From mboxrd@z Thu Jan 1 00:00:00 1970 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= Date: Fri, 16 May 2014 19:31:39 +0000 Subject: Re: [PATCH v2] ARM: imx: fix error handling Message-Id: <20140516193139.GQ16662@pengutronix.de> List-Id: References: <1400234045-6022-1-git-send-email-emilgoode@gmail.com> <5375EB13.8000200@bfs.de> <20140516111646.GC4366@lianli> <5375FB36.8020004@bfs.de> In-Reply-To: <5375FB36.8020004@bfs.de> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: linux-arm-kernel@lists.infradead.org Hello Walter, On Fri, May 16, 2014 at 01:49:10PM +0200, walter harms wrote: > Am 16.05.2014 13:16, schrieb Emil Goode: > > Hello Walter, > >=20 > > On Fri, May 16, 2014 at 12:40:19PM +0200, walter harms wrote: > >> > >> > >> Am 16.05.2014 11:54, schrieb Emil Goode: > >>> If we fail to allocate struct platform_device pdev we > >>> dereference it after the goto label err. > >>> > >>> I have rearranged the error handling a bit to fix the issue > >>> and also make it more clear. > >>> > >>> Signed-off-by: Emil Goode > >>> --- > >>> v2: Changed to return -ENOMEM instead of ret where possible and > >>> updated the subject line. > >>> > >>> arch/arm/mach-imx/devices/platform-ipu-core.c | 22 +++++++++++++--= ------- > >>> 1 file changed, 13 insertions(+), 9 deletions(-) > >>> > >>> diff --git a/arch/arm/mach-imx/devices/platform-ipu-core.c b/arch/arm= /mach-imx/devices/platform-ipu-core.c > >>> index fc4dd7c..68f2a4a 100644 > >>> --- a/arch/arm/mach-imx/devices/platform-ipu-core.c > >>> +++ b/arch/arm/mach-imx/devices/platform-ipu-core.c > >>> @@ -77,34 +77,38 @@ struct platform_device *__init imx_alloc_mx3_came= ra( > >>> =20 > >>> pdev =3D platform_device_alloc("mx3-camera", 0); > >>> if (!pdev) > >>> - goto err; > >>> + return ERR_PTR(-ENOMEM); > >>> =20 > >>> pdev->dev.dma_mask =3D kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KER= NEL); > >>> if (!pdev->dev.dma_mask) > >>> - goto err; > >>> + goto put_pdev; > >>> =20 > >>> *pdev->dev.dma_mask =3D DMA_BIT_MASK(32); > >>> pdev->dev.coherent_dma_mask =3D DMA_BIT_MASK(32); > >>> =20 > >>> ret =3D platform_device_add_resources(pdev, res, ARRAY_SIZE(res)); > >>> if (ret) > >>> - goto err; > >>> + goto free_dma_mask; > >>> =20 > >>> if (pdata) { > >>> struct mx3_camera_pdata *copied_pdata; > >>> =20 > >>> ret =3D platform_device_add_data(pdev, pdata, sizeof(*pdata)); > >>> - if (ret) { > >>> -err: > >>> - kfree(pdev->dev.dma_mask); > >>> - platform_device_put(pdev); > >>> - return ERR_PTR(-ENODEV); > >>> - } > >>> + if (ret) > >>> + goto free_dma_mask; > >>> + > >>> copied_pdata =3D dev_get_platdata(&pdev->dev); > >>> copied_pdata->dma_dev =3D &imx_ipu_coredev->dev; > >> > >> > >> the patch is fine, but what use is this copied_pdata ? > >> It scope ends next line ? > >> > >> re, > >> wh > >=20 > > I also thought that looked a bit odd, but copied_pdata is a temporary > > pointer to platform_data of the dev struct. > >=20 > > dev_get_platdata looks like this: > >=20 > > static inline void *dev_get_platdata(const struct device *dev) > > { > > return dev->platform_data; > > } > >=20 > > So I believe it's a more compact way of writing: > >=20 > > pdev->dev->platform_data->dma_dev =3D &imx_ipu_coredev->dev; It's not about compactness. The dev_get_platdata accessor exists to be used instead of directly accessing dev->platform_data. I admit a comment would be nice ... Anyhow this is all ugly, actually you'd want to have the dma_dev member already fixed when calling platform_device_add_data. But you cannot simply do pdata->dma_dev =3D &imx_ipu_coredev->dev; ret =3D platform_device_add_data(pdev, pdata, sizeof(*pdata)); because *pdata is const. Best regards Uwe --=20 Pengutronix e.K. | Uwe Kleine-K=F6nig | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html