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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= 
        <u.kleine-koenig@pengutronix.de>,
        Thierry Reding <thierry.reding@gmail.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 038/191] pwm: omap-dmtimer: Simplify error handling
Date:   Fri, 21 Feb 2020 08:40:11 +0100
Message-Id: <20200221072256.150152720@linuxfoundation.org>
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From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

[ Upstream commit c4cf7aa57eb83b108d2d9c6c37c143388fee2a4d ]

Instead of doing error handling in the middle of ->probe(), move error
handling and freeing the reference to timer to the end.

This fixes a resource leak as dm_timer wasn't freed when allocating
*omap failed.

Implementation note: The put: label was never reached without a goto and
ret being unequal to 0, so the removed return statement is fine.

Fixes: 6604c6556db9 ("pwm: Add PWM driver for OMAP using dual-mode timers")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pwm/pwm-omap-dmtimer.c | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
index f45798679e3c0..2d585c101d52e 100644
--- a/drivers/pwm/pwm-omap-dmtimer.c
+++ b/drivers/pwm/pwm-omap-dmtimer.c
@@ -301,15 +301,10 @@ static int pwm_omap_dmtimer_probe(struct platform_device *pdev)
 		goto put;
 	}
 
-put:
-	of_node_put(timer);
-	if (ret < 0)
-		return ret;
-
 	omap = devm_kzalloc(&pdev->dev, sizeof(*omap), GFP_KERNEL);
 	if (!omap) {
-		pdata->free(dm_timer);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto err_alloc_omap;
 	}
 
 	omap->pdata = pdata;
@@ -342,13 +337,28 @@ put:
 	ret = pwmchip_add(&omap->chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to register PWM\n");
-		omap->pdata->free(omap->dm_timer);
-		return ret;
+		goto err_pwmchip_add;
 	}
 
+	of_node_put(timer);
+
 	platform_set_drvdata(pdev, omap);
 
 	return 0;
+
+err_pwmchip_add:
+
+	/*
+	 * *omap is allocated using devm_kzalloc,
+	 * so no free necessary here
+	 */
+err_alloc_omap:
+
+	pdata->free(dm_timer);
+put:
+	of_node_put(timer);
+
+	return ret;
 }
 
 static int pwm_omap_dmtimer_remove(struct platform_device *pdev)
-- 
2.20.1