From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935214AbdDSOjU (ORCPT ); Wed, 19 Apr 2017 10:39:20 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:45752 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935181AbdDSOjO (ORCPT ); Wed, 19 Apr 2017 10:39:14 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Minchan Kim , Sergey Senozhatsky , Andrew Morton , Linus Torvalds Subject: [PATCH 4.10 08/69] zsmalloc: expand class bit Date: Wed, 19 Apr 2017 16:36:37 +0200 Message-Id: <20170419141555.451630205@linuxfoundation.org> X-Mailer: git-send-email 2.12.2 In-Reply-To: <20170419141555.114738231@linuxfoundation.org> References: <20170419141555.114738231@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Minchan Kim commit 85d492f28d056c40629fc25d79f54da618a29dc4 upstream. Now 64K page system, zsamlloc has 257 classes so 8 class bit is not enough. With that, it corrupts the system when zsmalloc stores 65536byte data(ie, index number 256) so that this patch increases class bit for simple fix for stable backport. We should clean up this mess soon. index size 0 32 1 288 .. .. 204 52256 256 65536 Fixes: 3783689a1 ("zsmalloc: introduce zspage structure") Link: http://lkml.kernel.org/r/1492042622-12074-3-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim Cc: Sergey Senozhatsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/zsmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -280,7 +280,7 @@ struct zs_pool { struct zspage { struct { unsigned int fullness:FULLNESS_BITS; - unsigned int class:CLASS_BITS; + unsigned int class:CLASS_BITS + 1; unsigned int isolated:ISOLATED_BITS; unsigned int magic:MAGIC_VAL_BITS; };