From: Eric Dumazet <dada1@cosmosbay.com>
Date: Tue, 13 Dec 2005 06:17:14 +0000 (-0800)
Subject: [PATCH] x86_64: Bug correction in populate_memnodemap()
X-Git-Tag: v2.6.15-rc6~86
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8309cf66fd90ccba9894adde2f3a8d7e1507e4d2;p=linux-2.6

[PATCH] x86_64: Bug correction in populate_memnodemap()

As reported by Keith Mannthey, there are problems in populate_memnodemap()

The bug was that the compute_hash_shift() was returning 31, with incorrect
initialization of memnodemap[]

To correct the bug, we must use (1UL << shift) instead of (1 << shift) to
avoid an integer overflow, and we must check that shift < 64 to avoid an
infinite loop.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
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 a828a01739..15b67d2760 100644
--- a/arch/x86_64/mm/numa.c
+++ b/arch/x86_64/mm/numa.c
@@ -53,6 +53,8 @@ static int __init populate_memnodemap(
 	int res = -1;
 	unsigned long addr, end;
 
+	if (shift >= 64)
+		return -1;
 	memset(memnodemap, 0xff, sizeof(memnodemap));
 	for (i = 0; i < numnodes; i++) {
 		addr = nodes[i].start;
@@ -65,7 +67,7 @@ static int __init populate_memnodemap(
 			if (memnodemap[addr >> shift] != 0xff)
 				return -1;
 			memnodemap[addr >> shift] = i;
-			addr += (1 << shift);
+                       addr += (1UL << shift);
 		} while (addr < end);
 		res = 1;
 	}