diff options
Diffstat (limited to 'kernel/printk')
| -rw-r--r-- | kernel/printk/printk.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index a06999d55278..ed7f738261cc 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -362,6 +362,34 @@ static int console_msg_format = MSG_FORMAT_DEFAULT; static DEFINE_MUTEX(syslog_lock); #ifdef CONFIG_PRINTK +static atomic_t printk_prefer_direct = ATOMIC_INIT(0); + +/** + * printk_prefer_direct_enter - cause printk() calls to attempt direct + * printing to all enabled consoles + * + * Since it is not possible to call into the console printing code from any + * context, there is no guarantee that direct printing will occur. + * + * This globally effects all printk() callers. + * + * Context: Any context. + */ +void printk_prefer_direct_enter(void) +{ + atomic_inc(&printk_prefer_direct); +} + +/** + * printk_prefer_direct_exit - restore printk() behavior + * + * Context: Any context. + */ +void printk_prefer_direct_exit(void) +{ + WARN_ON(atomic_dec_if_positive(&printk_prefer_direct) < 0); +} + DECLARE_WAIT_QUEUE_HEAD(log_wait); /* All 3 protected by @syslog_lock. */ /* the next printk record to read by syslog(READ) or /proc/kmsg */ |