commit 0444ef0832be74cd79fec026d552c5ffcff2cd41
author Axel Davy <axel.davy@ens.fr> Wed Mar 15 22:45:03 2017 +0100
committer Andres Gomez <agomez@igalia.com> Wed Mar 29 19:13:18 2017 +0300
tree 99178e671672237af380b39f5c6d93bc0de237c4
parent c57a03585052e3bd7d61d1307cae9a922e663c20

st/nine: Resolve deadlock in surface/volume dtors when using csmt

Surfaces and Volumes can be freed in the worker thread.

Without this patch, pending_uploads_counter could be non-zero
in the Surfaces or Volumes dtor, leading to deadlock.
Instead decrease properly the counter before releasing the
item.

Also avoid another potential deadlock if the item is not
properly unlocked: Do not call UnlockRect which will cause deadlock,
but free directly using the deadlock safe
nine_context_get_pipe_multithread.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99246

CC: "17.0" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Axel Davy <axel.davy@ens.fr>
Tested-by: James Harvey <lothmordor@gmail.com>
(cherry picked from commit bd85bb51c717a1858157c73adcb689e3986b2134)

src/gallium/state_trackers/nine/nine_csmt_helper.h

diff --git a/src/gallium/state_trackers/nine/nine_csmt_helper.h b/src/gallium/state_trackers/nine/nine_csmt_helper.h
index b0bbc05..dc46bbd 100644
--- a/src/gallium/state_trackers/nine/nine_csmt_helper.h
+++ b/src/gallium/state_trackers/nine/nine_csmt_helper.h
@@ -233,8 +233,8 @@
     name##_priv( \
         device ARGS_FOR_CALL( __VA_ARGS__ ) \
     ); \
-    ARGS_FOR_UNBIND( __VA_ARGS__ ) \
     p_atomic_dec(args->counter); \
+    ARGS_FOR_UNBIND( __VA_ARGS__ ) \
     return 0; \
 } \
 \

src/gallium/state_trackers/nine/surface9.c

diff --git a/src/gallium/state_trackers/nine/surface9.c b/src/gallium/state_trackers/nine/surface9.c
index 836369c..d917fa1 100644
--- a/src/gallium/state_trackers/nine/surface9.c
+++ b/src/gallium/state_trackers/nine/surface9.c
@@ -204,9 +204,15 @@
 {
     DBG("This=%p\n", This);
 
-    if (This->transfer)
-        NineSurface9_UnlockRect(This);
+    if (This->transfer) {
+        struct pipe_context *pipe = nine_context_get_pipe_multithread(This->base.base.device);
+        pipe->transfer_unmap(pipe, This->transfer);
+        This->transfer = NULL;
+    }
 
+    /* Note: Following condition cannot happen currently, since we
+     * refcount the surface in the functions increasing
+     * pending_uploads_counter. */
     if (p_atomic_read(&This->pending_uploads_counter))
         nine_csmt_process(This->base.base.device);
 

src/gallium/state_trackers/nine/volume9.c

diff --git a/src/gallium/state_trackers/nine/volume9.c b/src/gallium/state_trackers/nine/volume9.c
index 11236a0..62af3e6 100644
--- a/src/gallium/state_trackers/nine/volume9.c
+++ b/src/gallium/state_trackers/nine/volume9.c
@@ -142,9 +142,15 @@
 {
     DBG("This=%p\n", This);
 
-    if (This->transfer)
-        NineVolume9_UnlockBox(This);
+    if (This->transfer) {
+        struct pipe_context *pipe = nine_context_get_pipe_multithread(This->base.device);
+        pipe->transfer_unmap(pipe, This->transfer);
+        This->transfer = NULL;
+    }
 
+    /* Note: Following condition cannot happen currently, since we
+     * refcount the volume in the functions increasing
+     * pending_uploads_counter. */
     if (p_atomic_read(&This->pending_uploads_counter))
         nine_csmt_process(This->base.device);