From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e6.ny.us.ibm.com (e6.ny.us.ibm.com [32.97.182.146]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e6.ny.us.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 530772C007D for ; Wed, 22 Aug 2012 18:32:34 +1000 (EST) Received: from /spool/local by e6.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 22 Aug 2012 04:32:30 -0400 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id 7315D6E803C for ; Wed, 22 Aug 2012 04:32:28 -0400 (EDT) Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q7M8WSxs113798 for ; Wed, 22 Aug 2012 04:32:28 -0400 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q7M8WRNL023042 for ; Wed, 22 Aug 2012 04:32:28 -0400 Date: Wed, 22 Aug 2012 14:02:25 +0530 From: Ananth N Mavinakayanahalli To: Oleg Nesterov Subject: Re: [PATCH v3 2/2] powerpc: Uprobes port to powerpc Message-ID: <20120822083224.GC29216@in.ibm.com> References: <20120726051902.GA29466@in.ibm.com> <20120726052029.GB29466@in.ibm.com> <20120815165931.GA10059@redhat.com> <1345066913.11751.4.camel@pasglop> <20120816050030.GA12060@in.ibm.com> <20120816152112.GA8874@redhat.com> <20120817051307.GA4782@in.ibm.com> <20120817150031.GA5029@redhat.com> <20120821112433.GB3519@in.ibm.com> <20120821130930.GA10382@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20120821130930.GA10382@redhat.com> Cc: Srikar Dronamraju , peterz@infradead.org, 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 Tue, Aug 21, 2012 at 03:09:30PM +0200, Oleg Nesterov wrote: ... > > This is true for Intel like architectures that have *one* swbp > > instruction. On Powerpc, gdb for instance, can insert a trap variant at > > the address. Therefore, is_swbp_insn() by definition should return true > > for all trap variants. > > Not in this case, I think. > > OK, I was going to do this later, but this discussion makes me think > I should try to send the patch sooner. > > set_swbp()->is_swbp_at_addr() is simply unneeded and in fact should > be considered as unnecessary pessimization. > > set_orig_insn()->is_swbp_at_addr() makes more sense, but it can't fix > all races with userpace. Still it should die. > > > OK. I will separate out the is_swbp_insn() change into a separate patch. > > Great thanks. And if we remove is_swbp_insn() from set_swbp() and > set_orig_insn() then the semantics of is_swbp_insn() will much more > clear, and in this case I powerpc probably really needs to change it. Oleg, I have posted a new version for review [1] without the is_swbp_insn() change. I will await your changes around is_swbp_at_addr() and make changes to the powerpc code if necessary. Regards, Ananth [1] https://lists.ozlabs.org/pipermail/linuxppc-dev/2012-August/100524.html