WebContent no longer creates a GPU-backed Skia context, so its Linux
sandbox does not need the broad GPU device syscall allowance. Remove
allow_gpu_device_operations() from the renderer policy while keeping the
narrower file descriptor ioctl allowances used by IPC transport setup.
WebGL rasterization now happens in the Compositor process, but the GPU
runtime Landlock rules still lived only in WebContent. ANGLE initializes
native EGL when a page creates a WebGL context, which happens after the
Compositor sandbox is installed, so loading libEGL.so.1 and the
Mesa/GLVND driver stack was denied.
Grant the Compositor access to native GL/Vulkan driver and configuration
paths, DRI devices, /sys, LD_LIBRARY_PATH entries, the Mesa shader
cache, and executable mappings required by the driver stack.
Remove the corresponding late filesystem access from WebContent.
WebContent still initializes its Skia GPU backend before installing its
sandbox, so it does not need to open the GPU runtime afterward; keep the
GPU device seccomp allowance there because Skia continues to issue
operations on already-opened GPU fds for display-list painting.
Add opt-in Linux renderer sandbox support to WebContent and WebWorker.
Ladybird and test-web pass --enable-sandbox through when requested, and
the renderer services only install the shared sandbox when that flag is
present.
Share one renderer policy for both services. Allow resource, font,
shared library, WebGL, Wasm, audio, and local IPC paths needed at
runtime, while keeping renderer filesystem writes mediated by Landlock.
Allow Mesa and PulseAudio to probe their standard runtime state without
escaping the renderer sandbox. Return EPERM for scheduler and priority
changes so library initialization can fall back instead of crashing on a
seccomp violation.
