anv: Stop bounds-checking pushed UBOs
authorJason Ekstrand <jason@jlekstrand.net>
Fri, 8 Nov 2019 15:33:07 +0000 (09:33 -0600)
committerJason Ekstrand <jason@jlekstrand.net>
Mon, 18 Nov 2019 18:35:14 +0000 (18:35 +0000)
The bounds checking is actually less safe than just pushing the data.
If the bounds checking actually ever kicks in and it's not on the last
UBO push range, then the shrinking will cause all subsequent ranges to
be pushed to the wrong place in the GRF.  One of the behaviors we
definitely don't want is for OOB UBO access to result in completely
unrelated UBOs returning garbage values.  It's safer to just push the
UBOs as-requested.  If we're really concerned about robustness, we can
emit shader code to do bounds checking which should be stupid cheap (a
CMP followed by SEL).

Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
src/intel/vulkan/genX_cmd_buffer.c

index d5477ee43281165e782735bb05cc6cc2d2f525c4..a0df116b05cf5f7f70c0f4fd6fb2cdec3f9cfb1e 100644 (file)
@@ -2559,8 +2559,7 @@ cmd_buffer_flush_push_constants(struct anv_cmd_buffer *cmd_buffer,
                const struct anv_pipeline_binding *binding =
                   &bind_map->surface_to_descriptor[surface];
 
-               struct anv_address read_addr;
-               uint32_t read_len;
+               struct anv_address addr;
                if (binding->set == ANV_DESCRIPTOR_SET_DESCRIPTORS) {
                   /* This is a descriptor set buffer so the set index is
                    * actually given by binding->binding.  (Yes, that's
@@ -2568,14 +2567,8 @@ cmd_buffer_flush_push_constants(struct anv_cmd_buffer *cmd_buffer,
                    */
                   struct anv_descriptor_set *set =
                      gfx_state->base.descriptors[binding->index];
-                  struct anv_address desc_buffer_addr =
-                     anv_descriptor_set_address(cmd_buffer, set);
-                  const unsigned desc_buffer_size = set->desc_mem.alloc_size;
-
-                  read_len = MIN2(range->length,
-                     DIV_ROUND_UP(desc_buffer_size, 32) - range->start);
-                  read_addr = anv_address_add(desc_buffer_addr,
-                                              range->start * 32);
+
+                  addr = anv_descriptor_set_address(cmd_buffer, set);
                } else {
                   assert(binding->set < MAX_SETS);
                   struct anv_descriptor_set *set =
@@ -2584,32 +2577,21 @@ cmd_buffer_flush_push_constants(struct anv_cmd_buffer *cmd_buffer,
                      &set->descriptors[binding->index];
 
                   if (desc->type == VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER) {
-                     read_len = MIN2(range->length,
-                        DIV_ROUND_UP(desc->buffer_view->range, 32) - range->start);
-                     read_addr = anv_address_add(desc->buffer_view->address,
-                                                 range->start * 32);
+                     addr = desc->buffer_view->address;
                   } else {
                      assert(desc->type == VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC);
 
                      uint32_t dynamic_offset =
                         gfx_state->base.dynamic_offsets[binding->dynamic_offset_index];
-                     uint32_t buf_offset =
-                        MIN2(desc->offset + dynamic_offset, desc->buffer->size);
-                     uint32_t buf_range =
-                        MIN2(desc->range, desc->buffer->size - buf_offset);
-
-                     read_len = MIN2(range->length,
-                        DIV_ROUND_UP(buf_range, 32) - range->start);
-                     read_addr = anv_address_add(desc->buffer->address,
-                                                 buf_offset + range->start * 32);
+                     addr = anv_address_add(desc->buffer->address,
+                                            desc->offset + dynamic_offset);
                   }
                }
 
-               if (read_len > 0) {
-                  c.ConstantBody.Buffer[n] = read_addr;
-                  c.ConstantBody.ReadLength[n] = read_len;
-                  n--;
-               }
+               c.ConstantBody.Buffer[n] =
+                  anv_address_add(addr, range->start * 32);
+               c.ConstantBody.ReadLength[n] = range->length;
+               n--;
             }
 
             struct anv_state state =