[iOS] Fix media related sandbox issues in the GPU Process

[Per Arne Vollan]

Fix observed sandbox violations related to media playback.

[Per Arne Vollan]

Created attachment 391343 [details]
Patch

[Per Arne Vollan]

Created attachment 391346 [details]
Patch

[Per Arne Vollan]

Created attachment 391368 [details]
Patch

[Eric Carlson]

Comment on attachment 391368 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=391368&action=review

> Source/WebKit/UIProcess/GPU/GPUProcessProxy.cpp:289
> +    if (!parameters.mediaCacheDirectory.isEmpty()) {
> +        String parentFolder = parameters.mediaCacheDirectory;
> +        if ((auto position = parentFolder.reverseFind("/")) != notFound)
> +            parentFolder = parentFolder.substring(0, position);
> +        SandboxExtension::createHandleWithoutResolvingPath(parentFolder, SandboxExtension::Type::ReadWrite, parameters.mediaCacheDirectorySandboxExtensionHandle);
> +    }

Two things: 
  - I think it would be better to do this in the WebProcess, this process should just use the path provided.
  - This shouldn't be necessary at all, please file a bug about the media framework behavior.

[Per Arne Vollan]

Created attachment 391369 [details]
Patch

[Per Arne Vollan]

(In reply to Eric Carlson from comment #4)
> Comment on attachment 391368 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=391368&action=review
> 
> > Source/WebKit/UIProcess/GPU/GPUProcessProxy.cpp:289
> > +    if (!parameters.mediaCacheDirectory.isEmpty()) {
> > +        String parentFolder = parameters.mediaCacheDirectory;
> > +        if ((auto position = parentFolder.reverseFind("/")) != notFound)
> > +            parentFolder = parentFolder.substring(0, position);
> > +        SandboxExtension::createHandleWithoutResolvingPath(parentFolder, SandboxExtension::Type::ReadWrite, parameters.mediaCacheDirectorySandboxExtensionHandle);
> > +    }
> 
> Two things: 
>   - I think it would be better to do this in the WebProcess, this process
> should just use the path provided.
>   - This shouldn't be necessary at all, please file a bug about the media
> framework behavior.

Thanks for reviewing! I will file a bug about the media framework behavior.

[WebKit Commit Bot]

Comment on attachment 391369 [details]
Patch

Clearing flags on attachment: 391369

Committed r257135: <https://trac.webkit.org/changeset/257135>

[Radar WebKit Bug Importer]

<rdar://problem/59818090>