linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Michal Hocko <mhocko@kernel.org>
To: Nadav Amit <namit@vmware.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Andrew Morton <akpm@linux-foundation.org>,
	stable@vger.kernel.org
Subject: Re: [PATCH] mm: respect arch_dup_mmap() return value
Date: Thu, 23 Aug 2018 10:57:14 +0200	[thread overview]
Message-ID: <20180823085714.GY29735@dhcp22.suse.cz> (raw)
In-Reply-To: <20180823051229.211856-1-namit@vmware.com>

On Wed 22-08-18 22:12:29, Nadav Amit wrote:
> Commit d70f2a14b72a4 ("include/linux/sched/mm.h: uninline
> mmdrop_async(), etc") ignored the return value of arch_dup_mmap(). As a
> result, on x86, a failure to duplicate the LDT (e.g., due to memory
> allocation error), would leave the duplicated memory mapping in an
> inconsistent state.
> 
> Fix by regarding the return value, as it was before the change.

Ohh, well spotted! I have a vague recollection I didn't really like the
patch. For other reasons. I didn't get to review it properly back then
because I didn't have much time and I didn't have a high motivation
because I simple disagreed with the patch.

> Fixes: d70f2a14b72a4 ("include/linux/sched/mm.h: uninline mmdrop_async(), etc")
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: stable@vger.kernel.org
> Signed-off-by: Nadav Amit <namit@vmware.com>

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

Thanks!

> ---
>  kernel/fork.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 1b27babc4c78..4527d1d331de 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -549,8 +549,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
>  			goto out;
>  	}
>  	/* a new mm has just been created */
> -	arch_dup_mmap(oldmm, mm);
> -	retval = 0;
> +	retval = arch_dup_mmap(oldmm, mm);
>  out:
>  	up_write(&mm->mmap_sem);
>  	flush_tlb_mm(oldmm);
> -- 
> 2.17.1
> 

-- 
Michal Hocko
SUSE Labs

      reply	other threads:[~2018-08-23  8:57 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-23  5:12 [PATCH] mm: respect arch_dup_mmap() return value Nadav Amit
2018-08-23  8:57 ` Michal Hocko [this message]

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=20180823085714.GY29735@dhcp22.suse.cz \
    --to=mhocko@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=namit@vmware.com \
    --cc=stable@vger.kernel.org \
    /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).