Re: [PATCH 5.12 237/242] drm/ast: Remove reference to struct drm_device.pdev

Thomas Zimmermann
2021-07-19T14:35:33Z

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hi

Am 19.07.21 um 13:23 schrieb Greg Kroah-Hartman:
> On Mon, Jul 19, 2021 at 05:57:30PM +0800, Xiaotian Feng wrote:
>> On Fri, Jul 16, 2021 at 5:13 AM Greg Kroah-Hartman
>> <gregkh@linuxfoundation.org> wrote:
>>>
>>> From: Thomas Zimmermann <tzimmermann@suse.de>
>>>
>>> commit 0ecb51824e838372e01330752503ddf9c0430ef7 upstream.
>>>
>>> Using struct drm_device.pdev is deprecated. Upcast with to_pci_dev()
>>> from struct drm_device.dev to get the PCI device structure.
>>>
>>> v9:
>>> * fix remaining pdev references
>>>
>>> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
>>> Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
>>> Fixes: ba4e0339a6a3 ("drm/ast: Fixed CVE for DP501")
>>> Cc: KuoHsiang Chou <kuohsiang_chou@aspeedtech.com>
>>> Cc: kernel test robot <lkp@intel.com>
>>> Cc: Thomas Zimmermann <tzimmermann@suse.de>
>>> Cc: Dave Airlie <airlied@redhat.com>
>>> Cc: dri-devel@lists.freedesktop.org
>>> Link: https://patchwork.freedesktop.org/patch/msgid/20210429105101.25667-2-tzimmermann@suse.de
>>> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>> ---
>>> drivers/gpu/drm/ast/ast_main.c | 5 ++---
>>> 1 file changed, 2 insertions(+), 3 deletions(-)
>>>
>>> --- a/drivers/gpu/drm/ast/ast_main.c
>>> +++ b/drivers/gpu/drm/ast/ast_main.c
>>> @@ -411,7 +411,6 @@ struct ast_private *ast_device_create(co
>>> return ast;
>>> dev = &ast->base;
>>>
>>> - dev->pdev = pdev;
>>> pci_set_drvdata(pdev, dev);
>>>
>>> ast->regs = pcim_iomap(pdev, 1, 0);
>>> @@ -453,8 +452,8 @@ struct ast_private *ast_device_create(co
>>>
>>> /* map reserved buffer */
>>> ast->dp501_fw_buf = NULL;
>>> - if (dev->vram_mm->vram_size < pci_resource_len(dev->pdev, 0)) {
>>> - ast->dp501_fw_buf = pci_iomap_range(dev->pdev, 0, dev->vram_mm->vram_size, 0);
>>> + if (dev->vram_mm->vram_size < pci_resource_len(pdev, 0)) {
>>> + ast->dp501_fw_buf = pci_iomap_range(pdev, 0, dev->vram_mm->vram_size, 0);
>>> if (!ast->dp501_fw_buf)
>>> drm_info(dev, "failed to map reserved buffer!\n");
>>> }
>>>
>>
>> Hi Greg,
>>
>> This backport is incomplete for 5.10 kernel, kernel is panicked
>> on RIP: ast_device_create+0x7d. When I look into the crash code, I
>> found
>>
>> struct ast_private *ast_device_create(struct drm_driver *drv,
>> struct pci_dev *pdev,
>> unsigned long flags)
>> {
>> .......
>> dev->pdev = pdev; // This is removed
>> pci_set_drvdata(pdev, dev);
>>
>> ast->regs = pcim_iomap(pdev, 1, 0);
>> if (!ast->regs)
>> return ERR_PTR(-EIO);
>>
>> /*
>> * If we don't have IO space at all, use MMIO now and
>> * assume the chip has MMIO enabled by default (rev 0x20
>> * and higher).
>> */
>> if (!(pci_resource_flags(dev->pdev, 2) & IORESOURCE_IO)) { //
>> dev->pdev is in used here.
>> drm_info(dev, "platform has no IO space, trying MMIO\n");
>> ast->ioregs = ast->regs + AST_IO_MM_OFFSET;
>> }
>>
>> That's because commit 46fb883c3d0d8a823ef995ddb1f9b0817dea6882
>> is not backported to 5.10 kernel.
>
> So what should I do here? Backport that commit (was was not called
> out), or just revert this?

Best drop all these 'remove pdev' patches from stable. They are no bugfixes.

Best regards
Thomas

>
> thanks,
>
> greg k-h
>

--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer

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