From: kettenis <kettenis@openbsd.org>
Date: Tue, 1 Feb 2022 19:57:28 +0000 (+0000)
Subject: Make sure we always pass a page-aligned address to pmap_grow_map().
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=8d567340186ba22b9d2396ea8d6c2db96253cae7;p=openbsd

Make sure we always pass a page-aligned address to pmap_grow_map().
Fixes an issue uncovered by the recent change to enlarge kva space where
an unaligned address was passed resulting in memset() writing past the
end of the newly allocated page.

ok miod@
---

diff --git a/sys/arch/arm/arm/pmap7.c b/sys/arch/arm/arm/pmap7.c
index 45de66ba816..ffad79e0b5e 100644
--- a/sys/arch/arm/arm/pmap7.c
+++ b/sys/arch/arm/arm/pmap7.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pmap7.c,v 1.61 2021/03/25 04:12:00 jsg Exp $	*/
+/*	$OpenBSD: pmap7.c,v 1.62 2022/02/01 19:57:28 kettenis Exp $	*/
 /*	$NetBSD: pmap.c,v 1.147 2004/01/18 13:03:50 scw Exp $	*/
 
 /*
@@ -1968,6 +1968,8 @@ pmap_grow_map(vaddr_t va, pt_entry_t cache_mode, paddr_t *pap)
 	pt_entry_t *ptep;
 	paddr_t pa;
 
+	KASSERT((va & PAGE_MASK) == 0);
+
 	if (uvm.page_init_done == 0) {
 		if (uvm_page_physget(&pa) == 0)
 			return (1);
@@ -2032,7 +2034,8 @@ pmap_grow_l2_bucket(pmap_t pm, vaddr_t va)
 			 * The new l2_dtable straddles a page boundary.
 			 * Map in another page to cover it.
 			 */
-			if (pmap_grow_map(nva, pte_l2_s_cache_mode, NULL))
+			if (pmap_grow_map(trunc_page(nva),
+			    pte_l2_s_cache_mode, NULL))
 				return (NULL);
 		}