diff mbox series

drm/vmwgfx: Fix passing partly uninitialized drm_mode_fb_cmd2 struct

Message ID 20220509110425.165537-1-hdegoede@redhat.com (mailing list archive)
State New, archived
Headers show
Series drm/vmwgfx: Fix passing partly uninitialized drm_mode_fb_cmd2 struct | expand

Commit Message

Hans de Goede May 9, 2022, 11:04 a.m. UTC 
vmw_fb_kms_framebuffer() declares a drm_mode_fb_cmd2 struct on the stack
without zero-ing it and then continues with initializing only some fields.

This leads to drm_mode_fb_cmd2.modifiers[0] containing garbage,
which eventually gets used by drm_helper_mode_fill_fb_struct() to
set fb->modifier when leads to the following atomic-check failure:

vmwgfx 0000:00:02.0: [drm:drm_atomic_check_only] [PLANE:34:plane-0]
 invalid pixel format XR24 little-endian (0x34325258),
 modifier 0xffff94d64719e000
fbcon_init: detected unhandled fb_set_par error, error code -22

Which causes the fbdev emulation and thus also fbcon to not work.

Initialize the struct with all zeros to fix this.

Fixes: dabdcdc9822a ("drm/vmwgfx: Switch to mode_cmd2")
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=2072556
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
While working on this I noticed that at least the vmwgfx_fb.c code
has a tendency to declare structs on the stack without zero-ing
them, instead relying on manually initializing all the fields.
Specifically struct drm_mode_set is used multiple times like this
and there also is an occurence of struct drm_clip being used
like this, but that one is less worrying.

This is a bad idea because some of these structs may get new fields
added later. Someone really should do an audit of the entire
vmwgfx code for this pattern and make sure all structs declared
on the stack are zero-ed before use.
---
 drivers/gpu/drm/vmwgfx/vmwgfx_fb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Javier Martinez Canillas May 9, 2022, 11:52 a.m. UTC | #1 
Hello Hans,

On 5/9/22 13:04, Hans de Goede wrote:
> vmw_fb_kms_framebuffer() declares a drm_mode_fb_cmd2 struct on the stack
> without zero-ing it and then continues with initializing only some fields.
> 
> This leads to drm_mode_fb_cmd2.modifiers[0] containing garbage,
> which eventually gets used by drm_helper_mode_fill_fb_struct() to
> set fb->modifier when leads to the following atomic-check failure:
> 
> vmwgfx 0000:00:02.0: [drm:drm_atomic_check_only] [PLANE:34:plane-0]
>  invalid pixel format XR24 little-endian (0x34325258),
>  modifier 0xffff94d64719e000
> fbcon_init: detected unhandled fb_set_par error, error code -22
> 
> Which causes the fbdev emulation and thus also fbcon to not work.
> 
> Initialize the struct with all zeros to fix this.
> 
> Fixes: dabdcdc9822a ("drm/vmwgfx: Switch to mode_cmd2")
> BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=2072556
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---

Zack fixed this already:

https://cgit.freedesktop.org/drm/drm-misc/commit/?id=5405d25b9e8e6
Hans de Goede May 9, 2022, 11:55 a.m. UTC | #2 
Hi,

On 5/9/22 13:52, Javier Martinez Canillas wrote:
> Hello Hans,
> 
> On 5/9/22 13:04, Hans de Goede wrote:
>> vmw_fb_kms_framebuffer() declares a drm_mode_fb_cmd2 struct on the stack
>> without zero-ing it and then continues with initializing only some fields.
>>
>> This leads to drm_mode_fb_cmd2.modifiers[0] containing garbage,
>> which eventually gets used by drm_helper_mode_fill_fb_struct() to
>> set fb->modifier when leads to the following atomic-check failure:
>>
>> vmwgfx 0000:00:02.0: [drm:drm_atomic_check_only] [PLANE:34:plane-0]
>>  invalid pixel format XR24 little-endian (0x34325258),
>>  modifier 0xffff94d64719e000
>> fbcon_init: detected unhandled fb_set_par error, error code -22
>>
>> Which causes the fbdev emulation and thus also fbcon to not work.
>>
>> Initialize the struct with all zeros to fix this.
>>
>> Fixes: dabdcdc9822a ("drm/vmwgfx: Switch to mode_cmd2")
>> BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=2072556
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
> 
> Zack fixed this already:
> 
> https://cgit.freedesktop.org/drm/drm-misc/commit/?id=5405d25b9e8e6

I see, but it seems that this was never pushed to drm-misc-fixes,
so this is still broken in 5.18-rc#

Regards,

Hans
Javier Martinez Canillas May 9, 2022, 12:02 p.m. UTC | #3 
On 5/9/22 13:55, Hans de Goede wrote:

[snip]

>>>
>>> Fixes: dabdcdc9822a ("drm/vmwgfx: Switch to mode_cmd2")
>>> BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=2072556
>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>> ---
>>
>> Zack fixed this already:
>>
>> https://cgit.freedesktop.org/drm/drm-misc/commit/?id=5405d25b9e8e6
> 
> I see, but it seems that this was never pushed to drm-misc-fixes,
> so this is still broken in 5.18-rc#
> 

Indeed. Agreed that should be cherry-picked in -fixes as well.
Thorsten Leemhuis May 13, 2022, 7:43 a.m. UTC | #4 
CCing airlied

On 09.05.22 14:02, Javier Martinez Canillas wrote:
> On 5/9/22 13:55, Hans de Goede wrote:
> [snip]
>>>>
>>>> Fixes: dabdcdc9822a ("drm/vmwgfx: Switch to mode_cmd2")
>>>> BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=2072556
>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>> ---
>>>
>>> Zack fixed this already:
>>>
>>> https://cgit.freedesktop.org/drm/drm-misc/commit/?id=5405d25b9e8e6
>>
>> I see, but it seems that this was never pushed to drm-misc-fixes,
>> so this is still broken in 5.18-rc#
> 
> Indeed. Agreed that should be cherry-picked in -fixes as well.

Looks to me like nobody did that and this regression fix is missing in
the pull request Dave sent to Linus earlier today. Can anybody please
make sure it makes the next weeks pull? Or was there a change of plans?

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)

P.S.: As the Linux kernel's regression tracker I deal with a lot of
reports and sometimes miss something important when writing mails like
this. If that's the case here, don't hesitate to tell me in a public
reply, it's in everyone's interest to set the public record straight.
Zack Rusin May 13, 2022, 1:25 p.m. UTC | #5 
On May 13, 2022, at 3:43 AM, Thorsten Leemhuis <regressions@leemhuis.info<mailto:regressions@leemhuis.info>> wrote:

CCing airlied

On 09.05.22 14:02, Javier Martinez Canillas wrote:
On 5/9/22 13:55, Hans de Goede wrote:
[snip]

Fixes: dabdcdc9822a ("drm/vmwgfx: Switch to mode_cmd2")
BugLink: https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.redhat.com%2Fshow_bug.cgi%3Fid%3D2072556&amp;data=05%7C01%7Czackr%40vmware.com%7Ca34647a1351748917ad608da34b459a0%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880246471436744%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=LSQP%2Bqnf4p51QsF%2B7ZkvKlB5gSx0%2FgRUsgcIPChR33g%3D&amp;reserved=0
Signed-off-by: Hans de Goede <hdegoede@redhat.com<mailto:hdegoede@redhat.com>>
---

Zack fixed this already:

https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcgit.freedesktop.org%2Fdrm%2Fdrm-misc%2Fcommit%2F%3Fid%3D5405d25b9e8e6&amp;data=05%7C01%7Czackr%40vmware.com%7Ca34647a1351748917ad608da34b459a0%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880246471436744%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=IMtLj94VBo3Bv8oCGmbatBmT%2F2%2B9xkIptnlPTPuHMHc%3D&amp;reserved=0

I see, but it seems that this was never pushed to drm-misc-fixes,
so this is still broken in 5.18-rc#

Indeed. Agreed that should be cherry-picked in -fixes as well.

Looks to me like nobody did that and this regression fix is missing in

No, it has been done. It’s after rc6 so the patch is in drm-misc-next-fixes you can see it at:
https://cgit.freedesktop.org/drm/drm-misc/commit/drivers/gpu/drm/vmwgfx?h=drm-misc-next-fixes&id=5405d25b9e8e6e0d3bdb04833d528a9bb35fe7ce

z
Thorsten Leemhuis May 13, 2022, 1:47 p.m. UTC | #6 
On 13.05.22 15:25, Zack Rusin wrote:
>> On May 13, 2022, at 3:43 AM, Thorsten Leemhuis
>> <regressions@leemhuis.info <mailto:regressions@leemhuis.info>> wrote:
>>
>> CCing airlied
>>
>> On 09.05.22 14:02, Javier Martinez Canillas wrote:
>>> On 5/9/22 13:55, Hans de Goede wrote:
>>> [snip]
>>>>>>
>>>>>> Fixes: dabdcdc9822a ("drm/vmwgfx: Switch to mode_cmd2")
>>>>>> BugLink:
>>>>>> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.redhat.com%2Fshow_bug.cgi%3Fid%3D2072556&amp;data=05%7C01%7Czackr%40vmware.com%7Ca34647a1351748917ad608da34b459a0%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880246471436744%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=LSQP%2Bqnf4p51QsF%2B7ZkvKlB5gSx0%2FgRUsgcIPChR33g%3D&amp;reserved=0
>>>>>> <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.redhat.com%2Fshow_bug.cgi%3Fid%3D2072556&amp;data=05%7C01%7Czackr%40vmware.com%7Ca34647a1351748917ad608da34b459a0%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880246471436744%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=LSQP%2Bqnf4p51QsF%2B7ZkvKlB5gSx0%2FgRUsgcIPChR33g%3D&amp;reserved=0>
>>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com
>>>>>> <mailto:hdegoede@redhat.com>>
>>>>>> ---
>>>>>
>>>>> Zack fixed this already:
>>>>>
>>>>> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcgit.freedesktop.org%2Fdrm%2Fdrm-misc%2Fcommit%2F%3Fid%3D5405d25b9e8e6&amp;data=05%7C01%7Czackr%40vmware.com%7Ca34647a1351748917ad608da34b459a0%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880246471436744%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=IMtLj94VBo3Bv8oCGmbatBmT%2F2%2B9xkIptnlPTPuHMHc%3D&amp;reserved=0
>>>>> <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcgit.freedesktop.org%2Fdrm%2Fdrm-misc%2Fcommit%2F%3Fid%3D5405d25b9e8e6&amp;data=05%7C01%7Czackr%40vmware.com%7Ca34647a1351748917ad608da34b459a0%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880246471436744%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=IMtLj94VBo3Bv8oCGmbatBmT%2F2%2B9xkIptnlPTPuHMHc%3D&amp;reserved=0>
>>>>
>>>> I see, but it seems that this was never pushed to drm-misc-fixes,
>>>> so this is still broken in 5.18-rc#
>>>
>>> Indeed. Agreed that should be cherry-picked in -fixes as well.
>>
>> Looks to me like nobody did that and this regression fix is missing in
> 
> No, it has been done. It’s after rc6 so the patch is in
> drm-misc-next-fixes you can see it at:
> https://cgit.freedesktop.org/drm/drm-misc/commit/drivers/gpu/drm/vmwgfx?h=drm-misc-next-fixes&id=5405d25b9e8e6e0d3bdb04833d528a9bb35fe7ce
> <https://cgit.freedesktop.org/drm/drm-misc/commit/drivers/gpu/drm/vmwgfx?h=drm-misc-next-fixes&id=5405d25b9e8e6e0d3bdb04833d528a9bb35fe7ce>

Sorry, I try, but keeping track of subsystem specific rules and branches
is hard -- and Javier actually asked for "drm-misc-fixes".

That being said: I'd like to question the approach here, as the docs for
handling regression clearly explain that this regression fix should be
applied this cycle:
https://www.kernel.org/doc/html/latest/process/handling-regressions.html

[background: the fixes tag in the change mentions an older commit, but
it sees the problem surfaced post-5.17 cycle, as Hand pointed out at the
start of this thread where he linked here:
https://bugzilla.redhat.com/show_bug.cgi?id=2072556 ]

Sure, there are fixes that are dangerous and maybe should wait for the
next cycle, but from what I see this one doesn't look like one of those.
And if we don't fix this now many more people will run into this.

Dave, Daniel, could you please consider picking this up?

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)

P.S.: As the Linux kernel's regression tracker I deal with a lot of
reports and sometimes miss something important when writing mails like
this. If that's the case here, don't hesitate to tell me in a public
reply, it's in everyone's interest to set the public record straight.
Hans de Goede May 13, 2022, 2:18 p.m. UTC | #7 
Hi,

On 5/13/22 15:25, Zack Rusin wrote:
> 
> 
>> On May 13, 2022, at 3:43 AM, Thorsten Leemhuis <regressions@leemhuis.info <mailto:regressions@leemhuis.info>> wrote:
>>
>> CCing airlied
>>
>> On 09.05.22 14:02, Javier Martinez Canillas wrote:
>>> On 5/9/22 13:55, Hans de Goede wrote:
>>> [snip]
>>>>>>
>>>>>> Fixes: dabdcdc9822a ("drm/vmwgfx: Switch to mode_cmd2")
>>>>>> BugLink: https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.redhat.com%2Fshow_bug.cgi%3Fid%3D2072556&amp;data=05%7C01%7Czackr%40vmware.com%7Ca34647a1351748917ad608da34b459a0%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880246471436744%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=LSQP%2Bqnf4p51QsF%2B7ZkvKlB5gSx0%2FgRUsgcIPChR33g%3D&amp;reserved=0 <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.redhat.com%2Fshow_bug.cgi%3Fid%3D2072556&amp;data=05%7C01%7Czackr%40vmware.com%7Ca34647a1351748917ad608da34b459a0%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880246471436744%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=LSQP%2Bqnf4p51QsF%2B7ZkvKlB5gSx0%2FgRUsgcIPChR33g%3D&amp;reserved=0>
>>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com <mailto:hdegoede@redhat.com>>
>>>>>> ---
>>>>>
>>>>> Zack fixed this already:
>>>>>
>>>>> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcgit.freedesktop.org%2Fdrm%2Fdrm-misc%2Fcommit%2F%3Fid%3D5405d25b9e8e6&amp;data=05%7C01%7Czackr%40vmware.com%7Ca34647a1351748917ad608da34b459a0%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880246471436744%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=IMtLj94VBo3Bv8oCGmbatBmT%2F2%2B9xkIptnlPTPuHMHc%3D&amp;reserved=0 <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcgit.freedesktop.org%2Fdrm%2Fdrm-misc%2Fcommit%2F%3Fid%3D5405d25b9e8e6&amp;data=05%7C01%7Czackr%40vmware.com%7Ca34647a1351748917ad608da34b459a0%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880246471436744%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=IMtLj94VBo3Bv8oCGmbatBmT%2F2%2B9xkIptnlPTPuHMHc%3D&amp;reserved=0>
>>>>
>>>> I see, but it seems that this was never pushed to drm-misc-fixes,
>>>> so this is still broken in 5.18-rc#
>>>
>>> Indeed. Agreed that should be cherry-picked in -fixes as well.
>>
>> Looks to me like nobody did that and this regression fix is missing in
> 
> No, it has been done. It’s after rc6 so the patch is in drm-misc-next-fixes you can see it at:
> https://cgit.freedesktop.org/drm/drm-misc/commit/drivers/gpu/drm/vmwgfx?h=drm-misc-next-fixes&id=5405d25b9e8e6e0d3bdb04833d528a9bb35fe7ce <https://cgit.freedesktop.org/drm/drm-misc/commit/drivers/gpu/drm/vmwgfx?h=drm-misc-next-fixes&id=5405d25b9e8e6e0d3bdb04833d528a9bb35fe7ce>

Erm, the after rc6 rule is for fixes for the next cycle, if we want to
get this in this cycle (which IMHO we want) it should have been in
drm-misc-fixes before the PR which was send to Linus today.

At this point in the cycle the best thing is probably to just
send it directly to Linus. That or wait till 5.19, but it seems
that for some reason (likely changes elsewhere changing the stack)
this long standing bugs is hit 100% with 5.18, where as before
we seemed to be lucky and not hit it.

Regards,

Hans
Zack Rusin May 13, 2022, 3 p.m. UTC | #8 
On Fri, 2022-05-13 at 16:18 +0200, Hans de Goede wrote:
> Hi,
> 
> On 5/13/22 15:25, Zack Rusin wrote:
> > 
> > 
> > > On May 13, 2022, at 3:43 AM, Thorsten Leemhuis
> > > <regressions@leemhuis.info <mailto:regressions@leemhuis.info>> wrote:
> > > 
> > > CCing airlied
> > > 
> > > On 09.05.22 14:02, Javier Martinez Canillas wrote:
> > > > On 5/9/22 13:55, Hans de Goede wrote:
> > > > [snip]
> > > > > > > 
> > > > > > > Fixes: dabdcdc9822a ("drm/vmwgfx: Switch to mode_cmd2")
> > > > > > > BugLink:
> > > > > > > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.redhat.com%2Fshow_bug.cgi%3Fid%3D2072556&amp;data=05%7C01%7Czackr%40vmware.com%7C0ad9ee5503bf481d910408da34eb8284%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880483357287655%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=0Mru05SK5d7p6fYfIbsKzIMqMeFbaC8HZ81ls47tKic%3D&amp;reserved=0
> > > > > > >  <
> > > > > > > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.redhat.com%2Fshow_bug.cgi%3Fid%3D2072556&amp;data=05%7C01%7Czackr%40vmware.com%7C0ad9ee5503bf481d910408da34eb8284%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880483357287655%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=0Mru05SK5d7p6fYfIbsKzIMqMeFbaC8HZ81ls47tKic%3D&amp;reserved=0
> > > > > > > >
> > > > > > > Signed-off-by: Hans de Goede
> > > > > > > <hdegoede@redhat.com <mailto:hdegoede@redhat.com>>
> > > > > > > ---
> > > > > > 
> > > > > > Zack fixed this already:
> > > > > > 
> > > > > > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcgit.freedesktop.org%2Fdrm%2Fdrm-misc%2Fcommit%2F%3Fid%3D5405d25b9e8e6&amp;data=05%7C01%7Czackr%40vmware.com%7C0ad9ee5503bf481d910408da34eb8284%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880483357287655%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=uST30FgZjuY%2BmXP%2F6HhNsR9AWxAEsO5itJ%2FLRdKkRNA%3D&amp;reserved=0
> > > > > >  <
> > > > > > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcgit.freedesktop.org%2Fdrm%2Fdrm-misc%2Fcommit%2F%3Fid%3D5405d25b9e8e6&amp;data=05%7C01%7Czackr%40vmware.com%7C0ad9ee5503bf481d910408da34eb8284%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880483357287655%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=uST30FgZjuY%2BmXP%2F6HhNsR9AWxAEsO5itJ%2FLRdKkRNA%3D&amp;reserved=0
> > > > > > >
> > > > > 
> > > > > I see, but it seems that this was never pushed to drm-misc-fixes,
> > > > > so this is still broken in 5.18-rc#
> > > > 
> > > > Indeed. Agreed that should be cherry-picked in -fixes as well.
> > > 
> > > Looks to me like nobody did that and this regression fix is missing in
> > 
> > No, it has been done. It’s after rc6 so the patch is in drm-misc-next-fixes
> > you can see it at:
> > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcgit.freedesktop.org%2Fdrm%2Fdrm-misc%2Fcommit%2Fdrivers%2Fgpu%2Fdrm%2Fvmwgfx%3Fh%3Ddrm-misc-next-fixes%26id%3D5405d25b9e8e6e0d3bdb04833d528a9bb35fe7ce&amp;data=05%7C01%7Czackr%40vmware.com%7C0ad9ee5503bf481d910408da34eb8284%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880483357287655%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=cq7OXf1%2FP1ImGH%2BAjTRddDxF9ZnQtait6wQX3NVpdBQ%3D&amp;reserved=0
> >  <
> > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcgit.freedesktop.org%2Fdrm%2Fdrm-misc%2Fcommit%2Fdrivers%2Fgpu%2Fdrm%2Fvmwgfx%3Fh%3Ddrm-misc-next-fixes%26id%3D5405d25b9e8e6e0d3bdb04833d528a9bb35fe7ce&amp;data=05%7C01%7Czackr%40vmware.com%7C0ad9ee5503bf481d910408da34eb8284%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637880483357287655%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=cq7OXf1%2FP1ImGH%2BAjTRddDxF9ZnQtait6wQX3NVpdBQ%3D&amp;reserved=0
> > >
> 
> Erm, the after rc6 rule is for fixes for the next cycle, if we want to
> get this in this cycle (which IMHO we want) it should have been in
> drm-misc-fixes before the PR which was send to Linus today.
> 
> At this point in the cycle the best thing is probably to just
> send it directly to Linus. That or wait till 5.19, but it seems
> that for some reason (likely changes elsewhere changing the stack)
> this long standing bugs is hit 100% with 5.18, where as before
> we seemed to be lucky and not hit it.

Hmm, yes, agreed. Just in case Dave was planning to queue up something else I've
sent a pull request to Dave and Daniel for those changes. If they'll say we
should send it to Linus directly then I'll do that.

z
diff mbox series

Patch

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
index 8ee34576c7d0..7509013818ba 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
@@ -483,7 +483,7 @@  static int vmw_fb_kms_detach(struct vmw_fb_par *par,
 
 static int vmw_fb_kms_framebuffer(struct fb_info *info)
 {
-	struct drm_mode_fb_cmd2 mode_cmd;
+	struct drm_mode_fb_cmd2 mode_cmd = {};
 	struct vmw_fb_par *par = info->par;
 	struct fb_var_screeninfo *var = &info->var;
 	struct drm_framebuffer *cur_fb;