From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755587AbbAGHlo (ORCPT ); Wed, 7 Jan 2015 02:41:44 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:46133 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751161AbbAGHll (ORCPT ); Wed, 7 Jan 2015 02:41:41 -0500 From: Wang Nan To: , , , , , , , , CC: , , Subject: [RFC PATCH 01/11] ARM: kprobes: directly modify code if kprobe is not initialized. Date: Wed, 7 Jan 2015 15:35:24 +0800 Message-ID: <1420616124-42765-1-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1420616086-42692-1-git-send-email-wangnan0@huawei.com> References: <1420616086-42692-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.197.247] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020205.54ACE2FB.007C,ss=1,re=0.001,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 12074d3bc4a8d788e5193a746129849d Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If kprobe is optimized before kprobe is initialized, there should be only one core, the probed instruction is not armed with breakpoint, so simply patch text is okay. Signed-off-by: Wang Nan --- arch/arm/probes/kprobes/opt-arm.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/arm/probes/kprobes/opt-arm.c b/arch/arm/probes/kprobes/opt-arm.c index 15b37c0..a021474 100644 --- a/arch/arm/probes/kprobes/opt-arm.c +++ b/arch/arm/probes/kprobes/opt-arm.c @@ -325,8 +325,17 @@ void __kprobes arch_optimize_kprobes(struct list_head *oplist) * Similar to __arch_disarm_kprobe, operations which * removing breakpoints must be wrapped by stop_machine * to avoid racing. + * + * If this function is called before kprobes initialized, + * the kprobe should be an early kprobe, the instruction + * is not armed with breakpoint. There should be only + * one core now, so directly __patch_text is enough. */ - kprobes_remove_breakpoint(op->kp.addr, insn); + if (unlikely(!kprobes_initialized)) { + BUG_ON(!(op->kp.flags & KPROBE_FLAG_EARLY)); + __patch_text(op->kp.addr, insn); + } else + kprobes_remove_breakpoint(op->kp.addr, insn); list_del_init(&op->list); } -- 1.8.4