Re: [linux-next:master 1570/2472] mm/kasan/init.c:318:9: warning: variable 'pud' set but not used

From: Linus Walleij <linus.walleij@linaro.org>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: kernel test robot <lkp@intel.com>,
	kbuild-all@lists.01.org,
	 Linux Memory Management List <linux-mm@kvack.org>,
	Russell King <rmk+kernel@armlinux.org.uk>,
	 Abbott Liu <liuwenliang@huawei.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	 Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [linux-next:master 1570/2472] mm/kasan/init.c:318:9: warning: variable 'pud' set but not used
Date: Fri, 6 Nov 2020 09:53:29 +0100	[thread overview]
Message-ID: <CACRpkdbAXCMTW--BmVs8SQ_u5baaeUob+U57E=4=CrMxWtMO2g@mail.gmail.com> (raw)
In-Reply-To: <CAMj1kXG7uuXmyeDd4Fhfz9HP9APJzgBi_fdgpP4xaL4ObBJ_dA@mail.gmail.com>

On Tue, Nov 3, 2020 at 9:22 AM Ard Biesheuvel <ardb@kernel.org> wrote:

> What about
>
> diff --git a/mm/kasan/init.c b/mm/kasan/init.c
> index fe6be0be1f76..7c3eb1f5a439 100644
> --- a/mm/kasan/init.c
> +++ b/mm/kasan/init.c
> @@ -315,12 +315,10 @@ static void kasan_free_pmd(pmd_t *pmd_start, pud_t *pud)
>
>  static void kasan_free_pud(pud_t *pud_start, p4d_t *p4d)
>  {
> -       pud_t *pud;
>         int i;
>
>         for (i = 0; i < PTRS_PER_PUD; i++) {
> -               pud = pud_start + i;
> -               if (!pud_none(*pud))
> +               if (!pud_none(pud_start[i]))
>                         return;
>         }

Yeah that is way better, also makes the code a lot easier to read.

I sent a patch rewriting all the kasan_free_p??() calls like this.

Yours,
Linus Walleij