Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754984Ab2EHNSk (ORCPT ); Tue, 8 May 2012 09:18:40 -0400 Received: from casper.infradead.org ([85.118.1.10]:46889 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754294Ab2EHNSj convert rfc822-to-8bit (ORCPT ); Tue, 8 May 2012 09:18:39 -0400 Message-ID: <1336483073.16236.37.camel@twins> Subject: Re: [PATCH v20] tracing: Fix kconfig warning due to a typo From: Peter Zijlstra To: Steven Rostedt Cc: Srikar Dronamraju , Ingo Molnar , Linus Torvalds , Ananth N Mavinakayanahalli , LKML , Oleg Nesterov , Christoph Hellwig , Arnaldo Carvalho de Melo , Masami Hiramatsu , Anton Arapov , Stephen Boyd Date: Tue, 08 May 2012 15:17:53 +0200 In-Reply-To: <1336481312.14207.164.camel@gandalf.stny.rr.com> References: <20120508111126.21004.38285.sendpatchset@srdronam.in.ibm.com> <1336476588.16236.20.camel@twins> <1336481312.14207.164.camel@gandalf.stny.rr.com> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1457 Lines: 34 On Tue, 2012-05-08 at 08:48 -0400, Steven Rostedt wrote: > On Tue, 2012-05-08 at 13:29 +0200, Peter Zijlstra wrote: > > On Tue, 2012-05-08 at 16:41 +0530, Srikar Dronamraju wrote: > > > + p:uprobes/p_zsh_0x46420 /bin/zsh:0x00046420 arg1=%ip arg2=%ax > > > > can you also do things like: > > > > p:uprobes/ponies /bin/zsh:foo arg1=bar > > > > when bar is either a function argument of foo (or an otherwise live > > variable at the probe point)? > > > > Only sampling register content is somewhat limiting, you might want to > > have %ax[5] + 24 for example, or a pure memory deref -- and the dwarves > > know where it all lives. > > But this is for the raw entry into the kernel. The kernel wont know the > variable name. Although perf could do that parsing for you. Ah, ok. Yes I meant for perf to do this, I overlooked it was the kernel input. > That said, the %ax[5] + 24 could be done in kernel, and that would be > useful. Does kprobes handle that? In general something like: %mr + %c * %cr + %cr would be most useful I think (%m - memory address, %r - register, %c - constant). Although maybe it needs segment registers too, dunno. Also no idea if this covers the addressing scope of all archs. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/