thr3ads.net - Linux Virtualization - [PATCH] xen-blkfront: Use kcalloc instead of kzalloc to allocate array [Nov 2011]

If this information is useful, please help other people find it:
Share via:

Thomas Meyer

2011-Nov-29 21:08 UTC

[PATCH] xen-blkfront: Use kcalloc instead of kzalloc to allocate array

The advantage of kcalloc is, that will prevent integer overflows which could
result from the multiplication of number of elements and size and it is also
a bit nicer to read.

The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107

Signed-off-by: Thomas Meyer <thomas at m3y3r.de>
---

diff -u -p a/drivers/block/cciss_scsi.c b/drivers/block/cciss_scsi.c
--- a/drivers/block/cciss_scsi.c 2011-11-28 19:36:47.343430551 +0100
+++ b/drivers/block/cciss_scsi.c 2011-11-28 19:49:24.922716381 +0100
@@ -534,10 +534,10 @@ adjust_cciss_scsi_table(ctlr_info_t *h,
 	int nadded, nremoved;
 	struct Scsi_Host *sh = NULL;
 
-	added = kzalloc(sizeof(*added) * CCISS_MAX_SCSI_DEVS_PER_HBA,
-			GFP_KERNEL);
-	removed = kzalloc(sizeof(*removed) * CCISS_MAX_SCSI_DEVS_PER_HBA,
+	added = kcalloc(CCISS_MAX_SCSI_DEVS_PER_HBA, sizeof(*added),
 			GFP_KERNEL);
+	removed = kcalloc(CCISS_MAX_SCSI_DEVS_PER_HBA, sizeof(*removed),
+			  GFP_KERNEL);
 
 	if (!added || !removed) {
 		dev_warn(&h->pdev->dev,
@@ -1191,8 +1191,8 @@ cciss_update_non_disk_devices(ctlr_info_
 
 	ld_buff = kzalloc(reportlunsize, GFP_KERNEL);
 	inq_buff = kmalloc(OBDR_TAPE_INQ_SIZE, GFP_KERNEL);
-	currentsd = kzalloc(sizeof(*currentsd) *
-			(CCISS_MAX_SCSI_DEVS_PER_HBA+1), GFP_KERNEL);
+	currentsd = kcalloc(CCISS_MAX_SCSI_DEVS_PER_HBA + 1,
+			    sizeof(*currentsd), GFP_KERNEL);
 	if (ld_buff == NULL || inq_buff == NULL || currentsd == NULL) {
 		printk(KERN_ERR "cciss: out of memory\n");
 		goto out;
diff -u -p a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
--- a/drivers/block/xen-blkfront.c 2011-11-13 11:07:22.680095573 +0100
+++ b/drivers/block/xen-blkfront.c 2011-11-28 19:49:29.109460410 +0100
@@ -156,7 +156,7 @@ static int xlbd_reserve_minors(unsigned
 	if (end > nr_minors) {
 		unsigned long *bitmap, *old;
 
-		bitmap = kzalloc(BITS_TO_LONGS(end) * sizeof(*bitmap),
+		bitmap = kcalloc(BITS_TO_LONGS(end), sizeof(*bitmap),
 				 GFP_KERNEL);
 		if (bitmap == NULL)
 			return -ENOMEM;

Konrad Rzeszutek Wilk

2011-Dec-06 03:27 UTC

head link

[PATCH] xen-blkfront: Use kcalloc instead of kzalloc to allocate array

On Tue, Nov 29, 2011 at 10:08:00PM +0100, Thomas Meyer
wrote:> The advantage of kcalloc is, that will prevent integer overflows which
could
> result from the multiplication of number of elements and size and it is
also
> a bit nicer to read.
> 
> The semantic patch that makes this change is available
> in https://lkml.org/lkml/2011/11/25/107
> 
> Signed-off-by: Thomas Meyer <thomas at m3y3r.de>
> ---
> 
> diff -u -p a/drivers/block/cciss_scsi.c b/drivers/block/cciss_scsi.c
> --- a/drivers/block/cciss_scsi.c 2011-11-28 19:36:47.343430551 +0100
> +++ b/drivers/block/cciss_scsi.c 2011-11-28 19:49:24.922716381 +0100
> @@ -534,10 +534,10 @@ adjust_cciss_scsi_table(ctlr_info_t *h,
>  	int nadded, nremoved;
>  	struct Scsi_Host *sh = NULL;
>  
> -	added = kzalloc(sizeof(*added) * CCISS_MAX_SCSI_DEVS_PER_HBA,
> -			GFP_KERNEL);
> -	removed = kzalloc(sizeof(*removed) * CCISS_MAX_SCSI_DEVS_PER_HBA,
> +	added = kcalloc(CCISS_MAX_SCSI_DEVS_PER_HBA, sizeof(*added),
>  			GFP_KERNEL);
> +	removed = kcalloc(CCISS_MAX_SCSI_DEVS_PER_HBA, sizeof(*removed),
> +			  GFP_KERNEL);
>  
It looks like you mixed two patches together.
>  	if (!added || !removed) {
>  		dev_warn(&h->pdev->dev,
> @@ -1191,8 +1191,8 @@ cciss_update_non_disk_devices(ctlr_info_
>  
>  	ld_buff = kzalloc(reportlunsize, GFP_KERNEL);
>  	inq_buff = kmalloc(OBDR_TAPE_INQ_SIZE, GFP_KERNEL);
> -	currentsd = kzalloc(sizeof(*currentsd) *
> -			(CCISS_MAX_SCSI_DEVS_PER_HBA+1), GFP_KERNEL);
> +	currentsd = kcalloc(CCISS_MAX_SCSI_DEVS_PER_HBA + 1,
> +			    sizeof(*currentsd), GFP_KERNEL);
>  	if (ld_buff == NULL || inq_buff == NULL || currentsd == NULL) {
>  		printk(KERN_ERR "cciss: out of memory\n");
>  		goto out;
> diff -u -p a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> --- a/drivers/block/xen-blkfront.c 2011-11-13 11:07:22.680095573 +0100
> +++ b/drivers/block/xen-blkfront.c 2011-11-28 19:49:29.109460410 +0100
> @@ -156,7 +156,7 @@ static int xlbd_reserve_minors(unsigned
>  	if (end > nr_minors) {
>  		unsigned long *bitmap, *old;
>  
> -		bitmap = kzalloc(BITS_TO_LONGS(end) * sizeof(*bitmap),
> +		bitmap = kcalloc(BITS_TO_LONGS(end), sizeof(*bitmap),
>  				 GFP_KERNEL);
But this parts looks good.

Can you respin it with just that part please?>  		if (bitmap == NULL)
>  			return -ENOMEM;
> --
> To unsubscribe from this list: send the line "unsubscribe
linux-kernel" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

Konrad Rzeszutek Wilk

2011-Dec-14 18:56 UTC

head link

[PATCH] xen-blkfront: Use kcalloc instead of kzalloc to allocate array

On Tue, Nov 29, 2011 at 10:08:00PM +0100, Thomas Meyer
wrote:> The advantage of kcalloc is, that will prevent integer overflows which
could
> result from the multiplication of number of elements and size and it is
also
> a bit nicer to read.
> 
> The semantic patch that makes this change is available
> in https://lkml.org/lkml/2011/11/25/107
> 
Thomas,

I put the xen-blkfront part of the patch in my tree and dropped the cciss_scsi
one.
> Signed-off-by: Thomas Meyer <thomas at m3y3r.de>
> ---
> 
> diff -u -p a/drivers/block/cciss_scsi.c b/drivers/block/cciss_scsi.c
> --- a/drivers/block/cciss_scsi.c 2011-11-28 19:36:47.343430551 +0100
> +++ b/drivers/block/cciss_scsi.c 2011-11-28 19:49:24.922716381 +0100
> @@ -534,10 +534,10 @@ adjust_cciss_scsi_table(ctlr_info_t *h,
>  	int nadded, nremoved;
>  	struct Scsi_Host *sh = NULL;
>  
> -	added = kzalloc(sizeof(*added) * CCISS_MAX_SCSI_DEVS_PER_HBA,
> -			GFP_KERNEL);
> -	removed = kzalloc(sizeof(*removed) * CCISS_MAX_SCSI_DEVS_PER_HBA,
> +	added = kcalloc(CCISS_MAX_SCSI_DEVS_PER_HBA, sizeof(*added),
>  			GFP_KERNEL);
> +	removed = kcalloc(CCISS_MAX_SCSI_DEVS_PER_HBA, sizeof(*removed),
> +			  GFP_KERNEL);
>  
>  	if (!added || !removed) {
>  		dev_warn(&h->pdev->dev,
> @@ -1191,8 +1191,8 @@ cciss_update_non_disk_devices(ctlr_info_
>  
>  	ld_buff = kzalloc(reportlunsize, GFP_KERNEL);
>  	inq_buff = kmalloc(OBDR_TAPE_INQ_SIZE, GFP_KERNEL);
> -	currentsd = kzalloc(sizeof(*currentsd) *
> -			(CCISS_MAX_SCSI_DEVS_PER_HBA+1), GFP_KERNEL);
> +	currentsd = kcalloc(CCISS_MAX_SCSI_DEVS_PER_HBA + 1,
> +			    sizeof(*currentsd), GFP_KERNEL);
>  	if (ld_buff == NULL || inq_buff == NULL || currentsd == NULL) {
>  		printk(KERN_ERR "cciss: out of memory\n");
>  		goto out;
> diff -u -p a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> --- a/drivers/block/xen-blkfront.c 2011-11-13 11:07:22.680095573 +0100
> +++ b/drivers/block/xen-blkfront.c 2011-11-28 19:49:29.109460410 +0100
> @@ -156,7 +156,7 @@ static int xlbd_reserve_minors(unsigned
>  	if (end > nr_minors) {
>  		unsigned long *bitmap, *old;
>  
> -		bitmap = kzalloc(BITS_TO_LONGS(end) * sizeof(*bitmap),
> +		bitmap = kcalloc(BITS_TO_LONGS(end), sizeof(*bitmap),
>  				 GFP_KERNEL);
>  		if (bitmap == NULL)
>  			return -ENOMEM;
> --
> To unsubscribe from this list: send the line "unsubscribe
linux-kernel" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

Linux Virtualization - Nov 2011 - [PATCH] xen-blkfront: Use kcalloc instead of kzalloc to allocate array

[PATCH] xen-blkfront: Use kcalloc instead of kzalloc to allocate array

[PATCH] xen-blkfront: Use kcalloc instead of kzalloc to allocate array

[PATCH] xen-blkfront: Use kcalloc instead of kzalloc to allocate array