From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932852AbeCIWOg (ORCPT ); Fri, 9 Mar 2018 17:14:36 -0500 Received: from lelnx193.ext.ti.com ([198.47.27.77]:47938 "EHLO lelnx193.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932108AbeCIWOe (ORCPT ); Fri, 9 Mar 2018 17:14:34 -0500 Subject: Re: Nokia N900: refcount_t underflow, use after free To: Robin Murphy , Pavel Machek CC: , , Tony Lindgren , , kernel list , , , =?UTF-8?Q?Filip_Matijevi=c4=87?= , , , , , , , linux-arm-kernel , References: <20180308143053.GA17267@amd> <20180308165903.GM5799@atomide.com> <57c9f17b-fc9d-8506-4b5d-70ac216c9248@ti.com> <20180308185046.GA22796@amd> <1dfc05fe-1612-f5a5-b5f1-9038b3cecfe5@arm.com> From: Suman Anna Message-ID: <1643b74a-62ba-bea6-71c2-a2dd02430463@ti.com> Date: Fri, 9 Mar 2018 16:13:36 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <1dfc05fe-1612-f5a5-b5f1-9038b3cecfe5@arm.com> Content-Type: text/plain; charset="windows-1252" Content-Language: en-US Content-Transfer-Encoding: 8bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/09/2018 06:08 AM, Robin Murphy wrote: > On 08/03/18 18:50, Pavel Machek wrote: >> Hi! >> >>>> * Pavel Machek [180308 14:31]: >>>>> Hi! >>>>> >>>>> I'm getting this warning... Has anyone seen/debugged that before? >>>>> Unfortunately the backtrace does not seem to be too useful :-(. >>>> >>>> Adding Suman to Cc, as it points to arm_iommu_release_mapping(). >>> >>> Hmm, we need to find out if the failure paths in isp_probe() are >>> mismatched, or if this is coming from some mismatch between the OMAP >>> IOMMU driver and the DMA plumbing. AFAIK, the cleanup paths in this >> >> Well, camera only started to work on N900 pretty recently. Let me add >> some debug printks... >> >> Camera does not work in 4.16.0-rc4-next-20180308-dirty. >> >> I see this. It looks like problem in isp error paths, indeed: > > Well, there certainly seems to be an obvious bug wherein > isp_detach_iommu() just releases the mapping directly without calling > arm_iommu_detach_device() to balance the equivalent attach. That can't > be helping. Indeed, I have been able to reproduce the same warning using a standalone test module, and the missing arm_iommu_detach_device() is causing the warning after probe (during failure path) or during remove. regards Suman > > Robin. > >> >> [    1.672210] bus: 'platform': driver_probe_device: matched device >> 480bc000.isp with dr >> iver omap3isp >> [    1.681976] isp_probe: 1 >> [    1.684906] isp_probe: 2 >> [    1.687591] isp_probe: 3 >> [    1.690338] isp_probe: 4 >> [    1.693054] omap3isp 480bc000.isp: 480bc000.isp supply vdd-csiphy1 >> not found, using d >> ummy regulator >> [    1.702728] omap3isp 480bc000.isp: 480bc000.isp supply vdd-csiphy2 >> not found, using d >> ummy regulator >> [    1.712402] isp_probe: 5 >> [    1.715393] omap3isp 480bc000.isp: Revision 2.0 found >> [    1.720794] isp_probe: 6 >> [    1.723815] isp_probe: 7 >> [    1.726715] omap-iommu 480bd400.mmu: 480bd400.mmu: version 1.1 >> [    1.732849] isp_probe: 8 >> [    1.735656] isp_probe: 9 >> [    1.738403] isp_probe: 10 >> [    1.741241] isp_probe: f3 >> [    1.744018] iommu_release_mapping... ce4d9500 ce4d949c >> [    1.749450] iommu_release_mapping... ok >> [    1.753479] isp_probe: f4 >> [    1.756286] clk_unregister: unregistering prepared clock: cam_xclka >> [    1.762878] clk_unregister: unregistering prepared clock: cam_xclkb >> [    1.769500] isp_probe: f5 >> [    1.772430] iommu_release_mapping... ce4d9500 ce4d949c >> [    1.777862] ------------[ cut here ]------------ >> [    1.782745] WARNING: CPU: 0 PID: 1 at lib/refcount.c:187 >> refcount_sub_and_test+0x94/0 >> xa8 >> [    1.791290] refcount_t: underflow; use-after-free. >> [    1.796356] Modules linked in: >> [    1.799591] CPU: 0 PID: 1 Comm: swapper Not tainted >> 4.16.0-rc4-next-20180308-dirty #7 >> 3 >> [    1.807922] Hardware name: Nokia RX-51 board >> [    1.812469] [] (unwind_backtrace) from [] >> (show_stack+0x10/0x14) >> [    1.820648] [] (show_stack) from [] >> (__warn+0xe8/0x110) >> ... >> [    1.968688] iommu_release_mapping... ok >> [    1.973754] bus: 'platform': driver_probe_device: matched device >> n900-battery with driver rx51-battery >> [    1.984436] bus: 'platform': driver_probe_device: matched device >> 48002524.bandgap with driver ti-soc-thermal >> >> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c >> index 8c398fe..16f4c69 100644 >> --- a/arch/arm/mm/dma-mapping.c >> +++ b/arch/arm/mm/dma-mapping.c >> @@ -2251,8 +2251,11 @@ static int extend_iommu_mapping(struct >> dma_iommu_mapping *mapping) >>     void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping) >>   { >> +    printk("iommu_release_mapping... %lx %lx\n", mapping, >> mapping->domain); >>       if (mapping) >>           kref_put(&mapping->kref, release_iommu_mapping); >> +    printk("iommu_release_mapping... ok\n"); >> +    >>   } >>   EXPORT_SYMBOL_GPL(arm_iommu_release_mapping); >>   diff --git a/drivers/media/platform/omap3isp/isp.c >> b/drivers/media/platform/omap3isp/isp.c >> index 8eb000e..4d58683 100644 >> --- a/drivers/media/platform/omap3isp/isp.c >> +++ b/drivers/media/platform/omap3isp/isp.c >> @@ -2193,12 +2193,14 @@ static int isp_probe(struct platform_device >> *pdev) >>       int ret; >>       int i, m; >>   +    printk("isp_probe: 1\n"); >>       isp = devm_kzalloc(&pdev->dev, sizeof(*isp), GFP_KERNEL); >>       if (!isp) { >>           dev_err(&pdev->dev, "could not allocate memory\n"); >>           return -ENOMEM; >>       } >>   +        printk("isp_probe: 2\n"); >>       ret = fwnode_property_read_u32(of_fwnode_handle(pdev->dev.of_node), >>                          "ti,phy-type", &isp->phy_type); >>       if (ret) >> @@ -2219,6 +2221,8 @@ static int isp_probe(struct platform_device *pdev) >>       mutex_init(&isp->isp_mutex); >>       spin_lock_init(&isp->stat_lock); >>   +            printk("isp_probe: 3\n"); >> + >>       ret = v4l2_async_notifier_parse_fwnode_endpoints( >>           &pdev->dev, &isp->notifier, sizeof(struct isp_async_subdev), >>           isp_fwnode_parse); >> @@ -2232,6 +2236,7 @@ static int isp_probe(struct platform_device *pdev) >>       if (ret) >>           goto error; >>   +                printk("isp_probe: 4\n"); >>       platform_set_drvdata(pdev, isp); >>         /* Regulators */ >> @@ -2258,6 +2263,7 @@ static int isp_probe(struct platform_device *pdev) >>               return PTR_ERR(isp->mmio_base[map_idx]); >>       } >>   +    printk("isp_probe: 5\n"); >>       ret = isp_get_clocks(isp); >>       if (ret < 0) >>           goto error; >> @@ -2277,6 +2283,7 @@ static int isp_probe(struct platform_device *pdev) >>           goto error; >>       } >>   +        printk("isp_probe: 6\n"); >>       ret = isp_reset(isp); >>       if (ret < 0) >>           goto error_isp; >> @@ -2306,6 +2313,7 @@ static int isp_probe(struct platform_device *pdev) >>               isp->mmio_base[OMAP3_ISP_IOMEM_CSI2A_REGS1] >>               + isp_res_maps[m].offset[i]; >>   +        printk("isp_probe: 7\n"); >>       isp->mmio_hist_base_phys = >>           mem->start + isp_res_maps[m].offset[OMAP3_ISP_IOMEM_HIST]; >>   @@ -2316,6 +2324,8 @@ static int isp_probe(struct platform_device >> *pdev) >>           goto error_isp; >>       } >>   +        printk("isp_probe: 8\n"); >> + >>       /* Interrupt */ >>       ret = platform_get_irq(pdev, 0); >>       if (ret <= 0) { >> @@ -2325,6 +2335,7 @@ static int isp_probe(struct platform_device *pdev) >>       } >>       isp->irq_num = ret; >>   +            printk("isp_probe: 9\n"); >>       if (devm_request_irq(isp->dev, isp->irq_num, isp_isr, IRQF_SHARED, >>                    "OMAP3 ISP", isp)) { >>           dev_err(isp->dev, "Unable to request IRQ\n"); >> @@ -2332,6 +2343,7 @@ static int isp_probe(struct platform_device *pdev) >>           goto error_iommu; >>       } >>   +                printk("isp_probe: 10\n"); >>       /* Entities */ >>       ret = isp_initialize_modules(isp); >>       if (ret < 0) >> @@ -2345,27 +2357,35 @@ static int isp_probe(struct platform_device >> *pdev) >>       if (ret < 0) >>           goto error_register_entities; >>   +                    printk("isp_probe: 11\n"); >>       isp->notifier.ops = &isp_subdev_notifier_ops; >>         ret = v4l2_async_notifier_register(&isp->v4l2_dev, >> &isp->notifier); >>       if (ret) >>           goto error_register_entities; >>   +                    printk("isp_probe: 12\n");    >>       isp_core_init(isp, 1); >> +                    printk("isp_probe: 13\n");        >>       omap3isp_put(isp); >>         return 0; >>     error_register_entities: >> +                    printk("isp_probe: f1\n");        >>       isp_unregister_entities(isp); >>   error_modules: >> +                        printk("isp_probe: f2\n");        >>       isp_cleanup_modules(isp); >>   error_iommu: >> +                            printk("isp_probe: f3\n");        >>       isp_detach_iommu(isp); >>   error_isp: >> +                            printk("isp_probe: f4\n");        >>       isp_xclk_cleanup(isp); >>       __omap3isp_put(isp, false); >>   error: >> +                        printk("isp_probe: f5\n");            >>       v4l2_async_notifier_cleanup(&isp->notifier); >>       mutex_destroy(&isp->isp_mutex); >>   >> >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >>