From 681c896ceb411ccd2ce0a88059d86ccf8d7a497e Mon Sep 17 00:00:00 2001
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Date: Tue, 11 Feb 2020 14:05:49 -0600
Subject: [PATCH] ASoC: wm0010: Replace zero-length array with flexible-array member
Git-commit: 681c896ceb411ccd2ce0a88059d86ccf8d7a497e
Patch-mainline: v5.7-rc1
References: jsc#SLE-16518

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertenly introduced[3] to the codebase from now on.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20200211200549.GA12072@embeddedor
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 sound/soc/codecs/wm0010.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/soc/codecs/wm0010.c b/sound/soc/codecs/wm0010.c
index 727d6703c905..fbcee21736e8 100644
--- a/sound/soc/codecs/wm0010.c
+++ b/sound/soc/codecs/wm0010.c
@@ -43,7 +43,7 @@ struct dfw_binrec {
 	u8 command;
 	u32 length:24;
 	u32 address;
-	uint8_t data[0];
+	uint8_t data[];
 } __packed;
 
 struct dfw_inforec {
-- 
2.16.4