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Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index f9139dc1262c..88de94da596b 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3812,6 +3812,18 @@ void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
iter->fmt[i] = '\0';
trace_seq_vprintf(&iter->seq, iter->fmt, ap);
+ /*
+ * If iter->seq is full, the above call no longer guarantees
+ * that ap is in sync with fmt processing, and further calls
+ * to va_arg() can return wrong positional arguments.
+ *
+ * Ensure that ap is no longer used in this case.
+ */
+ if (iter->seq.full) {
+ p = "";
+ break;
+ }
+
if (star)
len = va_arg(ap, int);
@@ -6706,9 +6718,7 @@ waitagain:
cnt = PAGE_SIZE - 1;
/* reset all but tr, trace, and overruns */
- memset(&iter->seq, 0,
- sizeof(struct trace_iterator) -
- offsetof(struct trace_iterator, seq));
+ memset_startat(iter, 0, seq);
cpumask_clear(iter->started);
trace_seq_init(&iter->seq);
iter->pos = -1;