[Freedreno] [PATCH 2/2] drm/msm/a6xx: Fix NULL dereference during crashstate capture

[Sharat Masetty]

The gpu crashstate's base objects registers pointer can be NULL if the
target implementation decides to capture the register dump on its own.
This patch simply checks for NULL before dereferencing.

Signed-off-by: Sharat Masetty <smasetty at codeaurora.org>
---
 drivers/gpu/drm/msm/adreno/adreno_gpu.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index 40bcf32..a39cebc 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -415,6 +415,9 @@ void adreno_gpu_state_get(struct msm_gpu *gpu, struct msm_gpu_state *state)
 		}
 	}
 
+	if (!adreno_gpu->registers)
+		return;
+
 	/* Count the number of registers */
 	for (i = 0; adreno_gpu->registers[i] != ~0; i += 2)
 		count += adreno_gpu->registers[i + 1] -
@@ -550,12 +553,14 @@ void adreno_show(struct msm_gpu *gpu, struct msm_gpu_state *state,
 		}
 	}
 
-	drm_puts(p, "registers:\n");
+	if (state->nr_registers > 0) {
+		drm_puts(p, "registers:\n");
 
-	for (i = 0; i < state->nr_registers; i++) {
-		drm_printf(p, "  - { offset: 0x%04x, value: 0x%08x }\n",
-			state->registers[i * 2] << 2,
-			state->registers[(i * 2) + 1]);
+		for (i = 0; i < state->nr_registers; i++) {
+			drm_printf(p, "  - { offset: 0x%04x, value: 0x%08x }\n",
+					state->registers[i * 2] << 2,
+					state->registers[(i * 2) + 1]);
+		}
 	}
 }
 #endif
-- 
1.9.1