1 files changed, 19 insertions, 6 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 7d7a07e9b9e9..0aa75be843a0 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4575,20 +4575,33 @@ static size_t
 tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter)
 {
 	size_t count;
+	int save_len;
 	int ret;
 
 	/* Seq buffer is page-sized, exactly what we need. */
 	for (;;) {
-		count = iter->seq.seq.len;
+		save_len = iter->seq.seq.len;
 		ret = print_trace_line(iter);
-		count = iter->seq.seq.len - count;
-		if (rem < count) {
-			rem = 0;
-			iter->seq.seq.len -= count;
+
+		if (trace_seq_has_overflowed(&iter->seq)) {
+			iter->seq.seq.len = save_len;
 			break;
 		}
+
+		/*
+		 * This should not be hit, because it should only
+		 * be set if the iter->seq overflowed. But check it
+		 * anyway to be safe.
+		 */
 		if (ret == TRACE_TYPE_PARTIAL_LINE) {
-			iter->seq.seq.len -= count;
+			iter->seq.seq.len = save_len;
+			break;
+		}
+
+		count = iter->seq.seq.len - save_len;
+		if (rem < count) {
+			rem = 0;
+			iter->seq.seq.len = save_len;
 			break;
 		}