* Re: [PATCH] mtd: rawnand: jz4780: use struct_size() in devm_kzalloc()
2018-08-23 19:33 [PATCH] mtd: rawnand: jz4780: use struct_size() in devm_kzalloc() Gustavo A. R. Silva
@ 2018-08-23 21:27 ` Boris Brezillon
2018-08-23 21:50 ` Kees Cook
2018-09-04 21:57 ` Miquel Raynal
2 siblings, 0 replies; 4+ messages in thread
From: Boris Brezillon @ 2018-08-23 21:27 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Harvey Hunt, Miquel Raynal, Richard Weinberger, David Woodhouse,
Brian Norris, Marek Vasut, linux-mtd, linux-kernel, Kees Cook
On Thu, 23 Aug 2018 14:33:32 -0500
"Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote:
> One of the more common cases of allocation size calculations is finding
> the size of a structure that has a zero-sized array at the end, along
> with memory for some number of elements for that array. For example:
>
> struct foo {
> int stuff;
> void *entry[];
> };
>
> instance = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);
>
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
>
> instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);
Oh, I didn't know about that one. That's nice!
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
> ---
> drivers/mtd/nand/raw/jz4780_nand.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/raw/jz4780_nand.c b/drivers/mtd/nand/raw/jz4780_nand.c
> index db4fa60..ac62395 100644
> --- a/drivers/mtd/nand/raw/jz4780_nand.c
> +++ b/drivers/mtd/nand/raw/jz4780_nand.c
> @@ -352,7 +352,7 @@ static int jz4780_nand_probe(struct platform_device *pdev)
> return -ENODEV;
> }
>
> - nfc = devm_kzalloc(dev, sizeof(*nfc) + (sizeof(nfc->cs[0]) * num_banks), GFP_KERNEL);
> + nfc = devm_kzalloc(dev, struct_size(nfc, cs, num_banks), GFP_KERNEL);
> if (!nfc)
> return -ENOMEM;
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] mtd: rawnand: jz4780: use struct_size() in devm_kzalloc()
2018-08-23 19:33 [PATCH] mtd: rawnand: jz4780: use struct_size() in devm_kzalloc() Gustavo A. R. Silva
2018-08-23 21:27 ` Boris Brezillon
@ 2018-08-23 21:50 ` Kees Cook
2018-09-04 21:57 ` Miquel Raynal
2 siblings, 0 replies; 4+ messages in thread
From: Kees Cook @ 2018-08-23 21:50 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Harvey Hunt, Boris Brezillon, Miquel Raynal, Richard Weinberger,
David Woodhouse, Brian Norris, Marek Vasut, Linux mtd, LKML
On Thu, Aug 23, 2018 at 12:33 PM, Gustavo A. R. Silva
<gustavo@embeddedor.com> wrote:
> One of the more common cases of allocation size calculations is finding
> the size of a structure that has a zero-sized array at the end, along
> with memory for some number of elements for that array. For example:
>
> struct foo {
> int stuff;
> void *entry[];
> };
>
> instance = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);
>
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
>
> instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
-Kees
> ---
> drivers/mtd/nand/raw/jz4780_nand.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/raw/jz4780_nand.c b/drivers/mtd/nand/raw/jz4780_nand.c
> index db4fa60..ac62395 100644
> --- a/drivers/mtd/nand/raw/jz4780_nand.c
> +++ b/drivers/mtd/nand/raw/jz4780_nand.c
> @@ -352,7 +352,7 @@ static int jz4780_nand_probe(struct platform_device *pdev)
> return -ENODEV;
> }
>
> - nfc = devm_kzalloc(dev, sizeof(*nfc) + (sizeof(nfc->cs[0]) * num_banks), GFP_KERNEL);
> + nfc = devm_kzalloc(dev, struct_size(nfc, cs, num_banks), GFP_KERNEL);
> if (!nfc)
> return -ENOMEM;
>
> --
> 2.7.4
>
--
Kees Cook
Pixel Security
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] mtd: rawnand: jz4780: use struct_size() in devm_kzalloc()
2018-08-23 19:33 [PATCH] mtd: rawnand: jz4780: use struct_size() in devm_kzalloc() Gustavo A. R. Silva
2018-08-23 21:27 ` Boris Brezillon
2018-08-23 21:50 ` Kees Cook
@ 2018-09-04 21:57 ` Miquel Raynal
2 siblings, 0 replies; 4+ messages in thread
From: Miquel Raynal @ 2018-09-04 21:57 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Harvey Hunt, Boris Brezillon, Richard Weinberger, David Woodhouse,
Brian Norris, Marek Vasut, linux-mtd, linux-kernel, Kees Cook
Hi Gustavo,
"Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote on Thu, 23 Aug
2018 14:33:32 -0500:
> One of the more common cases of allocation size calculations is finding
> the size of a structure that has a zero-sized array at the end, along
> with memory for some number of elements for that array. For example:
>
> struct foo {
> int stuff;
> void *entry[];
> };
>
> instance = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);
>
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
>
> instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
> drivers/mtd/nand/raw/jz4780_nand.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/raw/jz4780_nand.c b/drivers/mtd/nand/raw/jz4780_nand.c
> index db4fa60..ac62395 100644
> --- a/drivers/mtd/nand/raw/jz4780_nand.c
> +++ b/drivers/mtd/nand/raw/jz4780_nand.c
> @@ -352,7 +352,7 @@ static int jz4780_nand_probe(struct platform_device *pdev)
> return -ENODEV;
> }
>
> - nfc = devm_kzalloc(dev, sizeof(*nfc) + (sizeof(nfc->cs[0]) * num_banks), GFP_KERNEL);
> + nfc = devm_kzalloc(dev, struct_size(nfc, cs, num_banks), GFP_KERNEL);
> if (!nfc)
> return -ENOMEM;
>
Applied to nand/next.
Thanks,
Miquèl
^ permalink raw reply [flat|nested] 4+ messages in thread