[PATCH printk v2 26/38] kdb: use srcu console list iterator

John Ogness
2022-10-19T15:07:08Z

Guarantee safe iteration of the console list by using SRCU.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
kernel/debug/kdb/kdb_io.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 550fe8b456ec..5c0bd93c3574 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -545,6 +545,7 @@ static void kdb_msg_write(const char *msg, int msg_len)
{
struct console *c;
const char *cp;
+ int cookie;
int len;

if (msg_len == 0)
@@ -558,7 +559,8 @@ static void kdb_msg_write(const char *msg, int msg_len)
cp++;
}

- for_each_console(c) {
+ cookie = console_srcu_read_lock();
+ for_each_console_srcu(c) {
if (!console_is_enabled(c))
continue;
if (c == dbg_io_ops->cons)
@@ -577,6 +579,7 @@ static void kdb_msg_write(const char *msg, int msg_len)
--oops_in_progress;
touch_nmi_watchdog();
}
+ console_srcu_read_unlock(cookie);
}

int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
--
2.30.2