diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-27 23:58:44 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-03-01 08:27:02 +0300 |
| commit | b90feaff2a2cbf339069adec4bfd6091cfb44b50 (patch) | |
| tree | 93bd8729ec50413d5a530bb7567abf4302de0fbd /include/net/pkt_sched.h | |
| parent | 9f0ca0c1a50a7de5c71970aa452941199ed210d9 (diff) | |
| download | linux-b90feaff2a2cbf339069adec4bfd6091cfb44b50.tar.xz | |
net: sched: 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/net/pkt_sched.h')
| -rw-r--r-- | include/net/pkt_sched.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h index 6a70845bd9ab..20d2c6419612 100644 --- a/include/net/pkt_sched.h +++ b/include/net/pkt_sched.h @@ -181,7 +181,7 @@ struct tc_taprio_qopt_offload { u64 cycle_time_extension; size_t num_entries; - struct tc_taprio_sched_entry entries[0]; + struct tc_taprio_sched_entry entries[]; }; /* Reference counting */ |