[PATCH 0/2] mtd: onenand: samsung: Simplify code and fix leaks in error handling paths

[PATCH 0/2] mtd: onenand: samsung: Simplify code and fix leaks in error handling paths

[Christophe JAILLET]

The first patch converts 's3c_onenand_probe()' to devm_ functions.
This fixes a leak in one path (line 872).
This also free_irq which was not handled at all. (I hope I'm correct :) )

The 2nd patch is about an un-handled error code which looks spurious.
Not sure if I'm right.


While compile-testing it, I had to tweak the code because I don't have any
cross-compiler.
I commented the line "#include <asm/mach/flash.h>" and the compilation
succeeded. So maybe, this include is also useless.
I've left it as-is, though.


Theses patches have been compile-tested-only.


Christophe JAILLET (2):
  mtd: onenand: samsung: use devm_ function to simplify code and fix
    some leaks
  mtd: onenand: samsung: return an error if
    'mtd_device_parse_register()' fails

 drivers/mtd/onenand/samsung.c | 145 ++++++++++++++----------------------------
 1 file changed, 47 insertions(+), 98 deletions(-)

-- 
2.14.1

[PATCH 1/2] mtd: onenand: samsung: use devm_ function to simplify code and fix some leaks

[Christophe JAILLET]

Convert all error handling code in 's3c_onenand_probe()' to
resource-managed alternatives in order to simplify code.

This fixes a resource leak if 'platform_get_resource()' fails at line 872.

The 'request_irq()' at line 971 was also un-balanced. It is now
resource-managed

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Compile tested-only
---
 drivers/mtd/onenand/samsung.c | 141 +++++++++++++-----------------------------
 1 file changed, 43 insertions(+), 98 deletions(-)

diff --git a/drivers/mtd/onenand/samsung.c b/drivers/mtd/onenand/samsung.c
index af0ac1a7bf8f..04039b967d59 100644
--- a/drivers/mtd/onenand/samsung.c
+++ b/drivers/mtd/onenand/samsung.c
@@ -851,15 +851,14 @@ static int s3c_onenand_probe(struct platform_device *pdev)
 	/* No need to check pdata. the platform data is optional */
 
 	size = sizeof(struct mtd_info) + sizeof(struct onenand_chip);
-	mtd = kzalloc(size, GFP_KERNEL);
+	mtd = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
 	if (!mtd)
 		return -ENOMEM;
 
-	onenand = kzalloc(sizeof(struct s3c_onenand), GFP_KERNEL);
-	if (!onenand) {
-		err = -ENOMEM;
-		goto onenand_fail;
-	}
+	onenand = devm_kzalloc(&pdev->dev, sizeof(struct s3c_onenand),
+			       GFP_KERNEL);
+	if (!onenand)
+		return -ENOMEM;
 
 	this = (struct onenand_chip *) &mtd[1];
 	mtd->priv = this;
@@ -873,22 +872,20 @@ static int s3c_onenand_probe(struct platform_device *pdev)
 	if (!r) {
 		dev_err(&pdev->dev, "no memory resource defined\n");
 		return -ENOENT;
-		goto ahb_resource_failed;
 	}
 
-	onenand->base_res = request_mem_region(r->start, resource_size(r),
-					       pdev->name);
+	onenand->base_res = devm_request_mem_region(&pdev->dev, r->start,
+						    resource_size(r),
+						    pdev->name);
 	if (!onenand->base_res) {
 		dev_err(&pdev->dev, "failed to request memory resource\n");
-		err = -EBUSY;
-		goto resource_failed;
+		return -EBUSY;
 	}
 
-	onenand->base = ioremap(r->start, resource_size(r));
+	onenand->base = devm_ioremap(&pdev->dev, r->start, resource_size(r));
 	if (!onenand->base) {
 		dev_err(&pdev->dev, "failed to map memory resource\n");
-		err = -EFAULT;
-		goto ioremap_failed;
+		return -EFAULT;
 	}
 	/* Set onenand_chip also */
 	this->base = onenand->base;
@@ -900,38 +897,35 @@ static int s3c_onenand_probe(struct platform_device *pdev)
 		r = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 		if (!r) {
 			dev_err(&pdev->dev, "no buffer memory resource defined\n");
-			err = -ENOENT;
-			goto ahb_resource_failed;
+			return -ENOENT;
 		}
 
-		onenand->ahb_res = request_mem_region(r->start, resource_size(r),
-						      pdev->name);
+		onenand->ahb_res = devm_request_mem_region(&pdev->dev,
+							   r->start,
+							   resource_size(r),
+							   pdev->name);
 		if (!onenand->ahb_res) {
 			dev_err(&pdev->dev, "failed to request buffer memory resource\n");
-			err = -EBUSY;
-			goto ahb_resource_failed;
+			return -EBUSY;
 		}
 
-		onenand->ahb_addr = ioremap(r->start, resource_size(r));
+		onenand->ahb_addr = devm_ioremap(&pdev->dev, r->start,
+						 resource_size(r));
 		if (!onenand->ahb_addr) {
 			dev_err(&pdev->dev, "failed to map buffer memory resource\n");
-			err = -EINVAL;
-			goto ahb_ioremap_failed;
+			return -EINVAL;
 		}
 
 		/* Allocate 4KiB BufferRAM */
-		onenand->page_buf = kzalloc(SZ_4K, GFP_KERNEL);
-		if (!onenand->page_buf) {
-			err = -ENOMEM;
-			goto page_buf_fail;
-		}
+		onenand->page_buf = devm_kzalloc(&pdev->dev, SZ_4K,
+						 GFP_KERNEL);
+		if (!onenand->page_buf)
+			return -ENOMEM;
 
 		/* Allocate 128 SpareRAM */
-		onenand->oob_buf = kzalloc(128, GFP_KERNEL);
-		if (!onenand->oob_buf) {
-			err = -ENOMEM;
-			goto oob_buf_fail;
-		}
+		onenand->oob_buf = devm_kzalloc(&pdev->dev, 128, GFP_KERNEL);
+		if (!onenand->oob_buf)
+			return -ENOMEM;
 
 		/* S3C doesn't handle subpage write */
 		mtd->subpage_sft = 0;
@@ -941,23 +935,23 @@ static int s3c_onenand_probe(struct platform_device *pdev)
 		r = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 		if (!r) {
 			dev_err(&pdev->dev, "no dma memory resource defined\n");
-			err = -ENOENT;
-			goto dma_resource_failed;
+			return -ENOENT;
 		}
 
-		onenand->dma_res = request_mem_region(r->start, resource_size(r),
-						      pdev->name);
+		onenand->dma_res = devm_request_mem_region(&pdev->dev,
+							   r->start,
+							   resource_size(r),
+							   pdev->name);
 		if (!onenand->dma_res) {
 			dev_err(&pdev->dev, "failed to request dma memory resource\n");
-			err = -EBUSY;
-			goto dma_resource_failed;
+			return -EBUSY;
 		}
 
-		onenand->dma_addr = ioremap(r->start, resource_size(r));
+		onenand->dma_addr = devm_ioremap(&pdev->dev, r->start,
+						 resource_size(r));
 		if (!onenand->dma_addr) {
 			dev_err(&pdev->dev, "failed to map dma memory resource\n");
-			err = -EINVAL;
-			goto dma_ioremap_failed;
+			return -EINVAL;
 		}
 
 		onenand->phys_base = onenand->base_res->start;
@@ -968,19 +962,19 @@ static int s3c_onenand_probe(struct platform_device *pdev)
 		if (r) {
 			init_completion(&onenand->complete);
 			s5pc110_dma_ops = s5pc110_dma_irq;
-			err = request_irq(r->start, s5pc110_onenand_irq,
-					IRQF_SHARED, "onenand", &onenand);
+			err = devm_request_irq(&pdev->dev, r->start,
+					       s5pc110_onenand_irq,
+					       IRQF_SHARED, "onenand",
+					       &onenand);
 			if (err) {
 				dev_err(&pdev->dev, "failed to get irq\n");
-				goto scan_failed;
+				return err;
 			}
 		}
 	}
 
-	if (onenand_scan(mtd, 1)) {
-		err = -EFAULT;
-		goto scan_failed;
-	}
+	if (onenand_scan(mtd, 1))
+		return -EFAULT;
 
 	if (onenand->type != TYPE_S5PC110) {
 		/* S3C doesn't handle subpage write */
@@ -998,36 +992,6 @@ static int s3c_onenand_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, mtd);
 
 	return 0;
-
-scan_failed:
-	if (onenand->dma_addr)
-		iounmap(onenand->dma_addr);
-dma_ioremap_failed:
-	if (onenand->dma_res)
-		release_mem_region(onenand->dma_res->start,
-				   resource_size(onenand->dma_res));
-	kfree(onenand->oob_buf);
-oob_buf_fail:
-	kfree(onenand->page_buf);
-page_buf_fail:
-	if (onenand->ahb_addr)
-		iounmap(onenand->ahb_addr);
-ahb_ioremap_failed:
-	if (onenand->ahb_res)
-		release_mem_region(onenand->ahb_res->start,
-				   resource_size(onenand->ahb_res));
-dma_resource_failed:
-ahb_resource_failed:
-	iounmap(onenand->base);
-ioremap_failed:
-	if (onenand->base_res)
-		release_mem_region(onenand->base_res->start,
-				   resource_size(onenand->base_res));
-resource_failed:
-	kfree(onenand);
-onenand_fail:
-	kfree(mtd);
-	return err;
 }
 
 static int s3c_onenand_remove(struct platform_device *pdev)
@@ -1035,25 +999,7 @@ static int s3c_onenand_remove(struct platform_device *pdev)
 	struct mtd_info *mtd = platform_get_drvdata(pdev);
 
 	onenand_release(mtd);
-	if (onenand->ahb_addr)
-		iounmap(onenand->ahb_addr);
-	if (onenand->ahb_res)
-		release_mem_region(onenand->ahb_res->start,
-				   resource_size(onenand->ahb_res));
-	if (onenand->dma_addr)
-		iounmap(onenand->dma_addr);
-	if (onenand->dma_res)
-		release_mem_region(onenand->dma_res->start,
-				   resource_size(onenand->dma_res));
-
-	iounmap(onenand->base);
-	release_mem_region(onenand->base_res->start,
-			   resource_size(onenand->base_res));
-
-	kfree(onenand->oob_buf);
-	kfree(onenand->page_buf);
-	kfree(onenand);
-	kfree(mtd);
+
 	return 0;
 }
 
-- 
2.14.1

Re: [PATCH 1/2] mtd: onenand: samsung: use devm_ function to simplify code and fix some leaks

[Boris Brezillon]

On Fri,  8 Dec 2017 22:11:04 +0100
Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote:

> Convert all error handling code in 's3c_onenand_probe()' to
> resource-managed alternatives in order to simplify code.
> 
> This fixes a resource leak if 'platform_get_resource()' fails at line 872.
> 
> The 'request_irq()' at line 971 was also un-balanced. It is now
> resource-managed
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> Compile tested-only
> ---
>  drivers/mtd/onenand/samsung.c | 141 +++++++++++++-----------------------------
>  1 file changed, 43 insertions(+), 98 deletions(-)
> 
> diff --git a/drivers/mtd/onenand/samsung.c b/drivers/mtd/onenand/samsung.c
> index af0ac1a7bf8f..04039b967d59 100644
> --- a/drivers/mtd/onenand/samsung.c
> +++ b/drivers/mtd/onenand/samsung.c
> @@ -851,15 +851,14 @@ static int s3c_onenand_probe(struct platform_device *pdev)
>  	/* No need to check pdata. the platform data is optional */
>  
>  	size = sizeof(struct mtd_info) + sizeof(struct onenand_chip);
> -	mtd = kzalloc(size, GFP_KERNEL);
> +	mtd = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
>  	if (!mtd)
>  		return -ENOMEM;
>  
> -	onenand = kzalloc(sizeof(struct s3c_onenand), GFP_KERNEL);
> -	if (!onenand) {
> -		err = -ENOMEM;
> -		goto onenand_fail;
> -	}
> +	onenand = devm_kzalloc(&pdev->dev, sizeof(struct s3c_onenand),
> +			       GFP_KERNEL);
> +	if (!onenand)
> +		return -ENOMEM;
>  
>  	this = (struct onenand_chip *) &mtd[1];
>  	mtd->priv = this;
> @@ -873,22 +872,20 @@ static int s3c_onenand_probe(struct platform_device *pdev)
>  	if (!r) {
>  		dev_err(&pdev->dev, "no memory resource defined\n");
>  		return -ENOENT;
> -		goto ahb_resource_failed;
>  	}
>  
> -	onenand->base_res = request_mem_region(r->start, resource_size(r),
> -					       pdev->name);
> +	onenand->base_res = devm_request_mem_region(&pdev->dev, r->start,
> +						    resource_size(r),
> +						    pdev->name);
>  	if (!onenand->base_res) {
>  		dev_err(&pdev->dev, "failed to request memory resource\n");
> -		err = -EBUSY;
> -		goto resource_failed;
> +		return -EBUSY;
>  	}
>  
> -	onenand->base = ioremap(r->start, resource_size(r));
> +	onenand->base = devm_ioremap(&pdev->dev, r->start, resource_size(r));
>  	if (!onenand->base) {
>  		dev_err(&pdev->dev, "failed to map memory resource\n");
> -		err = -EFAULT;
> -		goto ioremap_failed;
> +		return -EFAULT;
>  	}

Can still be simplified with the following pattern:

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	onenand->base = devm_ioremap_resource(&pdev->dev, r);
	if (IS_ERR(onenand->base))
		return PTR_ERR(onenand->base);

No need to keep the error messages, since devm_ioremap_resource()
already takes care of that.

Re: [PATCH 1/2] mtd: onenand: samsung: use devm_ function to simplify code and fix some leaks

[Boris Brezillon]

On Fri,  8 Dec 2017 22:11:04 +0100
Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote:

> Convert all error handling code in 's3c_onenand_probe()' to
> resource-managed alternatives in order to simplify code.
> 
> This fixes a resource leak if 'platform_get_resource()' fails at line 872.
> 
> The 'request_irq()' at line 971 was also un-balanced. It is now
> resource-managed
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> Compile tested-only
> ---
>  drivers/mtd/onenand/samsung.c | 141 +++++++++++++-----------------------------
>  1 file changed, 43 insertions(+), 98 deletions(-)
> 
> diff --git a/drivers/mtd/onenand/samsung.c b/drivers/mtd/onenand/samsung.c
> index af0ac1a7bf8f..04039b967d59 100644
> --- a/drivers/mtd/onenand/samsung.c
> +++ b/drivers/mtd/onenand/samsung.c
> @@ -851,15 +851,14 @@ static int s3c_onenand_probe(struct platform_device *pdev)
>  	/* No need to check pdata. the platform data is optional */
>  
>  	size = sizeof(struct mtd_info) + sizeof(struct onenand_chip);
> -	mtd = kzalloc(size, GFP_KERNEL);
> +	mtd = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
>  	if (!mtd)
>  		return -ENOMEM;
>  
> -	onenand = kzalloc(sizeof(struct s3c_onenand), GFP_KERNEL);
> -	if (!onenand) {
> -		err = -ENOMEM;
> -		goto onenand_fail;
> -	}
> +	onenand = devm_kzalloc(&pdev->dev, sizeof(struct s3c_onenand),
> +			       GFP_KERNEL);
> +	if (!onenand)
> +		return -ENOMEM;
>  
>  	this = (struct onenand_chip *) &mtd[1];
>  	mtd->priv = this;
> @@ -873,22 +872,20 @@ static int s3c_onenand_probe(struct platform_device *pdev)
>  	if (!r) {
>  		dev_err(&pdev->dev, "no memory resource defined\n");
>  		return -ENOENT;
> -		goto ahb_resource_failed;
>  	}
>  
> -	onenand->base_res = request_mem_region(r->start, resource_size(r),
> -					       pdev->name);
> +	onenand->base_res = devm_request_mem_region(&pdev->dev, r->start,
> +						    resource_size(r),
> +						    pdev->name);

Oh, and you should also get rid of all the onenand->xxx_res fields,
they're no longer needed after switching to devm_ helpers.

Just move the 'onenand->phys_base = r->start' assignment here and you
should be good.

>  	if (!onenand->base_res) {
>  		dev_err(&pdev->dev, "failed to request memory resource\n");
> -		err = -EBUSY;
> -		goto resource_failed;
> +		return -EBUSY;
>  	}
>  

[PATCH 2/2] mtd: onenand: samsung: return an error if 'mtd_device_parse_register()' fails

[Christophe JAILLET]

If 'mtd_device_parse_register()' fails, we still return 0 which mean
success.
Return the error code instead, as done in all the other error handling
paths.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Compile tested-only
---
 drivers/mtd/onenand/samsung.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/mtd/onenand/samsung.c b/drivers/mtd/onenand/samsung.c
index 04039b967d59..5410e654d3cf 100644
--- a/drivers/mtd/onenand/samsung.c
+++ b/drivers/mtd/onenand/samsung.c
@@ -987,6 +987,10 @@ static int s3c_onenand_probe(struct platform_device *pdev)
 	err = mtd_device_parse_register(mtd, NULL, NULL,
 					pdata ? pdata->parts : NULL,
 					pdata ? pdata->nr_parts : 0);
+	if (err) {
+		dev_err(&pdev->dev, "failed to parse partitions and register the MTD device\n");
+		return err;
+	}
 
 	platform_set_drvdata(pdev, mtd);
 
-- 
2.14.1

Re: [PATCH 2/2] mtd: onenand: samsung: return an error if 'mtd_device_parse_register()' fails

[Boris Brezillon]

On Fri,  8 Dec 2017 22:11:05 +0100
Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote:

> If 'mtd_device_parse_register()' fails, we still return 0 which mean
> success.
> Return the error code instead, as done in all the other error handling
> paths.
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> Compile tested-only
> ---
>  drivers/mtd/onenand/samsung.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/mtd/onenand/samsung.c b/drivers/mtd/onenand/samsung.c
> index 04039b967d59..5410e654d3cf 100644
> --- a/drivers/mtd/onenand/samsung.c
> +++ b/drivers/mtd/onenand/samsung.c
> @@ -987,6 +987,10 @@ static int s3c_onenand_probe(struct platform_device *pdev)
>  	err = mtd_device_parse_register(mtd, NULL, NULL,
>  					pdata ? pdata->parts : NULL,
>  					pdata ? pdata->nr_parts : 0);
> +	if (err) {
> +		dev_err(&pdev->dev, "failed to parse partitions and register the MTD device\n");

And you should call onenand_release() here, to release the resources
allocated in onenand_scan().

> +		return err;
> +	}
>  
>  	platform_set_drvdata(pdev, mtd);
>