[PATCH 2/2] ftrace: Adjust priority of ftrace module notifier

From	Jessica Yu <jeyu@redhat.com>
Newsgroups	linux.kernel
Subject	[PATCH 2/2] ftrace: Adjust priority of ftrace module notifier
Date	2016-01-29 07:50 +0100
Message-ID	<qWb2x-7fX-3@gated-at.bofh.it> (permalink)
References	<qWb2x-7fX-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Adjust the priority of the ftrace module notifier such that it will run
before the livepatch coming module notifier but after the livepatch going
module modifier.

This fixes a notifier ordering issue in which the ftrace module notifier
(and hence ftrace_module_enable()) for COMING modules was being called
after klp_module_notify(), which caused livepatch modules to initialize
incorrectly.

Signed-off-by: Jessica Yu <jeyu@redhat.com>
---
 kernel/trace/ftrace.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index eca592f..bdd7bfc 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5067,7 +5067,12 @@ static int ftrace_module_notify(struct notifier_block *self,
 
 struct notifier_block ftrace_module_nb = {
 	.notifier_call = ftrace_module_notify,
-	.priority = INT_MIN,	/* Run after anything that can remove kprobes */
+	/*
+	 * Run after anything that can remove kprobes and
+	 * after livepatch's going notifier, but run before
+	 * livepatch's coming notifier.
+	 */
+	.priority = INT_MIN+1,
 };
 
 void __init ftrace_init(void)
-- 
2.4.3

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[PATCH 2/2] ftrace: Adjust priority of ftrace module notifier Jessica Yu <jeyu@redhat.com> - 2016-01-29 07:50 +0100
  Re: [PATCH 2/2] ftrace: Adjust priority of ftrace module notifier Steven Rostedt <rostedt@goodmis.org> - 2016-01-29 15:40 +0100
    Re: [PATCH 2/2] ftrace: Adjust priority of ftrace module notifier Josh Poimboeuf <jpoimboe@redhat.com> - 2016-01-29 16:50 +0100
      Re: [PATCH 2/2] ftrace: Adjust priority of ftrace module notifier Josh Poimboeuf <jpoimboe@redhat.com> - 2016-01-29 17:00 +0100
      Re: [PATCH 2/2] ftrace: Adjust priority of ftrace module notifier Steven Rostedt <rostedt@goodmis.org> - 2016-01-29 17:00 +0100

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