| Message ID | 20240210161619.12656-1-erick.archer@gmx.com |
|---|---|
| State | New |
| Headers | show |
| Series | mtd: rawnand: Prefer struct_size over open coded arithmetic | expand |
On 2/10/24 10:16, Erick Archer wrote: > This is an effort to get rid of all multiplications from allocation > functions in order to prevent integer overflows [1]. > > As the "chip" variable is a pointer to "struct mtk_nfc_nand_chip" and > this structure ends in a flexible array: > > struct mtk_nfc_nand_chip { > [...] > u8 sels[] __counted_by(nsels); > }; > > the preferred way in the kernel is to use the struct_size() helper to > do the arithmetic instead of the argument "size + count * size" in the > devm_kzalloc() function. > > This way, the code is more readable and more safer. > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1] > Link: https://github.com/KSPP/linux/issues/160 [2] > Signed-off-by: Erick Archer <erick.archer@gmx.com> LGTM: Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Thanks!
On Sat, Feb 10, 2024 at 05:16:19PM +0100, Erick Archer wrote: > This is an effort to get rid of all multiplications from allocation > functions in order to prevent integer overflows [1]. > > As the "chip" variable is a pointer to "struct mtk_nfc_nand_chip" and > this structure ends in a flexible array: > > struct mtk_nfc_nand_chip { > [...] > u8 sels[] __counted_by(nsels); > }; > > the preferred way in the kernel is to use the struct_size() helper to > do the arithmetic instead of the argument "size + count * size" in the > devm_kzalloc() function. > > This way, the code is more readable and more safer. Unless you intend this non-English comparative: s/more safer/safer/ Best regards Uwe
Il 10/02/24 17:16, Erick Archer ha scritto: > This is an effort to get rid of all multiplications from allocation > functions in order to prevent integer overflows [1]. > > As the "chip" variable is a pointer to "struct mtk_nfc_nand_chip" and > this structure ends in a flexible array: > > struct mtk_nfc_nand_chip { > [...] > u8 sels[] __counted_by(nsels); > }; > > the preferred way in the kernel is to use the struct_size() helper to > do the arithmetic instead of the argument "size + count * size" in the > devm_kzalloc() function. > > This way, the code is more readable and more safer. This way, the code is more readable and safer. Apart from that, Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1] > Link: https://github.com/KSPP/linux/issues/160 [2] > Signed-off-by: Erick Archer <erick.archer@gmx.com> > --- > drivers/mtd/nand/raw/mtk_nand.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mtd/nand/raw/mtk_nand.c b/drivers/mtd/nand/raw/mtk_nand.c > index 60198e33d2d5..17477bb2d48f 100644 > --- a/drivers/mtd/nand/raw/mtk_nand.c > +++ b/drivers/mtd/nand/raw/mtk_nand.c > @@ -1356,7 +1356,7 @@ static int mtk_nfc_nand_chip_init(struct device *dev, struct mtk_nfc *nfc, > return -EINVAL; > } > > - chip = devm_kzalloc(dev, sizeof(*chip) + nsels * sizeof(u8), > + chip = devm_kzalloc(dev, struct_size(chip, sels, nsels), > GFP_KERNEL); > if (!chip) > return -ENOMEM; > -- > 2.25.1 >
diff --git a/drivers/mtd/nand/raw/mtk_nand.c b/drivers/mtd/nand/raw/mtk_nand.c index 60198e33d2d5..17477bb2d48f 100644 --- a/drivers/mtd/nand/raw/mtk_nand.c +++ b/drivers/mtd/nand/raw/mtk_nand.c @@ -1356,7 +1356,7 @@ static int mtk_nfc_nand_chip_init(struct device *dev, struct mtk_nfc *nfc, return -EINVAL; } - chip = devm_kzalloc(dev, sizeof(*chip) + nsels * sizeof(u8), + chip = devm_kzalloc(dev, struct_size(chip, sels, nsels), GFP_KERNEL); if (!chip) return -ENOMEM;
This is an effort to get rid of all multiplications from allocation functions in order to prevent integer overflows [1]. As the "chip" variable is a pointer to "struct mtk_nfc_nand_chip" and this structure ends in a flexible array: struct mtk_nfc_nand_chip { [...] u8 sels[] __counted_by(nsels); }; the preferred way in the kernel is to use the struct_size() helper to do the arithmetic instead of the argument "size + count * size" in the devm_kzalloc() function. This way, the code is more readable and more safer. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1] Link: https://github.com/KSPP/linux/issues/160 [2] Signed-off-by: Erick Archer <erick.archer@gmx.com> --- drivers/mtd/nand/raw/mtk_nand.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.25.1