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| author | Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> | 2023-02-08 17:36:49 +0200 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2023-02-13 07:22:08 +0100 |
| commit | 2062f9fb6445451b189595e295765c69f43bc12e (patch) | |
| tree | 661b42d3b11de2073477ce76555e490578dfd185 | |
| parent | c70b7741dda7586529cc270e0f2c4cae3921b9b1 (diff) | |
| download | lwn-2062f9fb6445451b189595e295765c69f43bc12e.tar.gz lwn-2062f9fb6445451b189595e295765c69f43bc12e.zip | |
xen/grant-dma-iommu: Implement a dummy probe_device() callback
Update stub IOMMU driver (which main purpose is to reuse generic
IOMMU device-tree bindings by Xen grant DMA-mapping layer on Arm)
according to the recent changes done in the following
commit 57365a04c921 ("iommu: Move bus setup to IOMMU device registration").
With probe_device() callback being called during IOMMU device registration,
the uninitialized callback just leads to the "kernel NULL pointer
dereference" issue during boot. Fix that by adding a dummy callback.
Looks like the release_device() callback is not mandatory to be
implemented as IOMMU framework makes sure that callback is initialized
before dereferencing.
Reported-by: Viresh Kumar <viresh.kumar@linaro.org>
Fixes: 57365a04c921 ("iommu: Move bus setup to IOMMU device registration")
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Tested-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20230208153649.3604857-1-olekstysh@gmail.com
Signed-off-by: Juergen Gross <jgross@suse.com>
| -rw-r--r-- | drivers/xen/grant-dma-iommu.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/xen/grant-dma-iommu.c b/drivers/xen/grant-dma-iommu.c index 16b8bc0c0b33..6a9fe02c6bfc 100644 --- a/drivers/xen/grant-dma-iommu.c +++ b/drivers/xen/grant-dma-iommu.c @@ -16,8 +16,15 @@ struct grant_dma_iommu_device { struct iommu_device iommu; }; -/* Nothing is really needed here */ -static const struct iommu_ops grant_dma_iommu_ops; +static struct iommu_device *grant_dma_iommu_probe_device(struct device *dev) +{ + return ERR_PTR(-ENODEV); +} + +/* Nothing is really needed here except a dummy probe_device callback */ +static const struct iommu_ops grant_dma_iommu_ops = { + .probe_device = grant_dma_iommu_probe_device, +}; static const struct of_device_id grant_dma_iommu_of_match[] = { { .compatible = "xen,grant-dma" }, |