From 6d45c81d229d71da54d374143e7d6abad4c0cf31 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Sat, 2 Jul 2016 12:17:10 -0700 Subject: drm/vc4: Add support for branching in shader validation. We're already checking that branch instructions are between the start of the shader and the proper PROG_END sequence. The other thing we need to make branching safe is to verify that the shader doesn't read past the end of the uniforms stream. To do that, we require that at any basic block reading uniforms have the following instructions: load_imm temp, add unif_addr, temp, unif The instructions are generated by userspace, and the kernel verifies that the load_imm is of the expected offset, and that the add adds it to a uniform. We track which uniform in the stream that is, and at draw call time fix up the uniform stream to have the address of the start of the shader's uniforms at that location. Signed-off-by: Eric Anholt --- drivers/gpu/drm/vc4/vc4_validate.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/vc4/vc4_validate.c') diff --git a/drivers/gpu/drm/vc4/vc4_validate.c b/drivers/gpu/drm/vc4/vc4_validate.c index 24c2c746e8f3..9ce1d0adf882 100644 --- a/drivers/gpu/drm/vc4/vc4_validate.c +++ b/drivers/gpu/drm/vc4/vc4_validate.c @@ -802,7 +802,7 @@ validate_gl_shader_rec(struct drm_device *dev, uint32_t src_offset = *(uint32_t *)(pkt_u + o); uint32_t *texture_handles_u; void *uniform_data_u; - uint32_t tex; + uint32_t tex, uni; *(uint32_t *)(pkt_v + o) = bo[i]->paddr + src_offset; @@ -840,6 +840,17 @@ validate_gl_shader_rec(struct drm_device *dev, } } + /* Fill in the uniform slots that need this shader's + * start-of-uniforms address (used for resetting the uniform + * stream in the presence of control flow). + */ + for (uni = 0; + uni < validated_shader->num_uniform_addr_offsets; + uni++) { + uint32_t o = validated_shader->uniform_addr_offsets[uni]; + ((uint32_t *)exec->uniforms_v)[o] = exec->uniforms_p; + } + *(uint32_t *)(pkt_v + o + 4) = exec->uniforms_p; exec->uniforms_u += validated_shader->uniforms_src_size; -- cgit v1.2.3