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: [email protected]
Signed-off-by: Frédéric Pierret (fepitre) <[email protected]>
---
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;
--
2.21.0
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: [email protected]
> Signed-off-by: Frédéric Pierret (fepitre) <[email protected]>
> ---
> 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;
>
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
<[email protected]> 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: [email protected]
> > Signed-off-by: Frédéric Pierret (fepitre) <[email protected]>
> > ---
> > 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
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/nouveau
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
> <[email protected]> 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: [email protected]
>>> Signed-off-by: Frédéric Pierret (fepitre) <[email protected]>
>>> ---
>>> 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
>> [email protected]
>> https://lists.freedesktop.org/mailman/listinfo/nouveau