From: Kees Cook keescook@chromium.org
commit c6d777acdf8f62d4ebaef0e5c6cd8fedbd6e8546 upstream.
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.
Link: https://lkml.kernel.org/r/20220125220037.2738923-1-keescook@chromium.org
Cc: Steven Rostedt rostedt@goodmis.org Cc: Masami Hiramatsu mhiramat@kernel.org Fixes: 55de2c0b5610c ("tracing: Add '__rel_loc' using trace event macros") Reported-by: Stephen Rothwell sfr@canb.auug.org.au Signed-off-by: Kees Cook keescook@chromium.org Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/trace/perf.h | 5 +++-- include/trace/trace_events.h | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-)
--- a/include/trace/perf.h +++ b/include/trace/perf.h @@ -23,8 +23,9 @@
#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 --- a/include/trace/trace_events.h +++ b/include/trace/trace_events.h @@ -128,7 +128,7 @@ 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;