remoteproc: qcom: Fix potential NULL dereference in adsp_init_mmio()

[ Upstream commit c3d4e5b ]

platform_get_resource() may fail and in this case a NULL dereference
will occur.

Fix it to use devm_platform_ioremap_resource() instead of calling
platform_get_resource() and devm_ioremap().

This is detected by Coccinelle semantic patch.

@@
expression pdev, res, n, t, e, e1, e2;
@@

res = \(platform_get_resource\|platform_get_resource_byname\)(pdev, t,
n);
+ if (!res)
+   return -EINVAL;
... when != res == NULL
e = devm_ioremap(e1, res->start, e2);

Fixes: dc160e4 ("remoteproc: qcom: Introduce Non-PAS ADSP PIL driver")
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1607392460-20516-1-git-send-email-zhangchangzhong@huawei.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/remoteproc/qcom_q6v5_adsp.c

@@ -364,15 +364,12 @@ static int adsp_init_mmio(struct qcom_adsp *adsp,
 				struct platform_device *pdev)
 {
 	struct device_node *syscon;
-	struct resource *res;
 	int ret;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	adsp->qdsp6ss_base = devm_ioremap(&pdev->dev, res->start,
-			resource_size(res));
-	if (!adsp->qdsp6ss_base) {
+	adsp->qdsp6ss_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(adsp->qdsp6ss_base)) {
 		dev_err(adsp->dev, "failed to map QDSP6SS registers\n");
-		return -ENOMEM;
+		return PTR_ERR(adsp->qdsp6ss_base);
 	}
 
 	syscon = of_parse_phandle(pdev->dev.of_node, "qcom,halt-regs", 0);