From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e7.ny.us.ibm.com (e7.ny.us.ibm.com [32.97.182.137]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e7.ny.us.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 97EA02C008A for ; Thu, 16 Aug 2012 15:00:57 +1000 (EST) Received: from /spool/local by e7.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 16 Aug 2012 01:00:54 -0400 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id 95EC26E8045 for ; Thu, 16 Aug 2012 01:00:52 -0400 (EDT) Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q7G50pwg068742 for ; Thu, 16 Aug 2012 01:00:52 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q7G50T6w031219 for ; Thu, 16 Aug 2012 02:00:30 -0300 Date: Thu, 16 Aug 2012 10:30:30 +0530 From: Ananth N Mavinakayanahalli To: Benjamin Herrenschmidt Subject: Re: [PATCH v3 2/2] powerpc: Uprobes port to powerpc Message-ID: <20120816050030.GA12060@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 In-Reply-To: <1345066913.11751.4.camel@pasglop> Cc: Srikar Dronamraju , peterz@infradead.org, Oleg Nesterov , lkml , Paul Mackerras , Anton Blanchard , Ingo Molnar , linuxppc-dev@lists.ozlabs.org Reply-To: ananth@in.ibm.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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