[PATCH] drm/amdgpu: fix potential null dereference

[Weiguo Li]

"ctx" is dereferenced but null checked later. Swap their positions
to avoid potential null dereference.

Found using a Coccinelle script:
https://coccinelle.gitlabpages.inria.fr/website/rules/mini_null_ref.cocci

Signed-off-by: Weiguo Li <liwg06 at foxmail.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
index f522b52725e4..b4f035ce44bc 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
@@ -258,11 +258,12 @@ static void amdgpu_ctx_fini_entity(struct amdgpu_ctx_entity *entity)
 static int amdgpu_ctx_get_stable_pstate(struct amdgpu_ctx *ctx,
 					u32 *stable_pstate)
 {
-	struct amdgpu_device *adev = ctx->adev;
+	struct amdgpu_device *adev;
 	enum amd_dpm_forced_level current_level;
 
 	if (!ctx)
 		return -EINVAL;
+	adev = ctx->adev;
 
 	current_level = amdgpu_dpm_get_performance_level(adev);
 
@@ -289,12 +290,13 @@ static int amdgpu_ctx_get_stable_pstate(struct amdgpu_ctx *ctx,
 static int amdgpu_ctx_set_stable_pstate(struct amdgpu_ctx *ctx,
 					u32 stable_pstate)
 {
-	struct amdgpu_device *adev = ctx->adev;
+	struct amdgpu_device *adev;
 	enum amd_dpm_forced_level level;
 	int r;
 
 	if (!ctx)
 		return -EINVAL;
+	adev = ctx->adev;
 
 	mutex_lock(&adev->pm.stable_pstate_ctx_lock);
 	if (adev->pm.stable_pstate_ctx && adev->pm.stable_pstate_ctx != ctx) {
-- 
2.25.1