[PATCH] ARM: mmp: Fix failure to remove sram device

Make sure in .probe() to set driver data before the function is left to
make it possible in .remove() to undo the actions done.

This fixes a potential memory leak and stops returning an error code in
.remove() that is ignored by the driver core anyhow.

Signed-off-by: Uwe Kleine-König <redacted>
---
 arch/arm/mach-mmp/sram.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/arm/mach-mmp/sram.c b/arch/arm/mach-mmp/sram.c
index 6794e2db1ad5..ecc46c31004f 100644
--- a/arch/arm/mach-mmp/sram.c
+++ b/arch/arm/mach-mmp/sram.c

@@ -72,6 +72,8 @@ static int sram_probe(struct platform_device *pdev)
 	if (!info)
 		return -ENOMEM;
 
+	platform_set_drvdata(pdev, info);
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (res == NULL) {
 		dev_err(&pdev->dev, "no memory resource defined\n");

@@ -107,8 +109,6 @@ static int sram_probe(struct platform_device *pdev)
 	list_add(&info->node, &sram_bank_list);
 	mutex_unlock(&sram_lock);
 
-	platform_set_drvdata(pdev, info);
-
 	dev_info(&pdev->dev, "initialized\n");
 	return 0;
 

@@ -127,17 +127,19 @@ static int sram_remove(struct platform_device *pdev)
 	struct sram_bank_info *info;
 
 	info = platform_get_drvdata(pdev);
-	if (info == NULL)
-		return -ENODEV;
 
-	mutex_lock(&sram_lock);
-	list_del(&info->node);
-	mutex_unlock(&sram_lock);
+	if (info->sram_size) {
+		mutex_lock(&sram_lock);
+		list_del(&info->node);
+		mutex_unlock(&sram_lock);
+
+		gen_pool_destroy(info->gpool);
+		iounmap(info->sram_virt);
+		kfree(info->pool_name);
+	}
 
-	gen_pool_destroy(info->gpool);
-	iounmap(info->sram_virt);
-	kfree(info->pool_name);
 	kfree(info);
+
 	return 0;
 }
 

-- 
2.30.2


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On Mon, Jul 26, 2021 at 10:01:58PM +0200, Uwe Kleine-König wrote:

Make sure in .probe() to set driver data before the function is left to
make it possible in .remove() to undo the actions done.

This fixes a potential memory leak and stops returning an error code in
.remove() that is ignored by the driver core anyhow.

Signed-off-by: Uwe Kleine-König <redacted>
---
 arch/arm/mach-mmp/sram.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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[adding soc@kernel.org to Cc]

On Mon, Jul 26, 2021 at 10:01:58PM +0200, Uwe Kleine-König wrote:

Make sure in .probe() to set driver data before the function is left to
make it possible in .remove() to undo the actions done.

This fixes a potential memory leak and stops returning an error code in
.remove() that is ignored by the driver core anyhow.

Signed-off-by: Uwe Kleine-König <redacted>

This problem is still real and the patch not applied. Who feels
responsible to pick this up?

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

On Mon, Feb 21, 2022 at 1:14 PM Uwe Kleine-König
[off-list ref] wrote:

[adding soc@kernel.org to Cc]

On Mon, Jul 26, 2021 at 10:01:58PM +0200, Uwe Kleine-König wrote:

quoted

Make sure in .probe() to set driver data before the function is left to
make it possible in .remove() to undo the actions done.

This fixes a potential memory leak and stops returning an error code in
.remove() that is ignored by the driver core anyhow.

Signed-off-by: Uwe Kleine-König <redacted>

This problem is still real and the patch not applied. Who feels
responsible to pick this up?

I've picked it up manually now, thank you for looping us in.

Note that I almost missed it again though, if you really want my attention,
send the patch to:soc@kernel.org so it makes it into patchwork. At that
point, I'll have to either apply it or actively discard the patch from there.

       Arnd

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