[PATCH v3 23/28] jump_label: Use RCU in all users of __module_address().

[Sebastian Andrzej Siewior]

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

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

Cc: Ard Biesheuvel <a...@kernel.org>
Cc: Jason Baron <jba...@akamai.com>
Cc: Josh Poimboeuf <jpoim...@kernel.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Steven Rostedt <rost...@goodmis.org>
Acked-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
---
 kernel/jump_label.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 93a822d3c468c..7fcf4017cb383 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -746,9 +746,9 @@ static int jump_label_add_module(struct module *mod)
                                kfree(jlm);
                                return -ENOMEM;
                        }
-                       preempt_disable();
-                       jlm2->mod = __module_address((unsigned long)key);
-                       preempt_enable();
+                       scoped_guard(rcu)
+                               jlm2->mod = __module_address((unsigned 
long)key);
+
                        jlm2->entries = static_key_entries(key);
                        jlm2->next = NULL;
                        static_key_set_mod(key, jlm2);
@@ -906,13 +906,13 @@ static void jump_label_update(struct static_key *key)
                return;
        }
 
-       preempt_disable();
-       mod = __module_address((unsigned long)key);
-       if (mod) {
-               stop = mod->jump_entries + mod->num_jump_entries;
-               init = mod->state == MODULE_STATE_COMING;
+       scoped_guard(rcu) {
+               mod = __module_address((unsigned long)key);
+               if (mod) {
+                       stop = mod->jump_entries + mod->num_jump_entries;
+                       init = mod->state == MODULE_STATE_COMING;
+               }
        }
-       preempt_enable();
 #endif
        entry = static_key_entries(key);
        /* if there are no users, entry can be NULL */
-- 
2.47.1