[PATCH v3 26/28] kprobes: Use RCU in all users of __module_text_address().

[Sebastian Andrzej Siewior]

__module_text_address() can be invoked within a RCU section, there is no
requirement to have preemption disabled.

Replace the preempt_disable() section around __module_text_address()
with RCU.

Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@xxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Naveen N Rao <naveen@xxxxxxxxxx>
Cc: linux-trace-kernel@xxxxxxxxxxxxxxx
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
 kernel/kprobes.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index b027a4030976a..22e47a27df4aa 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1566,7 +1566,7 @@ static int check_kprobe_address_safe(struct kprobe *p,
 	if (ret)
 		return ret;
 	jump_label_lock();
-	preempt_disable();
+	rcu_read_lock();
 
 	/* Ensure the address is in a text area, and find a module if exists. */
 	*probed_mod = NULL;
@@ -1612,7 +1612,7 @@ static int check_kprobe_address_safe(struct kprobe *p,
 	}
 
 out:
-	preempt_enable();
+	rcu_read_unlock();
 	jump_label_unlock();
 
 	return ret;
-- 
2.47.1