[Mesa-stable] [PATCH 1/3] nv50: reset TFB bufctx when we no longer hold a reference to the buffers

[Ilia Mirkin]

This fix is analogous to commit ff085d014.

This fixes some use-after-free situations in dEQP when an xfb state is
removed, and then a clear is triggered, which only does a partial
validation. It would attempt to read the no-longer-valid buffers,
resulting in crashes.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
Cc: "11.1 11.2" <mesa-stable at lists.freedesktop.org>
---
 src/gallium/drivers/nouveau/nv50/nv50_shader_state.c | 2 --
 src/gallium/drivers/nouveau/nv50/nv50_state.c        | 4 +++-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/gallium/drivers/nouveau/nv50/nv50_shader_state.c b/src/gallium/drivers/nouveau/nv50/nv50_shader_state.c
index 8e4b2b4..69115ba 100644
--- a/src/gallium/drivers/nouveau/nv50/nv50_shader_state.c
+++ b/src/gallium/drivers/nouveau/nv50/nv50_shader_state.c
@@ -633,8 +633,6 @@ nv50_stream_output_validate(struct nv50_context *nv50)
    BEGIN_NV04(push, NV50_3D(STRMOUT_BUFFERS_CTRL), 1);
    PUSH_DATA (push, ctrl);
 
-   nouveau_bufctx_reset(nv50->bufctx_3d, NV50_BIND_SO);
-
    for (i = 0; i < nv50->num_so_targets; ++i) {
       struct nv50_so_target *targ = nv50_so_target(nv50->so_target[i]);
       struct nv04_resource *buf = nv04_resource(targ->pipe.buffer);
diff --git a/src/gallium/drivers/nouveau/nv50/nv50_state.c b/src/gallium/drivers/nouveau/nv50/nv50_state.c
index 8504ba4..f8b8478 100644
--- a/src/gallium/drivers/nouveau/nv50/nv50_state.c
+++ b/src/gallium/drivers/nouveau/nv50/nv50_state.c
@@ -1180,8 +1180,10 @@ nv50_set_stream_output_targets(struct pipe_context *pipe,
    }
    nv50->num_so_targets = num_targets;
 
-   if (nv50->so_targets_dirty)
+   if (nv50->so_targets_dirty) {
+      nouveau_bufctx_reset(nv50->bufctx_3d, NV50_BIND_SO);
       nv50->dirty |= NV50_NEW_STRMOUT;
+   }
 }
 
 static void
-- 
2.7.3