From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934891AbcI2SPA (ORCPT ); Thu, 29 Sep 2016 14:15:00 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:36870 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934850AbcI2SOp (ORCPT ); Thu, 29 Sep 2016 14:14:45 -0400 From: Colin King To: Linus Walleij , Dan Williams , Vinod Koul , linux-arm-kernel@lists.infradead.org, dmaengine@vger.kernel.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH][V2] dmaengine: coh901318: fix integer overflow when shifting more than 32 places Date: Thu, 29 Sep 2016 19:14:38 +0100 Message-Id: <20160929181438.14374-1-colin.king@canonical.com> X-Mailer: git-send-email 2.9.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King Currently U300_DMA_CHANNELS is set to 40, meaning that the shift of 1 can be more than 32 places, which leads to a 32 bit integer overflow. Fix this by using 1ULL instead of 1 before shifting it. Also add braces on the for-loop to keep with coding style conventions. Signed-off-by: Colin Ian King --- drivers/dma/coh901318.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c index 2835f3e..74794c9 100644 --- a/drivers/dma/coh901318.c +++ b/drivers/dma/coh901318.c @@ -1352,9 +1352,10 @@ static ssize_t coh901318_debugfs_read(struct file *file, char __user *buf, tmp += sprintf(tmp, "DMA -- enabled dma channels\n"); - for (i = 0; i < U300_DMA_CHANNELS; i++) - if (started_channels & (1 << i)) + for (i = 0; i < U300_DMA_CHANNELS; i++) { + if (started_channels & (1ULL << i)) tmp += sprintf(tmp, "channel %d\n", i); + } tmp += sprintf(tmp, "Pool alloc nbr %d\n", pool_count); -- 2.9.3