Messages in this thread | | | Subject | Re: [Bug 206175] Fedora >= 5.4 kernels instantly freeze on boot without producing any display output | From | "Artem S. Tashkinov" <> | Date | Wed, 11 Mar 2020 16:02:39 +0000 |
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On 3/11/20 3:47 PM, Christoph Hellwig wrote: > And actually one more idea after looking at what slab interactions > could exist. platform_device_register_full frees the dma_mask > unconditionally, even if it didn't allocated it, which might lead > to weird memory corruption if we hit the failure path. So let's try > something like this, replacing the earlier patch in that file. > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > index b230beb6ccb4..04080a8d94e2 100644 > --- a/drivers/base/platform.c > +++ b/drivers/base/platform.c > @@ -632,19 +632,6 @@ struct platform_device *platform_device_register_full( > pdev->dev.of_node_reused = pdevinfo->of_node_reused; > > if (pdevinfo->dma_mask) { > - /* > - * This memory isn't freed when the device is put, > - * I don't have a nice idea for that though. Conceptually > - * dma_mask in struct device should not be a pointer. > - * See http://thread.gmane.org/gmane.linux.kernel.pci/9081 > - */ > - pdev->dev.dma_mask = > - kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KERNEL); > - if (!pdev->dev.dma_mask) > - goto err; > - > - kmemleak_ignore(pdev->dev.dma_mask); > - > *pdev->dev.dma_mask = pdevinfo->dma_mask; > pdev->dev.coherent_dma_mask = pdevinfo->dma_mask; > } > @@ -670,7 +657,6 @@ struct platform_device *platform_device_register_full( > if (ret) { > err: > ACPI_COMPANION_SET(&pdev->dev, NULL); > - kfree(pdev->dev.dma_mask); > platform_device_put(pdev); > return ERR_PTR(ret); > } >
With this patch the system works (I haven't created an initrd, so it doesn't completely boot and panics on not being able to mount root fs but that's expected).
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