diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-28 17:01:43 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-02-28 23:08:37 +0300 |
| commit | e955376277839db92774ec24d559ab42442b95fc (patch) | |
| tree | 9d3738f3acf1bb233d3f99113841990e643ca8fa /include/net/af_unix.h | |
| parent | 749db093040788ff474937d2452d4cf0176b5a1f (diff) | |
| download | linux-e955376277839db92774ec24d559ab42442b95fc.tar.xz | |
af_unix: 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/af_unix.h')
| -rw-r--r-- | include/net/af_unix.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/net/af_unix.h b/include/net/af_unix.h index 17e10fba2152..e51d727cc3cd 100644 --- a/include/net/af_unix.h +++ b/include/net/af_unix.h @@ -27,7 +27,7 @@ struct unix_address { refcount_t refcnt; int len; unsigned int hash; - struct sockaddr_un name[0]; + struct sockaddr_un name[]; }; struct unix_skb_parms { |