Do-not-merge: libc calls need to be audited for thread safety.
diff --git a/udev/test-udev.c b/udev/test-udev.c
index 929f752..49ddd5b 100644
--- a/udev/test-udev.c
+++ b/udev/test-udev.c
@@ -107,6 +107,7 @@ int main(int argc, char *argv[])
fail:
udev_rules_unref(rules);
exit:
+ udev_exec_cleanup(udev);
udev_selinux_exit(udev);
udev_unref(udev);
if (err != 0)
diff --git a/udev/udev.h b/udev/udev.h
index fd3c73d..53516e4 100644
--- a/udev/udev.h
+++ b/udev/udev.h
@@ -39,6 +39,9 @@
#define READ_END 0
#define WRITE_END 1
+#define UDEVD_PRIORITY -4 /* nice level for daemon */
+#define UDEV_PRIORITY -2 /* nice level for programs run by daemon*/
+
static inline void logging_init(const char *program_name)
{
openlog(program_name, LOG_PID | LOG_CONS, LOG_DAEMON);
@@ -77,7 +80,7 @@ struct udev_event {
int test;
struct udev_list_node node;
- pid_t pid;
+ pthread_t thread;
int exitstatus;
time_t queue_time;
};
@@ -106,6 +109,7 @@ extern void udev_node_update_old_links(struct udev_device *dev, struct udev_devi
/* udev-exec.c */
extern int udev_exec_init(struct udev *udev);
+extern void udev_exec_cleanup(struct udev *udev);
extern int udev_exec(struct udev_device *dev, const char *command,
char *result, size_t ressize, size_t *reslen);
diff --git a/udev/udevd.c b/udev/udevd.c
index a2c4230..9d2b67d 100644
--- a/udev/udevd.c
+++ b/udev/udevd.c
@@ -34,12 +34,10 @@
#ifdef HAVE_INOTIFY
#include <sys/inotify.h>
#endif
+#include <pthread.h>
#include "udev.h"
-#define UDEVD_PRIORITY -4
-#define UDEV_PRIORITY -2
-
/* maximum limit of forked childs */
#define UDEVD_MAX_CHILDS 256
@@ -64,7 +62,7 @@ static struct udev_monitor *kernel_monitor;
static int inotify_fd = -1;
static int signal_pipe[2] = {-1, -1};
-static volatile int sigchilds_waiting;
+static int event_done_pipe[2] = {-1, -1};
static volatile int udev_exit;
static volatile int reload_config;
static int run_exec_q;
@@ -74,6 +72,8 @@ static int max_childs;
static struct udev_list_node exec_list;
static struct udev_list_node running_list;
+pthread_attr_t thread_attr;
+
enum event_state {
EVENT_QUEUED,
EVENT_FINISHED,
@@ -168,71 +168,68 @@ static void event_queue_delete(struct udev_event *event)
udev_event_unref(event);
}
-static void asmlinkage event_sig_handler(int signum)
+static int event_run(struct udev_event *event)
{
- if (signum == SIGALRM)
- exit(1);
+ int err;
+
+ /* apply rules, create node, symlinks */
+ err = udev_event_execute_rules(event, rules);
+
+ /* execute RUN= */
+ if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
+ udev_event_execute_run(event);
+ info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
+
+ return err;
}
-static void event_fork(struct udev_event *event)
+static void *event_run_pthread(void *arg)
{
- pid_t pid;
- struct sigaction act;
+ struct udev_event *event = arg;
int err;
- pid = fork();
- switch (pid) {
- case 0:
- /* child */
- udev_monitor_unref(kernel_monitor);
- udev_ctrl_unref(udev_ctrl);
- if (inotify_fd >= 0)
- close(inotify_fd);
- close(signal_pipe[READ_END]);
- close(signal_pipe[WRITE_END]);
- logging_close();
- logging_init("udevd-event");
- setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
-
- /* set signal handlers */
- memset(&act, 0x00, sizeof(act));
- act.sa_handler = (void (*)(int)) event_sig_handler;
- sigemptyset (&act.sa_mask);
- act.sa_flags = 0;
- sigaction(SIGALRM, &act, NULL);
-
- /* reset to default */
- act.sa_handler = SIG_DFL;
- sigaction(SIGINT, &act, NULL);
- sigaction(SIGTERM, &act, NULL);
- sigaction(SIGCHLD, &act, NULL);
- sigaction(SIGHUP, &act, NULL);
-
- /* apply rules, create node, symlinks */
- err = udev_event_execute_rules(event, rules);
-
- /* execute RUN= */
- if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
- udev_event_execute_run(event);
- info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
- logging_close();
- if (err != 0)
- exit(1);
- exit(0);
- case -1:
- err(event->udev, "fork of child failed: %m\n");
+ err = event_run(event);
+
+ /* write to pipe, which will wakeup select() in our mainloop */
+ write(event_done_pipe[WRITE_END], &event, sizeof(struct udev_event *));
+
+ return (void *) (uintptr_t) err;
+}
+
+static void event_thread_create(struct udev_event *event)
+{
+ if (pthread_create(&event->thread, &thread_attr, event_run_pthread, event) != 0) {
+ err(event->udev, "create thread failed: %m\n");
event_queue_delete(event);
- break;
- default:
- /* get SIGCHLD in main loop */
- info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
- udev_device_get_seqnum(event->dev),
- pid,
- udev_device_get_action(event->dev),
- udev_device_get_subsystem(event->dev),
- time(NULL) - event->queue_time);
- event->pid = pid;
}
+
+ info(event->udev, "seq %llu created, '%s' '%s', %ld seconds old\n",
+ udev_device_get_seqnum(event->dev),
+ udev_device_get_action(event->dev),
+ udev_device_get_subsystem(event->dev),
+ time(NULL) - event->queue_time);
+}
+
+static int event_thread_join(struct udev_event *event)
+{
+ void *result;
+ int err;
+
+ err = pthread_join(event->thread, &result);
+ if (err) {
+ err(event->udev, "failed to retrieve thread return value: %m\n");
+ return -1;
+ }
+
+ return (int) (uintptr_t) result;
+}
+
+static void event_thread_kill(struct udev_event *event)
+{
+ pthread_kill(event->thread, SIGTERM);
+
+ /* Make sure thread has died before we return */
+ event_thread_join(event);
}
static void event_queue_insert(struct udev_event *event)
@@ -261,8 +258,7 @@ static void event_queue_insert(struct udev_event *event)
/* run one event after the other in debug mode */
if (debug_trace) {
udev_list_node_append(&event->node, &running_list);
- event_fork(event);
- waitpid(event->pid, NULL, 0);
+ event->exitstatus = event_run(event);
event_queue_delete(event);
return;
}
@@ -270,7 +266,7 @@ static void event_queue_insert(struct udev_event *event)
/* run all events with a timeout set immediately */
if (udev_device_get_timeout(event->dev) > 0) {
udev_list_node_append(&event->node, &running_list);
- event_fork(event);
+ event_thread_create(event);
return;
}
@@ -451,7 +447,7 @@ static void event_queue_manager(struct udev *udev)
/* move event to run list */
udev_list_node_remove(&loop_event->node);
udev_list_node_append(&loop_event->node, &running_list);
- event_fork(loop_event);
+ event_thread_create(loop_event);
dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
}
}
@@ -530,11 +526,8 @@ static void asmlinkage sig_handler(int signum)
switch (signum) {
case SIGINT:
case SIGTERM:
- udev_exit = 1;
- break;
case SIGCHLD:
- /* set flag, then write to pipe if needed */
- sigchilds_waiting = 1;
+ udev_exit = 1;
break;
case SIGHUP:
reload_config = 1;
@@ -545,45 +538,17 @@ static void asmlinkage sig_handler(int signum)
write(signal_pipe[WRITE_END], "", 1);
}
-static void udev_done(int pid, int exitstatus)
+static void udev_done(struct udev_event *event)
{
- struct udev_list_node *loop;
+ event->exitstatus = event_thread_join(event);
+ info(event->udev, "seq %llu cleanup, status %i, %ld seconds old\n",
+ udev_device_get_seqnum(event->dev),
+ event->exitstatus, time(NULL) - event->queue_time);
- /* find event associated with pid and delete it */
- udev_list_node_foreach(loop, &running_list) {
- struct udev_event *loop_event = node_to_event(loop);
-
- if (loop_event->pid == pid) {
- info(loop_event->udev, "seq %llu cleanup, pid [%d], status %i, %ld seconds old\n",
- udev_device_get_seqnum(loop_event->dev), loop_event->pid,
- exitstatus, time(NULL) - loop_event->queue_time);
- loop_event->exitstatus = exitstatus;
- event_queue_delete(loop_event);
+ event_queue_delete(event);
- /* there may be events waiting with the same devpath */
- run_exec_q = 1;
- return;
- }
- }
-}
-
-static void reap_sigchilds(void)
-{
- pid_t pid;
- int status;
-
- while (1) {
- pid = waitpid(-1, &status, WNOHANG);
- if (pid <= 0)
- break;
- if (WIFEXITED(status))
- status = WEXITSTATUS(status);
- else if (WIFSIGNALED(status))
- status = WTERMSIG(status) + 128;
- else
- status = 0;
- udev_done(pid, status);
- }
+ /* there may be events waiting with the same devpath */
+ run_exec_q = 1;
}
static void export_initial_seqnum(struct udev *udev)
@@ -620,6 +585,8 @@ int main(int argc, char *argv[])
int err;
int fd;
struct sigaction act;
+ int pagesize;
+ int stacksize;
fd_set readfds;
const char *value;
int daemonize = 0;
@@ -729,6 +696,11 @@ int main(int argc, char *argv[])
err(udev, "error getting pipes: %m\n");
goto exit;
}
+ err = pipe(event_done_pipe);
+ if (err < 0) {
+ err(udev, "error getting pipes: %m\n");
+ goto exit;
+ }
err = fcntl(signal_pipe[READ_END], F_GETFL, 0);
if (err < 0) {
@@ -791,6 +763,29 @@ int main(int argc, char *argv[])
/* set scheduling priority for the daemon */
setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
+ pthread_attr_init(&thread_attr);
+
+ /* To create many threads on 32-bit, it may be necessary to explicitly limit the stack size.
+
+ udevd doesn't use crazy recursion or deep call-chains.
+ But it does allocate quite a few buffers and temporary strings on the stack.
+ We may also need extra space for exotic NSS modules (user/group lookup, e.g. over LDAP).
+ Make a generous guess, double it, and double it again!
+
+ This comes to just over 200Kb. The default on i386 is 2Mb.
+ */
+ stacksize = PTHREAD_STACK_MIN;
+ stacksize += UTIL_PATH_SIZE * 8;
+ stacksize += UTIL_LINE_SIZE * 8;
+ stacksize += UTIL_NAME_SIZE * 8;
+ stacksize += 4096 * 8;
+ stacksize *= 4;
+
+ /* Round up to a whole number of pages */
+ pagesize = sysconf(_SC_PAGESIZE);
+ stacksize = ((stacksize / pagesize) + 1) * pagesize;
+ pthread_attr_setstacksize(&thread_attr, stacksize);
+
/* OOM_DISABLE == -17 */
fd = open("/proc/self/oom_adj", O_RDWR);
if (fd < 0)
@@ -872,12 +867,14 @@ int main(int argc, char *argv[])
maxfd = udev_ctrl_get_fd(udev_ctrl);
maxfd = UDEV_MAX(maxfd, udev_monitor_get_fd(kernel_monitor));
maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
+ maxfd = UDEV_MAX(maxfd, event_done_pipe[READ_END]);
maxfd = UDEV_MAX(maxfd, inotify_fd);
while (!udev_exit) {
int fdcount;
FD_ZERO(&readfds);
FD_SET(signal_pipe[READ_END], &readfds);
+ FD_SET(event_done_pipe[READ_END], &readfds);
FD_SET(udev_ctrl_get_fd(udev_ctrl), &readfds);
FD_SET(udev_monitor_get_fd(kernel_monitor), &readfds);
if (inotify_fd >= 0)
@@ -916,6 +913,21 @@ int main(int argc, char *argv[])
read(signal_pipe[READ_END], &buf, sizeof(buf));
}
+ /* processed events */
+ if (FD_ISSET(event_done_pipe[READ_END], &readfds)) {
+ struct udev_event *buf[32];
+ ssize_t count;
+ unsigned i;
+
+ count = read(event_done_pipe[READ_END], &buf, sizeof(buf));
+ if (count < 0) {
+ err(udev, "read error on thread pipe: %m\n");
+ } else {
+ for (i = 0; i < count / sizeof(buf[0]); i++)
+ udev_done(buf[i]);
+ }
+ }
+
/* rules directory inotify watch */
if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) {
int nbytes;
@@ -948,11 +960,6 @@ int main(int argc, char *argv[])
}
}
- if (sigchilds_waiting) {
- sigchilds_waiting = 0;
- reap_sigchilds();
- }
-
if (run_exec_q) {
run_exec_q = 0;
if (!stop_exec_q)
@@ -961,8 +968,20 @@ int main(int argc, char *argv[])
}
rc = 0;
+ /* Kill event threads before destroying global udev context */
+ if (!udev_list_is_empty(&running_list)) {
+ struct udev_list_node *loop;
+
+ udev_list_node_foreach(loop, &running_list) {
+ struct udev_event *loop_event = node_to_event(loop);
+
+ event_thread_kill(loop_event);
+ }
+ }
+
exit:
udev_rules_unref(rules);
+ pthread_attr_destroy(&thread_attr);
if (signal_pipe[READ_END] >= 0)
close(signal_pipe[READ_END]);
@@ -974,6 +993,7 @@ exit:
close(inotify_fd);
udev_monitor_unref(kernel_monitor);
+ udev_exec_cleanup(udev);
udev_selinux_exit(udev);
udev_unref(udev);
logging_close();
--
To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
