Merge tag 'trace-v5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing warning fix from Steven Rostedt:
"Make the GCC 9 warning for sub struct memset go away.
GCC 9 now warns about calling memset() on partial structures when it
goes across multiple fields. This adds a helper for the place in
tracing that does this type of clearing of a structure"
* tag 'trace-v5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Silence GCC 9 array bounds warning
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2c92b3d..1c80521 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -8910,12 +8910,8 @@
cnt++;
- /* reset all but tr, trace, and overruns */
- memset(&iter.seq, 0,
- sizeof(struct trace_iterator) -
- offsetof(struct trace_iterator, seq));
+ trace_iterator_reset(&iter);
iter.iter_flags |= TRACE_FILE_LAT_FMT;
- iter.pos = -1;
if (trace_find_next_entry_inc(&iter) != NULL) {
int ret;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 82c70b6..005f086 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1966,4 +1966,22 @@
extern struct trace_iterator *tracepoint_print_iter;
+/*
+ * Reset the state of the trace_iterator so that it can read consumed data.
+ * Normally, the trace_iterator is used for reading the data when it is not
+ * consumed, and must retain state.
+ */
+static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
+{
+ const size_t offset = offsetof(struct trace_iterator, seq);
+
+ /*
+ * Keep gcc from complaining about overwriting more than just one
+ * member in the structure.
+ */
+ memset((char *)iter + offset, 0, sizeof(struct trace_iterator) - offset);
+
+ iter->pos = -1;
+}
+
#endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c
index 6c1ae6b..cca6504 100644
--- a/kernel/trace/trace_kdb.c
+++ b/kernel/trace/trace_kdb.c
@@ -37,12 +37,8 @@
if (skip_entries)
kdb_printf("(skipping %d entries)\n", skip_entries);
- /* reset all but tr, trace, and overruns */
- memset(&iter.seq, 0,
- sizeof(struct trace_iterator) -
- offsetof(struct trace_iterator, seq));
+ trace_iterator_reset(&iter);
iter.iter_flags |= TRACE_FILE_LAT_FMT;
- iter.pos = -1;
if (cpu_file == RING_BUFFER_ALL_CPUS) {
for_each_tracing_cpu(cpu) {
