From: David Ahern <dsahern@gmail•com>
To: Sasha Levin <sasha.levin@oracle•com>,
davem@davemloft•net, kuznet@ms2•inr.ac.ru, jmorris@namei•org,
yoshfuji@linux-ipv6•org, kaber@trash•net
Cc: netdev@vger•kernel.org, linux-kernel@vger•kernel.org
Subject: Re: [PATCH] net: Revert "fib_trie: use seq_file_net rather than seq->private"
Date: Wed, 04 Jun 2014 16:11:46 -0600 [thread overview]
Message-ID: <538F99A2.2090102@gmail.com> (raw)
In-Reply-To: <1401919352-32263-1-git-send-email-sasha.levin@oracle.com>
On 6/4/14, 4:02 PM, Sasha Levin wrote:
> This reverts commit 30f38d2fdd79f13fc929489f7e6e517b4a4bfe63.
>
> fib_triestat is surrounded by a big lie: while it claims that it's a
> seq_file (fib_triestat_seq_open, fib_triestat_seq_show), it isn't:
>
> static const struct file_operations fib_triestat_fops = {
> .owner = THIS_MODULE,
> .open = fib_triestat_seq_open,
> .read = seq_read,
> .llseek = seq_lseek,
> .release = single_release_net,
> };
>
> Yes, fib_triestat is just a regular file.
>
> A small detail (assuming CONFIG_NET_NS=y) is that while for seq_files
> you could do seq_file_net() to get the net ptr, doing so for a regular
> file would be wrong and would dereference an invalid pointer.
>
> The fib_triestat lie claimed a victim, and trying to show the file would
> be bad for the kernel. This patch just reverts the issue and fixes
> fib_triestat, which still needs a rewrite to either be a seq_file or
> stop claiming it is.
It worked fine for me.
fib_triestat_seq_open() is a wrapper to single_open_net() which sets the
namespace as the private element (returned by get_proc_net).
If CONFIG_NETNS is not set:
- single_open_net essentially sets file->private to init_net which is
also what is returned by seq_file_net
If CONFIG_NETNS is set, all is fine.
What am I missing?
David
next prev parent reply other threads:[~2014-06-04 22:11 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-04 22:02 [PATCH] net: Revert "fib_trie: use seq_file_net rather than seq->private" Sasha Levin
2014-06-04 22:11 ` David Ahern [this message]
2014-06-04 22:44 ` David Ahern
2014-06-04 22:11 ` Sergei Shtylyov
2014-06-04 22:12 ` David Miller
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=538F99A2.2090102@gmail.com \
--to=dsahern@gmail$(echo .)com \
--cc=davem@davemloft$(echo .)net \
--cc=jmorris@namei$(echo .)org \
--cc=kaber@trash$(echo .)net \
--cc=kuznet@ms2$(echo .)inr.ac.ru \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=netdev@vger$(echo .)kernel.org \
--cc=sasha.levin@oracle$(echo .)com \
--cc=yoshfuji@linux-ipv6$(echo .)org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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