From: "H. Peter Anvin" <hpa@zytor.com>
To: David Miller <davem@davemloft.net>
Cc: joseph@codesourcery.com, linux-kernel@vger.kernel.org,
linux-mips@linux-mips.org, linux-arch@vger.kernel.org
Subject: Re: 64-bit syscall ABI issue
Date: Mon, 04 Jun 2007 17:04:12 -0700 [thread overview]
Message-ID: <4664A87C.5040609@zytor.com> (raw)
In-Reply-To: <20070604.142557.68139332.davem@davemloft.net>
David Miller wrote:
> From: "Joseph S. Myers" <joseph@codesourcery.com>
> Date: Mon, 4 Jun 2007 20:56:57 +0000 (UTC)
>
> [ added linux-arch which is a great place to discuss these
> kinds of issues. ]
>
>> What should the kernel syscall ABI be in such cases (any case where the
>> syscall implementations expect arguments narrower than registers, so
>> mainly 32-bit arguments on 64-bit platforms)? There are two obvious
>> possibilities:
>
> In general we've taken the stance that the syscall dispatch
> should create the proper calling environment for C code
> implementing the system calls, and this thus means properly
> sign and zero extending the arguments as expected by the C
> calling convention.
This is, in fact, rather fundamental (some ABIs don't require sign or
zero extension, e.g. x86-64); otherwise libc's job becomes a whole lot
harder.
-hpa
prev parent reply other threads:[~2007-06-05 0:06 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <Pine.LNX.4.64.0706042051280.16431@digraph.polyomino.org.uk>
2007-06-04 21:25 ` 64-bit syscall ABI issue David Miller
2007-06-05 0:04 ` H. Peter Anvin [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=4664A87C.5040609@zytor.com \
--to=hpa@zytor.com \
--cc=davem@davemloft.net \
--cc=joseph@codesourcery.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@linux-mips.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).