drm/amdgpu: Fix locking bugs in error paths

[ Upstream commit 480ad5f ]

Do not unlock psp->ras_context.mutex if it has not been locked. This has
been detected by the Clang thread-safety analyzer.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: YiPeng Chai <YiPeng.Chai@amd.com>
Cc: Hawking Zhang <Hawking.Zhang@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Fixes: b3fb79c ("drm/amdgpu: add mutex to protect ras shared memory")
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 6fa01b4335978051d2cd80841728fd63cc597970)
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: bvanassche

drivers/gpu/drm/amd/amdgpu/amdgpu_psp_ta.c

@@ -332,37 +332,39 @@ static ssize_t ta_if_invoke_debugfs_write(struct file *fp, const char *buf, size
 	if (!context || !context->initialized) {
 		dev_err(adev->dev, "TA is not initialized\n");
 		ret = -EINVAL;
-		goto err_free_shared_buf;
+		goto free_shared_buf;
 	}
 
 	if (!psp->ta_funcs || !psp->ta_funcs->fn_ta_invoke) {
 		dev_err(adev->dev, "Unsupported function to invoke TA\n");
 		ret = -EOPNOTSUPP;
-		goto err_free_shared_buf;
+		goto free_shared_buf;
 	}
 
 	context->session_id = ta_id;
 
 	mutex_lock(&psp->ras_context.mutex);
 	ret = prep_ta_mem_context(&context->mem_context, shared_buf, shared_buf_len);
 	if (ret)
-		goto err_free_shared_buf;
+		goto unlock;
 
 	ret = psp_fn_ta_invoke(psp, cmd_id);
 	if (ret || context->resp_status) {
 		dev_err(adev->dev, "Failed to invoke TA via debugfs (%d) and status (0x%X)\n",
 			ret, context->resp_status);
 		if (!ret) {
 			ret = -EINVAL;
-			goto err_free_shared_buf;
+			goto unlock;
 		}
 	}
 
 	if (copy_to_user((char *)&buf[copy_pos], context->mem_context.shared_buf, shared_buf_len))
 		ret = -EFAULT;
 
-err_free_shared_buf:
+unlock:
 	mutex_unlock(&psp->ras_context.mutex);
+
+free_shared_buf:
 	kfree(shared_buf);
 
 	return ret;