linux-kernel - Re: [PATCH] mm/cma: Replace snprintf with strscpy in cma_new

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Message-ID: <20260127004723.74422-1-sj@kernel.org>
Date: Mon, 26 Jan 2026 16:47:22 -0800
From: SeongJae Park <sj@...nel.org>
To: Thorsten Blum <thorsten.blum@...ux.dev>
Cc: SeongJae Park <sj@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	David Hildenbrand <david@...nel.org>,
	Lorenzo Stoakes <lorenzo.stoakes@...cle.com>,
	"Liam R. Howlett" <Liam.Howlett@...cle.com>,
	Vlastimil Babka <vbabka@...e.cz>,
	Mike Rapoport <rppt@...nel.org>,
	Suren Baghdasaryan <surenb@...gle.com>,
	Michal Hocko <mhocko@...e.com>,
	linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] mm/cma: Replace snprintf with strscpy in cma_new_area

Hello Thorsten,

On Mon, 26 Jan 2026 18:45:15 +0100 Thorsten Blum <thorsten.blum@...ux.dev> wrote:

> Replace snprintf("%s", ...) with the faster and more direct strscpy().
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@...ux.dev>
> ---
>  mm/cma.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/cma.c b/mm/cma.c
> index 813e6dc7b095..44b43de28c13 100644
> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -22,6 +22,7 @@
>  #include <linux/mm.h>
>  #include <linux/sizes.h>
>  #include <linux/slab.h>
> +#include <linux/string.h>
>  #include <linux/string_choices.h>
>  #include <linux/log2.h>
>  #include <linux/cma.h>
> @@ -233,7 +234,7 @@ static int __init cma_new_area(const char *name, phys_addr_t size,
>  	cma_area_count++;
>  
>  	if (name)
> -		snprintf(cma->name, CMA_MAX_NAME, "%s", name);
> +		strscpy(cma->name, name);

Any reason to drop CMA_MAX_NAME protection?  You can pass the size of
destination buffer as the third argument of strscpy().


Thanks,
SJ

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