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

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

[Zhiyuan Dai]

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.

Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn>
---
 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

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

[Alexander Potapenko]

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

Google Germany GmbH
Erika-Mann-Straße, 33
80636 München

Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
Registergericht und -nummer: Hamburg, HRB 86891
Sitz der Gesellschaft: Hamburg

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

[Andrey Konovalov]

On Mon, Feb 22, 2021 at 8:45 AM Alexander Potapenko <glider@google.com> wrote:
>
> 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
> >

Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>

Thanks!