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From:   "Paul E. McKenney" <paulmck@linux.ibm.com>
To:     linux-kernel@vger.kernel.org
Cc:     mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com,
        akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
        josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
        rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
        fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org,
        "Paul E. McKenney" <paulmck@linux.ibm.com>,
        "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
        Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
        "David S. Miller" <davem@davemloft.net>,
        Masami Hiramatsu <mhiramat@kernel.org>
Subject: [PATCH tip/core/rcu 20/41] kprobes: eplace synchronize_sched() with synchronize_rcu()
Date:   Sun, 11 Nov 2018 11:43:49 -0800
In-Reply-To: <20181111194104.GA4787@linux.ibm.com>
References: <20181111194104.GA4787@linux.ibm.com>
Message-Id: <20181111194410.6368-20-paulmck@linux.ibm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Now that synchronize_rcu() waits for preempt-disable regions of code
as well as RCU read-side critical sections, synchronize_sched() can be
replaced by synchronize_rcu().  This commit therefore makes this change.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
---
 kernel/kprobes.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 90e98e233647..08e31d863191 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -229,7 +229,7 @@ static int collect_garbage_slots(struct kprobe_insn_cache *c)
 	struct kprobe_insn_page *kip, *next;
 
 	/* Ensure no-one is interrupted on the garbages */
-	synchronize_sched();
+	synchronize_rcu();
 
 	list_for_each_entry_safe(kip, next, &c->pages, list) {
 		int i;
@@ -1382,7 +1382,7 @@ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p)
 			if (ret) {
 				ap->flags |= KPROBE_FLAG_DISABLED;
 				list_del_rcu(&p->list);
-				synchronize_sched();
+				synchronize_rcu();
 			}
 		}
 	}
@@ -1597,7 +1597,7 @@ int register_kprobe(struct kprobe *p)
 		ret = arm_kprobe(p);
 		if (ret) {
 			hlist_del_rcu(&p->hlist);
-			synchronize_sched();
+			synchronize_rcu();
 			goto out;
 		}
 	}
@@ -1776,7 +1776,7 @@ void unregister_kprobes(struct kprobe **kps, int num)
 			kps[i]->addr = NULL;
 	mutex_unlock(&kprobe_mutex);
 
-	synchronize_sched();
+	synchronize_rcu();
 	for (i = 0; i < num; i++)
 		if (kps[i]->addr)
 			__unregister_kprobe_bottom(kps[i]);
@@ -1966,7 +1966,7 @@ void unregister_kretprobes(struct kretprobe **rps, int num)
 			rps[i]->kp.addr = NULL;
 	mutex_unlock(&kprobe_mutex);
 
-	synchronize_sched();
+	synchronize_rcu();
 	for (i = 0; i < num; i++) {
 		if (rps[i]->kp.addr) {
 			__unregister_kprobe_bottom(&rps[i]->kp);
-- 
2.17.1