linux-kernel - Re: [patch] f2fs: use _safe() version of list_for

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 for Android: free password hash cracker in your pocket

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

Date:	Mon, 21 Jan 2013 19:27:52 +0900
From:	Namjae Jeon <linkinjeon@...il.com>
To:	jaegeuk.kim@...sung.com
Cc:	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	Dan Carpenter <dan.carpenter@...cle.com>,
	linux-f2fs-devel@...ts.sourceforge.net,
	linux-kernel@...r.kernel.org, kernel-janitors@...r.kernel.org
Subject: Re: [patch] f2fs: use _safe() version of list_for_each

2013/1/21, Jaegeuk Kim <jaegeuk.kim@...sung.com>:
> 2013-01-21 (월), 00:32 -0800, Dmitry Torokhov:
>> On Sun, Jan 20, 2013 at 06:02:58PM +0300, Dan Carpenter wrote:
>> > This is calling list_del() inside a loop which is a problem when we try
>> > move to the next item on the list.  I've converted it to use the _safe
>> > version.  And also, as a cleanup, I've converted it to use
>> > list_for_each_entry instead of list_for_each.
>> >
>> > Signed-off-by: Dan Carpenter <dan.carpenter@...cle.com>
>> > ---
>> > Static analysis stuff.  Untested.  Please review carefully.
>>
>> Makes sense to me.
>>
>> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
>>
>
> No doubt, applied.
> Thanks,
I agree in cases – where we will have chances of parallel access and
modification to the linked we should use list_for_each_entry_safe()
But my point was related with this code change case in the patch.
We will have path like this:
f2fs_fill_super->recover_fsync_data->destroy_fsync_dnodes()
>From this calling path – there can only be a single caller at any
given time. So, we will not have the case of having parallel access to
the list which is local to recover_fsync_data() and destroyed on exit
from this function.
>From the real issue point of view – this does not looks convincing to
me why expensive _safe fucntion should used.

Thanks.
>
> --
> Jaegeuk Kim
> Samsung
>
--
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/