[V2] modesetting: Fix X crash in ms_dirty_update()

[jimqu]

Anybody could give a RB? Michel?

Thanks

JimQu


On 2018年08月07日 12:47, jimqu wrote:
> ping....
>
>
> On 2018年08月06日 10:40, Jim Qu wrote:
>> On some Intel iGPU + AMD dGPU platform, when connect extern display
>> from dGPU, X will crash, show the log like:
>>
>> randr: falling back to unsynchronized pixmap sharing
>> (EE)
>> (EE) Backtrace:
>> (EE) 0: /usr/lib/xorg/Xorg (xorg_backtrace+0x4e)
>> (EE) 1: /usr/lib/xorg/Xorg (0x55cb0151a000+0x1b5ce9)
>> (EE) 2: /lib/x86_64-linux-gnu/libpthread.so.0 (0x7f1587a1d000+0x11390)
>> (EE)
>> (EE) Segmentation fault at address 0x0
>> (EE)
>>
>> There is NULL pointer accessing on ent->slave_dst->drawable.pScreen->
>> SharedPixmapNotifyDamage.
>>
>> On the platform, since the dGPU is GPU device, so that the iGPU is
>> output master device. SharedPixmapNotifyDamage() should be called when
>> current device is output master.
>>
>> Change-Id: I8fa6922a4f75b5e068970fc4d362f778052379f2
>> Signed-off-by: Jim Qu <Jim.Qu at amd.com>
>> ---
>>   hw/xfree86/drivers/modesetting/driver.c | 22 ++++++++++++----------
>>   1 file changed, 12 insertions(+), 10 deletions(-)
>>
>> diff --git a/hw/xfree86/drivers/modesetting/driver.c 
>> b/hw/xfree86/drivers/modesetting/driver.c
>> index 9362370..37fafb1 100644
>> --- a/hw/xfree86/drivers/modesetting/driver.c
>> +++ b/hw/xfree86/drivers/modesetting/driver.c
>> @@ -640,19 +640,21 @@ ms_dirty_update(ScreenPtr screen, int *timeout)
>>       xorg_list_for_each_entry(ent, &screen->pixmap_dirty_list, ent) {
>>           region = DamageRegion(ent->damage);
>>           if (RegionNotEmpty(region)) {
>> -            msPixmapPrivPtr ppriv =
>> -                msGetPixmapPriv(&ms->drmmode, ent->slave_dst);
>> +            if (!screen->isGPU) {
>> +                    msPixmapPrivPtr ppriv =
>> +                        msGetPixmapPriv(&ms->drmmode, 
>> ent->slave_dst->master_pixmap);
>>   -            if (ppriv->notify_on_damage) {
>> -                ppriv->notify_on_damage = FALSE;
>> +                    if (ppriv->notify_on_damage) {
>> +                        ppriv->notify_on_damage = FALSE;
>>   -                ent->slave_dst->drawable.pScreen->
>> - SharedPixmapNotifyDamage(ent->slave_dst);
>> -            }
>> + ent->slave_dst->drawable.pScreen->
>> + SharedPixmapNotifyDamage(ent->slave_dst);
>> +                    }
>>   -            /* Requested manual updating */
>> -            if (ppriv->defer_dirty_update)
>> -                continue;
>> +                    /* Requested manual updating */
>> +                    if (ppriv->defer_dirty_update)
>> +                        continue;
>> +            }
>>                 redisplay_dirty(screen, ent, timeout);
>>               DamageEmpty(ent->damage);
>