[PATCH] x86_64: Fix overflow in NUMA hash function setup

Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

arch/x86_64/mm/numa.c

@@ -36,11 +36,18 @@ int numa_off __initdata;
 int __init compute_hash_shift(struct node *nodes, int numnodes)
 {
 	int i; 
-	int shift = 24;
-	u64 addr;
+	int shift = 20;
+	unsigned long addr,maxend=0;
 	
-	/* When in doubt use brute force. */
-	while (shift < 48) { 
+	for (i = 0; i < numnodes; i++)
+		if ((nodes[i].start != nodes[i].end) && (nodes[i].end > maxend))
+				maxend = nodes[i].end;
+
+	while ((1UL << shift) <  (maxend / NODEMAPSIZE))
+		shift++;
+
+	printk (KERN_DEBUG"Using %d for the hash shift. Max adder is %lx \n",
+			shift,maxend);
 	memset(memnodemap,0xff,sizeof(*memnodemap) * NODEMAPSIZE);
 	for (i = 0; i < numnodes; i++) {
 		if (nodes[i].start == nodes[i].end)
@@ -48,22 +55,17 @@ int __init compute_hash_shift(struct node *nodes, int numnodes)
 		for (addr = nodes[i].start;
 		     addr < nodes[i].end;
 		     addr += (1UL << shift)) {
-				if (memnodemap[addr >> shift] != 0xff && 
-				    memnodemap[addr >> shift] != i) { 
+			if (memnodemap[addr >> shift] != 0xff) {
 				printk(KERN_INFO
-					    "node %d shift %d addr %Lx conflict %d\n", 
-					       i, shift, addr, memnodemap[addr>>shift]);
-					goto next; 
+	"Your memory is not aligned you need to rebuild your kernel "
+	"with a bigger NODEMAPSIZE shift=%d adder=%lu\n",
+					shift,addr);
+				return -1;
 			} 
 			memnodemap[addr >> shift] = i;
 		} 
 	} 
 	return shift;
-	next:
-		shift++; 
-	} 
-	memset(memnodemap,0,sizeof(*memnodemap) * NODEMAPSIZE); 
-	return -1; 
 }
 
 #ifdef CONFIG_SPARSEMEM