From: Jamie Lokier <jamie@shareable.org>
To: Linus Torvalds <torvalds@osdl.org>
Cc: chris@scary.beasts.org, akpm@osdl.org, linux-kernel@vger.kernel.org
Subject: Re: Nasty 2.6 sendfile() bug / regression; affects vsftpd
Date: Mon, 19 Apr 2004 01:46:57 +0100 [thread overview]
Message-ID: <20040419004657.GD11064@mail.shareable.org> (raw)
In-Reply-To: <Pine.LNX.4.58.0404172005260.23917@ppc970.osdl.org>
Looking at related code, sys_sendfile64 a few lines down.
if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
return -EFAULT;
if (unlikely(put_user(pos, offset)))
return -EFAULT;
It seems odd that put_user() is used to write an 8-byte value, but
get_user() cannot be used read one. I looked in <asm-i386/uaccess.h>
and indeed the asymmetry is there.
Is there a reason why put_user() supports 1/2/4/8 bytes and get_user()
supports only 1/2/4 bytes?
-- Jamie
next prev parent reply other threads:[~2004-04-19 0:47 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-04-18 0:28 Nasty 2.6 sendfile() bug / regression; affects vsftpd chris
2004-04-18 3:12 ` Linus Torvalds
2004-04-18 13:49 ` chris
2004-04-19 0:46 ` Jamie Lokier [this message]
2004-04-19 5:28 ` Linus Torvalds
2004-04-19 9:44 ` [PATCH] Add 64-bit get_user and __get_user for i386 Jamie Lokier
2004-04-19 10:14 ` Jamie Lokier
2004-04-19 10:17 ` [PATCH] Use get_user for 64-bit read in sendfile64 Jamie Lokier
2004-04-19 10:36 ` Jamie Lokier
2004-04-19 14:56 ` [PATCH] Add 64-bit get_user and __get_user for i386 Linus Torvalds
[not found] ` <20040420020922.GA18348@mail.shareable.org>
[not found] ` <Pine.LNX.4.58.0404191945490.29941@ppc970.osdl.org>
2004-04-20 17:41 ` Jamie Lokier
2004-04-21 1:15 ` Linus Torvalds
2004-04-20 23:21 ` Jim Wilson
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=20040419004657.GD11064@mail.shareable.org \
--to=jamie@shareable.org \
--cc=akpm@osdl.org \
--cc=chris@scary.beasts.org \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@osdl.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