Initialize and destroy the struct proc mutex in the proc zone's init and

fini routines instead of in fork() and wait().  This has the nice side
benefit that the proc lock of any process on the allproc list is always
valid and sched_lock doesn't have to be used to test against PRS_NEW
anymore.

3 files changed, 6 insertions, 5 deletions

diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index 8e16d3e..b77c1d9 100644
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -685,7 +685,6 @@ loop:
 			 * release while still running in process context.
 			 */
 			vm_waitproc(p);
-			mtx_destroy(&p->p_mtx);
 #ifdef MAC
 			mac_destroy_proc(p);
 #endif
diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index 7d2c65c..17387f8 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -447,6 +447,9 @@ again:
 	if (pages != 0)
 		pmap_new_altkstack(td2, pages);
 
+	PROC_LOCK(p2);
+	PROC_LOCK(p1);
+
 #define RANGEOF(type, start, end) (offsetof(type, end) - offsetof(type, start))
 
 	bzero(&p2->p_startzero,
@@ -458,10 +461,6 @@ again:
 	bzero(&kg2->kg_startzero,
 	    (unsigned) RANGEOF(struct ksegrp, kg_startzero, kg_endzero));
 
-	mtx_init(&p2->p_mtx, "process lock", NULL, MTX_DEF | MTX_DUPOK);
-	PROC_LOCK(p2);
-	PROC_LOCK(p1);
-
 	bcopy(&p1->p_startcopy, &p2->p_startcopy,
 	    (unsigned) RANGEOF(struct proc, p_startcopy, p_endcopy));
 	bcopy(&td->td_startcopy, &td2->td_startcopy,
diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index 5ad7882..6810537 100644
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -194,6 +194,8 @@ proc_init(void *mem, int size)
 	ke = kse_alloc();
 	kg = ksegrp_alloc();
 	proc_linkup(p, kg, ke, td);
+	bzero(&p->p_mtx, sizeof(struct mtx));
+	mtx_init(&p->p_mtx, "process lock", NULL, MTX_DEF | MTX_DUPOK);
 }
 
 /*
@@ -220,6 +222,7 @@ proc_fini(void *mem, int size)
 	thread_free(td);
 	ksegrp_free(kg);
 	kse_free(ke);
+	mtx_destroy(&p->p_mtx);
 }
 
 /*