
+			goto exit;
+		default:
+			goto exit;
+		}
+	}
+
 	if (getuid() != 0) {
-		err("need to be root, exit");
+		fprintf(stderr, "root privileges required\n");
+		err("root privileges required");
 		goto exit;
 	}
 
-	/* parse commandline options */
-	for (i = 1 ; i < argc; i++) {
-		char *arg = argv[i];
-		if (strcmp(arg, "--daemon") == 0 || strcmp(arg, "-d") == 0) {
-			info("will daemonize");
-			daemonize = 1;
-		}
-		if (strcmp(arg, "--stop-exec-queue") == 0) {
-			info("will not execute events until START_EXEC_QUEUE is received");
-			stop_exec_q = 1;
-		}
+	/* make sure std{in,out,err} fd's are in a sane state */
+	fd = open("/dev/null", O_RDWR);
+	if (fd < 0) {
+		fprintf(stderr, "cannot open /dev/null\n");
+		err("cannot open /dev/null");
 	}
+	if (fd > STDIN_FILENO)
+		dup2(fd, STDIN_FILENO);
+	if (write(STDOUT_FILENO, 0, 0) < 0)
+		dup2(fd, STDOUT_FILENO);
+	if (write(STDERR_FILENO, 0, 0) < 0)
+		dup2(fd, STDERR_FILENO);
 
 	/* init sockets to receive events */
 	if (init_udevd_socket() < 0) {
 		if (errno == EADDRINUSE) {
-			err("another udevd running, exit");
+			fprintf(stderr, "another udev daemon already running\n");
+			err("another udev daemon already running");
 			rc = 1;
 		} else {
-			err("error initializing udevd socket: %s", strerror(errno));
+			fprintf(stderr, "error initializing udevd socket\n");
+			err("error initializing udevd socket");
 			rc = 2;
 		}
 		goto exit;
 	}
 
 	if (init_uevent_netlink_sock() < 0) {
-		err("uevent socket not available");
+		fprintf(stderr, "error initializing netlink socket\n");
+		err("error initializing netlink socket");
 		rc = 3;
 		goto exit;
 	}
 
-	/* parse the rules and keep it in memory */
+	/* setup signal handler pipe */
+	retval = pipe(signal_pipe);
+	if (retval < 0) {
+		err("error getting pipes: %s", strerror(errno));
+		goto exit;
+	}
+
+	retval = fcntl(signal_pipe[READ_END], F_GETFL, 0);
+	if (retval < 0) {
+		err("error fcntl on read pipe: %s", strerror(errno));
+		goto exit;
+	}
+	retval = fcntl(signal_pipe[READ_END], F_SETFL, retval | O_NONBLOCK);
+	if (retval < 0) {
+		err("error fcntl on read pipe: %s", strerror(errno));
+		goto exit;
+	}
+
+	retval = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
+	if (retval < 0) {
+		err("error fcntl on write pipe: %s", strerror(errno));
+		goto exit;
+	}
+	retval = fcntl(signal_pipe[WRITE_END], F_SETFL, retval | O_NONBLOCK);
+	if (retval < 0) {
+		err("error fcntl on write pipe: %s", strerror(errno));
+		goto exit;
+	}
+
+	/* parse the rules and keep them in memory */
 	sysfs_init();
 	udev_rules_init(&rules, 1);
 
@@ -925,10 +1075,18 @@ int main(int argc, char *argv[], char *envp[])
 			goto exit;
 		default:
 			dbg("child [%u] running, parent exits", pid);
+			rc = 0;
 			goto exit;
 		}
 	}
 
+	/* redirect std{out,err} fd's */
+	if (!verbose)
+		dup2(fd, STDOUT_FILENO);
+	dup2(fd, STDERR_FILENO);
+	if (fd > STDERR_FILENO)
+		close(fd);
+
 	/* set scheduling priority for the daemon */
 	setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 
@@ -948,35 +1106,6 @@ int main(int argc, char *argv[], char *envp[])
 		close(fd);
 	}
 
-	/* setup signal handler pipe */
-	retval = pipe(signal_pipe);
-	if (retval < 0) {
-		err("error getting pipes: %s", strerror(errno));
-		goto exit;
-	}
-
-	retval = fcntl(signal_pipe[READ_END], F_GETFL, 0);
-	if (retval < 0) {
-		err("error fcntl on read pipe: %s", strerror(errno));
-		goto exit;
-	}
-	retval = fcntl(signal_pipe[READ_END], F_SETFL, retval | O_NONBLOCK);
-	if (retval < 0) {
-		err("error fcntl on read pipe: %s", strerror(errno));
-		goto exit;
-	}
-
-	retval = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
-	if (retval < 0) {
-		err("error fcntl on write pipe: %s", strerror(errno));
-		goto exit;
-	}
-	retval = fcntl(signal_pipe[WRITE_END], F_SETFL, retval | O_NONBLOCK);
-	if (retval < 0) {
-		err("error fcntl on write pipe: %s", strerror(errno));
-		goto exit;
-	}
-
 	/* set signal handlers */
 	memset(&act, 0x00, sizeof(struct sigaction));
 	act.sa_handler = (void (*)(int)) sig_handler;
@@ -990,7 +1119,7 @@ int main(int argc, char *argv[], char *envp[])
 	/* watch rules directory */
 	inotify_fd = inotify_init();
 	if (inotify_fd >= 0)
-		inotify_add_watch(inotify_fd, udev_rules_filename, IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
+		inotify_add_watch(inotify_fd, udev_rules_dir, IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 	else if (errno == ENOSYS)
 		err("the kernel does not support inotify, udevd can't monitor configuration file changes");
 	else
@@ -1000,16 +1129,26 @@ int main(int argc, char *argv[], char *envp[])
 	value = getenv("UDEVD_MAX_CHILDS");
 	if (value)
 		max_childs = strtoul(value, NULL, 10);
-	else
-		max_childs = UDEVD_MAX_CHILDS;
+	else {
+		int memsize = mem_size_mb();
+		if (memsize > 0)
+			max_childs = 128 + (memsize / 4);
+		else
+			max_childs = UDEVD_MAX_CHILDS;
+	}
 	info("initialize max_childs to %u", max_childs);
 
 	/* start to throttle forking if maximum number of _running_ childs is reached */
 	value = getenv("UDEVD_MAX_CHILDS_RUNNING");
 	if (value)
 		max_childs_running = strtoull(value, NULL, 10);
-	else
-		max_childs_running = UDEVD_MAX_CHILDS_RUNNING;
+	else {
+		int cpus = cpu_count();
+		if (cpus > 0)
+			max_childs_running = 8 + (8 * cpus);
+		else
+			max_childs_running = UDEVD_MAX_CHILDS_RUNNING;
+	}
 	info("initialize max_childs_running to %u", max_childs_running);
 
 	/* clear environment for forked event processes */
@@ -1018,6 +1157,8 @@ int main(int argc, char *argv[], char *envp[])
 	/* export log_priority , as called programs may want to follow that setting */
 	sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority);
 	putenv(udev_log);
+	if (debug_trace)
+		putenv("DEBUG=1");
 
 	maxfd = udevd_sock;
 	maxfd = UDEV_MAX(maxfd, uevent_netlink_sock);
@@ -1080,7 +1221,7 @@ int main(int argc, char *argv[], char *envp[])
 			}
 		}
 
-		/* rules changed, set by inotify or a signal*/
+		/* rules changed, set by inotify or a HUP signal */
 		if (reload_config) {
 			reload_config = 0;
 			udev_rules_cleanup(&rules);
@@ -1099,10 +1240,12 @@ int main(int argc, char *argv[], char *envp[])
 				msg_queue_manager();
 		}
 	}
+	rc = 0;
 
 exit:
 	udev_rules_cleanup(&rules);
 	sysfs_cleanup();
+	selinux_exit();
 
 	if (signal_pipe[READ_END] >= 0)
 		close(signal_pipe[READ_END]);