linux-kernel - Re: [PATCH -tip v8 19/26] kprobes: Show blacklist entries via debugfs

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]

Date:	Tue, 25 Mar 2014 19:30:34 +0900
From:	Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>
To:	Steven Rostedt <rostedt@...dmis.org>
Cc:	linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...nel.org>,
	Andi Kleen <andi@...stfloor.org>,
	Ananth N Mavinakayanahalli <ananth@...ibm.com>,
	Sandeepa Prabhu <sandeepa.prabhu@...aro.org>,
	Frederic Weisbecker <fweisbec@...il.com>, x86@...nel.org,
	fche@...hat.com, mingo@...hat.com, systemtap@...rceware.org,
	"H. Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	"David S. Miller" <davem@...emloft.net>
Subject: Re: [PATCH -tip v8 19/26] kprobes: Show blacklist entries via debugfs

(2014/03/25 5:19), Steven Rostedt wrote:
> On Wed, 05 Mar 2014 21:00:56 +0900
> Masami Hiramatsu <masami.hiramatsu.pt@...achi.com> wrote:
> 
> 
>>  kernel/kprobes.c |   61 +++++++++++++++++++++++++++++++++++++++++++++++-------
>>  1 file changed, 53 insertions(+), 8 deletions(-)
>>
>> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
>> index a21b4e6..3214289 100644
>> --- a/kernel/kprobes.c
>> +++ b/kernel/kprobes.c
>> @@ -2249,6 +2249,46 @@ static const struct file_operations debugfs_kprobes_operations = {
>>  	.release        = seq_release,
>>  };
>>  
>> +/* kprobes/blacklist -- shows which functions can not be probed */
>> +static void *kprobe_blacklist_seq_start(struct seq_file *m, loff_t *pos)
>> +{
>> +	return seq_list_start(&kprobe_blacklist, *pos);
>> +}
>> +
>> +static void *kprobe_blacklist_seq_next(struct seq_file *m, void *v, loff_t *pos)
>> +{
>> +	return seq_list_next(v, &kprobe_blacklist, pos);
>> +}
>> +
> 
> Can modules use NOKPROBE_SYMBOL() and have items being added to the
> list as this is being read? That is, do we need locks?

At this point, no, the NOKPROBE_SYMBOL()s in module are just ignored.

> Also, are items removed. I need to go back and look at the
> implementation of NOKPROBE_SYMBOL(), I'm just writing this as I think
> about it ;-)

Actually, I've introduced a lock with module NOKPROBE_SYMBOL() support in
the next patch. :)
I'd like to split it because module blacklist support involves module
subsystem update.

Thank you!

-- 
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@...achi.com


--
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/