Re: [PATCH 1/2 v2] mtd: onenand: samsung: use devm_ function to simplify code and fix some leaks

[Boris Brezillon]

On Sat,  9 Dec 2017 08:24:04 +0100
Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> 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@xxxxxxxxxx>
> ---
> Compile tested-only
> 
> v2: use devm_ioremap_resource()
> ---
>  drivers/mtd/onenand/samsung.c | 164 ++++++++----------------------------------
>  1 file changed, 29 insertions(+), 135 deletions(-)
> 
> diff --git a/drivers/mtd/onenand/samsung.c b/drivers/mtd/onenand/samsung.c
> index af0ac1a7bf8f..2e562c224060 100644
> --- a/drivers/mtd/onenand/samsung.c
> +++ b/drivers/mtd/onenand/samsung.c
> @@ -129,16 +129,13 @@ struct s3c_onenand {
>  	struct platform_device	*pdev;
>  	enum soc_type	type;
>  	void __iomem	*base;
> -	struct resource *base_res;
>  	void __iomem	*ahb_addr;
> -	struct resource *ahb_res;
>  	int		bootram_command;
>  	void __iomem	*page_buf;
>  	void __iomem	*oob_buf;
>  	unsigned int	(*mem_addr)(int fba, int fpa, int fsa);
>  	unsigned int	(*cmd_map)(unsigned int type, unsigned int val);
>  	void __iomem	*dma_addr;
> -	struct resource *dma_res;
>  	unsigned long	phys_base;
>  	struct completion	complete;
>  };
> @@ -851,15 +848,13 @@ 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;
> @@ -870,26 +865,10 @@ static int s3c_onenand_probe(struct platform_device *pdev)
>  	s3c_onenand_setup(mtd);
>  
>  	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	if (!r) {
> -		dev_err(&pdev->dev, "no memory resource defined\n");
> -		return -ENOENT;
> -		goto ahb_resource_failed;
> -	}
> +	onenand->base = devm_ioremap_resource(&pdev->dev, r);
> +	if (IS_ERR(onenand->base))
> +		return PTR_ERR(onenand->base);
>  
> -	onenand->base_res = request_mem_region(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;
> -	}
> -
> -	onenand->base = ioremap(r->start, resource_size(r));
> -	if (!onenand->base) {
> -		dev_err(&pdev->dev, "failed to map memory resource\n");
> -		err = -EFAULT;
> -		goto ioremap_failed;
> -	}
>  	/* Set onenand_chip also */
>  	this->base = onenand->base;
>  
> @@ -898,40 +877,20 @@ static int s3c_onenand_probe(struct platform_device *pdev)
>  
>  	if (onenand->type != TYPE_S5PC110) {
>  		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;
> -		}
> -
> -		onenand->ahb_res = request_mem_region(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;
> -		}
> -
> -		onenand->ahb_addr = ioremap(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;
> -		}
> +		onenand->ahb_addr = devm_ioremap_resource(&pdev->dev, r);
> +		if (IS_ERR(onenand->ahb_addr))
> +			return PTR_ERR(onenand->ahb_addr);
>  
>  		/* 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;
> @@ -939,28 +898,11 @@ static int s3c_onenand_probe(struct platform_device *pdev)
>  
>  	} else { /* S5PC110 */
>  		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;
> -		}
> -
> -		onenand->dma_res = request_mem_region(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;
> -		}
> +		onenand->dma_addr = devm_ioremap_resource(&pdev->dev, r);
> +		if (IS_ERR(onenand->dma_addr))
> +			return PTR_ERR(onenand->dma_addr);
>  
> -		onenand->dma_addr = ioremap(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;
> -		}
> -
> -		onenand->phys_base = onenand->base_res->start;
> +		onenand->phys_base = r->start;

This is wrong, ->phys_base should be assigned to base_res->start not
dma_res->start (I pointed it in my previous review).

>  
>  		s5pc110_dma_ops = s5pc110_dma_poll;
>  		/* Interrupt support */
> @@ -968,19 +910,19 @@ 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;

Not related to this patch, but we should return the error code returned
by onenand_scan() here instead of always returning -EFAULT.

>  
>  	if (onenand->type != TYPE_S5PC110) {
>  		/* S3C doesn't handle subpage write */
> @@ -998,36 +940,6 @@ 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 +947,7 @@ 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;
>  }
>