| Message ID | 20190104172637.GA28084@embeddedor (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mtd: rawnand: sunxi: Use struct_size() in devm_kzalloc() | expand |
Hi Gustavo, On Fri, 4 Jan 2019 11:26:37 -0600 "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); > > This code was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > --- > drivers/mtd/nand/raw/sunxi_nand.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c > index e828ee50a201..f66fffe663bf 100644 > --- a/drivers/mtd/nand/raw/sunxi_nand.c > +++ b/drivers/mtd/nand/raw/sunxi_nand.c > @@ -1870,10 +1870,7 @@ static int sunxi_nand_chip_init(struct device *dev, struct sunxi_nfc *nfc, > return -EINVAL; > } > > - chip = devm_kzalloc(dev, > - sizeof(*chip) + > - (nsels * sizeof(struct sunxi_nand_chip_sel)), > - GFP_KERNEL); > + chip = devm_kzalloc(dev, struct_size(chip, sels, nsels), GFP_KERNEL); > if (!chip) { > dev_err(dev, "could not allocate chip\n"); > return -ENOMEM; I posted the same patch a few days back [1]. [1]http://patchwork.ozlabs.org/patch/1013855/
Hey Boris, On 1/4/19 12:14 PM, Boris Brezillon wrote: > > I posted the same patch a few days back [1]. > > [1]http://patchwork.ozlabs.org/patch/1013855/ > Oh, that's great. It's good to see people adopting the struct_size helper. :) Happy new year. Thanks -- Gustavo
diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c index e828ee50a201..f66fffe663bf 100644 --- a/drivers/mtd/nand/raw/sunxi_nand.c +++ b/drivers/mtd/nand/raw/sunxi_nand.c @@ -1870,10 +1870,7 @@ static int sunxi_nand_chip_init(struct device *dev, struct sunxi_nfc *nfc, return -EINVAL; } - chip = devm_kzalloc(dev, - sizeof(*chip) + - (nsels * sizeof(struct sunxi_nand_chip_sel)), - GFP_KERNEL); + chip = devm_kzalloc(dev, struct_size(chip, sels, nsels), GFP_KERNEL); if (!chip) { dev_err(dev, "could not allocate chip\n"); return -ENOMEM;
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); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- drivers/mtd/nand/raw/sunxi_nand.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)