From patchwork Tue Sep 22 17:51:21 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 521295 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 88E391400A0; Wed, 23 Sep 2015 03:53:58 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ZeRlL-0007Kb-31; Tue, 22 Sep 2015 17:53:55 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ZeRky-00076y-W4 for kernel-team@lists.ubuntu.com; Tue, 22 Sep 2015 17:53:33 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1ZeRky-0000uN-Pb; Tue, 22 Sep 2015 17:53:32 +0000 Received: from kamal by fourier with local (Exim 4.82) (envelope-from ) id 1ZeRkw-0000a7-JD; Tue, 22 Sep 2015 10:53:30 -0700 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 3.19.y-ckt 025/102] regmap: regcache-rbtree: Clean new present bits on present bitmap resize Date: Tue, 22 Sep 2015 10:51:21 -0700 Message-Id: <1442944358-1248-26-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1442944358-1248-1-git-send-email-kamal@canonical.com> References: <1442944358-1248-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Cc: Kamal Mostafa , Mark Brown , Guenter Roeck X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.19.8-ckt7 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Guenter Roeck commit 8ef9724bf9718af81cfc5132253372f79c71b7e2 upstream. 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") Signed-off-by: Guenter Roeck Signed-off-by: Mark Brown Signed-off-by: Kamal Mostafa --- 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 81751a4..56486d9 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 */