Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20230628153342.53406-1-andriy.shevchenko@linux.intel.com>
In-Reply-To: <20230628153342.53406-1-andriy.shevchenko@linux.intel.com>
From:   Alexander Potapenko <glider@google.com>
Date:   Wed, 28 Jun 2023 17:39:26 +0200
Message-ID: <CAG_fn=WjLDsnUPKFwF8XJiyqYP6M+Q9ZqUweRPzPT3dW0i_E+A@mail.gmail.com>
Subject: Re: [PATCH v1 1/1] kasan: Replace strreplace() with strchrnul()
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        kasan-dev@googlegroups.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        Andrey Konovalov <andreyknvl@gmail.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Vincenzo Frascino <vincenzo.frascino@arm.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Wed, Jun 28, 2023 at 5:34=E2=80=AFPM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> We don't need to traverse over the entire string and replace
> occurrences of a character with '\0'. The first match will
> suffice. Hence, replace strreplace() with strchrnul().
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  mm/kasan/report_generic.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/mm/kasan/report_generic.c b/mm/kasan/report_generic.c
> index 51a1e8a8877f..63a34eac4a8c 100644
> --- a/mm/kasan/report_generic.c
> +++ b/mm/kasan/report_generic.c
> @@ -264,6 +264,7 @@ static void print_decoded_frame_descr(const char *fra=
me_descr)
>         while (num_objects--) {
>                 unsigned long offset;
>                 unsigned long size;
> +               char *p;
>
>                 /* access offset */
>                 if (!tokenize_frame_descr(&frame_descr, token, sizeof(tok=
en),
> @@ -282,7 +283,7 @@ static void print_decoded_frame_descr(const char *fra=
me_descr)
>                         return;
>
>                 /* Strip line number; without filename it's not very help=
ful. */
> -               strreplace(token, ':', '\0');
> +               p[strchrnul(token, ':') - token] =3D '\0';

Why not just
   *(strchrnul(token, ':')) =3D '\0';
?