From: Anshuman Khandual <anshuman.khandual@arm.com>
To: Russell King <rmk+kernel@armlinux.org.uk>,
linux-arm-kernel@lists.infradead.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
Allison Randal <allison@lohutok.net>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ARM: update __swp_entry_to_pte() to use PTE_TYPE_FAULT
Date: Mon, 17 May 2021 13:17:29 +0530 [thread overview]
Message-ID: <d28673fc-14db-dfd9-6d20-049807891b2e@arm.com> (raw)
In-Reply-To: <E1lh9VH-0002Lz-Pd@rmk-PC.armlinux.org.uk>
On 5/13/21 4:57 PM, Russell King wrote:
> Swap entries use a faulting PTE which have the least two significant
> bits as zero. Due to this, the use of PTE_TYPE_FAULT was overlooked,
> but really should have been included in __swp_entry_to_pte().
>
> Convert this macro to use PTE_TYPE_FAULT to properly document what is
> going on here, and use __pte() to convert the swp_entry_t to a pte_t.
>
> This results in no change to the resulting kernel text.
>
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
> ---
> arch/arm/include/asm/pgtable.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
> index c02f24400369..c43e07d6046d 100644
> --- a/arch/arm/include/asm/pgtable.h
> +++ b/arch/arm/include/asm/pgtable.h
> @@ -303,7 +303,7 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
> #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
>
> #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
> -#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
> +#define __swp_entry_to_pte(swp) __pte((swp).val | PTE_TYPE_FAULT)
LGTM and FWIW..
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
>
> /*
> * It is an error for the kernel to have more swap files than we can
>
next prev parent reply other threads:[~2021-05-17 7:46 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-13 11:27 [PATCH] ARM: update __swp_entry_to_pte() to use PTE_TYPE_FAULT Russell King
2021-05-17 7:47 ` Anshuman Khandual [this message]
2021-05-21 2:41 ` Hugh Dickins
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=d28673fc-14db-dfd9-6d20-049807891b2e@arm.com \
--to=anshuman.khandual@arm.com \
--cc=allison@lohutok.net \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=rmk+kernel@armlinux.org.uk \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).