[PATCH printk v2 20/38] um: kmsg_dumper: use srcu console list iterator

John Ogness john.ogness at linutronix.de
Wed Oct 19 07:55:42 PDT 2022


Rather than using the console_lock to guarantee safe console list
traversal, use srcu console list iteration.

Signed-off-by: John Ogness <john.ogness at linutronix.de>
---
 arch/um/kernel/kmsg_dump.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/arch/um/kernel/kmsg_dump.c b/arch/um/kernel/kmsg_dump.c
index 3a3bbbb22090..44a418dec919 100644
--- a/arch/um/kernel/kmsg_dump.c
+++ b/arch/um/kernel/kmsg_dump.c
@@ -16,20 +16,17 @@ static void kmsg_dumper_stdout(struct kmsg_dumper *dumper,
 	struct console *con;
 	unsigned long flags;
 	size_t len = 0;
+	int cookie;
 
 	/* only dump kmsg when no console is available */
-	if (!console_trylock())
-		return;
-
-	for_each_console(con) {
+	cookie = console_srcu_read_lock();
+	for_each_console_srcu(con) {
 		if (strcmp(con->name, "tty") == 0 &&
 		    (console_is_enabled(con) || (con->flags & CON_CONSDEV))) {
 			break;
 		}
 	}
-
-	console_unlock();
-
+	console_srcu_read_unlock(cookie);
 	if (con)
 		return;
 
-- 
2.30.2




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