draw: don't crash on vertex buffer overflow

We would crash when stride was bigger than the size of the buffer.
The correct behavior is to just fetch zero's in this case.
Unfortunatly with user_buffer's there's no way to validate the size
because currently we're just not getting it. Adjust the draw interface
to pass the size along the mapped buffer, which works perfectly
for buffer backed vertex_buffers and, in future, it will allow
us to plumb user_buffer sizes through the same interface.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: José Fonseca <jfonseca@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>

1 files changed, 14 insertions, 2 deletions

diff --git a/src/gallium/auxiliary/draw/draw_llvm.h b/src/gallium/auxiliary/draw/draw_llvm.h
index 5909fc1..d517b29 100644
--- a/src/gallium/auxiliary/draw/draw_llvm.h
+++ b/src/gallium/auxiliary/draw/draw_llvm.h
@@ -173,6 +173,18 @@ enum {
 #define draw_jit_vbuffer_offset(_gallivm, _ptr)         \
    lp_build_struct_get(_gallivm, _ptr, 1, "buffer_offset")
 
+enum {
+   DRAW_JIT_DVBUFFER_MAP = 0,
+   DRAW_JIT_DVBUFFER_SIZE,
+   DRAW_JIT_DVBUFFER_NUM_FIELDS  /* number of fields above */
+};
+
+#define draw_jit_dvbuffer_map(_gallivm, _ptr)         \
+   lp_build_struct_get(_gallivm, _ptr, DRAW_JIT_DVBUFFER_MAP, "map")
+
+#define draw_jit_dvbuffer_size(_gallivm, _ptr)        \
+   lp_build_struct_get(_gallivm, _ptr, DRAW_JIT_DVBUFFER_SIZE, "size")
+
 
 /**
  * This structure is passed directly to the generated geometry shader.
@@ -246,7 +258,7 @@ enum {
 typedef int
 (*draw_jit_vert_func)(struct draw_jit_context *context,
                       struct vertex_header *io,
-                      const char *vbuffers[PIPE_MAX_ATTRIBS],
+                      const struct draw_vertex_buffer vbuffers[PIPE_MAX_ATTRIBS],
                       unsigned start,
                       unsigned count,
                       unsigned stride,
@@ -257,7 +269,7 @@ typedef int
 typedef int
 (*draw_jit_vert_func_elts)(struct draw_jit_context *context,
                            struct vertex_header *io,
-                           const char *vbuffers[PIPE_MAX_ATTRIBS],
+                           const struct draw_vertex_buffer vbuffers[PIPE_MAX_ATTRIBS],
                            const unsigned *fetch_elts,
                            unsigned fetch_count,
                            unsigned stride,