From: Ben Gras <ben@minix3.org>
Date: Mon, 19 Jul 2010 18:19:16 +0000 (+0000)
Subject: vm: allow readonly pages when sanity checking when they're supposed to be rw.
X-Git-Tag: v3.1.8~191
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/invmod.png?a=commitdiff_plain;h=5e2c84b1194d601f69c64cfa92160f1e7ee49a8d;p=minix.git

vm: allow readonly pages when sanity checking when they're supposed to be rw.
---

diff --git a/servers/vm/arch/i386/pagetable.c b/servers/vm/arch/i386/pagetable.c
index ca7f37daa..8b8a4c426 100644
--- a/servers/vm/arch/i386/pagetable.c
+++ b/servers/vm/arch/i386/pagetable.c
@@ -581,6 +581,10 @@ PUBLIC int pt_writemap(pt_t *pt, vir_bytes v, phys_bytes physaddr,
 			maskedentry = pt->pt_pt[pde][pte];
 			maskedentry &= ~(I386_VM_ACC|I386_VM_DIRTY);
 			/* Verify pagetable entry. */
+			if(entry & I386_VM_WRITE) {
+				/* If we expect a writable page, allow a readonly page. */
+				maskedentry |= I386_VM_WRITE;
+			}
 			if(maskedentry != entry) {
 				printf("pt_writemap: mismatch: ");
 				if((entry & I386_VM_ADDR_MASK) !=