From: Andrei Vagin <avagin@gmail.com>
To: musl@lists.openwall.com
Subject: Re: Need to zero pads in msghdr
Date: Wed, 25 Jan 2017 10:56:22 -0800 [thread overview]
Message-ID: <CANaxB-x6+vAc_Jjc42h0J3cZD8hrRazCVRwr5fOgO+R2V9U8Jg@mail.gmail.com> (raw)
In-Reply-To: <CANaxB-wowvkVuSxEiGOMf16fnK+HkDqwEs465HC9m3YRdRhfCQ@mail.gmail.com>
On Wed, Jan 25, 2017 at 8:42 AM, Andrei Vagin <avagin@gmail.com> wrote:
> Hi,
>
> In this patch
> http://git.musl-libc.org/cgit/musl/commit/arch/x86_64/bits/socket.h?id=7168790763cdeb794df52be6e3b39fbb021c5a64
> you suppose that the kernel ignores the upper 32 bits of msg_iovlen,
> but it doesn't, so pads in msghdr structures have to be zeroed before
> calling sendmsg and recvmsg syscalls.
Actually the problem is a bit different. In CRIU we use the msghdr
structure from musl-libc, but in some cases we have to call raw system
calls. We don't expect to have pads in structures and so we don't zero
them.
I understand that it is not a bug for many users of mucl-libc, but in
case of CRIU we see this issue.
> https://github.com/xemul/criu/issues/276
>
> Thanks,
> Andrei
next prev parent reply other threads:[~2017-01-25 18:56 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-25 16:42 Andrei Vagin
2017-01-25 17:00 ` Rich Felker
2017-01-25 18:56 ` Andrei Vagin [this message]
2017-01-25 19:40 ` Szabolcs Nagy
2017-01-25 19:46 ` Andrei Vagin
2017-01-25 19:59 ` Rich Felker
2017-01-25 23:00 ` Szabolcs Nagy
2017-01-26 15:01 ` Rich Felker
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=CANaxB-x6+vAc_Jjc42h0J3cZD8hrRazCVRwr5fOgO+R2V9U8Jg@mail.gmail.com \
--to=avagin@gmail.com \
--cc=musl@lists.openwall.com \
/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.
Code repositories for project(s) associated with this public inbox
https://git.vuxu.org/mirror/musl/
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).