[PATCH][next] drm/amdgpu/powerplay: fix dereference before null check of pointer hwmgr

From: Colin King
Date: Fri Nov 15 2019 - 04:48:00 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

The assignment of adev dereferences pointer hwmgr before hwmgr is null
checked, hence there is a potential null pointer deference issue. Fix
this by assigning adev after the null check.

Addresses-Coverity: ("Dereference before null check")
Fixes: 0896d2f7ba4d ("drm/amdgpu/powerplay: properly set PP_GFXOFF_MASK")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/powerplay/hwmgr/hwmgr.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/hwmgr.c b/drivers/gpu/drm/amd/powerplay/hwmgr/hwmgr.c
index 443625c83ec9..d2909c91d65b 100644
--- a/drivers/gpu/drm/amd/powerplay/hwmgr/hwmgr.c
+++ b/drivers/gpu/drm/amd/powerplay/hwmgr/hwmgr.c
@@ -81,7 +81,7 @@ static void hwmgr_init_workload_prority(struct pp_hwmgr *hwmgr)

int hwmgr_early_init(struct pp_hwmgr *hwmgr)
{
- struct amdgpu_device *adev = hwmgr->adev;
+ struct amdgpu_device *adev;

if (!hwmgr)
return -EINVAL;
@@ -96,6 +96,8 @@ int hwmgr_early_init(struct pp_hwmgr *hwmgr)
hwmgr_init_workload_prority(hwmgr);
hwmgr->gfxoff_state_changed_by_workload = false;

+ adev = hwmgr->adev;
+
switch (hwmgr->chip_family) {
case AMDGPU_FAMILY_CI:
adev->pm.pp_feature &= ~PP_GFXOFF_MASK;
--
2.20.1