[PATCH 5.15 437/917] drm/msm: Fix potential Oops in a6xx_gmu_rpmh_init()

Greg Kroah-Hartman
2021-11-16T00:31:39Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 3d91e50ff58364f6572ad268b508175d27800e51 ]

There are two problems here:
1) The "seqptr" is used uninitalized when we free it at the end.
2) The a6xx_gmu_get_mmio() function returns error pointers. It never
returns true.

Fixes: 64245fc55172 ("drm/msm/a6xx: use AOP-initialized PDC for a650")
Fixes: f8fc924e088e ("drm/msm/a6xx: Fix PDC register overlap")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20211004134530.GB11689@kili
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index 8b73f70766a47..4347a104755a9 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -516,11 +516,11 @@ static void a6xx_gmu_rpmh_init(struct a6xx_gmu *gmu)
struct adreno_gpu *adreno_gpu = &a6xx_gpu->base;
struct platform_device *pdev = to_platform_device(gmu->dev);
void __iomem *pdcptr = a6xx_gmu_get_mmio(pdev, "gmu_pdc");
- void __iomem *seqptr;
+ void __iomem *seqptr = NULL;
uint32_t pdc_address_offset;
bool pdc_in_aop = false;

- if (!pdcptr)
+ if (IS_ERR(pdcptr))
goto err;

if (adreno_is_a650(adreno_gpu) || adreno_is_a660_family(adreno_gpu))
@@ -532,7 +532,7 @@ static void a6xx_gmu_rpmh_init(struct a6xx_gmu *gmu)

if (!pdc_in_aop) {
seqptr = a6xx_gmu_get_mmio(pdev, "gmu_pdc_seq");
- if (!seqptr)
+ if (IS_ERR(seqptr))
goto err;
}

--
2.33.0