Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934804AbdDSOnd (ORCPT ); Wed, 19 Apr 2017 10:43:33 -0400 Received: from mail.kernel.org ([198.145.29.136]:55588 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764878AbdDSOn3 (ORCPT ); Wed, 19 Apr 2017 10:43:29 -0400 Date: Wed, 19 Apr 2017 23:43:19 +0900 From: Masami Hiramatsu To: "Naveen N. Rao" Cc: Michael Ellerman , Ingo Molnar , Ananth N Mavinakayanahalli , Masami Hiramatsu , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 6/7] powerpc: kprobes: emulate instructions on kprobe handler re-entry Message-Id: <20170419234319.7893df9c158e565fede4a386@kernel.org> In-Reply-To: <0d4193a90e4b2ad3cd2ef33d41228b80a2ac9f91.1492604782.git.naveen.n.rao@linux.vnet.ibm.com> References: <0d4193a90e4b2ad3cd2ef33d41228b80a2ac9f91.1492604782.git.naveen.n.rao@linux.vnet.ibm.com> X-Mailer: Sylpheed 3.5.0 (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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1219 Lines: 44 BTW, as I pointed, 5/7 and 6/7 should be merged since this actually makes meaningful change. Thank you, On Wed, 19 Apr 2017 18:21:05 +0530 "Naveen N. Rao" wrote: > On kprobe handler re-entry, try to emulate the instruction rather than > single stepping always. > > Acked-by: Ananth N Mavinakayanahalli > Signed-off-by: Naveen N. Rao > --- > arch/powerpc/kernel/kprobes.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c > index 46e8c1e03ce4..067e9863bfdf 100644 > --- a/arch/powerpc/kernel/kprobes.c > +++ b/arch/powerpc/kernel/kprobes.c > @@ -276,6 +276,14 @@ int __kprobes kprobe_handler(struct pt_regs *regs) > kprobes_inc_nmissed_count(p); > prepare_singlestep(p, regs); > kcb->kprobe_status = KPROBE_REENTER; > + if (p->ainsn.boostable >= 0) { > + ret = try_to_emulate(p, regs); > + > + if (ret > 0) { > + restore_previous_kprobe(kcb); > + return 1; > + } > + } > return 1; > } else { > if (*addr != BREAKPOINT_INSTRUCTION) { > -- > 2.12.1 > -- Masami Hiramatsu