From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 8 Jan 2025 09:04:53 +0000 (+0100)
Subject: jump_label: Use RCU in all users of __module_text_address().
X-Git-Tag: v6.15-rc1~94^2~8
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=72ee1c20b0b5ee0e303cc4fbe2bae6523e382451;p=thirdparty%2Flinux.git

jump_label: Use RCU in all users of __module_text_address().

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

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

Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250108090457.512198-25-bigeasy@linutronix.de
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
---

diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 7fcf4017cb383..7cb19e6014266 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -653,13 +653,12 @@ static int __jump_label_mod_text_reserved(void *start, void *end)
 	struct module *mod;
 	int ret;
 
-	preempt_disable();
-	mod = __module_text_address((unsigned long)start);
-	WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod);
-	if (!try_module_get(mod))
-		mod = NULL;
-	preempt_enable();
-
+	scoped_guard(rcu) {
+		mod = __module_text_address((unsigned long)start);
+		WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod);
+		if (!try_module_get(mod))
+			mod = NULL;
+	}
 	if (!mod)
 		return 0;