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authorJonathan Kim <jonathan.kim@amd.com>2021-06-11 13:36:34 -0400
committerAlex Deucher <alexander.deucher@amd.com>2021-06-15 17:25:40 -0400
commit63f6e01237257e7226efc5087f3f0b525d320f54 (patch)
treeeaa4d754b46c64074c8fa277aa2733992e28ba9e
parent03fc4cf45d30533d54f0f4ebc02aacfa12f52ce2 (diff)
drm/amdkfd: fix circular locking on get_wave_state
get_wave_state acquires the mmap_lock on copy_to_user but so do mmu_notifiers. mmu_notifiers allows dqm locking so do get_wave_state outside the dqm_lock to prevent circular locking. v2: squash in unused variable removal. Signed-off-by: Jonathan Kim <jonathan.kim@amd.com> Reviewed-by: Felix Kuehling <felix.kuehling@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
-rw-r--r--drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c28
1 files changed, 13 insertions, 15 deletions
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index edb14e4a9f33..72bea5278add 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -1674,29 +1674,27 @@ static int get_wave_state(struct device_queue_manager *dqm,
u32 *save_area_used_size)
{
struct mqd_manager *mqd_mgr;
- int r;
dqm_lock(dqm);
- if (q->properties.type != KFD_QUEUE_TYPE_COMPUTE ||
- q->properties.is_active || !q->device->cwsr_enabled) {
- r = -EINVAL;
- goto dqm_unlock;
- }
-
mqd_mgr = dqm->mqd_mgrs[KFD_MQD_TYPE_CP];
- if (!mqd_mgr->get_wave_state) {
- r = -EINVAL;
- goto dqm_unlock;
+ if (q->properties.type != KFD_QUEUE_TYPE_COMPUTE ||
+ q->properties.is_active || !q->device->cwsr_enabled ||
+ !mqd_mgr->get_wave_state) {
+ dqm_unlock(dqm);
+ return -EINVAL;
}
- r = mqd_mgr->get_wave_state(mqd_mgr, q->mqd, ctl_stack,
- ctl_stack_used_size, save_area_used_size);
-
-dqm_unlock:
dqm_unlock(dqm);
- return r;
+
+ /*
+ * get_wave_state is outside the dqm lock to prevent circular locking
+ * and the queue should be protected against destruction by the process
+ * lock.
+ */
+ return mqd_mgr->get_wave_state(mqd_mgr, q->mqd, ctl_stack,
+ ctl_stack_used_size, save_area_used_size);
}
static int process_termination_cpsch(struct device_queue_manager *dqm,