From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751581AbbG0Ee4 (ORCPT ); Mon, 27 Jul 2015 00:34:56 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:42191 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750723AbbG0Eez (ORCPT ); Mon, 27 Jul 2015 00:34:55 -0400 From: Guenter Roeck To: Mark Brown Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Guenter Roeck , Lars-Peter Clausen Subject: [PATCH] regmap: regcache-rbtree: Clean new present bits on present bitmap resize Date: Sun, 26 Jul 2015 21:34:50 -0700 Message-Id: <1437971690-20796-1-git-send-email-linux@roeck-us.net> X-Mailer: git-send-email 2.1.0 X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: guenter@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When inserting a new register into a block, the present bit map size is increased using krealloc. krealloc does not clear the additionally allocated memory, leaving it filled with random values. Result is that some registers are considered cached even though this is not the case. Fix the problem by clearing the additionally allocated memory. Also, if the bitmap size does not increase, do not reallocate the bitmap at all to reduce overhead. Fixes: 3f4ff561bc88 ("regmap: rbtree: Make cache_present bitmap per node") Cc: Lars-Peter Clausen Signed-off-by: Guenter Roeck --- drivers/base/regmap/regcache-rbtree.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c index 81751a49d8bf..56486d92c4e7 100644 --- a/drivers/base/regmap/regcache-rbtree.c +++ b/drivers/base/regmap/regcache-rbtree.c @@ -296,11 +296,20 @@ static int regcache_rbtree_insert_to_block(struct regmap *map, if (!blk) return -ENOMEM; - present = krealloc(rbnode->cache_present, - BITS_TO_LONGS(blklen) * sizeof(*present), GFP_KERNEL); - if (!present) { - kfree(blk); - return -ENOMEM; + if (BITS_TO_LONGS(blklen) > BITS_TO_LONGS(rbnode->blklen)) { + present = krealloc(rbnode->cache_present, + BITS_TO_LONGS(blklen) * sizeof(*present), + GFP_KERNEL); + if (!present) { + kfree(blk); + return -ENOMEM; + } + + memset(present + BITS_TO_LONGS(rbnode->blklen), 0, + (BITS_TO_LONGS(blklen) - BITS_TO_LONGS(rbnode->blklen)) + * sizeof(*present)); + } else { + present = rbnode->cache_present; } /* insert the register value in the correct place in the rbnode block */ -- 2.1.0