gpu: nvgpu: serialize debug session IOCTLs

Hold debug_s->ioctl_lock for all debug session
IOCTLs to prevent multi-threaded user space
IOCTL calls

debug session IOCTL calls are not thread-safe
and hence this serialization is required

Bug 1832267

Change-Id: I847ac951601d4f0093546b592bdb8c8f00185317
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/1286436
Reviewed-by: svccoveritychecker <svccoveritychecker@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.h b/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.h
index 600715f5..773a669c 100644
--- a/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.h
@@ -1,7 +1,7 @@
 /*
  * Tegra GK20A GPU Debugger Driver
  *
- * Copyright (c) 2013-2016, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2013-2017, NVIDIA CORPORATION.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -73,6 +73,8 @@ struct dbg_session_gk20a {
         struct dbg_gpu_session_events dbg_events;
 
         bool broadcast_stop_trigger;
+
+        struct mutex ioctl_lock;
 };
 
 struct dbg_session_data {