Re: [ros-dev] [ros-diffs] [janderwald] 40694: - Fix allocation of CM_RESOURCE_LIST - Might fix bug 4354 See issue #4354 for more details.

[Timo Kreuzer]

Isn't that actually the same?

It also ignores the number of full descriptors, which I guess is wrong.
And it looks like the whole parsing code is broken. It ignores the
number of partial descriptors and does FullList++

Timo

janderwald(a)svn.reactos.org schrieb:
>   Author: janderwald
>  Date: Sat Apr 25 16:05:08 2009
>  New Revision: 40694
>
>  URL: http://svn.reactos.org/svn/reactos?rev=40694&view=rev
>  Log:
>  - Fix allocation of CM_RESOURCE_LIST
>  - Might fix bug 4354
>  See issue #4354 for more details.
>
>  Modified:
>      trunk/reactos/drivers/video/videoprt/dispatch.c
>
>  Modified: trunk/reactos/drivers/video/videoprt/dispatch.c
>  URL:
> http://svn.reactos.org/svn/reactos/trunk/reactos/drivers/video/videoprt/dis…
>  ==============================================================================
>  --- trunk/reactos/drivers/video/videoprt/dispatch.c [iso-8859-1] (original)
>  +++ trunk/reactos/drivers/video/videoprt/dispatch.c [iso-8859-1] Sat Apr 25 16:05:08
> 2009
>  @@ -340,9 +340,11 @@
>   
>         /* Save the resource list */
>         ResourceCount = AllocatedResources->List[0].PartialResourceList.Count;
>  -      ResourceListSize =
>  -         FIELD_OFFSET(CM_RESOURCE_LIST, List[0].PartialResourceList.
>  -                      PartialDescriptors[ResourceCount]);
>  +      ResourceListSize = sizeof(CM_RESOURCE_LIST);
>  +
>  +      if (ResourceCount > 1)
>  +         ResourceListSize += (ResourceCount-1) *
> sizeof(CM_PARTIAL_RESOURCE_DESCRIPTOR);
>  +
>         DeviceExtension->AllocatedResources = ExAllocatePool(PagedPool,
> ResourceListSize);
>         if (DeviceExtension->AllocatedResources == NULL)
>         {
>
>
>

[Johannes Anderwald]

Timo Kreuzer wrote:
>   Isn't that actually the same?
>
>     
Hi,

IMO the old code only calculated the offset from PartialDescriptors 
array to CM_RESOURCE_LIST. This works fine if there are no partial 
descriptors. But it breaks if there are.

>   It also ignores the number of full descriptors, which
> I guess is wrong.
>  And it looks like the whole parsing code is broken. It ignores the
>  number of partial descriptors and does FullList++
>     
The MSDN states the number of CM_FULL_RESOURCE_DESCRIPTOR in 
CM_RESOURCE_LIST is always 1 for WDM drivers.
The partial descriptors are handeled in the 2nd for loop.
>   Timo
>     
regards,
Johannes

[Timo Kreuzer]

Johannes Anderwald schrieb:
>   Timo Kreuzer wrote:
>    
> >   Isn't that actually the same?
> >
> >    
> >       
>  Hi,
>
>  IMO the old code only calculated the offset from PartialDescriptors 
>  array to CM_RESOURCE_LIST. This works fine if there are no partial 
>  descriptors. But it breaks if there are.
>     
It was

FIELD_OFFSET(CM_RESOURCE_LIST,
List[0].PartialResourceList.PartialDescriptors[ResourceCount]);

So it should have calculated the offset of
PartialDescriptors[ResourceCount] which is one after the last one that
belongs to the list or (ResourceCount-1) entries after the end of
CM_RESOURCE_LIST.

>     
> >   It also ignores the number of full descriptors,
> > which I guess is wrong.
> >  And it looks like the whole parsing code is broken. It ignores the
> >  number of partial descriptors and does FullList++
> >    
> >       
>  The MSDN states the number of CM_FULL_RESOURCE_DESCRIPTOR in 
>  CM_RESOURCE_LIST is always 1 for WDM drivers.
>  The partial descriptors are handeled in the 2nd for loop.
>     
Ah, ok, but in this case the outer loop makes no sense and is only
confusing. Maybe an ASSERT(..Count == 1) should be put instead?