From: Juergen Gross <jgross@suse.com>
Date: Tue, 21 Nov 2023 09:49:51 +0000 (+0100)
Subject: Mini-OS: don't crash if no shutdown node is available
X-Git-Tag: xen-4.19.0-rc4~45
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=961ed15f04f5d8fc96279836cf52bc36d0a5141e;p=mini-os.git

Mini-OS: don't crash if no shutdown node is available

It might be perfectly fine not to have a control/shutdown Xenstore
node. If this is the case, don't crash, but just terminate the
shutdown thread after issuing a message that shutdown isn't available.

In fini_shutdown() clearing the watch can result in an error now, in
case the early exit above was taken. Just ignore this error now.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
---

diff --git a/shutdown.c b/shutdown.c
index bb2c6f1..ded6b64 100644
--- a/shutdown.c
+++ b/shutdown.c
@@ -75,7 +75,9 @@ static void shutdown_thread(void *p)
         xenbus_wait_for_watch(&events);
         if ((err = xenbus_read(XBT_NIL, path, &shutdown))) {
             free(err);
-            do_exit();
+            free(xenbus_unwatch_path_token(XBT_NIL, path, token));
+            printk("Shutdown Xenstore node not available.\n");
+            return;
         }
 
         if (end_shutdown_thread)
@@ -117,15 +119,9 @@ void init_shutdown(void)
 
 void fini_shutdown(void)
 {
-    char *err;
-
     end_shutdown_thread = 1;
     xenbus_release_wait_for_watch(&events);
-    err = xenbus_unwatch_path_token(XBT_NIL, path, token);
-    if (err) {
-        free(err);
-        do_exit();
-    }
+    free(xenbus_unwatch_path_token(XBT_NIL, path, token));
 }
 #endif