From 5f701324c0fb6f9f5aaac3f8d1575321375f6d8f Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Wed, 22 Jun 2022 10:02:43 +0200 Subject: [PATCH] drm/vc4: perfmon: Fix variable dereferenced before check MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reported-by: Dan Carpenter Fixes: 30f8c74ca9b7 ("drm/vc4: Warn if some v3d code is run on BCM2711") Signed-off-by: Maxime Ripard Reviewed-by: José Expósito Link: https://patchwork.freedesktop.org/patch/msgid/20220622080243.22119-1-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 c7f5adb..79a7418 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) -- 2.7.4