diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-02 06:02:09 -0600 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-03-02 11:16:28 -0800 |
| commit | 1776658da830eb024b63ac34167dfd4bd6c21cf9 (patch) | |
| tree | ab2c9b7ac55de5e8377e492f2a87bf60036f69cc /include | |
| parent | 2e83abdcb30e3881e9569fd8f4a600beef6cfadc (diff) | |
drop_monitor: 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 <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/uapi/linux/net_dropmon.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/uapi/linux/net_dropmon.h b/include/uapi/linux/net_dropmon.h index 66048cc5d7b3..67e31f329190 100644 --- a/include/uapi/linux/net_dropmon.h +++ b/include/uapi/linux/net_dropmon.h @@ -29,12 +29,12 @@ struct net_dm_config_entry { struct net_dm_config_msg { __u32 entries; - struct net_dm_config_entry options[0]; + struct net_dm_config_entry options[]; }; struct net_dm_alert_msg { __u32 entries; - struct net_dm_drop_point points[0]; + struct net_dm_drop_point points[]; }; struct net_dm_user_msg { |