diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index c55cd1820689..c7239d169bbe 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -736,9 +736,9 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
 		logbuf_lock_irq();
 	}
 
-	if (user->seq < prb_first_valid_seq(prb)) {
+	if (r->info->seq != user->seq) {
 		/* our last seen message is gone, return error and reset */
-		user->seq = prb_first_valid_seq(prb);
+		user->seq = r->info->seq;
 		ret = -EPIPE;
 		logbuf_unlock_irq();
 		goto out;
@@ -813,6 +813,7 @@ static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
 static __poll_t devkmsg_poll(struct file *file, poll_table *wait)
 {
 	struct devkmsg_user *user = file->private_data;
+	struct printk_info info;
 	__poll_t ret = 0;
 
 	if (!user)
@@ -821,9 +822,9 @@ static __poll_t devkmsg_poll(struct file *file, poll_table *wait)
 	poll_wait(file, &log_wait, wait);
 
 	logbuf_lock_irq();
-	if (prb_read_valid(prb, user->seq, NULL)) {
+	if (prb_read_valid_info(prb, user->seq, &info, NULL)) {
 		/* return error when data has vanished underneath us */
-		if (user->seq < prb_first_valid_seq(prb))
+		if (info.seq != user->seq)
 			ret = EPOLLIN|EPOLLRDNORM|EPOLLERR|EPOLLPRI;
 		else
 			ret = EPOLLIN|EPOLLRDNORM;
@@ -1560,6 +1561,7 @@ static void syslog_clear(void)
 
 int do_syslog(int type, char __user *buf, int len, int source)
 {
+	struct printk_info info;
 	bool clear = false;
 	static int saved_console_loglevel = LOGLEVEL_DEFAULT;
 	int error;
@@ -1630,9 +1632,14 @@ int do_syslog(int type, char __user *buf, int len, int source)
 	/* Number of chars in the log buffer */
 	case SYSLOG_ACTION_SIZE_UNREAD:
 		logbuf_lock_irq();
-		if (syslog_seq < prb_first_valid_seq(prb)) {
+		if (!prb_read_valid_info(prb, syslog_seq, &info, NULL)) {
+			/* No unread messages. */
+			logbuf_unlock_irq();
+			return 0;
+		}
+		if (info.seq != syslog_seq) {
 			/* messages are gone, move to first one */
-			syslog_seq = prb_first_valid_seq(prb);
+			syslog_seq = info.seq;
 			syslog_partial = 0;
 		}
 		if (source == SYSLOG_FROM_PROC) {
@@ -1644,7 +1651,6 @@ int do_syslog(int type, char __user *buf, int len, int source)
 			error = prb_next_seq(prb) - syslog_seq;
 		} else {
 			bool time = syslog_partial ? syslog_time : printk_time;
-			struct printk_info info;
 			unsigned int line_count;
 			u64 seq;
 
@@ -3425,9 +3431,11 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 		goto out;
 
 	logbuf_lock_irqsave(flags);
-	if (dumper->cur_seq < prb_first_valid_seq(prb)) {
-		/* messages are gone, move to first available one */
-		dumper->cur_seq = prb_first_valid_seq(prb);
+	if (prb_read_valid_info(prb, dumper->cur_seq, &info, NULL)) {
+		if (info.seq != dumper->cur_seq) {
+			/* messages are gone, move to first available one */
+			dumper->cur_seq = info.seq;
+		}
 	}
 
 	/* last entry */