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Date: Wed, 10 Nov 2021 20:22:56 -0500
From: Steven Rostedt <rostedt@...dmis.org>
To: linux-kernel@...r.kernel.org
Cc: Ingo Molnar <mingo@...nel.org>,
Andrew Morton <akpm@...ux-foundation.org>,
Jiri Olsa <jolsa@...nel.org>
Subject: [for-linus][PATCH 2/2] ftrace/direct: Fix lockup in modify_ftrace_direct_multi
From: Jiri Olsa <jolsa@...hat.com>
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@...nel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@...dmis.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 b4ed1a301232..fc49e8809a56 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;
--
2.33.0
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