Merge tag 'printk-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk

Pull printk updates from Petr Mladek:

 - Help userspace log daemons to catch up with a flood of messages. They
   will get woken after each message even if the console is far behind
   and handled by another process.

 - Flush printk safe buffers safely even when panic() happens in the
   normal context.

 - Fix possible va_list reuse when race happened in printk_safe().

 - Remove %pCr printf format to prevent sleeping in the atomic context.

 - Misc vsprintf code cleanup.

* tag 'printk-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
  printk: drop in_nmi check from printk_safe_flush_on_panic()
  lib/vsprintf: Remove atomic-unsafe support for %pCr
  serial: sh-sci: Stop using printk format %pCr
  thermal: bcm2835: Stop using printk format %pCr
  clk: renesas: cpg-mssr: Stop using printk format %pCr
  printk: fix possible reuse of va_list variable
  printk: wake up klogd in vprintk_emit
  vsprintf: Tweak pF/pf comment
  lib/vsprintf: Mark expected switch fall-through
  lib/vsprintf: Replace space with '_' before crng is ready
  lib/vsprintf: Deduplicate pointer_string()
  lib/vsprintf: Move pointer_string() upper
  lib/vsprintf: Make flag_spec global
  lib/vsprintf: Make strspec global
  lib/vsprintf: Make dec_spec global
  lib/test_printf: Mark big constant with UL

1 files changed, 2 insertions, 12 deletions

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 2f4af216bd6e..247808333ba4 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1908,6 +1908,7 @@ asmlinkage int vprintk_emit(int facility, int level,
 		preempt_enable();
 	}
 
+	wake_up_klogd();
 	return printed_len;
 }
 EXPORT_SYMBOL(vprintk_emit);
@@ -2289,9 +2290,7 @@ void console_unlock(void)
 {
 	static char ext_text[CONSOLE_EXT_LOG_MAX];
 	static char text[LOG_LINE_MAX + PREFIX_MAX];
-	static u64 seen_seq;
 	unsigned long flags;
-	bool wake_klogd = false;
 	bool do_cond_resched, retry;
 
 	if (console_suspended) {
@@ -2335,11 +2334,6 @@ again:
 
 		printk_safe_enter_irqsave(flags);
 		raw_spin_lock(&logbuf_lock);
-		if (seen_seq != log_next_seq) {
-			wake_klogd = true;
-			seen_seq = log_next_seq;
-		}
-
 		if (console_seq < log_first_seq) {
 			len = sprintf(text, "** %u printk messages dropped **\n",
 				      (unsigned)(log_first_seq - console_seq));
@@ -2397,7 +2391,7 @@ skip:
 
 		if (console_lock_spinning_disable_and_check()) {
 			printk_safe_exit_irqrestore(flags);
-			goto out;
+			return;
 		}
 
 		printk_safe_exit_irqrestore(flags);
@@ -2429,10 +2423,6 @@ skip:
 
 	if (retry && console_trylock())
 		goto again;
-
-out:
-	if (wake_klogd)
-		wake_up_klogd();
 }
 EXPORT_SYMBOL(console_unlock);