From 2e6e9058d13a22a6fdd36a8c444ac71d9656003a Mon Sep 17 00:00:00 2001
From: Jiri Olsa <jolsa@redhat.com>
Date: Tue, 9 Nov 2021 12:42:17 +0100
Subject: [PATCH] ftrace/direct: Fix lockup in modify_ftrace_direct_multi
We can't call unregister_ftrace_function under ftrace_lock.
Link: https://lkml.kernel.org/r/20211109114217.1645296-1-jolsa@kernel.org
Fixes: ed29271894aa ("ftrace/direct: Do not disable when switching direct callers")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/ftrace.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index b4ed1a301232a..fc49e8809a566 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5602,10 +5602,11 @@ int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
}
}
+ mutex_unlock(&ftrace_lock);
+
/* Removing the tmp_ops will add the updated direct callers to the functions */
unregister_ftrace_function(&tmp_ops);
- mutex_unlock(&ftrace_lock);
out_direct:
mutex_unlock(&direct_mutex);
return err;
--
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