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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Stephen Rothwell <sfr@canb.auug.org.au>,
        Kees Cook <keescook@chromium.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        "Steven Rostedt (Google)" <rostedt@goodmis.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 740/779] tracing: Avoid -Warray-bounds warning for __rel_loc macro
Date:   Mon, 15 Aug 2022 20:06:24 +0200
Message-Id: <20220815180409.073906833@linuxfoundation.org>
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From: Masami Hiramatsu <mhiramat@kernel.org>

[ Upstream commit 58c5724ec2cdd72b22107ec5de00d90cc4797796 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/trace/trace_events.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 8c6f7c433518..65d927e059d3 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
-- 
2.35.1