Commit 30f8c74ca9b7 ("drm/vc4: Warn if some v3d code is run on BCM2711") introduced a check in vc4_perfmon_get() that dereferences a pointer before we checked whether that pointer is valid or not.

Let's rework that function a bit to do things in the proper order.

Reported-by: kernel test robot lkp@intel.com Reported-by: Dan Carpenter dan.carpenter@oracle.com Fixes: 30f8c74ca9b7 ("drm/vc4: Warn if some v3d code is run on BCM2711") Signed-off-by: Maxime Ripard maxime@cerno.tech --- drivers/gpu/drm/vc4/vc4_perfmon.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_perfmon.c b/drivers/gpu/drm/vc4/vc4_perfmon.c index c7f5adb6bcf8..79a74184d732 100644 --- a/drivers/gpu/drm/vc4/vc4_perfmon.c +++ b/drivers/gpu/drm/vc4/vc4_perfmon.c @@ -17,13 +17,16 @@

void vc4_perfmon_get(struct vc4_perfmon *perfmon) { - struct vc4_dev *vc4 = perfmon->dev; + struct vc4_dev *vc4;

+ if (!perfmon) + return; + + vc4 = perfmon->dev; if (WARN_ON_ONCE(vc4->is_vc5)) return;

- if (perfmon) - refcount_inc(&perfmon->refcnt); + refcount_inc(&perfmon->refcnt); }

void vc4_perfmon_put(struct vc4_perfmon *perfmon)