kmsg-console-cont-flush-merge.patch

---
 kernel/printk.c |   31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -231,6 +231,11 @@ static u32 log_first_idx;
 static u64 log_next_seq;
 static u32 log_next_idx;
 
+/* the next printk record to write to the console */
+static u64 console_seq;
+static u32 console_idx;
+static enum log_flags console_prev;
+
 /* the next printk record to read after the last 'clear' command */
 static u64 clear_seq;
 static u32 clear_idx;
@@ -480,9 +485,9 @@ static ssize_t devkmsg_read(struct file
 		 ((user->prev & LOG_CONT) && !(msg->flags & LOG_PREFIX)))
 		cont = '+';
 
-	len = sprintf(user->buf, "%u,%llu,%llu,%c;",
+	len = sprintf(user->buf, "%u,%llu,%llu,%c,XXX%u;",
 		      (msg->facility << 3) | msg->level,
-		      user->seq, ts_usec, cont);
+		      user->seq, ts_usec, cont, msg->flags);
 	user->prev = msg->flags;
 
 	/* escape non-printable characters */
@@ -1386,6 +1391,7 @@ static struct cont {
 	u64 ts_nsec;			/* time of first print */
 	u8 level;			/* log level of first message */
 	u8 facility;			/* log level of first message */
+	enum log_flags flags;		/* prefix, newline flags */
 	bool flushed:1;			/* buffer sealed and committed */
 } cont;
 
@@ -1404,6 +1410,7 @@ static void cont_flush(enum log_flags fl
 		 */
 		log_store(cont.facility, cont.level, flags | LOG_NOCONS,
 			  cont.ts_nsec, NULL, 0, cont.buf, cont.len);
+		cont.flags = flags;
 		cont.flushed = true;
 	} else {
 		/*
@@ -1432,6 +1439,7 @@ static bool cont_add(int facility, int l
 		cont.level = level;
 		cont.owner = current;
 		cont.ts_nsec = local_clock();
+		cont.flags = 0;
 		cont.cons = 0;
 		cont.flushed = false;
 	}
@@ -1446,7 +1454,7 @@ static size_t cont_print_text(char *text
 	size_t textlen = 0;
 	size_t len;
 
-	if (cont.cons == 0) {
+	if (cont.cons == 0 && (console_prev & LOG_NEWLINE)) {
 		textlen += print_time(cont.ts_nsec, text);
 		size -= textlen;
 	}
@@ -1461,7 +1469,8 @@ static size_t cont_print_text(char *text
 	}
 
 	if (cont.flushed) {
-		text[textlen++] = '\n';
+		if (cont.flags & LOG_NEWLINE)
+			text[textlen++] = '\n';
 		/* got everything, release buffer */
 		cont.len = 0;
 	}
@@ -1559,7 +1568,7 @@ asmlinkage int vprintk_emit(int facility
 		 * or another task also prints continuation lines.
 		 */
 		if (cont.len && (lflags & LOG_PREFIX || cont.owner != current))
-			cont_flush(0);
+			cont_flush(LOG_NEWLINE);
 
 		/* buffer line if possible, otherwise store it right away */
 		if (!cont_add(facility, level, text, text_len))
@@ -1577,7 +1586,7 @@ asmlinkage int vprintk_emit(int facility
 		if (cont.len && cont.owner == current) {
 			if (!(lflags & LOG_PREFIX))
 				stored = cont_add(facility, level, text, text_len);
-			cont_flush(0);
+			cont_flush(LOG_NEWLINE);
 		}
 
 		if (!stored)
@@ -1679,6 +1688,7 @@ static enum log_flags syslog_prev;
 static u64 log_first_seq;
 static u32 log_first_idx;
 static u64 log_next_seq;
+static enum log_flags console_prev;
 static struct cont {
 	size_t len;
 	size_t cons;
@@ -1962,11 +1972,6 @@ void wake_up_klogd(void)
 		this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
 }
 
-/* the next printk record to write to the console */
-static u64 console_seq;
-static u32 console_idx;
-static enum log_flags console_prev;
-
 /**
  * console_unlock - unlock the console system
  *
@@ -1998,7 +2003,8 @@ void console_unlock(void)
 
 	/* flush buffered message fragment immediately to console */
 	raw_spin_lock_irqsave(&logbuf_lock, flags);
-	if (cont.len && (cont.cons < cont.len || cont.flushed)) {
+	if ((console_seq == log_next_seq && cont.len && (cont.cons < cont.len || cont.flushed)) ||
+	    (cont.len && cont.cons)) {
 		size_t len;
 
 		len = cont_print_text(text, sizeof(text));
@@ -2046,6 +2052,7 @@ skip:
 			 * will properly dump everything later.
 			 */
 			msg->flags &= ~LOG_NOCONS;
+			console_prev = msg->flags;
 			goto skip;
 		}