Reset to 3.12.19

1 files changed, 28 insertions, 120 deletions

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 0a63f7b..c59896c 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1029,7 +1029,6 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 {
 	char *text;
 	int len = 0;
-	int attempts = 0;
 
 	text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
 	if (!text)
@@ -1041,14 +1040,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		u64 seq;
 		u32 idx;
 		enum log_flags prev;
-		int num_msg;
-try_again:
-		attempts++;
-		if (attempts > 10) {
-			len = -EBUSY;
-			goto out;
-		}
-		num_msg = 0;
+
 		if (clear_seq < log_first_seq) {
 			/* messages are gone, move to first available one */
 			clear_seq = log_first_seq;
@@ -1069,14 +1061,6 @@ try_again:
 			prev = msg->flags;
 			idx = log_next(idx);
 			seq++;
-			num_msg++;
-			if (num_msg > 5) {
-				num_msg = 0;
-				raw_spin_unlock_irq(&logbuf_lock);
-				raw_spin_lock_irq(&logbuf_lock);
-				if (clear_seq < log_first_seq)
-					goto try_again;
-			}
 		}
 
 		/* move first record forward until length fits into the buffer */
@@ -1090,21 +1074,12 @@ try_again:
 			prev = msg->flags;
 			idx = log_next(idx);
 			seq++;
-			num_msg++;
-			if (num_msg > 5) {
-				num_msg = 0;
-				raw_spin_unlock_irq(&logbuf_lock);
-				raw_spin_lock_irq(&logbuf_lock);
-				if (clear_seq < log_first_seq)
-					goto try_again;
-			}
 		}
 
 		/* last message fitting into this dump */
 		next_seq = log_next_seq;
 
 		len = 0;
-		prev = 0;
 		while (len >= 0 && seq < next_seq) {
 			struct printk_log *msg = log_from_idx(idx);
 			int textlen;
@@ -1139,7 +1114,6 @@ try_again:
 		clear_seq = log_next_seq;
 		clear_idx = log_next_idx;
 	}
-out:
 	raw_spin_unlock_irq(&logbuf_lock);
 
 	kfree(text);
@@ -1297,7 +1271,6 @@ static void call_console_drivers(int level, const char *text, size_t len)
 	if (!console_drivers)
 		return;
 
-	migrate_disable();
 	for_each_console(con) {
 		if (exclusive_console && con != exclusive_console)
 			continue;
@@ -1310,7 +1283,6 @@ static void call_console_drivers(int level, const char *text, size_t len)
 			continue;
 		con->write(con, text, len);
 	}
-	migrate_enable();
 }
 
 /*
@@ -1370,18 +1342,12 @@ static inline int can_use_console(unsigned int cpu)
  * interrupts disabled. It should return with 'lockbuf_lock'
  * released but interrupts still disabled.
  */
-static int console_trylock_for_printk(unsigned int cpu, unsigned long flags)
+static int console_trylock_for_printk(unsigned int cpu)
 	__releases(&logbuf_lock)
 {
 	int retval = 0, wake = 0;
-#ifdef CONFIG_PREEMPT_RT_FULL
-	int lock = !early_boot_irqs_disabled && !irqs_disabled_flags(flags) &&
-		(preempt_count() <= 1);
-#else
-	int lock = 1;
-#endif
 
-	if (lock && console_trylock()) {
+	if (console_trylock()) {
 		retval = 1;
 
 		/*
@@ -1521,62 +1487,6 @@ static size_t cont_print_text(char *text, size_t size)
 	return textlen;
 }
 
-#ifdef CONFIG_EARLY_PRINTK
-struct console *early_console;
-
-void early_vprintk(const char *fmt, va_list ap)
-{
-	if (early_console) {
-		char buf[512];
-		int n = vscnprintf(buf, sizeof(buf), fmt, ap);
-
-		early_console->write(early_console, buf, n);
-	}
-}
-
-asmlinkage void early_printk(const char *fmt, ...)
-{
-	va_list ap;
-
-	va_start(ap, fmt);
-	early_vprintk(fmt, ap);
-	va_end(ap);
-}
-
-/*
- * This is independent of any log levels - a global
- * kill switch that turns off all of printk.
- *
- * Used by the NMI watchdog if early-printk is enabled.
- */
-static bool __read_mostly printk_killswitch;
-
-static int __init force_early_printk_setup(char *str)
-{
-	printk_killswitch = true;
-	return 0;
-}
-early_param("force_early_printk", force_early_printk_setup);
-
-void printk_kill(void)
-{
-	printk_killswitch = true;
-}
-
-static int forced_early_printk(const char *fmt, va_list ap)
-{
-	if (!printk_killswitch)
-		return 0;
-	early_vprintk(fmt, ap);
-	return 1;
-}
-#else
-static inline int forced_early_printk(const char *fmt, va_list ap)
-{
-	return 0;
-}
-#endif
-
 asmlinkage int vprintk_emit(int facility, int level,
 			    const char *dict, size_t dictlen,
 			    const char *fmt, va_list args)
@@ -1590,13 +1500,6 @@ asmlinkage int vprintk_emit(int facility, int level,
 	int this_cpu;
 	int printed_len = 0;
 
-	/*
-	 * Fall back to early_printk if a debugging subsystem has
-	 * killed printk output
-	 */
-	if (unlikely(forced_early_printk(fmt, args)))
-		return 1;
-
 	boot_delay_msec(level);
 	printk_delay();
 
@@ -1716,15 +1619,8 @@ asmlinkage int vprintk_emit(int facility, int level,
 	 * The console_trylock_for_printk() function will release 'logbuf_lock'
 	 * regardless of whether it actually gets the console semaphore or not.
 	 */
-	if (console_trylock_for_printk(this_cpu, flags)) {
-#ifndef CONFIG_PREEMPT_RT_FULL
+	if (console_trylock_for_printk(this_cpu))
 		console_unlock();
-#else
-		raw_local_irq_restore(flags);
-		console_unlock();
-		raw_local_irq_save(flags);
-#endif
-	}
 
 	lockdep_on();
 out_restore_irqs:
@@ -1826,6 +1722,29 @@ static size_t cont_print_text(char *text, size_t size) { return 0; }
 
 #endif /* CONFIG_PRINTK */
 
+#ifdef CONFIG_EARLY_PRINTK
+struct console *early_console;
+
+void early_vprintk(const char *fmt, va_list ap)
+{
+	if (early_console) {
+		char buf[512];
+		int n = vscnprintf(buf, sizeof(buf), fmt, ap);
+
+		early_console->write(early_console, buf, n);
+	}
+}
+
+asmlinkage void early_printk(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	early_vprintk(fmt, ap);
+	va_end(ap);
+}
+#endif
+
 static int __add_preferred_console(char *name, int idx, char *options,
 				   char *brl_options)
 {
@@ -2066,16 +1985,11 @@ static void console_cont_flush(char *text, size_t size)
 		goto out;
 
 	len = cont_print_text(text, size);
-#ifndef CONFIG_PREEMPT_RT_FULL
 	raw_spin_unlock(&logbuf_lock);
 	stop_critical_timings();
 	call_console_drivers(cont.level, text, len);
 	start_critical_timings();
 	local_irq_restore(flags);
-#else
-	raw_spin_unlock_irqrestore(&logbuf_lock, flags);
-	call_console_drivers(cont.level, text, len);
-#endif
 	return;
 out:
 	raw_spin_unlock_irqrestore(&logbuf_lock, flags);
@@ -2158,17 +2072,12 @@ skip:
 		console_idx = log_next(console_idx);
 		console_seq++;
 		console_prev = msg->flags;
-
-#ifndef CONFIG_PREEMPT_RT_FULL
 		raw_spin_unlock(&logbuf_lock);
+
 		stop_critical_timings();	/* don't trace print latency */
 		call_console_drivers(level, text, len);
 		start_critical_timings();
 		local_irq_restore(flags);
-#else
-		raw_spin_unlock_irqrestore(&logbuf_lock, flags);
-		call_console_drivers(level, text, len);
-#endif
 	}
 	console_locked = 0;
 	mutex_release(&console_lock_dep_map, 1, _RET_IP_);
@@ -2880,7 +2789,6 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	next_idx = idx;
 
 	l = 0;
-	prev = 0;
 	while (seq < dumper->next_seq) {
 		struct printk_log *msg = log_from_idx(idx);