linux-kernel - Re: [PATCH v2] [RFC] tracepoint: Add signal coredump tracepoint

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:	Sat, 5 Dec 2009 08:16:35 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	Masami Hiramatsu <mhiramat@...hat.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	lkml <linux-kernel@...r.kernel.org>,
	systemtap <systemtap@...rces.redhat.com>,
	DLE <dle-develop@...ts.sourceforge.net>,
	Oleg Nesterov <oleg@...hat.com>,
	Roland McGrath <roland@...hat.com>,
	Jason Baron <jbaron@...hat.com>,
	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
Subject: Re: [PATCH v2] [RFC] tracepoint: Add signal coredump tracepoint

* Masami Hiramatsu <mhiramat@...hat.com> wrote:

> Ingo Molnar wrote:
> > 
> > * Masami Hiramatsu <mhiramat@...hat.com> wrote:
> > 
> >> Add signal coredump tracepoint which shows signal number, mm->flags, 
> >> limits, pointer to file structure and core file name.
> > 
> > Why is the kernel pointer to the file structure logged? User-space has 
> > no use for it and the analysis value is low.
> 
> Ah, if open() or opening pipe fails, it becomes 0 or -ERRNO, so we can 
> check if there is an error.

ok, that wasnt obvious from the patch - worth adding it to the 
changelog.

> Perhaps, we can do below in trace_printk for trace users.
> "open %s", (!file || IS_ERR((void *)file)) ? "failed" : "succeeded"

i'd rather suggest to pass an error code (and keep it 0 if none), 
instead of some ad-hoc string message.

But ... the whole issue of VFS event logging and new tracepoints should 
be approached from a more generic direction i think. Do we want to log 
inode_nr:dev pairs as well? Shouldnt there be a generic event-class 
definition via DECLARE_EVENT_CLASS for file related events, with 'core 
dumped' just being a sub-event-code?

I sense reluctance from the direction of Andrew and disinterest from the 
VFS folks - not a good backdrop in general.

	Ingo
--
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/