[PATCH] accel/habanalabs: use kcalloc() instead of kzalloc()

[PATCH] accel/habanalabs: use kcalloc() instead of kzalloc()

[Erick Archer]

As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.

So, use the purpose specific kcalloc() function instead of the argument
size * count in the kzalloc() function.

Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
Link: https://github.com/KSPP/linux/issues/162

Signed-off-by: Erick Archer <erick.archer@gmx.com>
---
 drivers/accel/habanalabs/common/mmu/mmu_v1.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/accel/habanalabs/common/mmu/mmu_v1.c b/drivers/accel/habanalabs/common/mmu/mmu_v1.c
index d925dc4dd097..e3d42cfead27 100644
--- a/drivers/accel/habanalabs/common/mmu/mmu_v1.c
+++ b/drivers/accel/habanalabs/common/mmu/mmu_v1.c
@@ -232,7 +232,7 @@ static int dram_default_mapping_init(struct hl_ctx *ctx)
 	/* add hop1 and hop2 */
 	total_hops = num_of_hop3 + 2;

-	ctx->dram_default_hops = kzalloc(HL_PTE_SIZE * total_hops,  GFP_KERNEL);
+	ctx->dram_default_hops = kcalloc(total_hops, HL_PTE_SIZE,  GFP_KERNEL);
 	if (!ctx->dram_default_hops)
 		return -ENOMEM;

--
2.25.1

Re: [PATCH] accel/habanalabs: use kcalloc() instead of kzalloc()

[Gustavo A. R. Silva]

On 1/20/24 09:10, Erick Archer wrote:
> As noted in the "Deprecated Interfaces, Language Features, Attributes,
> and Conventions" documentation [1], size calculations (especially
> multiplication) should not be performed in memory allocator (or similar)
> function arguments due to the risk of them overflowing. This could lead
> to values wrapping around and a smaller allocation being made than the
> caller was expecting. Using those allocations could lead to linear
> overflows of heap memory and other misbehaviors.
> 
> So, use the purpose specific kcalloc() function instead of the argument
> size * count in the kzalloc() function.
> 
> Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
> Link: https://github.com/KSPP/linux/issues/162
> 
> Signed-off-by: Erick Archer <erick.archer@gmx.com>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks!
-- 
Gustavo

> ---
>   drivers/accel/habanalabs/common/mmu/mmu_v1.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/accel/habanalabs/common/mmu/mmu_v1.c b/drivers/accel/habanalabs/common/mmu/mmu_v1.c
> index d925dc4dd097..e3d42cfead27 100644
> --- a/drivers/accel/habanalabs/common/mmu/mmu_v1.c
> +++ b/drivers/accel/habanalabs/common/mmu/mmu_v1.c
> @@ -232,7 +232,7 @@ static int dram_default_mapping_init(struct hl_ctx *ctx)
>   	/* add hop1 and hop2 */
>   	total_hops = num_of_hop3 + 2;
> 
> -	ctx->dram_default_hops = kzalloc(HL_PTE_SIZE * total_hops,  GFP_KERNEL);
> +	ctx->dram_default_hops = kcalloc(total_hops, HL_PTE_SIZE,  GFP_KERNEL);
>   	if (!ctx->dram_default_hops)
>   		return -ENOMEM;
> 
> --
> 2.25.1
> 
> 

Re: [PATCH] accel/habanalabs: use kcalloc() instead of kzalloc()

[Oded Gabbay]

On 22/01/2024 18:45, Gustavo A. R. Silva wrote:
> 
> 
> On 1/20/24 09:10, Erick Archer wrote:
>> As noted in the "Deprecated Interfaces, Language Features, Attributes,
>> and Conventions" documentation [1], size calculations (especially
>> multiplication) should not be performed in memory allocator (or similar)
>> function arguments due to the risk of them overflowing. This could lead
>> to values wrapping around and a smaller allocation being made than the
>> caller was expecting. Using those allocations could lead to linear
>> overflows of heap memory and other misbehaviors.
>>
>> So, use the purpose specific kcalloc() function instead of the argument
>> size * count in the kzalloc() function.
>>
>> Link: 
>> https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
>> Link: https://github.com/KSPP/linux/issues/162
>>
>> Signed-off-by: Erick Archer <erick.archer@gmx.com>
> 
> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> 
> Thanks!
Applied to -next.
Thanks,
Oded