From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org by pdx-caf-mail.web.codeaurora.org (Dovecot) with LMTP id +4KGNdpAGVsKZgAAmS7hNA ; Thu, 07 Jun 2018 14:28:10 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 869F0607E7; Thu, 7 Jun 2018 14:28:10 +0000 (UTC) Authentication-Results: smtp.codeaurora.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="v6jAzqmf" X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,T_DKIMWL_WL_HIGH autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by smtp.codeaurora.org (Postfix) with ESMTP id C835C602FC; Thu, 7 Jun 2018 14:28:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C835C602FC Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933442AbeFGO2H (ORCPT + 25 others); Thu, 7 Jun 2018 10:28:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:47170 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933109AbeFGO2F (ORCPT ); Thu, 7 Jun 2018 10:28:05 -0400 Received: from devbox (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C634F20874; Thu, 7 Jun 2018 14:28:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1528381685; bh=cKfTWHn4bApmxNupxe0cN6bVHenJzbuAqXzobEilQlc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=v6jAzqmf7DAFZdhPSDM7gzi0mBnAFJH1J56pCOb/oAnZJ+RH8IIWF+4k4JMpNA9Hz +QxGDdQ7POOj95EmzTiuBgLP3AB5vplXkzTD0dqt+ezeW8U5f4DBy3WwjurIG7snZE 0Hp2G4p4Pf7TfgxKEDE+Z6AAtIy4USgJ7CcRm608= Date: Thu, 7 Jun 2018 23:28:02 +0900 From: Masami Hiramatsu To: "Naveen N. Rao" Cc: Ingo Molnar , Thomas Gleixner , Andrew Morton , "H . Peter Anvin" , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Ingo Molnar , Paul Mackerras , Steven Rostedt Subject: Re: [RFC PATCH -tip v5 18/27] powerpc/kprobes: Don't call the ->break_handler() in arm kprobes code Message-Id: <20180607232802.c5fcea960e94ef2f3cd4cde8@kernel.org> In-Reply-To: <1528371112.vwnh1m0k39.naveen@linux.ibm.com> References: <152812730943.10068.5166429445118734697.stgit@devbox> <152812783350.10068.4690566636762511152.stgit@devbox> <1528371112.vwnh1m0k39.naveen@linux.ibm.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 07 Jun 2018 17:07:00 +0530 "Naveen N. Rao" wrote: > Masami Hiramatsu wrote: > > Don't call the ->break_handler() from the arm kprobes code, > ^^^ powerpc > > > because it was only used by jprobes which got removed. > > > > This also makes skip_singlestep() a static function since > > only ftrace-kprobe.c is using this function. > > > > Signed-off-by: Masami Hiramatsu > > Cc: Benjamin Herrenschmidt > > Cc: Paul Mackerras > > Cc: Michael Ellerman > > Cc: "Naveen N. Rao" > > Cc: linuxppc-dev@lists.ozlabs.org > > --- > > arch/powerpc/include/asm/kprobes.h | 10 ---------- > > arch/powerpc/kernel/kprobes-ftrace.c | 16 +++------------- > > arch/powerpc/kernel/kprobes.c | 31 +++++++++++-------------------- > > 3 files changed, 14 insertions(+), 43 deletions(-) > > With 2 small comments... 2 ? or 1 ? > Acked-by: Naveen N. Rao > > - Naveen > > > > > diff --git a/arch/powerpc/include/asm/kprobes.h b/arch/powerpc/include/asm/kprobes.h > > index 674036db558b..785c464b6588 100644 > > --- a/arch/powerpc/include/asm/kprobes.h > > +++ b/arch/powerpc/include/asm/kprobes.h > > @@ -102,16 +102,6 @@ extern int kprobe_exceptions_notify(struct notifier_block *self, > > extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr); > > extern int kprobe_handler(struct pt_regs *regs); > > extern int kprobe_post_handler(struct pt_regs *regs); > > -#ifdef CONFIG_KPROBES_ON_FTRACE > > -extern int skip_singlestep(struct kprobe *p, struct pt_regs *regs, > > - struct kprobe_ctlblk *kcb); > > -#else > > -static inline int skip_singlestep(struct kprobe *p, struct pt_regs *regs, > > - struct kprobe_ctlblk *kcb) > > -{ > > - return 0; > > -} > > -#endif > > #else > > static inline int kprobe_handler(struct pt_regs *regs) { return 0; } > > static inline int kprobe_post_handler(struct pt_regs *regs) { return 0; } > > diff --git a/arch/powerpc/kernel/kprobes-ftrace.c b/arch/powerpc/kernel/kprobes-ftrace.c > > index 1b316331c2d9..3869b0e5d5c7 100644 > > --- a/arch/powerpc/kernel/kprobes-ftrace.c > > +++ b/arch/powerpc/kernel/kprobes-ftrace.c > > @@ -26,8 +26,8 @@ > > #include > > > > static nokprobe_inline > > -int __skip_singlestep(struct kprobe *p, struct pt_regs *regs, > > - struct kprobe_ctlblk *kcb, unsigned long orig_nip) > > +int skip_singlestep(struct kprobe *p, struct pt_regs *regs, > > + struct kprobe_ctlblk *kcb, unsigned long orig_nip) > > { > > /* > > * Emulate singlestep (and also recover regs->nip) > > @@ -44,16 +44,6 @@ int __skip_singlestep(struct kprobe *p, struct pt_regs *regs, > > return 1; > > } > > > > -int skip_singlestep(struct kprobe *p, struct pt_regs *regs, > > - struct kprobe_ctlblk *kcb) > > -{ > > - if (kprobe_ftrace(p)) > > - return __skip_singlestep(p, regs, kcb, 0); > > - else > > - return 0; > > -} > > -NOKPROBE_SYMBOL(skip_singlestep); > > - > > /* Ftrace callback handler for kprobes */ > > void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip, > > struct ftrace_ops *ops, struct pt_regs *regs) > > @@ -82,7 +72,7 @@ void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip, > > __this_cpu_write(current_kprobe, p); > > kcb->kprobe_status = KPROBE_HIT_ACTIVE; > > if (!p->pre_handler || !p->pre_handler(p, regs)) > > - __skip_singlestep(p, regs, kcb, orig_nip); > > + skip_singlestep(p, regs, kcb, orig_nip); > > We can probably get rid of skip_singlestep() completely along with > orig_nip since instructions are always 4 bytes on powerpc. So, the > changes we do to nip should help to recover the value automatically. Good point! Yes, skip_singlestep() is no more exported, so we just consolidate it into kprobe_ftrace_handler() for simplifying operation. Thank you! > > - Naveen > > -- Masami Hiramatsu