Mesa (master): i965: Fix software primitive restart with indirect draws.

[Kenneth Graunke]

Module: Mesa
Branch: master
Commit: 406df68736a213f17f21a38a7c2da4ea15acd053
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=406df68736a213f17f21a38a7c2da4ea15acd053

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Sat Apr 11 02:21:48 2015 -0700

i965: Fix software primitive restart with indirect draws.

new_prim was declared as a stack variable within a nested scope; we
tried to retain a pointer to that data beyond the scope, which is bogus.

GCC with -O1 eliminated most of the code that set new_prim's fields.

Move the declaration to fix the bug.

v2: Also fix new_ib (thanks to Matt Turner and Ben Widawsky).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=81025
Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Matt Turner <mattst88 at gmail.com>
Reviewed-by: Ben Widawsky <ben at bwidawsk.net>
Cc: mesa-stable at lists.freedesktop.org

---

 src/mesa/vbo/vbo_primitive_restart.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/mesa/vbo/vbo_primitive_restart.c b/src/mesa/vbo/vbo_primitive_restart.c
index 562dedc..dafc4fd 100644
--- a/src/mesa/vbo/vbo_primitive_restart.c
+++ b/src/mesa/vbo/vbo_primitive_restart.c
@@ -167,6 +167,8 @@ vbo_sw_primitive_restart(struct gl_context *ctx,
                          struct gl_buffer_object *indirect)
 {
    GLuint prim_num;
+   struct _mesa_prim new_prim;
+   struct _mesa_index_buffer new_ib;
    struct sub_primitive *sub_prims;
    struct sub_primitive *sub_prim;
    GLuint num_sub_prims;
@@ -182,8 +184,6 @@ vbo_sw_primitive_restart(struct gl_context *ctx,
 
    /* If there is an indirect buffer, map it and extract the draw params */
    if (indirect && prims[0].is_indirect) {
-      struct _mesa_prim new_prim = *prims;
-      struct _mesa_index_buffer new_ib = *ib;
       const uint32_t *indirect_params;
       if (!ctx->Driver.MapBufferRange(ctx, 0, indirect->Size, GL_MAP_READ_BIT,
                                       indirect, MAP_INTERNAL)) {
@@ -195,6 +195,7 @@ vbo_sw_primitive_restart(struct gl_context *ctx,
       }
 
       assert(nr_prims == 1);
+      new_prim = prims[0];
       indirect_params = (const uint32_t *)
                         ADD_POINTERS(indirect->Mappings[MAP_INTERNAL].Pointer,
                                      new_prim.indirect_offset);
@@ -206,6 +207,7 @@ vbo_sw_primitive_restart(struct gl_context *ctx,
       new_prim.basevertex = indirect_params[3];
       new_prim.base_instance = indirect_params[4];
 
+      new_ib = *ib;
       new_ib.count = new_prim.count;
 
       prims = &new_prim;