From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Ujfalusi 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> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Return-path: Sender: linux-kernel-owner@vger.kernel.org To: vinod.koul@intel.com, dan.j.williams@intel.com Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, stable@vger.kernel.org List-Id: linux-omap@vger.kernel.org =EF=BB=BFWhen looking for unused xbar_out lane we should also protect the s= et_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_ph= andle_args *dma_spec, mutex_lock(&xbar->mutex); map->xbar_out =3D find_first_zero_bit(xbar->dma_inuse, xbar->dma_requests); - mutex_unlock(&xbar->mutex); if (map->xbar_out =3D=3D 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); =20 map->xbar_in =3D (u16)dma_spec->args[0]; =20 --=20 2.14.1 Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Bu= siness ID: 0615521-4. Kotipaikka/Domicile: Helsinki