Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753252Ab2HPFAh (ORCPT ); Thu, 16 Aug 2012 01:00:37 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:57689 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752807Ab2HPFAf (ORCPT ); Thu, 16 Aug 2012 01:00:35 -0400 Date: Thu, 16 Aug 2012 10:30:30 +0530 From: Ananth N Mavinakayanahalli To: Benjamin Herrenschmidt Cc: Oleg Nesterov , linuxppc-dev@lists.ozlabs.org, lkml , Paul Mackerras , Anton Blanchard , michael@ellerman.id.au, Ingo Molnar , peterz@infradead.org, Srikar Dronamraju Subject: Re: [PATCH v3 2/2] powerpc: Uprobes port to powerpc Message-ID: <20120816050030.GA12060@in.ibm.com> Reply-To: ananth@in.ibm.com References: <20120726051902.GA29466@in.ibm.com> <20120726052029.GB29466@in.ibm.com> <20120815165931.GA10059@redhat.com> <1345066913.11751.4.camel@pasglop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1345066913.11751.4.camel@pasglop> User-Agent: Mutt/1.5.17 (2007-11-01) X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12081605-5930-0000-0000-00000AEC3B23 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2242 Lines: 57 On Thu, Aug 16, 2012 at 07:41:53AM +1000, Benjamin Herrenschmidt wrote: > On Wed, 2012-08-15 at 18:59 +0200, Oleg Nesterov wrote: > > On 07/26, Ananth N Mavinakayanahalli wrote: > > > > > > From: Ananth N Mavinakayanahalli > > > > > > This is the port of uprobes to powerpc. Usage is similar to x86. > > > > I am just curious why this series was ignored by powerpc maintainers... > > Because it arrived too late for the previous merge window considering my > limited bandwidth for reviewing things and that nobody else seems to > have reviewed it :-) > > It's still on track for the next one, and I'm hoping to dedicate most of > next week going through patches & doing a powerpc -next. Thanks Ben! > > Of course I can not review this code, I know nothing about powerpc, > > but the patches look simple/straightforward. > > > > Paul, Benjamin? > > > > Just one question... Shouldn't arch_uprobe_pre_xol() forbid to probe > > UPROBE_SWBP_INSN (at least) ? > > > > (I assume that emulate_step() can't handle this case but of course I > > do not understand arch/powerpc/lib/sstep.c) > > > > Note that uprobe_pre_sstep_notifier() sets utask->state = UTASK_BP_HIT > > without any checks. This doesn't look right if it was UTASK_SSTEP... > > > > But again, I do not know what powepc will actually do if we try to > > single-step over UPROBE_SWBP_INSN. > > Ananth ? set_swbp() will return -EEXIST to install_breakpoint if we are trying to put a breakpoint on UPROBE_SWBP_INSN. So, the arch agnostic code itself takes care of this case... or am I missing something? However, I see that we need a powerpc specific is_swbp_insn() implementation since we will have to take care of all the trap variants. I will need to update the patches based on changes being made by Oleg and Sebastien for the single-step issues. Will incorporate the powerpc specific is_swbp_insn() change along with the changes required for the single-step part and send out the next version. Ananth -- 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/