From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754088AbbAWGm6 (ORCPT ); Fri, 23 Jan 2015 01:42:58 -0500 Received: from mail9.hitachi.co.jp ([133.145.228.44]:35607 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752120AbbAWGmz (ORCPT ); Fri, 23 Jan 2015 01:42:55 -0500 Subject: [PATCH -tip/urgent 1/2] [BUGFIX]kprobes: set kprobes_all_disarmed earlier to enable re-optimization. From: Masami Hiramatsu To: Ingo Molnar Cc: tixy@linaro.org, Wang Nan , linux@arm.linux.org.uk, Linux Kernel Mailing List , lizefan@huawei.com, linux-arm-kernel@lists.infradead.org Date: Fri, 23 Jan 2015 15:42:24 +0900 Message-ID: <20150123064224.30731.30127.stgit@localhost.localdomain> In-Reply-To: <20150123064217.30731.49156.stgit@localhost.localdomain> References: <20150123064217.30731.49156.stgit@localhost.localdomain> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wang Nan 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 Acked-by: Masami Hiramatsu --- kernel/kprobes.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 06f5830..9471710 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: From mboxrd@z Thu Jan 1 00:00:00 1970 From: masami.hiramatsu.pt@hitachi.com (Masami Hiramatsu) Date: Fri, 23 Jan 2015 15:42:24 +0900 Subject: [PATCH -tip/urgent 1/2] [BUGFIX]kprobes: set kprobes_all_disarmed earlier to enable re-optimization. In-Reply-To: <20150123064217.30731.49156.stgit@localhost.localdomain> References: <20150123064217.30731.49156.stgit@localhost.localdomain> Message-ID: <20150123064224.30731.30127.stgit@localhost.localdomain> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Wang Nan 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 Acked-by: Masami Hiramatsu --- kernel/kprobes.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 06f5830..9471710 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: