linux-kernel - Re: An incorrect assumption over radix_tree_tag

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20100406170903.GH5288@laptop>
Date:	Wed, 7 Apr 2010 03:09:03 +1000
From:	Nick Piggin <npiggin@...e.de>
To:	David Howells <dhowells@...hat.com>
Cc:	paulmck@...ux.vnet.ibm.com, corbet@....net,
	linux-kernel@...r.kernel.org, linux-cachefs@...hat.com
Subject: Re: An incorrect assumption over radix_tree_tag_get()

On Tue, Apr 06, 2010 at 05:19:49PM +0100, David Howells wrote:
> 
> Hi,
> 
> I think I've made a bad assumption over my usage of radix_tree_tag_get() in
> fs/fscache/page.c.
> 
> I've assumed that radix_tree_tag_get() is protected from radix_tree_tag_set()
> and radix_tree_tag_clear() by the RCU read lock.  However, now I'm not so
> sure.  I think it's only protected against removal of part of the tree.
> 
> Can you confirm?

It is safe. Synchronization requirements for using the radix tree API
are documented.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/