From nobody Wed Apr 8 15:52:31 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3CAB4C433FE for ; Wed, 26 Oct 2022 22:47:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233791AbiJZWry (ORCPT ); Wed, 26 Oct 2022 18:47:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54916 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233745AbiJZWrg (ORCPT ); Wed, 26 Oct 2022 18:47:36 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0C6C4550BE for ; Wed, 26 Oct 2022 15:47:23 -0700 (PDT) Received: from dimapc.. (109-252-112-196.nat.spd-mgts.ru [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 A74CB66028B0; Wed, 26 Oct 2022 23:47:20 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1666824441; bh=6QiRYUSIMrwPPW/bBvP2JzfoL5s94stAk7lsEZE9m8Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FxHJGJrXr3g7J0J0RfrP4JFa3nf0DcPezfn4+8uA+S1ghQJkSPIgCGWeSfQj2nYQ5 JteVO3aWq8EK78cA3C2H9IKn5y3f+biO5ugA3yV6zqc976O+uzJEWaxxXo9zSlRbHY qpnaRMgGJ8RVu8iKcErs8ZXZjcuzdVjOKLRI6UrdtQCYUvmL4cDQb4LHR7TY6kbrOn s1Qzkg4NpCasK0MI2cO7jirXKaZRQCnbNzD1H9vFBAYe7akc7zKzBndF7ER9yMNaVu xLcCOMfL7LuBqXOwamj/BEpoxXF4nOXQru2umqRKw4t0wxANEL4+LZc2lIu0sk8Qgb It/Hk6J8WUfyA== From: Dmitry Osipenko To: Maarten Lankhorst , Maxime Ripard , Sumit Semwal , Thomas Zimmermann , =?UTF-8?q?Christian=20K=C3=B6nig?= , David Airlie , Daniel Vetter , noralf@tronnes.org, Dan Carpenter Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH v1 1/2] dma-buf: Make locking consistent in dma_buf_detach() Date: Thu, 27 Oct 2022 01:46:39 +0300 Message-Id: <20221026224640.7542-2-dmitry.osipenko@collabora.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221026224640.7542-1-dmitry.osipenko@collabora.com> References: <20221026224640.7542-1-dmitry.osipenko@collabora.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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 Link: https://lore.kernel.org/dri-devel/Y1fLfsccW3AS%2Fo+%2F@kili/ Fixes: 809d9c72c2f8 ("dma-buf: Move dma_buf_attach() to dynamic locking spe= cification") Signed-off-by: Dmitry Osipenko --- drivers/dma-buf/dma-buf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index c40d72d318fd..6e33ef4fde34 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -998,9 +998,10 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma= _buf_attachment *attach) if (WARN_ON(!dmabuf || !attach)) return; =20 - dma_resv_lock(attach->dmabuf->resv, NULL); + dma_resv_lock(dmabuf->resv, NULL); =20 if (attach->sgt) { + WARN_ON(dmabuf !=3D attach->dmabuf); =20 __unmap_dma_buf(attach, attach->sgt, attach->dir); =20 --=20 2.37.3