diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-05 05:12:16 -0600 |
|---|---|---|
| committer | Kalle Valo <kvalo@codeaurora.org> | 2020-03-23 19:13:28 +0200 |
| commit | 8622a0e5a499e99aeee4df66eacfb25830c57388 (patch) | |
| tree | 14025c78ab934b548abe1eb41e95254bfd0b6fb1 /drivers/net/wireless/zydas/zd1211rw/zd_usb.h | |
| parent | 232c897eb5ca21fce241f75b98c78f2cb36af00f (diff) | |
zd1211rw: 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: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200305111216.GA24982@embeddedor
Diffstat (limited to 'drivers/net/wireless/zydas/zd1211rw/zd_usb.h')
| -rw-r--r-- | drivers/net/wireless/zydas/zd1211rw/zd_usb.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/net/wireless/zydas/zd1211rw/zd_usb.h b/drivers/net/wireless/zydas/zd1211rw/zd_usb.h index a52ee323a142..8f03b09a602c 100644 --- a/drivers/net/wireless/zydas/zd1211rw/zd_usb.h +++ b/drivers/net/wireless/zydas/zd1211rw/zd_usb.h @@ -69,7 +69,7 @@ enum control_requests { struct usb_req_read_regs { __le16 id; - __le16 addr[0]; + __le16 addr[]; } __packed; struct reg_data { @@ -79,7 +79,7 @@ struct reg_data { struct usb_req_write_regs { __le16 id; - struct reg_data reg_writes[0]; + struct reg_data reg_writes[]; } __packed; enum { @@ -95,7 +95,7 @@ struct usb_req_rfwrite { /* 2: other (default) */ __le16 bits; /* RF2595: 24 */ - __le16 bit_values[0]; + __le16 bit_values[]; /* (ZD_CR203 & ~(RF_IF_LE | RF_CLK | RF_DATA)) | (bit ? RF_DATA : 0) */ } __packed; @@ -118,7 +118,7 @@ struct usb_int_header { struct usb_int_regs { struct usb_int_header hdr; - struct reg_data regs[0]; + struct reg_data regs[]; } __packed; struct usb_int_retry_fail { |