From 3b9274ea1c0279b369212ccd440c9d61efdfa562 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Tue, 11 Feb 2020 17:14:21 -0600 Subject: [PATCH] efi/apple-properties: 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/20200211231421.GA15697@embeddedor Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/apple-properties.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/efi/apple-properties.c b/drivers/firmware/efi/apple-properties.c index 5ccf39986a14..084942846f4d 100644 --- a/drivers/firmware/efi/apple-properties.c +++ b/drivers/firmware/efi/apple-properties.c @@ -31,7 +31,7 @@ __setup("dump_apple_properties", dump_properties_enable); struct dev_header { u32 len; u32 prop_count; - struct efi_dev_path path[0]; + struct efi_dev_path path[]; /* * followed by key/value pairs, each key and value preceded by u32 len, * len includes itself, value may be empty (in which case its len is 4) @@ -42,7 +42,7 @@ struct properties_header { u32 len; u32 version; u32 dev_count; - struct dev_header dev_header[0]; + struct dev_header dev_header[]; }; static void __init unmarshal_key_value_pairs(struct dev_header *dev_header,