USB: serial: ti_usb_3410_5052: 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 inadvertenly introduced[3] to the codebase from now on.

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 <[email protected]>

---
 drivers/usb/serial/ti_usb_3410_5052.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

drivers/usb/serial/ti_usb_3410_5052.c +1 -1

index dd0ad67aa71e..db3ab25d9228 100644
@@ -219,7 +219,7 @@ struct ti_write_data_bytes {
 	u8	bDataCounter;
 	__be16	wBaseAddrHi;
 	__be16	wBaseAddrLo;
-	u8	bData[0];
+	u8	bData[];
 } __packed;
 
 struct ti_read_data_request {

Quoted 10 lines · Gustavo A. R. Silva

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[];
};

Quoted 6 lines

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 inadvertenly introduced[3] to the codebase from now on.

This issue was found with the help of Coccinelle.

Same here, the scripts may need to be updated as you missed a couple of instances:

	$ git grep '\[0\];' drivers/usb/serial
	...
	drivers/usb/serial/io_usbvend.h:        __u8    Data[0];                // Data starts here
	drivers/usb/serial/io_usbvend.h:        __u8    Data[0];                // Download starts here
	...

Could you replace these as well so that is done in one patch per subsystem?