From 402ee30714c2cefa9116ff2031672bc6a8cd5c0b Mon Sep 17 00:00:00 2001
From: cinap_lenrek <cinap_lenrek@localhost>
Date: Mon, 27 Jun 2011 06:47:18 +0200
Subject: [PATCH] kernel: fix issue #62 (vunmap bug) reported from
 http://9fans.net/archive/2011/06/262

---
 sys/src/9/pc/mmu.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/sys/src/9/pc/mmu.c b/sys/src/9/pc/mmu.c
index 06b195fca..823c9a6d8 100644
--- a/sys/src/9/pc/mmu.c
+++ b/sys/src/9/pc/mmu.c
@@ -739,16 +739,13 @@ pdbunmap(ulong *pdb, ulong va, int size)
 	vae = va+size;
 	while(va < vae){
 		table = &pdb[PDX(va)];
-		if(!(*table & PTEVALID)){
+		if(!(*table & PTEVALID))
 			panic("vunmap: not mapped");
-			/* 
-			va = (va+4*MB-1) & ~(4*MB-1);
-			continue;
-			*/
-		}
 		if(*table & PTESIZE){
+			if(va & 4*MB-1)
+				panic("vunmap: misaligned: %#p\n", va);
 			*table = 0;
-			va = (va+4*MB-1) & ~(4*MB-1);
+			va += 4*MB;
 			continue;
 		}
 		table = KADDR(PPN(*table));