From patchwork Sun Jan 3 13:57:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 11995741 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0BA48C433DB for ; Sun, 3 Jan 2021 13:58:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CEFE2208C7 for ; Sun, 3 Jan 2021 13:58:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726969AbhACN6X (ORCPT ); Sun, 3 Jan 2021 08:58:23 -0500 Received: from mail.kernel.org ([198.145.29.99]:35262 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726129AbhACN6X (ORCPT ); Sun, 3 Jan 2021 08:58:23 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 632DE208C7; Sun, 3 Jan 2021 13:57:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1609682262; bh=w6s5kcebAimhgTVacPtTiUtHsUatLmTZP8NLc4JsnK4=; h=From:To:Cc:Subject:Date:From; b=OJjp4WMn408IY0DKvguUQR/l+RzDopHMYgkO326QJjAwxCrvQcSEMEbN5lVDulUqy qqLYkxW6kHrhJbdrkDpQr/VwVH1sdnXBZNXVs+34m2ccbRtVOZa362iV/v+i3FLQUh YTJArNRhdXBW0G4PSHssB1Uk7lRrCiHA/EPSdfK5kWESbtv1eX+o1wQB6aalORtbVx PAyPQtFhCIupKKirFvSW1L4Wpj+x+8zJHzFTlUWhGOmBYOcbY/NZVUQXTDPfxpceQN MSTK8dZz/AkvmX5/mV3KtblrTYnlnM6RxXsgBrV0fxwpIZiYbdL0RgclXxhK+hNLjS VQYGxV8y4LHKg== From: Arnd Bergmann To: Andy Gross , Bjorn Andersson , Vinod Koul Cc: Arnd Bergmann , Dan Williams , linux-arm-msm@vger.kernel.org, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] dmaengine: qcom: fix gpi undefined behavior Date: Sun, 3 Jan 2021 14:57:29 +0100 Message-Id: <20210103135738.3741123-1-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org From: Arnd Bergmann gcc points out an incorrect error handling loop: drivers/dma/qcom/gpi.c: In function 'gpi_ch_init': drivers/dma/qcom/gpi.c:1254:15: error: iteration 2 invokes undefined behavior [-Werror=aggressive-loop-optimizations] 1254 | struct gpii *gpii = gchan->gpii; | ^~~~ drivers/dma/qcom/gpi.c:1951:2: note: within this loop 1951 | for (i = i - 1; i >= 0; i++) { | ^~~ Change the loop to correctly walk backwards through the initialized fields rather than off into the woods. Fixes: 5d0c3533a19f ("dmaengine: qcom: Add GPI dma driver") Signed-off-by: Arnd Bergmann --- drivers/dma/qcom/gpi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dma/qcom/gpi.c b/drivers/dma/qcom/gpi.c index 8d39d3e24686..9c211104ddbf 100644 --- a/drivers/dma/qcom/gpi.c +++ b/drivers/dma/qcom/gpi.c @@ -1948,7 +1948,7 @@ static int gpi_ch_init(struct gchan *gchan) return ret; error_start_chan: - for (i = i - 1; i >= 0; i++) { + for (i = i - 1; i >= 0; i--) { gpi_stop_chan(&gpii->gchan[i]); gpi_send_cmd(gpii, gchan, GPI_CH_CMD_RESET); }