From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: riel@redhat.com
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
fweimer@redhat.com, colm@allcosts.net, akpm@linux-foundation.org,
rppt@linux.vnet.ibm.com, keescook@chromium.org,
luto@amacapital.net, wad@chromium.org, mingo@kernel.org
Subject: Re: [PATCH 0/2] mm,fork,security: introduce MADV_WIPEONFORK
Date: Sat, 5 Aug 2017 02:44:35 +0300 [thread overview]
Message-ID: <20170804234435.lkblljl3f3ud2spm@node.shutemov.name> (raw)
In-Reply-To: <20170804190730.17858-1-riel@redhat.com>
On Fri, Aug 04, 2017 at 03:07:28PM -0400, riel@redhat.com wrote:
> [resend because half the recipients got dropped due to IPv6 firewall issues]
>
> Introduce MADV_WIPEONFORK semantics, which result in a VMA being
> empty in the child process after fork. This differs from MADV_DONTFORK
> in one important way.
>
> If a child process accesses memory that was MADV_WIPEONFORK, it
> will get zeroes. The address ranges are still valid, they are just empty.
I feel like we are repeating mistake we made with MADV_DONTNEED.
MADV_WIPEONFORK would require a specific action from kernel, ignoring
the /advise/ would likely lead to application misbehaviour.
Is it something we really want to see from madvise()?
--
Kirill A. Shutemov
--
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>
next prev parent reply other threads:[~2017-08-04 23:44 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-04 19:07 [PATCH 0/2] mm,fork,security: introduce MADV_WIPEONFORK riel
2017-08-04 19:07 ` [PATCH 1/2] x86,mpx: make mpx depend on x86-64 to free up VMA flag riel
2017-08-04 19:25 ` Dave Hansen
2017-08-04 19:07 ` [PATCH 2/2] mm,fork: introduce MADV_WIPEONFORK riel
2017-08-04 23:09 ` Mike Kravetz
2017-08-05 14:05 ` Rik van Riel
2017-08-14 15:45 ` kbuild test robot
2017-08-04 23:44 ` Kirill A. Shutemov [this message]
2017-08-05 15:21 ` [PATCH 0/2] mm,fork,security: " Rik van Riel
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=20170804234435.lkblljl3f3ud2spm@node.shutemov.name \
--to=kirill@shutemov.name \
--cc=akpm@linux-foundation.org \
--cc=colm@allcosts.net \
--cc=fweimer@redhat.com \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@amacapital.net \
--cc=mingo@kernel.org \
--cc=riel@redhat.com \
--cc=rppt@linux.vnet.ibm.com \
--cc=wad@chromium.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).