From 1e6709b352e7432289d6384213d5222f8d8f8fdf Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Fri, 20 Mar 2020 17:12:42 -0500 Subject: pcmcia: cs_internal.h: 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 Signed-off-by: Dominik Brodowski --- drivers/pcmcia/cs_internal.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/pcmcia') diff --git a/drivers/pcmcia/cs_internal.h b/drivers/pcmcia/cs_internal.h index 33c9b6ea7364..fb9b17fa0fb5 100644 --- a/drivers/pcmcia/cs_internal.h +++ b/drivers/pcmcia/cs_internal.h @@ -40,7 +40,7 @@ struct cis_cache_entry { unsigned int addr; unsigned int len; unsigned int attr; - unsigned char cache[0]; + unsigned char cache[]; }; struct pccard_resource_ops { -- cgit