From 6736041f9606f195339cacb4bcce232f1a2a1ed3 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Tue, 11 Feb 2020 15:08:22 -0600 Subject: [PATCH] mei: bus: replace zero-length array with flexible-array member 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 Link: https://lore.kernel.org/r/20200211210822.GA31368@embeddedor Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mei/bus-fixup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/misc/mei/bus-fixup.c b/drivers/misc/mei/bus-fixup.c index 9ad9c01ddf41..910f059b3384 100644 --- a/drivers/misc/mei/bus-fixup.c +++ b/drivers/misc/mei/bus-fixup.c @@ -91,7 +91,7 @@ struct mkhi_rule_id { struct mkhi_fwcaps { struct mkhi_rule_id id; u8 len; - u8 data[0]; + u8 data[]; } __packed; struct mkhi_fw_ver_block { @@ -119,7 +119,7 @@ struct mkhi_msg_hdr { struct mkhi_msg { struct mkhi_msg_hdr hdr; - u8 data[0]; + u8 data[]; } __packed; #define MKHI_OSVER_BUF_LEN (sizeof(struct mkhi_msg_hdr) + \ -- 2.20.1