| Message ID | 20190830185716.GA10044@embeddedor (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 84b0b66352470e6491c06159735ac916dc69a2ef |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | [next] zd1211rw: zd_usb: Use struct_size() helper | expand |
"Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote: > One of the more common cases of allocation size calculations is finding > the size of a structure that has a zero-sized array at the end, along > with memory for some number of elements for that array. For example: > > struct usb_int_regs { > ... > struct reg_data regs[0]; > } __packed; > > Make use of the struct_size() helper instead of an open-coded version > in order to avoid any potential type mistakes. > > So, replace the following function: > > static int usb_int_regs_length(unsigned int count) > { > return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data); > } > > with: > > struct_size(regs, regs, count) > > This code was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Patch applied to wireless-drivers-next.git, thanks. 84b0b6635247 zd1211rw: zd_usb: Use struct_size() helper
diff --git a/drivers/net/wireless/zydas/zd1211rw/zd_usb.c b/drivers/net/wireless/zydas/zd1211rw/zd_usb.c index 1965cd0fafc4..4e44ea8c652d 100644 --- a/drivers/net/wireless/zydas/zd1211rw/zd_usb.c +++ b/drivers/net/wireless/zydas/zd1211rw/zd_usb.c @@ -1597,11 +1597,6 @@ static int zd_ep_regs_out_msg(struct usb_device *udev, void *data, int len, } } -static int usb_int_regs_length(unsigned int count) -{ - return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data); -} - static void prepare_read_regs_int(struct zd_usb *usb, struct usb_req_read_regs *req, unsigned int count) @@ -1636,10 +1631,10 @@ static bool check_read_regs(struct zd_usb *usb, struct usb_req_read_regs *req, /* The created block size seems to be larger than expected. * However results appear to be correct. */ - if (rr->length < usb_int_regs_length(count)) { + if (rr->length < struct_size(regs, regs, count)) { dev_dbg_f(zd_usb_dev(usb), - "error: actual length %d less than expected %d\n", - rr->length, usb_int_regs_length(count)); + "error: actual length %d less than expected %ld\n", + rr->length, struct_size(regs, regs, count)); return false; }
One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct usb_int_regs { ... struct reg_data regs[0]; } __packed; Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. So, replace the following function: static int usb_int_regs_length(unsigned int count) { return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data); } with: struct_size(regs, regs, count) This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- drivers/net/wireless/zydas/zd1211rw/zd_usb.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-)