From: Peter Zijlstra <peterz@infradead.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>,
linux-kernel@vger.kernel.org, Paul Mackerras <paulus@samba.org>,
Frederic Weisbecker <fweisbec@gmail.com>
Subject: Re: [PATCH 2/2] perf lock: Fix output of tracing lock events
Date: Thu, 17 Dec 2009 11:26:14 +0100 [thread overview]
Message-ID: <1261045574.27920.179.camel@laptop> (raw)
In-Reply-To: <20091217100922.GA23778@elte.hu>
On Thu, 2009-12-17 at 11:09 +0100, Ingo Molnar wrote:
> * Peter Zijlstra <peterz@infradead.org> wrote:
>
> > > TP_STRUCT__entry(
> > > + __field(struct lockdep_map *, lockdep_addr)
> > > __field(unsigned int, flags)
> > > __string(name, lock->name)
> > > ),
> >
> > I feel a bit awkward explicitly leaking kernel pointers like that. All this
> > is accessible by root only (for now) so its not too harmfull, but sitll.
>
> What would you suggest as a 'natural lock class key'? The name? It might not
> be unique enough.
>
> Other kernel objects like tasks, cpus, inodes, pages all have some natural key
> that isnt a kernel pointer - but locks are a bit special.
Well, yeah, that's the problem, and we use the pointer for exactly this
purpose inside the kernel too, its just that its a blatant data leak
when we expose it to userspace like that.
On the other hand, adding some ID generation just so we can expose it
seems silly too.
Why do we need to have instance resolution?
next prev parent reply other threads:[~2009-12-17 10:26 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-16 3:28 [PATCH 1/2] perf: Add util/include/linuxhash.h to include hash.h of kernel Hitoshi Mitake
2009-12-16 3:28 ` [PATCH 2/2] perf lock: Fix output of tracing lock events Hitoshi Mitake
2009-12-16 8:19 ` [tip:perf/lock] " tip-bot for Hitoshi Mitake
2009-12-17 8:50 ` [PATCH 2/2] " Ingo Molnar
2009-12-17 9:24 ` Peter Zijlstra
2009-12-17 10:09 ` Ingo Molnar
2009-12-17 10:26 ` Peter Zijlstra [this message]
2009-12-17 10:51 ` Ingo Molnar
2009-12-26 13:43 ` Hitoshi Mitake
2009-12-28 10:01 ` Peter Zijlstra
2009-12-31 13:24 ` Hitoshi Mitake
2010-01-07 10:38 ` Hitoshi Mitake
2010-01-07 10:39 ` [PATCH 0/5] lockdep: Add information of file and line to lockdep_map Hitoshi Mitake
2010-01-13 9:52 ` Peter Zijlstra
2010-01-13 10:09 ` Ingo Molnar
2010-01-16 13:01 ` Hitoshi Mitake
2010-01-18 7:20 ` Peter Zijlstra
2010-01-26 5:56 ` [PATCH] Add type of locks to lock trace events Hitoshi Mitake
2010-01-28 10:21 ` Peter Zijlstra
2010-01-29 17:29 ` Frederic Weisbecker
2010-01-29 17:41 ` Peter Zijlstra
2010-01-29 22:12 ` Frederic Weisbecker
2010-02-24 9:02 ` [PATCH] Separate lock events with types Hitoshi Mitake
2010-03-26 23:33 ` Frederic Weisbecker
2010-04-05 10:37 ` Hitoshi Mitake
2010-04-06 8:26 ` Peter Zijlstra
2010-04-06 9:44 ` Frederic Weisbecker
2010-01-07 10:39 ` [PATCH 1/5] lockdep: Add file and line to initialize sequence of spin and rw lock Hitoshi Mitake
2010-01-07 10:39 ` [PATCH 2/5] lockdep: Add file and line to initialize sequence of rwsem Hitoshi Mitake
2010-01-07 10:39 ` [PATCH 3/5] " Hitoshi Mitake
2010-01-07 10:39 ` [PATCH 4/5] lockdep: Add file and line to initialize sequence of mutex Hitoshi Mitake
2010-01-07 10:39 ` [PATCH 5/5] lockdep: Fix the way to initialize class_mutex for information of file and line Hitoshi Mitake
2010-01-13 10:00 ` Ingo Molnar
2010-01-13 23:17 ` Greg KH
2010-01-13 23:19 ` Greg KH
2010-01-16 12:55 ` Hitoshi Mitake
2009-12-16 8:18 ` [tip:perf/lock] perf: Add util/include/linuxhash.h to include hash.h of kernel tip-bot for Hitoshi Mitake
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