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

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/x86_64/mm/numa.c b/arch/x86_64/mm/numa.c
index ac61c186eb0218862f59e8638bef6ef918e11064..70cb2904a90f9dd8c9310bb368976bc67124d784 100644 (file)
--- a/arch/x86_64/mm/numa.c
+++ b/arch/x86_64/mm/numa.c
@@ -36,34 +36,36 @@ 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) { 
-               memset(memnodemap,0xff,sizeof(*memnodemap) * NODEMAPSIZE); 
-               for (i = 0; i < numnodes; i++) {
-                       if (nodes[i].start == nodes[i].end) 
-                               continue;
-                       for (addr = nodes[i].start; 
-                            addr < nodes[i].end; 
-                            addr += (1UL << shift)) {
-                               if (memnodemap[addr >> shift] != 0xff && 
-                                   memnodemap[addr >> shift] != i) { 
-                                       printk(KERN_INFO 
-                                           "node %d shift %d addr %Lx conflict %d\n", 
-                                              i, shift, addr, memnodemap[addr>>shift]);
-                                       goto next; 
-                               } 
-                               memnodemap[addr >> shift] = i; 
+       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)
+                       continue;
+               for (addr = nodes[i].start;
+                    addr < nodes[i].end;
+                    addr += (1UL << shift)) {
+                       if (memnodemap[addr >> shift] != 0xff) {
+                               printk(KERN_INFO
+       "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; 
+       return shift;
 }
 
 #ifdef CONFIG_SPARSEMEM