linux-kernel - (trying again) how to get kernel stack trace if process not blocked?

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>] [day] [month] [year] [list]

Message-ID: <53F45A29.6060604@shiftmail.org>
Date:	Wed, 20 Aug 2014 10:19:53 +0200
From:	Ethan Wilson <ethan.wilson@...ftmail.org>
To:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: (trying again) how to get kernel stack trace if process not blocked?

Hello list,
I know cat /proc/pid/stack shows the kernel call stack of a process, and 
this is so good, but it will show just 0xffffffffffffffff if the process 
is running in kernel space and not blocked (sleeping).

It would be *very* useful to get the kernel stack trace for a running 
process, even if imprecise, or at least knowing the name of the kernel 
function executing now (top of the stack). Why is it not doable?

I tried to disable CONFIG_SCHED_OMIT_FRAME_POINTER but it didn't allow 
to print the stack from /proc/pid/stack anyway. What is the benefit of 
disabling such kernel option (i.e. having the frame pointer)?

I guessed that maybe with EIP from /proc/pid/stat it is possible to do 
something like that but I can't find much information on how to do that.

Thanks for any information
EW
--
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/