From mboxrd@z Thu Jan 1 00:00:00 1970 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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 50A8BC2BA83 for ; Fri, 14 Feb 2020 17:15:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2975E2082F for ; Fri, 14 Feb 2020 17:15:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581700527; bh=zpzh7jTzlav5vmENnBuXbz1FGPBgaAbtcDNvY9gavbU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NB27MWnCsFVXYNyGvS2HzwS49joOM5pG6RuBjB7qLNdj+w1T0Xdlq+85rPvoiPnzm fWCpHtIp57wN2e2TxpGiGNXgIvPqq/mFhDa6gODtqJZY+VCk7GiOMRPufmrg8O/gvV F4E7E197awdID9W2kvGlRsFQc2b+ob4nIvpe0esc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392497AbgBNRP0 (ORCPT ); Fri, 14 Feb 2020 12:15:26 -0500 Received: from mail.kernel.org ([198.145.29.99]:39592 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391946AbgBNQMQ (ORCPT ); Fri, 14 Feb 2020 11:12:16 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E7C762469F; Fri, 14 Feb 2020 16:12:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581696735; bh=zpzh7jTzlav5vmENnBuXbz1FGPBgaAbtcDNvY9gavbU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ag48VvDA9Tnv1eAr824aBbw1WVPdJ70tgWspY8Ce6uaSQlFPn3pKDkn6KQZT9cEXP RUQSNGXHcidOA230UZktEvgct+qrDt2Zl+CuUw8lx6afs4iHMXVjLUZpNgZ4aMO8Eb FxY8+NaDF0yIWW2DVCWYUFMkdCpmr1eMT9hLbLvc= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jia-Ju Bai , Fabien Dessenne , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin , linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 021/252] media: sti: bdisp: fix a possible sleep-in-atomic-context bug in bdisp_device_run() Date: Fri, 14 Feb 2020 11:07:56 -0500 Message-Id: <20200214161147.15842-21-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214161147.15842-1-sashal@kernel.org> References: <20200214161147.15842-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: Jia-Ju Bai [ Upstream commit bb6d42061a05d71dd73f620582d9e09c8fbf7f5b ] The driver may sleep while holding a spinlock. The function call path (from bottom to top) in Linux 4.19 is: drivers/media/platform/sti/bdisp/bdisp-hw.c, 385: msleep in bdisp_hw_reset drivers/media/platform/sti/bdisp/bdisp-v4l2.c, 341: bdisp_hw_reset in bdisp_device_run drivers/media/platform/sti/bdisp/bdisp-v4l2.c, 317: _raw_spin_lock_irqsave in bdisp_device_run To fix this bug, msleep() is replaced with udelay(). This bug is found by a static analysis tool STCheck written by myself. Signed-off-by: Jia-Ju Bai Reviewed-by: Fabien Dessenne Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/platform/sti/bdisp/bdisp-hw.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/media/platform/sti/bdisp/bdisp-hw.c b/drivers/media/platform/sti/bdisp/bdisp-hw.c index 26d9fa7aeb5f2..d57f659d740a1 100644 --- a/drivers/media/platform/sti/bdisp/bdisp-hw.c +++ b/drivers/media/platform/sti/bdisp/bdisp-hw.c @@ -14,8 +14,8 @@ #define MAX_SRC_WIDTH 2048 /* Reset & boot poll config */ -#define POLL_RST_MAX 50 -#define POLL_RST_DELAY_MS 20 +#define POLL_RST_MAX 500 +#define POLL_RST_DELAY_MS 2 enum bdisp_target_plan { BDISP_RGB, @@ -382,7 +382,7 @@ int bdisp_hw_reset(struct bdisp_dev *bdisp) for (i = 0; i < POLL_RST_MAX; i++) { if (readl(bdisp->regs + BLT_STA1) & BLT_STA1_IDLE) break; - msleep(POLL_RST_DELAY_MS); + udelay(POLL_RST_DELAY_MS * 1000); } if (i == POLL_RST_MAX) dev_err(bdisp->dev, "Reset timeout\n"); -- 2.20.1