From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3w7MMN68v4zDqFH for ; Wed, 19 Apr 2017 22:51:44 +1000 (AEST) Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v3JCnCjn103378 for ; Wed, 19 Apr 2017 08:51:32 -0400 Received: from e28smtp07.in.ibm.com (e28smtp07.in.ibm.com [125.16.236.7]) by mx0b-001b2d01.pphosted.com with ESMTP id 29x6yv43hg-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 19 Apr 2017 08:51:32 -0400 Received: from localhost by e28smtp07.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 19 Apr 2017 18:21:28 +0530 Received: from d28av07.in.ibm.com (d28av07.in.ibm.com [9.184.220.146]) by d28relay02.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v3JCpQfG19464424 for ; Wed, 19 Apr 2017 18:21:26 +0530 Received: from d28av07.in.ibm.com (localhost [127.0.0.1]) by d28av07.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v3JCpPIJ026796 for ; Wed, 19 Apr 2017 18:21:26 +0530 From: "Naveen N. Rao" To: Michael Ellerman , Ingo Molnar Cc: Ananth N Mavinakayanahalli , Masami Hiramatsu , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 5/7] powerpc: kprobes: factor out code to emulate instruction into a helper Date: Wed, 19 Apr 2017 18:21:04 +0530 In-Reply-To: References: In-Reply-To: References: Message-Id: <4fbd6652c2dd8944448fd4d84efa92f20a016d3b.1492604782.git.naveen.n.rao@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , No functional changes. Acked-by: Ananth N Mavinakayanahalli Signed-off-by: Naveen N. Rao --- arch/powerpc/kernel/kprobes.c | 52 ++++++++++++++++++++++++++----------------- 1 file changed, 31 insertions(+), 21 deletions(-) diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index d743bacefa8c..46e8c1e03ce4 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -206,6 +206,35 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, regs->link = (unsigned long)kretprobe_trampoline; } +int __kprobes try_to_emulate(struct kprobe *p, struct pt_regs *regs) +{ + int ret; + unsigned int insn = *p->ainsn.insn; + + /* regs->nip is also adjusted if emulate_step returns 1 */ + ret = emulate_step(regs, insn); + if (ret > 0) { + /* + * Once this instruction has been boosted + * successfully, set the boostable flag + */ + if (unlikely(p->ainsn.boostable == 0)) + p->ainsn.boostable = 1; + } else if (ret < 0) { + /* + * We don't allow kprobes on mtmsr(d)/rfi(d), etc. + * So, we should never get here... but, its still + * good to catch them, just in case... + */ + printk("Can't step on instruction %x\n", insn); + BUG(); + } else if (ret == 0) + /* This instruction can't be boosted */ + p->ainsn.boostable = -1; + + return ret; +} + int __kprobes kprobe_handler(struct pt_regs *regs) { struct kprobe *p; @@ -301,18 +330,9 @@ int __kprobes kprobe_handler(struct pt_regs *regs) ss_probe: if (p->ainsn.boostable >= 0) { - unsigned int insn = *p->ainsn.insn; + ret = try_to_emulate(p, regs); - /* regs->nip is also adjusted if emulate_step returns 1 */ - ret = emulate_step(regs, insn); if (ret > 0) { - /* - * Once this instruction has been boosted - * successfully, set the boostable flag - */ - if (unlikely(p->ainsn.boostable == 0)) - p->ainsn.boostable = 1; - if (p->post_handler) p->post_handler(p, regs, 0); @@ -320,17 +340,7 @@ int __kprobes kprobe_handler(struct pt_regs *regs) reset_current_kprobe(); preempt_enable_no_resched(); return 1; - } else if (ret < 0) { - /* - * We don't allow kprobes on mtmsr(d)/rfi(d), etc. - * So, we should never get here... but, its still - * good to catch them, just in case... - */ - printk("Can't step on instruction %x\n", insn); - BUG(); - } else if (ret == 0) - /* This instruction can't be boosted */ - p->ainsn.boostable = -1; + } } prepare_singlestep(p, regs); kcb->kprobe_status = KPROBE_HIT_SS; -- 2.12.1