[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 a828a01739cc791015d1bd02e8e04a555bdf288f..15b67d2760cbf8116eba1762a59e821adaddb073 100644 (file)
--- 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;
        }