[uml-devel] Patch to show status of UML

[Frank S. <fr...@tu...>]

Here is a patch to UML to allow uml_mconsole to report the 'status' of the
UML (whether the UML is Stopped or Running).  The 'status' command could
easily be extended to add other information.  This patch should apply to 
the 2.4.24 kernel, after the standard UML patch.

Frank
fr...@tu...
http://sco.tuxrocks.com



##### uml-status-patch #####
diff -Naur orig/arch/um/drivers/mconsole_kern.c linux-2.4.24/arch/um/drivers/mconsole_kern.c
--- orig/arch/um/drivers/mconsole_kern.c	2004-03-27 02:00:28.000000000 -0700
+++ linux-2.4.24/arch/um/drivers/mconsole_kern.c	2004-03-27 02:10:11.000000000 -0700
@@ -216,6 +216,7 @@
     sysrq <letter> - Performs the SysRq action controlled by the letter \n\
     cad - invoke the Ctl-Alt-Del handler \n\
     stop - pause the UML; it will do nothing until it receives a 'go' \n\
+    status - check to see if the UML is stopped or running\n\
     go - continue the UML after a 'stop' \n\
     log <string> - make UML enter <string> into the kernel log\n\
     proc <file> - returns the contents of the UML's /proc/<file>\n\
@@ -251,15 +252,39 @@
 	mconsole_reply(req, "Not stopped", 1, 0);
 }
 
+void mconsole_status(struct mc_request *req)
+{
+	/* CurrentStatus of 'R' indicates running */
+	/* CurrentStatus of 'S' indicates a stopped UML */
+	static char CurrentStatus = 'R';
+
+	if (req->cmd->handler == mconsole_status)
+	{
+		if (CurrentStatus == 'S') mconsole_reply(req, "Stopped", 0, 0);
+		else mconsole_reply(req, "Running", 0, 0);
+	}
+	else if (req->cmd->handler == mconsole_stop)
+	{
+		CurrentStatus = 'S';
+	}
+	else if (req->cmd->handler == mconsole_go)
+	{
+		CurrentStatus = 'R';
+	}
+	else mconsole_reply(req, "", 1, 0);
+}
+
 void mconsole_stop(struct mc_request *req)
 {
 	deactivate_fd(req->originating_fd, MCONSOLE_IRQ);
 	os_set_fd_block(req->originating_fd, 1);
+	mconsole_status(req); /* change the status to stopped */
 	mconsole_reply(req, "", 0, 0);
 	while(mconsole_get_request(req->originating_fd, req)){
 		if(req->cmd->handler == mconsole_go) break;
 		(*req->cmd->handler)(req);
 	}
+	mconsole_status(req); /* change the status back to running */
 	os_set_fd_block(req->originating_fd, 0);
 	reactivate_fd(req->originating_fd, MCONSOLE_IRQ);
 	mconsole_reply(req, "", 0, 0);
diff -Naur orig/arch/um/drivers/mconsole_user.c linux-2.4.24/arch/um/drivers/mconsole_user.c
--- orig/arch/um/drivers/mconsole_user.c	2004-03-27 02:00:28.000000000 -0700
+++ linux-2.4.24/arch/um/drivers/mconsole_user.c	2004-03-27 02:11:09.000000000 -0700
@@ -28,6 +28,7 @@
 	{ "cad", mconsole_cad, MCONSOLE_INTR },
 	{ "stop", mconsole_stop, MCONSOLE_PROC },
 	{ "go", mconsole_go, MCONSOLE_INTR },
+	{ "status", mconsole_status, MCONSOLE_PROC },
 	{ "log", mconsole_log, MCONSOLE_INTR },
 	{ "proc", mconsole_proc, MCONSOLE_PROC },
 };
diff -Naur orig/arch/um/include/mconsole.h linux-2.4.24/arch/um/include/mconsole.h
--- orig/arch/um/include/mconsole.h	2004-03-27 02:00:28.000000000 -0700
+++ linux-2.4.24/arch/um/include/mconsole.h	2004-03-27 02:11:30.000000000 -0700
@@ -79,6 +79,7 @@
 extern void mconsole_cad(struct mc_request *req);
 extern void mconsole_stop(struct mc_request *req);
 extern void mconsole_go(struct mc_request *req);
+extern void mconsole_status(struct mc_request *req);
 extern void mconsole_log(struct mc_request *req);
 extern void mconsole_proc(struct mc_request *req);