Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753185Ab3JVDp6 (ORCPT ); Mon, 21 Oct 2013 23:45:58 -0400 Received: from mail-qe0-f47.google.com ([209.85.128.47]:50839 "EHLO mail-qe0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752928Ab3JVDp5 (ORCPT ); Mon, 21 Oct 2013 23:45:57 -0400 Message-ID: <5265F4EB.2060803@linaro.org> Date: Mon, 21 Oct 2013 23:45:47 -0400 From: David Long User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: Oleg Nesterov CC: linux-arm-kernel@lists.infradead.org, Rabin Vincent , "Jon Medhurst (Tixy)" , Srikar Dronamraju , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 02/13] uprobes: allow ignoring of probe hits References: <1381871068-27660-1-git-send-email-dave.long@linaro.org> <1381871068-27660-3-git-send-email-dave.long@linaro.org> <20131019170214.GA8324@redhat.com> In-Reply-To: <20131019170214.GA8324@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1162 Lines: 34 On 10/19/13 13:02, Oleg Nesterov wrote: > On 10/15, David Long wrote: >> >> @@ -1732,9 +1732,6 @@ static void handle_swbp(struct pt_regs *regs) >> return; >> } >> >> - /* change it in advance for ->handler() and restart */ >> - instruction_pointer_set(regs, bp_vaddr); >> - > > Well, this looks obviously wrong. This SET_IP() has the comment ;) > > Note also that with this breaks __skip_sstep() on x86. > > Oleg. > Yes, and there's a missing weak stub function in there too. It was a surprise to me that declaring an external as weak means that it quietly ignores the fact there is no definition for it at link time, and makes it zero. I think there may be some similar land mines elsewhere in the kernel, unrelated to these changes or uprobes in general. I have an updated version to go out with the v3 patches. It is working with v3.12-rc6 on x86 and ARM, to the extent I'm able to test it. -dl -- 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/