From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753918AbbAEMg1 (ORCPT ); Mon, 5 Jan 2015 07:36:27 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:43272 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753215AbbAEMgZ (ORCPT ); Mon, 5 Jan 2015 07:36:25 -0500 From: Wang Nan To: , , CC: , Subject: [PATCH] kprobes: bugfix: set kprobes_all_disarmed earlier to enable re-optimization. Date: Mon, 5 Jan 2015 20:31:15 +0800 Message-ID: <1420461075-27012-1-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.4 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=0001.0A020203.54AA8544.00B3,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: 19ea364152f4af10c72bc9f89b317e5a Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In original code, the probed instruction doesn't get optimized after echo 0 > /sys/kernel/debug/kprobes/enabled echo 1 > /sys/kernel/debug/kprobes/enabled This is because original code checks kprobes_all_disarmed in optimize_kprobe(), but this flag is turned off after calling that function. Therefore, optimize_kprobe() will see kprobes_all_disarmed == true and doesn't do the optimization. This patch simply turns off kprobes_all_disarmed earlier to enable optimization. Signed-off-by: Wang Nan --- kernel/kprobes.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index bad4e95..b185464 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2320,6 +2320,12 @@ static void arm_all_kprobes(void) if (!kprobes_all_disarmed) goto already_enabled; + /* + * optimize_kprobe() called by arm_kprobe() checks + * kprobes_all_disarmed, so set kprobes_all_disarmed before + * arm_kprobe. + */ + kprobes_all_disarmed = false; /* Arming kprobes doesn't optimize kprobe itself */ for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; @@ -2328,7 +2334,6 @@ static void arm_all_kprobes(void) arm_kprobe(p); } - kprobes_all_disarmed = false; printk(KERN_INFO "Kprobes globally enabled\n"); already_enabled: -- 1.8.4