1 files changed, 78 insertions, 42 deletions

diff --git a/kernel/printk.c b/kernel/printk.c
index 50c33411442d..177fa49357a5 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -194,8 +194,10 @@ static int console_may_schedule;
  */
 
 enum log_flags {
-	LOG_DEFAULT = 0,
-	LOG_NOCONS = 1,		/* already flushed, do not print to console */
+	LOG_NOCONS	= 1,	/* already flushed, do not print to console */
+	LOG_NEWLINE	= 2,	/* text ended with a newline */
+	LOG_PREFIX	= 4,	/* text started with a prefix */
+	LOG_CONT	= 8,	/* text is a fragment of a continuation line */
 };
 
 struct log {
@@ -217,6 +219,7 @@ static DEFINE_RAW_SPINLOCK(logbuf_lock);
 /* the next printk record to read by syslog(READ) or /proc/kmsg */
 static u64 syslog_seq;
 static u32 syslog_idx;
+static enum log_flags syslog_prev;
 static size_t syslog_partial;
 
 /* index and sequence number of the first record stored in the buffer */
@@ -839,13 +842,26 @@ static size_t print_prefix(const struct log *msg, bool syslog, char *buf)
 	return len;
 }
 
-static size_t msg_print_text(const struct log *msg, bool syslog,
-			     char *buf, size_t size)
+static size_t msg_print_text(const struct log *msg, enum log_flags prev,
+			     bool syslog, char *buf, size_t size)
 {
 	const char *text = log_text(msg);
 	size_t text_size = msg->text_len;
+	bool prefix = true;
+	bool newline = true;
 	size_t len = 0;
 
+	if ((prev & LOG_CONT) && !(msg->flags & LOG_PREFIX))
+		prefix = false;
+
+	if (msg->flags & LOG_CONT) {
+		if ((prev & LOG_CONT) && !(prev & LOG_NEWLINE))
+			prefix = false;
+
+		if (!(msg->flags & LOG_NEWLINE))
+			newline = false;
+	}
+
 	do {
 		const char *next = memchr(text, '\n', text_size);
 		size_t text_len;
@@ -863,16 +879,22 @@ static size_t msg_print_text(const struct log *msg, bool syslog,
 			    text_len + 1>= size - len)
 				break;
 
-			len += print_prefix(msg, syslog, buf + len);
+			if (prefix)
+				len += print_prefix(msg, syslog, buf + len);
 			memcpy(buf + len, text, text_len);
 			len += text_len;
-			buf[len++] = '\n';
+			if (next || newline)
+				buf[len++] = '\n';
 		} else {
 			/* SYSLOG_ACTION_* buffer size only calculation */
-			len += print_prefix(msg, syslog, NULL);
-			len += text_len + 1;
+			if (prefix)
+				len += print_prefix(msg, syslog, NULL);
+			len += text_len;
+			if (next || newline)
+				len++;
 		}
 
+		prefix = true;
 		text = next;
 	} while (text);
 
@@ -898,6 +920,7 @@ static int syslog_print(char __user *buf, int size)
 			/* messages are gone, move to first one */
 			syslog_seq = log_first_seq;
 			syslog_idx = log_first_idx;
+			syslog_prev = 0;
 			syslog_partial = 0;
 		}
 		if (syslog_seq == log_next_seq) {
@@ -907,11 +930,12 @@ static int syslog_print(char __user *buf, int size)
 
 		skip = syslog_partial;
 		msg = log_from_idx(syslog_idx);
-		n = msg_print_text(msg, true, text, LOG_LINE_MAX);
+		n = msg_print_text(msg, syslog_prev, true, text, LOG_LINE_MAX);
 		if (n - syslog_partial <= size) {
 			/* message fits into buffer, move forward */
 			syslog_idx = log_next(syslog_idx);
 			syslog_seq++;
+			syslog_prev = msg->flags;
 			n -= syslog_partial;
 			syslog_partial = 0;
 		} else if (!len){
@@ -954,6 +978,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		u64 next_seq;
 		u64 seq;
 		u32 idx;
+		enum log_flags prev;
 
 		if (clear_seq < log_first_seq) {
 			/* messages are gone, move to first available one */
@@ -967,10 +992,11 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		 */
 		seq = clear_seq;
 		idx = clear_idx;
+		prev = 0;
 		while (seq < log_next_seq) {
 			struct log *msg = log_from_idx(idx);
 
-			len += msg_print_text(msg, true, NULL, 0);
+			len += msg_print_text(msg, prev, true, NULL, 0);
 			idx = log_next(idx);
 			seq++;
 		}
@@ -978,10 +1004,11 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		/* move first record forward until length fits into the buffer */
 		seq = clear_seq;
 		idx = clear_idx;
+		prev = 0;
 		while (len > size && seq < log_next_seq) {
 			struct log *msg = log_from_idx(idx);
 
-			len -= msg_print_text(msg, true, NULL, 0);
+			len -= msg_print_text(msg, prev, true, NULL, 0);
 			idx = log_next(idx);
 			seq++;
 		}
@@ -990,17 +1017,19 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		next_seq = log_next_seq;
 
 		len = 0;
+		prev = 0;
 		while (len >= 0 && seq < next_seq) {
 			struct log *msg = log_from_idx(idx);
 			int textlen;
 
-			textlen = msg_print_text(msg, true, text, LOG_LINE_MAX);
+			textlen = msg_print_text(msg, prev, true, text, LOG_LINE_MAX);
 			if (textlen < 0) {
 				len = textlen;
 				break;
 			}
 			idx = log_next(idx);
 			seq++;
+			prev = msg->flags;
 
 			raw_spin_unlock_irq(&logbuf_lock);
 			if (copy_to_user(buf + len, text, textlen))
@@ -1013,6 +1042,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 				/* messages are gone, move to next one */
 				seq = log_first_seq;
 				idx = log_first_idx;
+				prev = 0;
 			}
 		}
 	}
@@ -1117,6 +1147,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
 			/* messages are gone, move to first one */
 			syslog_seq = log_first_seq;
 			syslog_idx = log_first_idx;
+			syslog_prev = 0;
 			syslog_partial = 0;
 		}
 		if (from_file) {
@@ -1127,18 +1158,18 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
 			 */
 			error = log_next_idx - syslog_idx;
 		} else {
-			u64 seq;
-			u32 idx;
+			u64 seq = syslog_seq;
+			u32 idx = syslog_idx;
+			enum log_flags prev = syslog_prev;
 
 			error = 0;
-			seq = syslog_seq;
-			idx = syslog_idx;
 			while (seq < log_next_seq) {
 				struct log *msg = log_from_idx(idx);
 
-				error += msg_print_text(msg, true, NULL, 0);
+				error += msg_print_text(msg, prev, true, NULL, 0);
 				idx = log_next(idx);
 				seq++;
+				prev = msg->flags;
 			}
 			error -= syslog_partial;
 		}
@@ -1408,10 +1439,9 @@ asmlinkage int vprintk_emit(int facility, int level,
 	static char textbuf[LOG_LINE_MAX];
 	char *text = textbuf;
 	size_t text_len;
+	enum log_flags lflags = 0;
 	unsigned long flags;
 	int this_cpu;
-	bool newline = false;
-	bool prefix = false;
 	int printed_len = 0;
 
 	boot_delay_msec();
@@ -1450,7 +1480,7 @@ asmlinkage int vprintk_emit(int facility, int level,
 		recursion_bug = 0;
 		printed_len += strlen(recursion_msg);
 		/* emit KERN_CRIT message */
-		log_store(0, 2, LOG_DEFAULT, 0,
+		log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0,
 			  NULL, 0, recursion_msg, printed_len);
 	}
 
@@ -1463,7 +1493,7 @@ asmlinkage int vprintk_emit(int facility, int level,
 	/* mark and strip a trailing newline */
 	if (text_len && text[text_len-1] == '\n') {
 		text_len--;
-		newline = true;
+		lflags |= LOG_NEWLINE;
 	}
 
 	/* strip syslog prefix and extract log level or control flags */
@@ -1473,7 +1503,7 @@ asmlinkage int vprintk_emit(int facility, int level,
 			if (level == -1)
 				level = text[1] - '0';
 		case 'd':	/* KERN_DEFAULT */
-			prefix = true;
+			lflags |= LOG_PREFIX;
 		case 'c':	/* KERN_CONT */
 			text += 3;
 			text_len -= 3;
@@ -1483,22 +1513,20 @@ asmlinkage int vprintk_emit(int facility, int level,
 	if (level == -1)
 		level = default_message_loglevel;
 
-	if (dict) {
-		prefix = true;
-		newline = true;
-	}
+	if (dict)
+		lflags |= LOG_PREFIX|LOG_NEWLINE;
 
-	if (!newline) {
+	if (!(lflags & LOG_NEWLINE)) {
 		/*
 		 * Flush the conflicting buffer. An earlier newline was missing,
 		 * or another task also prints continuation lines.
 		 */
-		if (cont.len && (prefix || cont.owner != current))
+		if (cont.len && (lflags & LOG_PREFIX || cont.owner != current))
 			cont_flush();
 
 		/* buffer line if possible, otherwise store it right away */
 		if (!cont_add(facility, level, text, text_len))
-			log_store(facility, level, LOG_DEFAULT, 0,
+			log_store(facility, level, lflags | LOG_CONT, 0,
 				  dict, dictlen, text, text_len);
 	} else {
 		bool stored = false;
@@ -1510,13 +1538,13 @@ asmlinkage int vprintk_emit(int facility, int level,
 		 * flush it out and store this line separately.
 		 */
 		if (cont.len && cont.owner == current) {
-			if (!prefix)
+			if (!(lflags & LOG_PREFIX))
 				stored = cont_add(facility, level, text, text_len);
 			cont_flush();
 		}
 
 		if (!stored)
-			log_store(facility, level, LOG_DEFAULT, 0,
+			log_store(facility, level, lflags, 0,
 				  dict, dictlen, text, text_len);
 	}
 	printed_len += text_len;
@@ -1615,8 +1643,8 @@ static struct cont {
 static struct log *log_from_idx(u32 idx) { return NULL; }
 static u32 log_next(u32 idx) { return 0; }
 static void call_console_drivers(int level, const char *text, size_t len) {}
-static size_t msg_print_text(const struct log *msg, bool syslog,
-			     char *buf, size_t size) { return 0; }
+static size_t msg_print_text(const struct log *msg, enum log_flags prev,
+			     bool syslog, char *buf, size_t size) { return 0; }
 static size_t cont_print_text(char *text, size_t size) { return 0; }
 
 #endif /* CONFIG_PRINTK */
@@ -1892,6 +1920,7 @@ void wake_up_klogd(void)
 /* 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
@@ -1952,6 +1981,7 @@ again:
 			/* messages are gone, move to first one */
 			console_seq = log_first_seq;
 			console_idx = log_first_idx;
+			console_prev = 0;
 		}
 skip:
 		if (console_seq == log_next_seq)
@@ -1975,10 +2005,11 @@ skip:
 		}
 
 		level = msg->level;
-		len = msg_print_text(msg, false, text, sizeof(text));
-
+		len = msg_print_text(msg, console_prev, false,
+				     text, sizeof(text));
 		console_idx = log_next(console_idx);
 		console_seq++;
+		console_prev = msg->flags;
 		raw_spin_unlock(&logbuf_lock);
 
 		stop_critical_timings();	/* don't trace print latency */
@@ -2241,6 +2272,7 @@ void register_console(struct console *newcon)
 		raw_spin_lock_irqsave(&logbuf_lock, flags);
 		console_seq = syslog_seq;
 		console_idx = syslog_idx;
+		console_prev = syslog_prev;
 		raw_spin_unlock_irqrestore(&logbuf_lock, flags);
 		/*
 		 * We're about to replay the log buffer.  Only do this to the
@@ -2534,8 +2566,7 @@ bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
 	}
 
 	msg = log_from_idx(dumper->cur_idx);
-	l = msg_print_text(msg, syslog,
-			      line, size);
+	l = msg_print_text(msg, 0, syslog, line, size);
 
 	dumper->cur_idx = log_next(dumper->cur_idx);
 	dumper->cur_seq++;
@@ -2575,6 +2606,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	u32 idx;
 	u64 next_seq;
 	u32 next_idx;
+	enum log_flags prev;
 	size_t l = 0;
 	bool ret = false;
 
@@ -2597,23 +2629,27 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	/* calculate length of entire buffer */
 	seq = dumper->cur_seq;
 	idx = dumper->cur_idx;
+	prev = 0;
 	while (seq < dumper->next_seq) {
 		struct log *msg = log_from_idx(idx);
 
-		l += msg_print_text(msg, true, NULL, 0);
+		l += msg_print_text(msg, prev, true, NULL, 0);
 		idx = log_next(idx);
 		seq++;
+		prev = msg->flags;
 	}
 
 	/* move first record forward until length fits into the buffer */
 	seq = dumper->cur_seq;
 	idx = dumper->cur_idx;
+	prev = 0;
 	while (l > size && seq < dumper->next_seq) {
 		struct log *msg = log_from_idx(idx);
 
-		l -= msg_print_text(msg, true, NULL, 0);
+		l -= msg_print_text(msg, prev, true, NULL, 0);
 		idx = log_next(idx);
 		seq++;
+		prev = msg->flags;
 	}
 
 	/* last message in next interation */
@@ -2621,14 +2657,14 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	next_idx = idx;
 
 	l = 0;
+	prev = 0;
 	while (seq < dumper->next_seq) {
 		struct log *msg = log_from_idx(idx);
 
-		l += msg_print_text(msg, syslog,
-				    buf + l, size - l);
-
+		l += msg_print_text(msg, prev, syslog, buf + l, size - l);
 		idx = log_next(idx);
 		seq++;
+		prev = msg->flags;
 	}
 
 	dumper->next_seq = next_seq;