when all you have is a hammer, make it a big one. add more checks to pool_chk

and a pool_init flag to aggressively run pool_chk.  ok art deraadt

1 files changed, 50 insertions, 14 deletions

diff --git a/sys/kern/subr_pool.c b/sys/kern/subr_pool.c
index fcc74a92fd6..29e1bbb6576 100644
--- a/sys/kern/subr_pool.c
+++ b/sys/kern/subr_pool.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: subr_pool.c,v 1.104 2011/04/18 19:23:46 art Exp $	*/
+/*	$OpenBSD: subr_pool.c,v 1.105 2011/07/05 16:36:15 tedu Exp $	*/
 /*	$NetBSD: subr_pool.c,v 1.61 2001/09/26 07:14:56 chs Exp $	*/
 
 /*-
@@ -113,7 +113,7 @@ void	*pool_do_get(struct pool *, int);
 void	 pool_do_put(struct pool *, void *);
 void	 pr_rmpage(struct pool *, struct pool_item_header *,
 	    struct pool_pagelist *);
-int	pool_chk_page(struct pool *, const char *, struct pool_item_header *);
+int	pool_chk_page(struct pool *, struct pool_item_header *, int);
 struct pool_item_header *pool_alloc_item_header(struct pool *, caddr_t , int);
 
 void	*pool_allocator_alloc(struct pool *, int, int *);
@@ -468,7 +468,19 @@ pool_get(struct pool *pp, int flags)
 #endif /* DIAGNOSTIC */
 
 	mtx_enter(&pp->pr_mtx);
+#ifdef POOL_DEBUG
+	if (pp->pr_roflags & PR_DEBUGCHK) {
+		if (pool_chk(pp))
+			panic("before pool_get");
+	}
+#endif
 	v = pool_do_get(pp, flags);
+#ifdef POOL_DEBUG
+	if (pp->pr_roflags & PR_DEBUGCHK) {
+		if (pool_chk(pp))
+			panic("after pool_get");
+	}
+#endif
 	mtx_leave(&pp->pr_mtx);
 	if (v == NULL)
 		return (v);
@@ -692,7 +704,19 @@ pool_put(struct pool *pp, void *v)
 	if (pp->pr_dtor)
 		pp->pr_dtor(pp->pr_arg, v);
 	mtx_enter(&pp->pr_mtx);
+#ifdef POOL_DEBUG
+	if (pp->pr_roflags & PR_DEBUGCHK) {
+		if (pool_chk(pp))
+			panic("before pool_put");
+	}
+#endif
 	pool_do_put(pp, v);
+#ifdef POOL_DEBUG
+	if (pp->pr_roflags & PR_DEBUGCHK) {
+		if (pool_chk(pp))
+			panic("after pool_put");
+	}
+#endif
 	mtx_leave(&pp->pr_mtx);
 	pp->pr_nput++;
 }
@@ -1237,12 +1261,12 @@ db_show_all_pools(db_expr_t expr, int haddr, db_expr_t count, char *modif)
 		PRWORD(ovflw, " %*s", 6, 1, maxp);
 		PRWORD(ovflw, " %*lu\n", 5, 1, pp->pr_nidle);
 
-		pool_chk(pp, pp->pr_wchan);
+		pool_chk(pp);
 	}
 }
 
 int
-pool_chk_page(struct pool *pp, const char *label, struct pool_item_header *ph)
+pool_chk_page(struct pool *pp, struct pool_item_header *ph, int expected)
 {
 	struct pool_item *pi;
 	caddr_t page;
@@ -1250,12 +1274,12 @@ pool_chk_page(struct pool *pp, const char *label, struct pool_item_header *ph)
 #if defined(DIAGNOSTIC) && defined(POOL_DEBUG)
 	int i, *ip;
 #endif
+	const char *label = pp->pr_wchan;
 
 	page = (caddr_t)((u_long)ph & pp->pr_alloc->pa_pagemask);
 	if (page != ph->ph_page &&
 	    (pp->pr_roflags & PR_PHINPAGE) != 0) {
-		if (label != NULL)
-			printf("%s: ", label);
+		printf("%s: ", label);
 		printf("pool(%p:%s): page inconsistency: page %p; "
 		    "at page head addr %p (p %p)\n",
 		    pp, pp->pr_wchan, ph->ph_page, ph, page);
@@ -1268,8 +1292,7 @@ pool_chk_page(struct pool *pp, const char *label, struct pool_item_header *ph)
 
 #ifdef DIAGNOSTIC
 		if (pi->pi_magic != PI_MAGIC) {
-			if (label != NULL)
-				printf("%s: ", label);
+			printf("%s: ", label);
 			printf("pool(%s): free list modified: "
 			    "page %p; item ordinal %d; addr %p "
 			    "(p %p); offset 0x%x=0x%x\n",
@@ -1297,28 +1320,41 @@ pool_chk_page(struct pool *pp, const char *label, struct pool_item_header *ph)
 		if (page == ph->ph_page)
 			continue;
 
-		if (label != NULL)
-			printf("%s: ", label);
+		printf("%s: ", label);
 		printf("pool(%p:%s): page inconsistency: page %p;"
 		    " item ordinal %d; addr %p (p %p)\n", pp,
 		    pp->pr_wchan, ph->ph_page, n, pi, page);
 		return 1;
 	}
+	if (n + ph->ph_nmissing != pp->pr_itemsperpage) {
+		printf("pool(%p:%s): page inconsistency: page %p;"
+		    " %d on list, %d missing, %d items per page\n", pp,
+		    pp->pr_wchan, ph->ph_page, n, ph->ph_nmissing,
+		    pp->pr_itemsperpage);
+		return 1;
+	}
+	if (expected >= 0 && n != expected) {
+		printf("pool(%p:%s): page inconsistency: page %p;"
+		    " %d on list, %d missing, %d expected\n", pp,
+		    pp->pr_wchan, ph->ph_page, n, ph->ph_nmissing,
+		    expected);
+		return 1;
+	}
 	return 0;
 }
 
 int
-pool_chk(struct pool *pp, const char *label)
+pool_chk(struct pool *pp)
 {
 	struct pool_item_header *ph;
 	int r = 0;
 
 	LIST_FOREACH(ph, &pp->pr_emptypages, ph_pagelist)
-		r += pool_chk_page(pp, label, ph);
+		r += pool_chk_page(pp, ph, pp->pr_itemsperpage);
 	LIST_FOREACH(ph, &pp->pr_fullpages, ph_pagelist)
-		r += pool_chk_page(pp, label, ph);
+		r += pool_chk_page(pp, ph, 0);
 	LIST_FOREACH(ph, &pp->pr_partpages, ph_pagelist)
-		r += pool_chk_page(pp, label, ph);
+		r += pool_chk_page(pp, ph, -1);
 
 	return (r);
 }