ftrace: print continue index fix
An item in the trace buffer that is bigger than one entry may be split
up using the TRACE_CONT entry. This makes it a virtual single entry.
The current code increments the iterator index even while traversing
TRACE_CONT entries, making it look like the iterator is further than
it actually is.
This patch adds code to not increment the iterator index while skipping
over TRACE_CONT entries.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 9639e45..d24101c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1117,9 +1117,8 @@
}
/* Increment the index counter of an iterator by one */
-static void trace_iterator_increment(struct trace_iterator *iter, int cpu)
+static void __trace_iterator_increment(struct trace_iterator *iter, int cpu)
{
- iter->idx++;
iter->next_idx[cpu]++;
iter->next_page_idx[cpu]++;
@@ -1132,6 +1131,12 @@
}
}
+static void trace_iterator_increment(struct trace_iterator *iter, int cpu)
+{
+ iter->idx++;
+ __trace_iterator_increment(iter, cpu);
+}
+
static struct trace_entry *
trace_entry_next(struct trace_array *tr, struct trace_array_cpu *data,
struct trace_iterator *iter, int cpu)
@@ -1153,7 +1158,7 @@
/* find a real entry */
do {
- trace_iterator_increment(iter, cpu);
+ __trace_iterator_increment(iter, cpu);
ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu);
} while (ent && ent->type != TRACE_CONT);
@@ -1187,7 +1192,7 @@
ent = trace_entry_next(tr, data, iter, cpu);
else {
while (ent && ent->type == TRACE_CONT) {
- trace_iterator_increment(iter, cpu);
+ __trace_iterator_increment(iter, cpu);
ent = trace_entry_idx(tr, tr->data[cpu],
iter, cpu);
}
@@ -1566,7 +1571,7 @@
do {
trace_seq_printf(s, "%s", ent->cont.buf);
- trace_iterator_increment(iter, iter->cpu);
+ __trace_iterator_increment(iter, iter->cpu);
ent = trace_entry_idx(tr, data, iter, iter->cpu);
} while (ent && ent->type == TRACE_CONT);
}