[v3,27/28] static_call: Use RCU in all users of __module_text_address().

Commit Message

Sebastian Sewior Jan. 8, 2025, 9:04 a.m. UTC

__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.

Acked-by: Peter Zijlstra (Intel) <[e-mail]>
Signed-off-by: Sebastian Andrzej Siewior <[e-mail]>
---
 kernel/static_call_inline.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

Patch

diff --git a/kernel/static_call_inline.c b/kernel/static_call_inline.c
index bb7d066a7c397..c2c59e6ef35d0 100644
--- a/kernel/static_call_inline.c
+++ b/kernel/static_call_inline.c
@@ -325,13 +325,12 @@  static int __static_call_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;