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 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/lib/objagg.c b/lib/objagg.c
index 55621fb..5e1676c 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)