[for-next][PATCH 10/19] tracing: Prevent further users of zero size static arrays in trace events

From: Steven Rostedt
Date: Tue May 29 2018 - 11:27:17 EST


From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

A zero size static array has special meaning in the ftrace infrastructure.
Trace events are for recording data in the trace buffers that is normally
difficult to obtain via probes or function tracing. There is no reason for
any trace event to declare a zero size static array.

If one does, BUILD_BUG_ON() will trigger and prevent the kernel from
compiling.

Reviewed-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
include/trace/trace_events.h | 1 +
1 file changed, 1 insertion(+)

diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index bfda803b0a09..4ecdfe2e3580 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -422,6 +422,7 @@ static struct trace_event_functions trace_event_type_funcs_##call = { \
do { \
char *type_str = #type"["__stringify(len)"]"; \
BUILD_BUG_ON(len > MAX_FILTER_STR_VAL); \
+ BUILD_BUG_ON(len <= 0); \
ret = trace_define_field(event_call, type_str, #item, \
offsetof(typeof(field), item), \
sizeof(field.item), \
--
2.17.0