Mesa (master): anv: Stop bounds-checking pushed UBOs

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Module: Mesa
Branch: master
Commit: 4b392ced2d744fccffe95490ff57e6b41033c266
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=4b392ced2d744fccffe95490ff57e6b41033c266

Author: Jason Ekstrand <jason at jlekstrand.net>
Date:   Fri Nov  8 09:33:07 2019 -0600

anv: Stop bounds-checking pushed UBOs

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 at lists.freedesktop.org
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>

---

 src/intel/vulkan/genX_cmd_buffer.c | 38 ++++++++++----------------------------
 1 file changed, 10 insertions(+), 28 deletions(-)

diff --git a/src/intel/vulkan/genX_cmd_buffer.c b/src/intel/vulkan/genX_cmd_buffer.c
index d5477ee4328..a0df116b05c 100644
--- a/src/intel/vulkan/genX_cmd_buffer.c
+++ b/src/intel/vulkan/genX_cmd_buffer.c
@@ -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 =