From: Masami Hiramatsu <mhiramat@kernel.org>
Date: Tue, 25 Jan 2022 14:19:30 +0000 (+0900)
Subject: tracing: Avoid -Warray-bounds warning for __rel_loc macro
X-Git-Tag: baikal/mips/sdk6.1~6534^2~7
X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=f40a3d11f3b0a55f0f33d0d7d325a08f6db91564;p=kernel.git

tracing: Avoid -Warray-bounds warning for __rel_loc macro

Since -Warray-bounds checks the destination size from the type of given
pointer, __assign_rel_str() macro gets warned because it passes the
pointer to the 'u32' field instead of 'trace_event_raw_*' data structure.
Pass the data address calculated from the 'trace_event_raw_*' instead of
'u32' __rel_loc field.

Link: https://lkml.kernel.org/r/20220125233154.dac280ed36944c0c2fe6f3ac@kernel.org

Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
[ This did not fix the warning, but is still a nice clean up ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---

diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 8c6f7c4335185..65d927e059d31 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -318,9 +318,10 @@ TRACE_MAKE_SYSTEM_STR();
 #define __get_str(field) ((char *)__get_dynamic_array(field))
 
 #undef __get_rel_dynamic_array
-#define __get_rel_dynamic_array(field)	\
-		((void *)(&__entry->__rel_loc_##field) +	\
-		 sizeof(__entry->__rel_loc_##field) +		\
+#define __get_rel_dynamic_array(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