External programs triggered by events (via RUN=) will inherit udev's
signal mask, which is set to block all but SIGALRM. For most utilities,
this is OK, but if we start daemons from RUN=, we run into trouble
(especially as SIGCHLD is blocked).
This change saves the original sigmask when udev starts, and restores it
just before we exec() the external command.
Signed-off-by: Jeremy Kerr <jk@xxxxxxxxxx>
---
libudev/libudev-private.h | 4 +++-
libudev/libudev-util-private.c | 7 ++++++-
udev/test-udev.c | 2 +-
udev/udev-event.c | 4 ++--
udev/udev-rules.c | 4 ++--
udev/udev.h | 3 ++-
udev/udevd.c | 6 ++++--
7 files changed, 20 insertions(+), 10 deletions(-)
diff --git a/libudev/libudev-private.h b/libudev/libudev-private.h
index b735298..e90c79c 100644
--- a/libudev/libudev-private.h
+++ b/libudev/libudev-private.h
@@ -13,6 +13,7 @@
#define _LIBUDEV_PRIVATE_H_
#include <syslog.h>
+#include <signal.h>
#include "libudev.h"
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
@@ -214,7 +215,8 @@ int util_unlink_secure(struct udev *udev, const char *filename);
uid_t util_lookup_user(struct udev *udev, const char *user);
gid_t util_lookup_group(struct udev *udev, const char *group);
int util_run_program(struct udev *udev, const char *command, char **envp,
- char *result, size_t ressize, size_t *reslen);
+ char *result, size_t ressize, size_t *reslen,
+ const sigset_t *sigmask);
int util_resolve_subsys_kernel(struct udev *udev, const char *string,
char *result, size_t maxsize, int read_value);
diff --git a/libudev/libudev-util-private.c b/libudev/libudev-util-private.c
index fe8f29b..dfde5a9 100644
--- a/libudev/libudev-util-private.c
+++ b/libudev/libudev-util-private.c
@@ -242,7 +242,8 @@ int util_resolve_subsys_kernel(struct udev *udev, const char *string,
}
int util_run_program(struct udev *udev, const char *command, char **envp,
- char *result, size_t ressize, size_t *reslen)
+ char *result, size_t ressize, size_t *reslen,
+ const sigset_t *sigmask)
{
int status;
int outpipe[2] = {-1, -1};
@@ -330,6 +331,10 @@ int util_run_program(struct udev *udev, const char *command, char **envp,
dup2(errpipe[WRITE_END], STDERR_FILENO);
close(errpipe[WRITE_END]);
}
+
+ if (sigmask)
+ sigprocmask(SIG_BLOCK, sigmask, NULL);
+
execve(argv[0], argv, envp);
if (errno == ENOENT || errno == ENOTDIR) {
/* may be on a filesystem which is not mounted right now */
diff --git a/udev/test-udev.c b/udev/test-udev.c
index c6b8bf5..0806fbf 100644
--- a/udev/test-udev.c
+++ b/udev/test-udev.c
@@ -103,7 +103,7 @@ int main(int argc, char *argv[])
alarm(udev_device_get_event_timeout(dev));
if (err == 0 && !event->ignore_device && udev_get_run(udev))
- udev_event_execute_run(event);
+ udev_event_execute_run(event, NULL);
udev_event_unref(event);
udev_device_unref(dev);
diff --git a/udev/udev-event.c b/udev/udev-event.c
index 8183793..7b4e4ac 100644
--- a/udev/udev-event.c
+++ b/udev/udev-event.c
@@ -722,7 +722,7 @@ exit:
return err;
}
-int udev_event_execute_run(struct udev_event *event)
+int udev_event_execute_run(struct udev_event *event, const sigset_t *sigmask)
{
struct udev_list_entry *list_entry;
int err = 0;
@@ -745,7 +745,7 @@ int udev_event_execute_run(struct udev_event *event)
udev_event_apply_format(event, cmd, program, sizeof(program));
envp = udev_device_get_properties_envp(event->dev);
- if (util_run_program(event->udev, program, envp, NULL, 0, NULL) != 0) {
+ if (util_run_program(event->udev, program, envp, NULL, 0, NULL, sigmask) != 0) {
if (udev_list_entry_get_flag(list_entry))
err = -1;
}
diff --git a/udev/udev-rules.c b/udev/udev-rules.c
index da08bc1..1799424 100644
--- a/udev/udev-rules.c
+++ b/udev/udev-rules.c
@@ -749,7 +749,7 @@ static int import_program_into_properties(struct udev_device *dev, const char *p
char *line;
envp = udev_device_get_properties_envp(dev);
- if (util_run_program(udev, program, envp, result, sizeof(result), &reslen) != 0)
+ if (util_run_program(udev, program, envp, result, sizeof(result), &reslen, NULL) != 0)
return -1;
line = result;
@@ -2202,7 +2202,7 @@ int udev_rules_apply_to_event(struct udev_rules *rules, struct udev_event *event
program,
&rules->buf[rule->rule.filename_off],
rule->rule.filename_line);
- if (util_run_program(event->udev, program, envp, result, sizeof(result), NULL) != 0) {
+ if (util_run_program(event->udev, program, envp, result, sizeof(result), NULL, NULL) != 0) {
if (cur->key.op != OP_NOMATCH)
goto nomatch;
} else {
diff --git a/udev/udev.h b/udev/udev.h
index 391276f..8f0a301 100644
--- a/udev/udev.h
+++ b/udev/udev.h
@@ -21,6 +21,7 @@
#include <sys/types.h>
#include <sys/param.h>
+#include <signal.h>
#include "libudev.h"
#include "libudev-private.h"
@@ -67,7 +68,7 @@ int udev_rules_apply_to_event(struct udev_rules *rules, struct udev_event *event
struct udev_event *udev_event_new(struct udev_device *dev);
void udev_event_unref(struct udev_event *event);
int udev_event_execute_rules(struct udev_event *event, struct udev_rules *rules);
-int udev_event_execute_run(struct udev_event *event);
+int udev_event_execute_run(struct udev_event *event, const sigset_t *sigset);
size_t udev_event_apply_format(struct udev_event *event, const char *src, char *dest, size_t size);
int udev_event_apply_subsys_kernel(struct udev_event *event, const char *string,
char *result, size_t maxsize, int read_value);
diff --git a/udev/udevd.c b/udev/udevd.c
index 54064cb..2eb914a 100644
--- a/udev/udevd.c
+++ b/udev/udevd.c
@@ -79,6 +79,7 @@ static bool stop_exec_queue;
static bool reload_config;
static int max_childs;
static int childs;
+static sigset_t orig_sigmask;
static struct udev_list_node event_list;
static struct udev_list_node worker_list;
static bool udev_exit;
@@ -292,7 +293,8 @@ static void worker_new(struct event *event)
/* execute RUN= */
if (err == 0 && !udev_event->ignore_device && udev_get_run(udev_event->udev))
- failed = udev_event_execute_run(udev_event);
+ failed = udev_event_execute_run(udev_event,
+ &orig_sigmask);
/* reset alarm */
alarm(0);
@@ -926,7 +928,7 @@ int main(int argc, char *argv[])
/* block and listen to all signals on signalfd */
sigfillset(&mask);
- sigprocmask(SIG_SETMASK, &mask, NULL);
+ sigprocmask(SIG_SETMASK, &mask, &orig_sigmask);
pfd[FD_SIGNAL].fd = signalfd(-1, &mask, 0);
if (pfd[FD_SIGNAL].fd < 0) {
fprintf(stderr, "error getting signalfd\n");
--
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
