From patchwork Thu Sep 21 11:35:32 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Peter Ujfalusi X-Patchwork-Id: 9963763 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C6ED56020C for ; Thu, 21 Sep 2017 11:36:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B02442930B for ; Thu, 21 Sep 2017 11:36:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A4D2F29461; Thu, 21 Sep 2017 11:36:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 3D9E32930B for ; Thu, 21 Sep 2017 11:36:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=IYnBAfBkeKByEZQcCxp+XLpCFbR2uRLZ+xr61T0NnE8=; b=CAdltiDf9oVQKZ c6jkNLWtDmS2kU78yHvwKefAtU0tfrKuynmDFM4C6mxA+MABbCM+33VAsLPVLR8UZDhWhe5aTzbdp 1S3g96aTPj4TtR2fopq2srawua9JTce6cak4z5ceNRj/kf924PS8stiNB5T+OL+BmQ6AEaBcaYeLJ N6GFhgJfM3aGJJvVbwiwPsiQr+jij7OUR81zHYJEpuq1fZm3e8HgNsX52SwdZYI1Jh0JaYmOVm3/o G3Nqk5gscY4L66ZAem6KcG5hwgcPd93W+xIH611A08iVlKEnhJQVwTKrn6iKP3kLCRpBPVOI3swqM q7y7jhObF9kmUxC4QHeQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1duzlr-0005mr-BH; Thu, 21 Sep 2017 11:35:55 +0000 Received: from fllnx210.ext.ti.com ([198.47.19.17]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1duzln-0005jI-Sz for linux-arm-kernel@lists.infradead.org; Thu, 21 Sep 2017 11:35:53 +0000 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by fllnx210.ext.ti.com (8.15.1/8.15.1) with ESMTP id v8LBZTjH002102; Thu, 21 Sep 2017 06:35:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ti.com; s=ti-com-17Q1; t=1505993729; bh=znv92LQRhqJ3o8k5ir3JOXHt74Vt1GL/W9mLf329wW0=; h=From:To:CC:Subject:Date; b=nvRB52tqYsLk/noEjApKx4h4LvcPpsth8WgoTpztUp2qgGO+DBE5omsCDHGvxCpTC iSRIbnYyZg1HzvXTKydfwOzpMPxHkEb3rIqS6M1gXZOCiOon0iz3UVXFygnggt0SDM iWRux5q18FcOlDlPAAAlDSp6/msf6fOBSE9H1rqk= Received: from DLEE103.ent.ti.com (dlee103.ent.ti.com [157.170.170.33]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id v8LBZTsA015609; Thu, 21 Sep 2017 06:35:29 -0500 Received: from DLEE101.ent.ti.com (157.170.170.31) by DLEE103.ent.ti.com (157.170.170.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P256) id 15.1.845.34; Thu, 21 Sep 2017 06:35:29 -0500 Received: from dflp33.itg.ti.com (10.64.6.16) by DLEE101.ent.ti.com (157.170.170.31) with Microsoft SMTP Server (version=TLS1_0, cipher=TLS_RSA_WITH_AES_256_CBC_SHA) id 15.1.845.34 via Frontend Transport; Thu, 21 Sep 2017 06:35:29 -0500 Received: from feketebors.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id v8LBZQNg023682; Thu, 21 Sep 2017 06:35:27 -0500 From: Peter Ujfalusi To: , Subject: [PATCH] dmaengine: ti-dma-crossbar: Fix possible race condition with dma_inuse Date: Thu, 21 Sep 2017 14:35:32 +0300 Message-ID: <20170921113532.15297-1-peter.ujfalusi@ti.com> X-Mailer: git-send-email 2.14.1 MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170921_043552_045493_D072CBDC X-CRM114-Status: UNSURE ( 7.75 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: dmaengine@vger.kernel.org, stable@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP When looking for unused xbar_out lane we should also protect the set_bit() call with the same mutex to protect against concurrent threads picking the same ID. Fixes: ec9bfa1e1a796 ("dmaengine: ti-dma-crossbar: dra7: Use bitops instead of idr") Signed-off-by: Peter Ujfalusi Cc: stable@vger.kernel.org --- drivers/dma/ti-dma-crossbar.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/dma/ti-dma-crossbar.c b/drivers/dma/ti-dma-crossbar.c index 10ef9d5d5a66..7df910e7c348 100644 --- a/drivers/dma/ti-dma-crossbar.c +++ b/drivers/dma/ti-dma-crossbar.c @@ -262,13 +262,14 @@ static void *ti_dra7_xbar_route_allocate(struct of_phandle_args *dma_spec, mutex_lock(&xbar->mutex); map->xbar_out = find_first_zero_bit(xbar->dma_inuse, xbar->dma_requests); - mutex_unlock(&xbar->mutex); if (map->xbar_out == xbar->dma_requests) { + mutex_unlock(&xbar->mutex); dev_err(&pdev->dev, "Run out of free DMA requests\n"); kfree(map); return ERR_PTR(-ENOMEM); } set_bit(map->xbar_out, xbar->dma_inuse); + mutex_unlock(&xbar->mutex); map->xbar_in = (u16)dma_spec->args[0];