From: Jorrit Herder <jnherder@minix3.org>
Date: Fri, 27 May 2005 13:10:58 +0000 (+0000)
Subject: Fixed a bug in PM: sending of reply messages didn't check if destination
X-Git-Tag: v3.1.0~810
X-Git-Url: http://zhaoyanbai.com/repos/%22/xml/v3/status/static/gitweb.js?a=commitdiff_plain;h=07d582872fa1fd448a0421abe7cef80ae8693979;p=minix.git

Fixed a bug in PM: sending of reply messages didn't check if destination
process is still alive. This caused a panic in some situations, e.g., when
all processes are killed on a shutdown.
---

diff --git a/servers/pm/main.c b/servers/pm/main.c
index 671a97b0c..9f214a4a4 100644
--- a/servers/pm/main.c
+++ b/servers/pm/main.c
@@ -37,7 +37,7 @@ PUBLIC void main()
 {
 /* Main routine of the process manager. */
 
-  int result, proc_nr;
+  int result, s, proc_nr;
   struct mproc *rmp;
 
   pm_init();			/* initialize process manager tables */
@@ -74,9 +74,12 @@ PUBLIC void main()
 	 * the call just made above.  The processes must not be swapped out.
 	 */
 	for (proc_nr=0, rmp=mproc; proc_nr < NR_PROCS; proc_nr++, rmp++) {
-		if ((rmp->mp_flags & (REPLY | ONSWAP)) == REPLY) {
-			if (send(proc_nr, &rmp->mp_reply) != OK)
+		if ((rmp->mp_flags & IN_USE) &&
+		    (rmp->mp_flags & (REPLY | ONSWAP)) == REPLY) {
+			if ((s=send(proc_nr, &rmp->mp_reply)) != OK) {
+				printf("Warning, PM send failed: %d, ", s);
 				panic("PM can't reply to", proc_nr);
+			}
 			rmp->mp_flags &= ~REPLY;
 		}
 	}
diff --git a/servers/pm/misc.c b/servers/pm/misc.c
index 32aa327d5..fa18427cc 100644
--- a/servers/pm/misc.c
+++ b/servers/pm/misc.c
@@ -71,8 +71,10 @@ PUBLIC int do_reboot()
   tell_fs(REBOOT,0,0,0);		/* tell FS to prepare for shutdown */
   check_sig(-1, SIGKILL); 		/* kill all processes except init */
 
+  /* Ask the kernel to abort. All system services, including the PM, will 
+   * get a HARD_STOP notification. Await the notification in the main loop.
+   */
   sys_abort(m_in.reboot_flag, PM_PROC_NR, monitor_code, m_in.reboot_size);
-  sys_exit(0);
 }
 
 /*=====================================================================*