LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Michal Hocko <mhocko@kernel.org>
To: Weikang shi <swkhack@gmail.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: Change count_mm_mlocked_page_nr return type
Date: Mon, 13 May 2019 11:15:22 +0200	[thread overview]
Message-ID: <20190513091522.GA30100@dhcp22.suse.cz> (raw)
In-Reply-To: <20190513023701.83056-1-swkhack@gmail.com>

On Mon 13-05-19 10:37:01, Weikang shi wrote:
> From: swkhack <swkhack@gmail.com>
> 
> In 64-bit machine,the value of "vma->vm_end - vma->vm_start"
> maybe negative in 32bit int and the "count >> PAGE_SHIFT"'s result
> will be wrong.So change the local variable and return
> value to unsigned long will fix the problem.
> 
> Signed-off-by: swkhack <swkhack@gmail.com>

Fixes: 0cf2f6f6dc60 ("mm: mlock: check against vma for actual mlock() size")

Acked-by: Michal Hocko <mhocko@suse.com>

Most users probably never noticed because large mlocked areas are not
allowed by default. So I am not really sure this is worth backporting to
stable trees.

> ---
>  mm/mlock.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/mlock.c b/mm/mlock.c
> index 080f3b364..d614163f5 100644
> --- a/mm/mlock.c
> +++ b/mm/mlock.c
> @@ -636,11 +636,11 @@ static int apply_vma_lock_flags(unsigned long start, size_t len,
>   * is also counted.
>   * Return value: previously mlocked page counts
>   */
> -static int count_mm_mlocked_page_nr(struct mm_struct *mm,
> +static unsigned long count_mm_mlocked_page_nr(struct mm_struct *mm,
>  		unsigned long start, size_t len)
>  {
>  	struct vm_area_struct *vma;
> -	int count = 0;
> +	unsigned long count = 0;
>  
>  	if (mm == NULL)
>  		mm = current->mm;
> -- 
> 2.17.1

-- 
Michal Hocko
SUSE Labs

  reply	other threads:[~2019-05-13  9:15 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-13  2:37 Weikang shi
2019-05-13  9:15 ` Michal Hocko [this message]
  -- strict thread matches above, loose matches on Subject: below --
2019-04-22 10:38 Weikang shi
2019-05-11  8:10 ` Souptick Joarder

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=20190513091522.GA30100@dhcp22.suse.cz \
    --to=mhocko@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=swkhack@gmail.com \
    --subject='Re: [PATCH] mm: Change count_mm_mlocked_page_nr return type' \
    /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

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).