diff options
Diffstat (limited to 'drivers/gpu/drm/vc4/vc4_validate_shaders.c')
| -rw-r--r-- | drivers/gpu/drm/vc4/vc4_validate_shaders.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/drivers/gpu/drm/vc4/vc4_validate_shaders.c b/drivers/gpu/drm/vc4/vc4_validate_shaders.c index 5dba13dd1e9b..0b2df5c6efb4 100644 --- a/drivers/gpu/drm/vc4/vc4_validate_shaders.c +++ b/drivers/gpu/drm/vc4/vc4_validate_shaders.c @@ -24,16 +24,21 @@ /** * DOC: Shader validator for VC4. * - * The VC4 has no IOMMU between it and system memory, so a user with - * access to execute shaders could escalate privilege by overwriting - * system memory (using the VPM write address register in the - * general-purpose DMA mode) or reading system memory it shouldn't - * (reading it as a texture, or uniform data, or vertex data). + * Since the VC4 has no IOMMU between it and system memory, a user + * with access to execute shaders could escalate privilege by + * overwriting system memory (using the VPM write address register in + * the general-purpose DMA mode) or reading system memory it shouldn't + * (reading it as a texture, uniform data, or direct-addressed TMU + * lookup). * - * This walks over a shader BO, ensuring that its accesses are - * appropriately bounded, and recording how many texture accesses are - * made and where so that we can do relocations for them in the + * The shader validator walks over a shader's BO, ensuring that its + * accesses are appropriately bounded, and recording where texture + * accesses are made so that we can do relocations for them in the * uniform stream. + * + * Shader BO are immutable for their lifetimes (enforced by not + * allowing mmaps, GEM prime export, or rendering to from a CL), so + * this validation is only performed at BO creation time. */ #include "vc4_drv.h" |