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From: robin.murphy@arm•com (Robin Murphy)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH V7 01/11] iommu/of: Refactor of_iommu_configure() for error handling
Date: Fri, 27 Jan 2017 18:19:51 +0000	[thread overview]
Message-ID: <d27f04da-7d34-9640-1639-790d0732ed93@arm.com> (raw)
In-Reply-To: <009901d278c7$34fee230$9efca690$@codeaurora.org>

On 27/01/17 18:00, Sricharan wrote:
> Hi Robin,
> 
> [..]
> 
>>>> +const struct iommu_ops *of_iommu_configure(struct device *dev,
>>>> +                       struct device_node *master_np)
>>>> +{
>>>> +    const struct iommu_ops *ops;
>>>> +
>>>> +    if (!master_np)
>>>> +        return NULL;
>>>> +
>>>> +    if (dev_is_pci(dev))
>>>> +        ops = of_pci_iommu_init(to_pci_dev(dev), master_np);
>>>
>>> I gave the whole patch set a try on ThunderX. really_probe() is failing
>>> on dma_configure()->of_pci_iommu_init() for each PCI device.
>>
>> When you say "failing", do you mean cleanly, or with a crash? I've
>> managed to hit __of_match_node() dereferencing NULL from
>> of_iommu_xlate() in a horribly complicated chain of events, which I'm
>> trying to figure out now, and I wonder if the two might be related.
> 
> Sorry that there is crash still. __of_match_node seems to checking
> for NULL arguments , feels like some invalid pointer was passed in.
> Is there any particular sequence to try for this ?

Ah, I did figure it out - it wasn't actually a NULL dereference, but an
unmapped address. Turns out __iommu_of_table is in initdata, so any
driver probing after init, connected to an unprobed IOMMU (in this case
disabled in DT), trips over trying to match the now-freed table. I'm
working on the fix - technically the bug's in my patch (#2) anyway ;)

Robin.

> 
> Regards,
>  Sricharan
> 
> 
> 
> 

  reply	other threads:[~2017-01-27 18:19 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20170123161926epcas2p1cf464a2978d89d0c1fdd2f7cc6d38317@epcas2p1.samsung.com>
2017-01-23 16:18 ` [PATCH V7 00/11] IOMMU probe deferral support Sricharan R
2017-01-23 16:18   ` [PATCH V7 01/11] iommu/of: Refactor of_iommu_configure() for error handling Sricharan R
2017-01-25 17:17     ` Tomasz Nowicki
2017-01-25 17:35       ` Robin Murphy
2017-01-25 18:13         ` Tomasz Nowicki
2017-01-27 18:00         ` Sricharan
2017-01-27 18:19           ` Robin Murphy [this message]
2017-01-30  7:00             ` Sricharan
2017-01-30 18:42               ` Robin Murphy
2017-01-31 13:11                 ` Sricharan
2017-01-23 16:18   ` [PATCH V7 02/11] iommu/of: Prepare for deferred IOMMU configuration Sricharan R
2017-01-23 16:18   ` [PATCH V7 03/11] of: dma: Move range size workaround to of_dma_get_range() Sricharan R
2017-01-23 16:18   ` [PATCH V7 04/11] of: dma: Make of_dma_deconfigure() public Sricharan R
2017-01-23 16:18   ` [PATCH V7 05/11] ACPI/IORT: Add function to check SMMUs drivers presence Sricharan R
2017-01-23 16:18   ` [PATCH V7 06/11] of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices Sricharan R
2017-01-28 21:08     ` Bjorn Helgaas
2017-01-30  7:09     ` Rafael J. Wysocki
2017-01-23 16:18   ` [PATCH V7 07/11] iommu: of: Handle IOMMU lookup failure with deferred probing or error Sricharan R
2017-01-28 21:03     ` Bjorn Helgaas
2017-01-30  8:01       ` Sricharan
2017-01-29 16:36     ` Sinan Kaya
2017-01-30 12:00       ` Sricharan
2017-01-23 16:18   ` [PATCH V7 08/11] drivers: acpi: " Sricharan R
2017-01-24 12:37     ` Lorenzo Pieralisi
2017-01-24 13:14       ` Hanjun Guo
2017-01-25  7:31       ` Sricharan
2017-01-29 17:53       ` Sinan Kaya
2017-01-30 12:22         ` Robin Murphy
2017-01-30 13:59           ` Sinan Kaya
2017-01-30 14:23             ` Nate Watterson
2017-01-30 14:33               ` Sinan Kaya
2017-01-30 14:38                 ` Will Deacon
2017-01-30 14:54                   ` Nate Watterson
2017-01-30 15:46                     ` Sinan Kaya
2017-01-30 16:51                       ` Lorenzo Pieralisi
2017-01-30 20:03                         ` Sinan Kaya
2017-02-01 18:52                           ` Lorenzo Pieralisi
2017-02-01 19:10                             ` Sinan Kaya
2017-02-02 19:01                             ` Nate Watterson
2017-02-03  3:37                               ` Hanjun Guo
2017-02-03  3:37                               ` Sricharan
2017-01-23 16:18   ` [PATCH V7 09/11] arm64: dma-mapping: Remove the notifier trick to handle early setting of dma_ops Sricharan R
2017-01-28 21:06     ` Bjorn Helgaas
2017-01-30  8:04       ` Sricharan
2017-01-23 16:18   ` [PATCH V7 10/11] iommu/arm-smmu: Clean up early-probing workarounds Sricharan R
2017-01-25 17:28     ` Tomasz Nowicki
2017-01-28 21:07     ` Bjorn Helgaas
2017-01-30  8:05       ` Sricharan
2017-01-23 16:18   ` [PATCH V7 11/11] ACPI/IORT: Remove linker section for IORT entries probing Sricharan R
2017-01-24  7:40   ` [PATCH V7 00/11] IOMMU probe deferral support Marek Szyprowski
2017-01-24 11:15     ` Sricharan
2017-01-25  4:33   ` Hanjun Guo
2017-01-25  7:33     ` Sricharan
2017-01-28 21:10   ` Bjorn Helgaas
2017-01-30  9:20     ` Sricharan

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