| Message ID | 20200211232148.GA20644@embeddedor (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 6a9746fb0b1bf79777b709dd9f045ded89c6b373 |
| Headers | show |
| Series | USB: atm: Replace zero-length array with flexible-array member | expand |
diff --git a/drivers/usb/atm/ueagle-atm.c b/drivers/usb/atm/ueagle-atm.c index 2754b4ce7136..25cf94131987 100644 --- a/drivers/usb/atm/ueagle-atm.c +++ b/drivers/usb/atm/ueagle-atm.c @@ -394,7 +394,7 @@ struct l1_code { u8 string_header[E4_L1_STRING_HEADER]; u8 page_number_to_block_index[E4_MAX_PAGE_NUMBER]; struct block_index page_header[E4_NO_SWAPPAGE_HEADERS]; - u8 code[0]; + u8 code[]; } __packed; /* structures describing a block within a DSP page */
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 <gustavo@embeddedor.com> --- drivers/usb/atm/ueagle-atm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)