CVS commit: [netbsd-5] src/sys/kern

[Jeff Rizzo]

Module Name:    src
Committed By:   riz
Date:           Sun Nov 21 17:36:45 UTC 2010

Modified Files:
        src/sys/kern [netbsd-5]: sys_lwp.c

Log Message:
Pull up following revision(s) (requested by skrll in ticket #1415):
        sys/kern/sys_lwp.c: revision 1.50
Follow the correct locking protocol when creating an LWP and the process
is stopping.
Problem found by running the gdb testsuite (gdb didn't have pthreads
support)
Thanks to rmind for help with this.


To generate a diff of this commit:
cvs rdiff -u -r1.43 -r1.43.4.1 src/sys/kern/sys_lwp.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/kern/sys_lwp.c
diff -u src/sys/kern/sys_lwp.c:1.43 src/sys/kern/sys_lwp.c:1.43.4.1
--- src/sys/kern/sys_lwp.c:1.43	Thu Oct 16 08:47:07 2008
+++ src/sys/kern/sys_lwp.c	Sun Nov 21 17:36:45 2010
@@ -1,4 +1,4 @@
-/*	$NetBSD: sys_lwp.c,v 1.43 2008/10/16 08:47:07 ad Exp $	*/
+/*	$NetBSD: sys_lwp.c,v 1.43.4.1 2010/11/21 17:36:45 riz Exp $	*/
 
 /*-
  * Copyright (c) 2001, 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_lwp.c,v 1.43 2008/10/16 08:47:07 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_lwp.c,v 1.43.4.1 2010/11/21 17:36:45 riz Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -81,6 +81,7 @@
 	} */
 	struct proc *p = l->l_proc;
 	struct lwp *l2;
+	struct schedstate_percpu *spc;
 	vaddr_t uaddr;
 	bool inmem;
 	ucontext_t *newuc;
@@ -134,20 +135,23 @@
 	 */
 	mutex_enter(p->p_lock);
 	lwp_lock(l2);
+	spc = &l2->l_cpu->ci_schedstate;
 	if ((SCARG(uap, flags) & LWP_SUSPENDED) == 0 &&
 	    (l->l_flag & (LW_WREBOOT | LW_WSUSPEND | LW_WEXIT)) == 0) {
-	    	if (p->p_stat == SSTOP || (p->p_sflag & PS_STOPPING) != 0)
+	    	if (p->p_stat == SSTOP || (p->p_sflag & PS_STOPPING) != 0) {
+			KASSERT(l2->l_wchan == NULL);
 	    		l2->l_stat = LSSTOP;
-		else {
-			KASSERT(lwp_locked(l2, l2->l_cpu->ci_schedstate.spc_mutex));
+			lwp_unlock_to(l2, spc->spc_lwplock);
+		} else {
+			KASSERT(lwp_locked(l2, spc->spc_mutex));
 			p->p_nrlwps++;
 			l2->l_stat = LSRUN;
 			sched_enqueue(l2, false);
+			lwp_unlock(l2);
 		}
-		lwp_unlock(l2);
 	} else {
 		l2->l_stat = LSSUSPENDED;
-		lwp_unlock_to(l2, l2->l_cpu->ci_schedstate.spc_lwplock);
+		lwp_unlock_to(l2, spc->spc_lwplock);
 	}
 	mutex_exit(p->p_lock);