From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
To: Davidlohr Bueso <dave@stgolabs.net>, Oleg Nesterov <oleg@redhat.com>
Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH] mm: rcu-protected get_mm_exe_file()
Date: Mon, 16 Mar 2015 19:18:03 +0300 [thread overview]
Message-ID: <5507023B.4090905@yandex-team.ru> (raw)
In-Reply-To: <1426517419.28068.118.camel@stgolabs.net>
On 16.03.2015 17:50, Davidlohr Bueso wrote:
> On Mon, 2015-03-16 at 15:07 +0100, Oleg Nesterov wrote:
>> 3. and we can remove down_write(mmap_sem) from prctl paths.
>>
>> Actually we can do this even without xchg() above, but we might
>> want to kill MMF_EXE_FILE_CHANGED and test_and_set_bit() check.
>
> Yeah I was waiting for security folks input about this, otherwise this
> still doesn't do it for me as we still have to deal with mmap_sem.
>
Why? mm->flags are updated atomically. mmap_sem isn't required here.
--
Konstantin
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
WARNING: multiple messages have this Message-ID (diff)
From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
To: Davidlohr Bueso <dave@stgolabs.net>, Oleg Nesterov <oleg@redhat.com>
Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH] mm: rcu-protected get_mm_exe_file()
Date: Mon, 16 Mar 2015 19:18:03 +0300 [thread overview]
Message-ID: <5507023B.4090905@yandex-team.ru> (raw)
In-Reply-To: <1426517419.28068.118.camel@stgolabs.net>
On 16.03.2015 17:50, Davidlohr Bueso wrote:
> On Mon, 2015-03-16 at 15:07 +0100, Oleg Nesterov wrote:
>> 3. and we can remove down_write(mmap_sem) from prctl paths.
>>
>> Actually we can do this even without xchg() above, but we might
>> want to kill MMF_EXE_FILE_CHANGED and test_and_set_bit() check.
>
> Yeah I was waiting for security folks input about this, otherwise this
> still doesn't do it for me as we still have to deal with mmap_sem.
>
Why? mm->flags are updated atomically. mmap_sem isn't required here.
--
Konstantin
next prev parent reply other threads:[~2015-03-16 16:18 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-16 13:12 [PATCH] mm: rcu-protected get_mm_exe_file() Konstantin Khlebnikov
2015-03-16 13:12 ` Konstantin Khlebnikov
2015-03-16 14:07 ` Oleg Nesterov
2015-03-16 14:07 ` Oleg Nesterov
2015-03-16 14:50 ` Davidlohr Bueso
2015-03-16 14:50 ` Davidlohr Bueso
2015-03-16 16:18 ` Konstantin Khlebnikov [this message]
2015-03-16 16:18 ` Konstantin Khlebnikov
2015-03-16 17:04 ` Davidlohr Bueso
2015-03-16 17:04 ` Davidlohr Bueso
2015-03-16 16:15 ` Konstantin Khlebnikov
2015-03-16 16:15 ` Konstantin Khlebnikov
2015-03-16 16:35 ` Oleg Nesterov
2015-03-16 16:35 ` Oleg Nesterov
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=5507023B.4090905@yandex-team.ru \
--to=khlebnikov@yandex-team.ru \
--cc=akpm@linux-foundation.org \
--cc=dave@stgolabs.net \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=oleg@redhat.com \
--cc=viro@zeniv.linux.org.uk \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.