From 51022f8715bbb365de8521a5b6a2fcf967ee76ca Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Mon, 6 Apr 2020 20:10:06 -0700 Subject: [PATCH] lib/ts_kmp.c: 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 Signed-off-by: Andrew Morton Link: http://lkml.kernel.org/r/20200211205948.GA26459@embeddedor Signed-off-by: Linus Torvalds --- lib/ts_kmp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/ts_kmp.c b/lib/ts_kmp.c index 94617e014b3a..c77a3d537f24 100644 --- a/lib/ts_kmp.c +++ b/lib/ts_kmp.c @@ -36,7 +36,7 @@ struct ts_kmp { u8 * pattern; unsigned int pattern_len; - unsigned int prefix_tbl[0]; + unsigned int prefix_tbl[]; }; static unsigned int kmp_find(struct ts_config *conf, struct ts_state *state)