soc: qcom: ocmem: don't return NULL in of_get_ocmem

If ocmem probe fails for whatever reason, of_get_ocmem returned NULL.
Without this, users must check for both NULL and IS_ERR on the returned
pointer - which didn't happen in drivers/gpu/drm/msm/adreno/adreno_gpu.c
leading to a NULL pointer dereference.

Reviewed-by: Brian Masney <masneyb@onstation.org>
Fixes: 88c1e9404f1d ("soc: qcom: add OCMEM driver")
Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Link: https://lore.kernel.org/r/20210130142349.53335-1-luca@z3ntu.xyz
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

diff --git a/drivers/soc/qcom/ocmem.c b/drivers/soc/qcom/ocmem.c
index 7f9e9944d1eaec3c40e77f720dcffa24418b48ce..f1875dc31ae2cb8991e98a3a28e6b52fcd5405a9 100644 (file)
--- a/drivers/soc/qcom/ocmem.c
+++ b/drivers/soc/qcom/ocmem.c
@@ -189,6 +189,7 @@ struct ocmem *of_get_ocmem(struct device *dev)
 {
        struct platform_device *pdev;
        struct device_node *devnode;
+       struct ocmem *ocmem;
 
        devnode = of_parse_phandle(dev->of_node, "sram", 0);
        if (!devnode || !devnode->parent) {
@@ -202,7 +203,12 @@ struct ocmem *of_get_ocmem(struct device *dev)
                return ERR_PTR(-EPROBE_DEFER);
        }
 
-       return platform_get_drvdata(pdev);
+       ocmem = platform_get_drvdata(pdev);
+       if (!ocmem) {
+               dev_err(dev, "Cannot get ocmem\n");
+               return ERR_PTR(-ENODEV);
+       }
+       return ocmem;
 }
 EXPORT_SYMBOL(of_get_ocmem);