From bdc9f373551dd3f1e6fae1618f2394ee9bc7db2e Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Wed, 27 Jul 2016 12:17:35 +0930
Subject: jump_label: disable preemption around __module_text_address().
Steven reported a warning caused by not holding module_mutex or
rcu_read_lock_sched: his backtrace was corrupted but a quick audit
found this possible cause. It's wrong anyway...
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
kernel/jump_label.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
(limited to 'kernel')
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 0dbea887d625..0eef93962a91 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -284,11 +284,14 @@ static int __jump_label_mod_text_reserved(void *start, void *end)
{
struct module *mod;
+ preempt_disable();
mod = __module_text_address((unsigned long)start);
+ WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod);
+ preempt_enable();
+
if (!mod)
return 0;
- WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod);
return __jump_label_text_reserved(mod->jump_entries,
mod->jump_entries + mod->num_jump_entries,
--
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