diff options
| -rw-r--r-- | kernel/printk/printk.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 13bc960c7aa5..abdbd3ffb068 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -3561,6 +3561,7 @@ static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progre struct console *c; u64 last_diff = 0; u64 printk_seq; + int cookie; u64 diff; u64 seq; @@ -3571,9 +3572,15 @@ static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progre for (;;) { diff = 0; + /* + * Hold the console_lock to guarantee safe access to + * console->seq and to prevent changes to @console_suspended + * until all consoles have been processed. + */ console_lock(); - for_each_console(c) { + cookie = console_srcu_read_lock(); + for_each_console_srcu(c) { if (con && con != c) continue; if (!console_is_usable(c)) @@ -3582,6 +3589,7 @@ static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progre if (printk_seq < seq) diff += seq - printk_seq; } + console_srcu_read_unlock(cookie); /* * If consoles are suspended, it cannot be expected that they |