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From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        linux-arm-msm@vger.kernel.org, linux-gpio@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Subject: [PATCH] pinctrl: qcom: sc8180x: gracefully handle missing IO memory resource
Date:   Sat, 13 May 2023 13:35:10 +0200
Message-Id: <20230513113510.177666-1-krzysztof.kozlowski@linaro.org>
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If device was probed with incorrect DT or ACPI tables, the IO memory
resource would be missing and driver would derefernce NULL pointer in
sc8180x_pinctrl_add_tile_resources().  Add simplep check if IO memory
resource was provided to silence Smatch warning:

  drivers/pinctrl/qcom/pinctrl-sc8180x.c:1664 sc8180x_pinctrl_add_tile_resources() error: potentially dereferencing uninitialized 'mres'.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 drivers/pinctrl/qcom/pinctrl-sc8180x.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/pinctrl/qcom/pinctrl-sc8180x.c b/drivers/pinctrl/qcom/pinctrl-sc8180x.c
index 704a99d2f93c..2fabec096aae 100644
--- a/drivers/pinctrl/qcom/pinctrl-sc8180x.c
+++ b/drivers/pinctrl/qcom/pinctrl-sc8180x.c
@@ -1630,7 +1630,8 @@ static const struct msm_pinctrl_soc_data sc8180x_acpi_pinctrl = {
 static int sc8180x_pinctrl_add_tile_resources(struct platform_device *pdev)
 {
 	int nres_num = pdev->num_resources + ARRAY_SIZE(sc8180x_tiles) - 1;
-	struct resource *mres, *nres, *res;
+	struct resource *mres = NULL;
+	struct resource *nres, *res;
 	int i, ret;
 
 	/*
@@ -1657,6 +1658,9 @@ static int sc8180x_pinctrl_add_tile_resources(struct platform_device *pdev)
 			*res++ = *r;
 	}
 
+	if (!mres)
+		return -EINVAL;
+
 	/* Append tile memory resources */
 	for (i = 0; i < ARRAY_SIZE(sc8180x_tiles); i++, res++) {
 		const struct tile_info *info = &sc8180x_tile_info[i];
-- 
2.34.1