From 00168b415a60cec7558608efb4fc50f2a73daae2 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Thu, 23 Mar 2023 14:41:16 -0600 Subject: [PATCH] uapi: net: ipv6: Replace fake flex-array with flex-array member MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Zero-length arrays as fake flexible arrays are deprecated and we are moving towards adopting C99 flexible-array members instead. Address the following warning found with GCC-13 and -fstrict-flex-arrays=3 enabled: net/ipv6/exthdrs.c: In function ‘fl6_update_dst’: net/ipv6/exthdrs.c:1393:28: warning: array subscript 0 is outside array bounds of ‘struct in6_addr[0]’ [-Warray-bounds=] 1393 | fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr; | ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from ./include/linux/ipv6.h:5, from ./include/linux/icmpv6.h:6, from net/ipv6/exthdrs.c:27: ./include/uapi/linux/ipv6.h:84:33: note: while referencing ‘addr’ 84 | struct in6_addr addr[0]; | ^~~~ net/ipv6/exthdrs.c: In function ‘ipv6_push_rthdr0.isra’: net/ipv6/exthdrs.c:1125:19: warning: array subscript is outside array bounds of ‘struct in6_addr[0]’ [-Warray-bounds=] 1125 | phdr->addr[hops - 1] = **addr_p; | ~~~~~~~~~~^~~~~~~~~~ ./include/uapi/linux/ipv6.h:84:33: note: while referencing ‘addr’ 84 | struct in6_addr addr[0]; | ^~~~ This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. Link: https://github.com/KSPP/linux/issues/21 Link: https://github.com/KSPP/linux/issues/276 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Signed-off-by: Gustavo A. R. Silva --- include/uapi/linux/ipv6.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h index 53326df..ac56605 100644 --- a/include/uapi/linux/ipv6.h +++ b/include/uapi/linux/ipv6.h @@ -81,7 +81,7 @@ struct ipv6_opt_hdr { struct rt0_hdr { struct ipv6_rt_hdr rt_hdr; __u32 reserved; - struct in6_addr addr[0]; + struct in6_addr addr[]; #define rt0_type rt_hdr.type }; -- 2.7.4