From 5979afa2c4d1c8acce28a176ebe27ea13265626a Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Thu, 20 Feb 2020 07:29:08 -0600 Subject: staging: 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 inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] 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/20200220132908.GA30501@embeddedor Signed-off-by: Greg Kroah-Hartman --- drivers/staging/octeon-usb/octeon-hcd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/staging/octeon-usb') diff --git a/drivers/staging/octeon-usb/octeon-hcd.c b/drivers/staging/octeon-usb/octeon-hcd.c index 582c9187559d..61471a19d4e6 100644 --- a/drivers/staging/octeon-usb/octeon-hcd.c +++ b/drivers/staging/octeon-usb/octeon-hcd.c @@ -406,7 +406,7 @@ struct octeon_hcd { */ struct octeon_temp_buffer { void *orig_buffer; - u8 data[0]; + u8 data[]; }; static inline struct usb_hcd *octeon_to_hcd(struct octeon_hcd *p) -- cgit v1.2.3