From 9d1f2858cd2ba49066ca319164b4e3e2769fc0fb Mon Sep 17 00:00:00 2001
From: "Edward A. James" <eajames@us.ibm.com>
Date: Fri, 8 Dec 2017 11:26:30 -0600
Subject: [PATCH 1/3] watchdog: allow a device path to be specified

Currently systemd hardcodes the use of /dev/watchdog. This is a legacy
chardev that points to watchdog0 in the system.

Modify the watchdog API to allow a different device path to be passed
and stored. Opening the watchdog defaults to /dev/watchdog, maintaining
existing behavior.
---
 src/shared/watchdog.c | 9 ++++++++-
 src/shared/watchdog.h | 5 +++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/shared/watchdog.c b/src/shared/watchdog.c
index 4f3e012..8068e95 100644
--- a/src/shared/watchdog.c
+++ b/src/shared/watchdog.c
@@ -26,10 +26,12 @@
 
 #include "fd-util.h"
 #include "log.h"
+#include "string-util.h"
 #include "time-util.h"
 #include "watchdog.h"
 
 static int watchdog_fd = -1;
+static char *watchdog_device = NULL;
 static usec_t watchdog_timeout = USEC_INFINITY;
 
 static int update_timeout(void) {
@@ -83,7 +85,8 @@ static int open_watchdog(void) {
         if (watchdog_fd >= 0)
                 return 0;
 
-        watchdog_fd = open("/dev/watchdog", O_WRONLY|O_CLOEXEC);
+        watchdog_fd = open(watchdog_device ?: "/dev/watchdog",
+                           O_WRONLY|O_CLOEXEC);
         if (watchdog_fd < 0)
                 return -errno;
 
@@ -95,6 +98,10 @@ static int open_watchdog(void) {
         return update_timeout();
 }
 
+int watchdog_set_device(char *path) {
+        return free_and_strdup(&watchdog_device, path);
+}
+
 int watchdog_set_timeout(usec_t *usec) {
         int r;
 
diff --git a/src/shared/watchdog.h b/src/shared/watchdog.h
index f6ec178..90a075a 100644
--- a/src/shared/watchdog.h
+++ b/src/shared/watchdog.h
@@ -24,6 +24,11 @@
 #include "time-util.h"
 #include "util.h"
 
+int watchdog_set_device(char *path);
 int watchdog_set_timeout(usec_t *usec);
 int watchdog_ping(void);
 void watchdog_close(bool disarm);
+
+static inline void watchdog_free_device(void) {
+        (void) watchdog_set_device(NULL);
+}
-- 
1.8.3.1