[Nouveau] [PATCH] nv50_disp_chan_mthd: ensure mthd is not NULL

[Frédéric Pierret]

Hi Ilia,
Well...if Ben made it's own version you mean using my patch given on comment https://bugzilla.kernel.org/show_bug.cgi?id=206299#c9 and then adding commit message without quoting me as reporter ok...

At least, upstream is patched.

Best,
Frédéric

On 2020-02-20 18:32, Ilia Mirkin wrote:
> Hi Frédéric,
> 
> It appears Ben made his own version of this patch (probably based on
> the one you added to the kernel bz), and it's already upstream:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.6-rc2&id=0e6176c6d286316e9431b4f695940cfac4ffe6c2
> 
> Cheers,
> 
>   -ilia
> 
> On Thu, Feb 20, 2020 at 12:19 PM Frédéric Pierret
> <frederic.pierret at qubes-os.org> wrote:
>>
>> Hi,
>> Is anything missing here? How can I get this merged?
>>
>> Best regards,
>> Frédéric Pierret
>>
>> On 2020-02-08 20:43, Frédéric Pierret wrote:
>>> Pointer to structure array is assumed not NULL by default. It has
>>> the consequence to raise a kernel panic when it's not the case.
>>>
>>> Basically, running at least a RTX2080TI on Xen makes a bad mmio error
>>> which causes having 'mthd' pointer to be NULL in 'channv50.c'. From the
>>> code, it's assumed to be not NULL by accessing directly 'mthd->data[0]'
>>> which is the reason of the kernel panic. Simply check if the pointer
>>> is not NULL before continuing.
>>>
>>> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=206299
>>> Cc: stable at vger.kernel.org
>>> Signed-off-by: Frédéric Pierret (fepitre) <frederic.pierret at qubes-os.org>
>>> ---
>>>  drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c | 2 ++
>>>  1 file changed, 2 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c
>>> index bcf32d92ee5a..50e3539f33d2 100644
>>> --- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c
>>> +++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/channv50.c
>>> @@ -74,6 +74,8 @@ nv50_disp_chan_mthd(struct nv50_disp_chan *chan, int debug)
>>>
>>>       if (debug > subdev->debug)
>>>               return;
>>> +     if (!mthd)
>>> +             return;
>>>
>>>       for (i = 0; (list = mthd->data[i].mthd) != NULL; i++) {
>>>               u32 base = chan->head * mthd->addr;
>>>
>>
>> _______________________________________________
>> Nouveau mailing list
>> Nouveau at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/nouveau

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