From b45e577dbf040f40d37c9c915b7cec011c90af08 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Tue, 11 Feb 2020 14:53:56 -0600 Subject: [PATCH] lib: objagg: Replace zero-length arrays 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 4287773bdd7a ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- lib/objagg.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/objagg.c b/lib/objagg.c index 55621fb82e0a3..5e1676ccdaddd 100644 --- a/lib/objagg.c +++ b/lib/objagg.c @@ -28,7 +28,7 @@ struct objagg_hints_node { struct objagg_hints_node *parent; unsigned int root_id; struct objagg_obj_stats_info stats_info; - unsigned long obj[0]; + unsigned long obj[]; }; static struct objagg_hints_node * @@ -66,7 +66,7 @@ struct objagg_obj { * including nested objects */ struct objagg_obj_stats stats; - unsigned long obj[0]; + unsigned long obj[]; }; static unsigned int objagg_obj_ref_inc(struct objagg_obj *objagg_obj) -- 2.39.5