linux-kernel - [patch 1/3] x86: fix numa emulation calculation of big nodes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <alpine.DEB.2.00.1002151342230.26927@chino.kir.corp.google.com>
Date:	Mon, 15 Feb 2010 13:43:25 -0800 (PST)
From:	David Rientjes <rientjes@...gle.com>
To:	Ingo Molnar <mingo@...hat.com>, "H. Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>
cc:	x86@...nel.org, linux-kernel@...r.kernel.org
Subject: [patch 1/3] x86: fix numa emulation calculation of big nodes

numa=fake=N uses split_nodes_interleave() to partition the system into N
fake nodes.  Each node size must have be a multiple of
FAKE_NODE_MIN_SIZE, otherwise it is possible to get strange alignments.
Because of this, the remaining memory from each node when rounded to
FAKE_NODE_MIN_SIZE is consolidated into a number of "big nodes" that are
bigger than the rest.

The calculation of the number of big nodes is incorrect since it is using
a logical AND operator when it should be multiplying the rounded-off
portion of each node with N.

Signed-off-by: David Rientjes <rientjes@...gle.com>
---
 arch/x86/mm/numa_64.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c
--- a/arch/x86/mm/numa_64.c
+++ b/arch/x86/mm/numa_64.c
@@ -427,7 +427,7 @@ static int __init split_nodes_interleave(u64 addr, u64 max_addr,
 	 * Calculate the number of big nodes that can be allocated as a result
 	 * of consolidating the remainder.
 	 */
-	big = ((size & ~FAKE_NODE_MIN_HASH_MASK) & nr_nodes) /
+	big = ((size & ~FAKE_NODE_MIN_HASH_MASK) * nr_nodes) /
 		FAKE_NODE_MIN_SIZE;
 
 	size &= FAKE_NODE_MIN_HASH_MASK;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/