unblock signals we might want to handle

On Thu, Oct 29, 2009 at 19:15, Christian P. Schmidt <schmidt@digadd.de> wrote:
> After the getty replaces itself with login the pam module pam_mount
> calls mount. This in turn determines that the partition to be mounted is
> LUKS encrypted, and calls cryptsetup. Cryptsetup receives the password,
> unlocks the partition, and calls udevadm settle in order to avoid some
> problems in interaction with LVM.
>
> udevadm settle never returns.
>
> The problem here is that SIGUSR1 and SIGALRM are both blocked in oldmask
> already, and never reach udevadm. No care is ever taken to ensure those
> signals are not blocked.

3 files changed, 17 insertions, 1 deletions

diff --git a/udev/test-udev.c b/udev/test-udev.c
index 0806fbf9ce..bd61aa0695 100644
--- a/udev/test-udev.c
+++ b/udev/test-udev.c
@@ -52,6 +52,7 @@ int main(int argc, char *argv[])
 	const char *action;
 	const char *subsystem;
 	struct sigaction act;
+	sigset_t mask;
 	int err = -EINVAL;
 
 	udev = udev_new();
@@ -68,6 +69,11 @@ int main(int argc, char *argv[])
 	sigaction(SIGALRM, &act, NULL);
 	sigaction(SIGINT, &act, NULL);
 	sigaction(SIGTERM, &act, NULL);
+	sigemptyset(&mask);
+	sigaddset(&mask, SIGALRM);
+	sigaddset(&mask, SIGINT);
+	sigaddset(&mask, SIGTERM);
+	sigprocmask(SIG_UNBLOCK, &mask, NULL);
 
 	/* trigger timeout to prevent hanging processes */
 	alarm(UDEV_EVENT_TIMEOUT);
diff --git a/udev/udevadm-monitor.c b/udev/udevadm-monitor.c
index 90388db58e..00b130dafe 100644
--- a/udev/udevadm-monitor.c
+++ b/udev/udevadm-monitor.c
@@ -67,6 +67,7 @@ static void print_device(struct udev_device *device, const char *source, int pro
 int udevadm_monitor(struct udev *udev, int argc, char *argv[])
 {
 	struct sigaction act;
+	sigset_t mask;
 	int option;
 	int prop = 0;
 	int print_kernel = 0;
@@ -142,6 +143,10 @@ int udevadm_monitor(struct udev *udev, int argc, char *argv[])
 	act.sa_flags = SA_RESTART;
 	sigaction(SIGINT, &act, NULL);
 	sigaction(SIGTERM, &act, NULL);
+	sigemptyset(&mask);
+	sigaddset(&mask, SIGINT);
+	sigaddset(&mask, SIGTERM);
+	sigprocmask(SIG_UNBLOCK, &mask, NULL);
 
 	printf("monitor will print the received events for:\n");
 	if (print_udev) {
diff --git a/udev/udevadm-settle.c b/udev/udevadm-settle.c
index 5030f18602..4f422f9092 100644
--- a/udev/udevadm-settle.c
+++ b/udev/udevadm-settle.c
@@ -66,6 +66,7 @@ int udevadm_settle(struct udev *udev, int argc, char *argv[])
 	const char *exists = NULL;
 	int timeout = DEFAULT_TIMEOUT;
 	struct sigaction act;
+	sigset_t mask;
 	struct udev_queue *udev_queue = NULL;
 	int rc = 1;
 
@@ -78,6 +79,10 @@ int udevadm_settle(struct udev *udev, int argc, char *argv[])
 	act.sa_flags = 0;
 	sigaction(SIGALRM, &act, NULL);
 	sigaction(SIGUSR1, &act, NULL);
+	sigemptyset(&mask);
+	sigaddset(&mask, SIGUSR1);
+	sigaddset(&mask, SIGALRM);
+	sigprocmask(SIG_UNBLOCK, &mask, NULL);
 
 	while (1) {
 		int option;
@@ -163,7 +168,7 @@ int udevadm_settle(struct udev *udev, int argc, char *argv[])
 
 		uctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 		if (uctrl != NULL) {
-			sigset_t mask, oldmask;
+			sigset_t oldmask;
 
 			sigemptyset(&mask);
 			sigaddset(&mask, SIGUSR1);