amdgpu: fix race issue between two bo functions(v2)
there is race issue between two threads on amdgpu_bo_reference and
amdgpu_bo_import, this patch tends to fix it by moving the
pthread_mutex_lock out of bo_free_internal and move to bo_reference
to cover the update_reference part.
The mutex_unlock in bo_import should also cover bo refcount
increasement.
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Monk Liu <monk.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/amdgpu/amdgpu_bo.c b/amdgpu/amdgpu_bo.c
index d2725da..803fe54 100644
--- a/amdgpu/amdgpu_bo.c
+++ b/amdgpu/amdgpu_bo.c
@@ -56,14 +56,12 @@
drm_private void amdgpu_bo_free_internal(amdgpu_bo_handle bo)
{
/* Remove the buffer from the hash tables. */
- pthread_mutex_lock(&bo->dev->bo_table_mutex);
util_hash_table_remove(bo->dev->bo_handles,
(void*)(uintptr_t)bo->handle);
if (bo->flink_name) {
util_hash_table_remove(bo->dev->bo_flink_names,
(void*)(uintptr_t)bo->flink_name);
}
- pthread_mutex_unlock(&bo->dev->bo_table_mutex);
/* Release CPU access. */
if (bo->cpu_map_count > 0) {
@@ -342,10 +340,9 @@
}
if (bo) {
- pthread_mutex_unlock(&dev->bo_table_mutex);
-
/* The buffer already exists, just bump the refcount. */
atomic_inc(&bo->refcount);
+ pthread_mutex_unlock(&dev->bo_table_mutex);
output->buf_handle = bo;
output->alloc_size = bo->alloc_size;
diff --git a/amdgpu/amdgpu_internal.h b/amdgpu/amdgpu_internal.h
index e68246b..28d1f38 100644
--- a/amdgpu/amdgpu_internal.h
+++ b/amdgpu/amdgpu_internal.h
@@ -206,8 +206,17 @@
static inline void amdgpu_bo_reference(struct amdgpu_bo **dst,
struct amdgpu_bo *src)
{
- if (update_references(&(*dst)->refcount, &src->refcount))
- amdgpu_bo_free_internal(*dst);
+ pthread_mutex_t *mlock;
+ struct amdgpu_bo* bo = *dst;
+
+ assert(bo != NULL);
+ mlock = &bo->dev->bo_table_mutex;
+ pthread_mutex_lock(mlock);
+
+ if (update_references(&bo->refcount, src?&src->refcount:NULL))
+ amdgpu_bo_free_internal(bo);
+
+ pthread_mutex_unlock(mlock);
*dst = src;
}
