wdmd/main.c | 11 +++++++++++
1 file changed, 11 insertions(+)
New commits:
commit 7e43623a8ccf59411e4a43d5aff48d9326fbed26
Author: David Teigland <teigland(a)redhat.com>
Date: Wed Nov 18 13:50:21 2015 -0600
wdmd: prevent probe while watchdog is used
If the wdmd daemon is killed uncleanly, /dev/watchdog
is closed uncleanly and the watchdog should fire to
reset the machine.
If 'wdmd -p' is run to probe available watchdog devices
after wdmd is killed and before the machine is reset,
it will unintentionally interfere with the expiring
watchdog by doing open/magic-close on each device.
This silently prevents the watchdog from firing when
it should.
The probe function can check for the shm flag before
touching any watchdog devices, just like another wdmd
daemon process does, to avoid interfering with the
watchdog state of a previous wdmd daemon that was
terminated uncleanly.
diff --git a/wdmd/main.c b/wdmd/main.c
index c29667f..911d833 100644
--- a/wdmd/main.c
+++ b/wdmd/main.c
@@ -1604,7 +1604,18 @@ int main(int argc, char *argv[])
}
if (do_probe) {
+ rv = setup_shm();
+ if (rv < 0) {
+ fprintf(stderr, "cannot probe watchdog devices while wdmd is in use.\n");
+ openlog("wdmd-probe", LOG_CONS | LOG_PID, LOG_DAEMON);
+ syslog(LOG_ERR, "cannot probe watchdog devices while wdmd is in use.\n");
+ exit(EXIT_FAILURE);
+ }
+
rv = probe_watchdog();
+
+ close_shm();
+
if (rv < 0)
exit(EXIT_FAILURE);
else
