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From: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: tixy@linaro.org, Wang Nan <wangnan0@huawei.com>,
	linux@arm.linux.org.uk,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	lizefan@huawei.com, linux-arm-kernel@lists.infradead.org
Subject: [PATCH -tip/urgent 2/2] [BUGFIX]kprobes: makes kprobes/enabled works correctly for optimized kprobes.
Date: Fri, 23 Jan 2015 15:42:31 +0900	[thread overview]
Message-ID: <20150123064230.30731.29584.stgit@localhost.localdomain> (raw)
In-Reply-To: <20150123064217.30731.49156.stgit@localhost.localdomain>

From: Wang Nan <wangnan0@huawei.com>

debugfs/kprobes/enabled doesn't work correctly on optimized kprobes.
Masami Hiramatsu has a test report on x86_64 platform:

https://lkml.org/lkml/2015/1/19/274

This patch forces it to unoptimize kprobe if kprobes_all_disarmed
is set. It also checks the flag in unregistering path for skipping
unneeded disarming process when kprobes globally disarmed.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
---
 kernel/kprobes.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 9471710..fb995ef 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -869,7 +869,8 @@ static void __disarm_kprobe(struct kprobe *p, bool reopt)
 {
 	struct kprobe *_p;
 
-	unoptimize_kprobe(p, false);	/* Try to unoptimize */
+	/* Try to unoptimize */
+	unoptimize_kprobe(p, kprobes_all_disarmed);
 
 	if (!kprobe_queued(p)) {
 		arch_disarm_kprobe(p);
@@ -1571,7 +1572,13 @@ static struct kprobe *__disable_kprobe(struct kprobe *p)
 
 		/* Try to disarm and disable this/parent probe */
 		if (p == orig_p || aggr_kprobe_disabled(orig_p)) {
-			disarm_kprobe(orig_p, true);
+			/*
+			 * If kprobes_all_disarmed is set, orig_p
+			 * should have already been disarmed, so
+			 * skip unneed disarming process.
+			 */
+			if (!kprobes_all_disarmed)
+				disarm_kprobe(orig_p, true);
 			orig_p->flags |= KPROBE_FLAG_DISABLED;
 		}
 	}


  parent reply	other threads:[~2015-01-23  6:43 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-23  6:42 [PATCH -tip/urgent 0/2]kprobes bugfixes around optprobe Masami Hiramatsu
2015-01-23  6:42 ` [PATCH -tip/urgent 1/2] [BUGFIX]kprobes: set kprobes_all_disarmed earlier to enable re-optimization Masami Hiramatsu
2015-02-05 22:49   ` Andrew Morton
2015-01-23  6:42 ` Masami Hiramatsu [this message]
2015-01-26  5:38 ` [PATCH -tip/urgent 0/2]kprobes bugfixes around optprobe Wang Nan
2015-02-04 11:01   ` Wang Nan
2015-02-05  1:59     ` Wang Nan

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