As done for trace_events.h, also fix the __rel_loc macro in perf.h,
which silences the -Warray-bounds warning:
In file included from ./include/linux/string.h:253,
from ./include/linux/bitmap.h:11,
from ./include/linux/cpumask.h:12,
from ./include/linux/mm_types_task.h:14,
from ./include/linux/mm_types.h:5,
from ./include/linux/buildid.h:5,
from ./include/linux/module.h:14,
from samples/trace_events/trace-events-sample.c:2:
In function '__fortify_strcpy',
inlined from 'perf_trace_foo_rel_loc' at samples/trace_events/./trace-events-sample.h:519:1:
./include/linux/fortify-string.h:47:33: warning: '__builtin_strcpy' offset 12 is out of the bounds [
0, 4] [-Warray-bounds]
47 | #define __underlying_strcpy __builtin_strcpy
| ^
./include/linux/fortify-string.h:445:24: note: in expansion of macro '__underlying_strcpy'
445 | return __underlying_strcpy(p, q);
| ^~~~~~~~~~~~~~~~~~~
Also make __data struct member a proper flexible array to avoid future
problems.
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
include/trace/perf.h | 5 +++--
include/trace/trace_events.h | 2 +-
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/include/trace/perf.h b/include/trace/perf.h
index b77d09c70a93..5800d13146c3 100644
--- a/include/trace/perf.h
+++ b/include/trace/perf.h
@@ -26,8 +26,9 @@
#undef __get_rel_dynamic_array
#define __get_rel_dynamic_array(field) \
- ((void *)(&__entry->__rel_loc_##field) + \
- sizeof(__entry->__rel_loc_##field) + \
+ ((void *)__entry + \
+ offsetof(typeof(*__entry), __rel_loc_##field) + \
+ sizeof(__entry->__rel_loc_##field) + \
(__entry->__rel_loc_##field & 0xffff))
#undef __get_rel_dynamic_array_len
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index cefefed18e85..7c86cc541c7a 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -134,7 +134,7 @@ TRACE_MAKE_SYSTEM_STR();
struct trace_event_raw_##name { \
struct trace_entry ent; \
tstruct \
- char __data[0]; \
+ char __data[]; \
}; \
\
static struct trace_event_class event_class_##name;
--
2.30.2
