| Message ID | 20240209183128.10273-1-erick.archer@gmx.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | irqchip/irq-bcm7038-l1: Prefer struct_size over open coded arithmetic | expand |
On 2/9/24 12:31, 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 cpu variable is a pointer to "struct bcm7038_l1_cpu" and this > structure ends in a flexible array: > > struct bcm7038_l1_cpu { > void __iomem *map_base; > u32 mask_cache[]; > }; > > 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 > 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/162 [2] > > Signed-off-by: Erick Archer <erick.archer@gmx.com> LGTM: Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Thanks
On Fri, Feb 09, 2024 at 07:31:28PM +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 cpu variable is a pointer to "struct bcm7038_l1_cpu" and this > structure ends in a flexible array: > > struct bcm7038_l1_cpu { > void __iomem *map_base; > u32 mask_cache[]; > }; > > 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 > 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/162 [2] > > Signed-off-by: Erick Archer <erick.archer@gmx.com> Yeah, looks right to me. Reviewed-by: Kees Cook <keescook@chromium.org>
On 2/9/2024 10:31 AM, 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 cpu variable is a pointer to "struct bcm7038_l1_cpu" and this > structure ends in a flexible array: > > struct bcm7038_l1_cpu { > void __iomem *map_base; > u32 mask_cache[]; > }; > > 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 > 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/162 [2] > > Signed-off-by: Erick Archer <erick.archer@gmx.com> Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
diff --git a/drivers/irqchip/irq-bcm7038-l1.c b/drivers/irqchip/irq-bcm7038-l1.c index 24ca1d656adc..36e71af054e9 100644 --- a/drivers/irqchip/irq-bcm7038-l1.c +++ b/drivers/irqchip/irq-bcm7038-l1.c @@ -249,7 +249,7 @@ static int __init bcm7038_l1_init_one(struct device_node *dn, return -EINVAL; } - cpu = intc->cpus[idx] = kzalloc(sizeof(*cpu) + n_words * sizeof(u32), + cpu = intc->cpus[idx] = kzalloc(struct_size(cpu, mask_cache, n_words), GFP_KERNEL); if (!cpu) return -ENOMEM;
This is an effort to get rid of all multiplications from allocation functions in order to prevent integer overflows [1]. As the cpu variable is a pointer to "struct bcm7038_l1_cpu" and this structure ends in a flexible array: struct bcm7038_l1_cpu { void __iomem *map_base; u32 mask_cache[]; }; 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 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/162 [2] Signed-off-by: Erick Archer <erick.archer@gmx.com> --- drivers/irqchip/irq-bcm7038-l1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.25.1