Re: [PATCH] mm/kasan: switch from strlcpy to strscpy

From: Alexander Potapenko <glider@google.com>
To: Zhiyuan Dai <daizhiyuan@phytium.com.cn>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>,
	Andrey Konovalov <andreyknvl@gmail.com>,
	Dmitriy Vyukov <dvyukov@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linux Memory Management List <linux-mm@kvack.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm/kasan: switch from strlcpy to strscpy
Date: Mon, 22 Feb 2021 08:45:16 +0100	[thread overview]
Message-ID: <CAG_fn=WqixC0B+dW50gRFn3Qm63rQ5x6jP+2eGVAkRcuBOwQ6A@mail.gmail.com> (raw)
In-Reply-To: <1613970647-23272-1-git-send-email-daizhiyuan@phytium.com.cn>

On Mon, Feb 22, 2021 at 6:10 AM Zhiyuan Dai <daizhiyuan@phytium.com.cn> wrote:
>
> strlcpy is marked as deprecated in Documentation/process/deprecated.rst,
> and there is no functional difference when the caller expects truncation
> (when not checking the return value). strscpy is relatively better as it
> also avoids scanning the whole source string.

Looks like a good thing to do.

> Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn>
Acked-by: Alexander Potapenko <glider@google.com>

> ---
>  mm/kasan/report_generic.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/kasan/report_generic.c b/mm/kasan/report_generic.c
> index 8a9c889..fc7f7ad 100644
> --- a/mm/kasan/report_generic.c
> +++ b/mm/kasan/report_generic.c
> @@ -148,7 +148,7 @@ static bool __must_check tokenize_frame_descr(const char **frame_descr,
>                 }
>
>                 /* Copy token (+ 1 byte for '\0'). */
> -               strlcpy(token, *frame_descr, tok_len + 1);
> +               strscpy(token, *frame_descr, tok_len + 1);
>         }
>
>         /* Advance frame_descr past separator. */
> --
> 1.8.3.1
>

-- 
Alexander Potapenko
Software Engineer

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