[PATCH 2/3] drm/amd/amdgpu: Fix crash in amdgpu_bo_reserve

[Pratik Vishwakarma]

Fixes null pointer access in ww_mutex_lock
where lock->base is NULL

Crash dump is as follows:
Call Trace:
ww_mutex_lock+0x3a/0x8e
amdgpu_bo_reserve+0x40/0x87
amdgpu_device_suspend+0xf4/0x210
pci_pm_suspend+0x12a/0x1a5
? pci_dev_driver+0x36/0x36
dpm_run_callback+0x59/0xbf
__device_suspend+0x215/0x33f
async_suspend+0x1f/0x5c
async_run_entry_fn+0x3d/0xd2
process_one_work+0x1b0/0x314
worker_thread+0x1cb/0x2c1
? create_worker+0x1da/0x1da
kthread+0x156/0x15e
? kthread_flush_work+0xea/0xea
ret_from_fork+0x22/0x40

Signed-off-by: Pratik Vishwakarma <Pratik.Vishwakarma at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
index 7317480..c9df7ae 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
@@ -152,6 +152,8 @@ static inline int amdgpu_bo_reserve(struct amdgpu_bo *bo, bool no_intr)
 	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
 	int r;
 
+	if (&(bo->tbo.resv->lock) == NULL)
+		return -EINVAL;
 	r = ttm_bo_reserve(&bo->tbo, !no_intr, false, NULL);
 	if (unlikely(r != 0)) {
 		if (r != -ERESTARTSYS)
-- 
1.9.1