From patchwork Sun Oct 30 15:44:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dmitry Osipenko X-Patchwork-Id: 13025105 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E4F8AECAAA1 for ; Sun, 30 Oct 2022 15:45:10 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7D91A10E107; Sun, 30 Oct 2022 15:45:05 +0000 (UTC) Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2E31110E0FC for ; Sun, 30 Oct 2022 15:44:52 +0000 (UTC) Received: from dimapc.. (unknown [109.252.112.196]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: dmitry.osipenko) by madras.collabora.co.uk (Postfix) with ESMTPSA id 539C7660225F; Sun, 30 Oct 2022 15:44:49 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1667144690; bh=9L1UGeJdnkFYaRnE59XJ8gv48CnIdhLcIsE2uZ/nI0w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NrgMQ4JJcS/wCdnXA8AG/2ltnRc/459pzQVz+tPEzTYMw+l7wUlkqJ3gZn7BQsjRv 9EqSxbTZQnHVfP80TN7xvKFBhY/gqWfvUuzxwqLZJzFlY/fllOOfADR9n2UjVY/Ovw vC2W3JH7CUfTxnn47rZPq8ltpqZkp44vY1VcNNd7WV7ugzd5Wn+KLCw30/TaqhP6IR BTFkOYacsIhlK0YpHKh2lzNCdwaG/NrrN6UBYAaGFaRd+fLrIv1r9kp7pMPoIXazJr hYSBvQpvrwDbcLRpxvHRM31eY6ni/XCZvj9Zmntx78pHz5itR4y+dreooXnjBow/ia PZ8gz0SH1PJQg== From: Dmitry Osipenko To: Maarten Lankhorst , Maxime Ripard , Sumit Semwal , Thomas Zimmermann , =?utf-8?q?Christian_K=C3=B6nig?= , David Airlie , Daniel Vetter , noralf@tronnes.org, Dan Carpenter Subject: [PATCH v2 1/2] dma-buf: Make locking consistent in dma_buf_detach() Date: Sun, 30 Oct 2022 18:44:11 +0300 Message-Id: <20221030154412.8320-2-dmitry.osipenko@collabora.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221030154412.8320-1-dmitry.osipenko@collabora.com> References: <20221030154412.8320-1-dmitry.osipenko@collabora.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The dma_buf_detach() locks attach->dmabuf->resv and then unlocks dmabuf->resv, which could be a two different locks from a static code checker perspective. In particular this triggers Smatch to report the "double unlock" error. Make the locking pointers consistent. Reported-by: Dan Carpenter Reviewed-by: Christian König Link: https://lore.kernel.org/dri-devel/Y1fLfsccW3AS%2Fo+%2F@kili/ Fixes: 809d9c72c2f8 ("dma-buf: Move dma_buf_attach() to dynamic locking specification") Signed-off-by: Dmitry Osipenko --- drivers/dma-buf/dma-buf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index c40d72d318fd..13bfd2d09c56 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -995,10 +995,10 @@ static void __unmap_dma_buf(struct dma_buf_attachment *attach, */ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) { - if (WARN_ON(!dmabuf || !attach)) + if (WARN_ON(!dmabuf || !attach || dmabuf != attach->dmabuf)) return; - dma_resv_lock(attach->dmabuf->resv, NULL); + dma_resv_lock(dmabuf->resv, NULL); if (attach->sgt) {