linux-kernel - Re: [PATCH] crypto: ecc - Streamline alloc_point and remove {alloc,free}_digits

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Message-ID: <0c62719b-adef-4796-ae15-07467de478c8@linux.ibm.com>
Date: Mon, 5 Jan 2026 12:08:31 -0500
From: Stefan Berger <stefanb@...ux.ibm.com>
To: Thorsten Blum <thorsten.blum@...ux.dev>, Lukas Wunner <lukas@...ner.de>,
        Ignat Korchagin <ignat@...udflare.com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        "David S. Miller" <davem@...emloft.net>
Cc: linux-crypto@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] crypto: ecc - Streamline alloc_point and remove
 {alloc,free}_digits_space



On 12/18/25 4:27 PM, Thorsten Blum wrote:
> Check 'ndigits' before allocating 'struct ecc_point' to return early if
> needed. Inline the code from and remove ecc_alloc_digits_space() and
> ecc_free_digits_space(), respectively.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@...ux.dev>
> ---
>   crypto/ecc.c | 27 +++++++++------------------
>   1 file changed, 9 insertions(+), 18 deletions(-)
> 
> diff --git a/crypto/ecc.c b/crypto/ecc.c
> index 6cf9a945fc6c..9b8e4ba9719a 100644
> --- a/crypto/ecc.c
> +++ b/crypto/ecc.c
> @@ -90,33 +90,24 @@ void ecc_digits_from_bytes(const u8 *in, unsigned int nbytes,
>   }
>   EXPORT_SYMBOL(ecc_digits_from_bytes);
>   
> -static u64 *ecc_alloc_digits_space(unsigned int ndigits)
> +struct ecc_point *ecc_alloc_point(unsigned int ndigits)
>   {
> -	size_t len = ndigits * sizeof(u64);
> +	struct ecc_point *p;
> +	size_t ndigits_sz;
>   
> -	if (!len)
> +	if (!ndigits)
>   		return NULL;
>   
> -	return kmalloc(len, GFP_KERNEL);
> -}
> -
> -static void ecc_free_digits_space(u64 *space)
> -{
> -	kfree_sensitive(space);
> -}
> -
> -struct ecc_point *ecc_alloc_point(unsigned int ndigits)
> -{
> -	struct ecc_point *p = kmalloc(sizeof(*p), GFP_KERNEL);
> -
> +	p = kmalloc(sizeof(*p), GFP_KERNEL);
>   	if (!p)
>   		return NULL;
>   
> -	p->x = ecc_alloc_digits_space(ndigits);
> +	ndigits_sz = ndigits * sizeof(u64);
> +	p->x = kmalloc(ndigits_sz, GFP_KERNEL);
>   	if (!p->x)
>   		goto err_alloc_x;
>   
> -	p->y = ecc_alloc_digits_space(ndigits);
> +	p->y = kmalloc(ndigits_sz, GFP_KERNEL);
>   	if (!p->y)
>   		goto err_alloc_y;
>   
> @@ -125,7 +116,7 @@ struct ecc_point *ecc_alloc_point(unsigned int ndigits)
>   	return p;
>   
>   err_alloc_y:
> -	ecc_free_digits_space(p->x);
> +	kfree_sensitive(p->x);

With no data in the buffer a kfree() should be sufficient.

>   err_alloc_x:
>   	kfree(p);
>   	return NULL;