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authorRusty Russell <rusty@rustcorp.com.au>2016-07-27 12:17:35 +0930
committerRusty Russell <rusty@rustcorp.com.au>2016-08-04 10:16:54 +0930
commitbdc9f373551dd3f1e6fae1618f2394ee9bc7db2e (patch)
tree544ec1154b88d6e39134f4d2bf7b3110639ba8ee /kernel/jump_label.c
parent0ef7653797addea8ba1bf97f8208a54a62498d94 (diff)
downloadlinux-bdc9f373551dd3f1e6fae1618f2394ee9bc7db2e.tar.gz
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>

Diffstat (limited to 'kernel/jump_label.c')
-rw-r--r--kernel/jump_label.c5
1 files changed, 4 insertions, 1 deletions
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,