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@xxxxxxxxxxxxxx>
---
drivers/net/wireless/admtek/adm8211.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/wireless/admtek/adm8211.h b/drivers/net/wireless/admtek/adm8211.h
index 2c55c629de28..095625ecb8ff 100644
--- a/drivers/net/wireless/admtek/adm8211.h
+++ b/drivers/net/wireless/admtek/adm8211.h
@@ -531,7 +531,7 @@ struct adm8211_eeprom {
u8 lpf_cutoff[14]; /* 0x62 */
u8 lnags_threshold[14]; /* 0x70 */
__le16 checksum; /* 0x7E */
- u8 cis_data[0]; /* 0x80, 384 bytes */
+ u8 cis_data[]; /* 0x80, 384 bytes */
} __packed;
struct adm8211_priv {
--
2.23.0
