Hi Greg, thanks for replying. On 03/04/2019 01:26, Greg KH wrote: > On Tue, Apr 02, 2019 at 10:04:05PM -0300, Andre Dainez wrote: >> Fix checkpatch errors: >> >> CHECK: Macro argument 'len' may be better as '(len)' to avoid precedence issues >> CHECK: Macro argument 'nlh' may be better as '(nlh)' to avoid precedence issues >> >> Signed-off-by: Andre Dainez <andredainez@xxxxxxxxx> >> --- >> drivers/staging/gdm724x/netlink_k.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/staging/gdm724x/netlink_k.c b/drivers/staging/gdm724x/netlink_k.c >> index 92440c3..36d88f4 100644 >> --- a/drivers/staging/gdm724x/netlink_k.c >> +++ b/drivers/staging/gdm724x/netlink_k.c >> @@ -19,8 +19,8 @@ static DEFINE_MUTEX(netlink_mutex); >> #define ND_NLMSG_SPACE(len) (NLMSG_SPACE(len) + ND_IFINDEX_LEN) >> #define ND_NLMSG_DATA(nlh) ((void *)((char *)NLMSG_DATA(nlh) + \ >> ND_IFINDEX_LEN)) >> -#define ND_NLMSG_S_LEN(len) (len + ND_IFINDEX_LEN) >> -#define ND_NLMSG_R_LEN(nlh) (nlh->nlmsg_len - ND_IFINDEX_LEN) >> +#define ND_NLMSG_S_LEN(len) ((len) + ND_IFINDEX_LEN) > > This makes sense, but: > >> +#define ND_NLMSG_R_LEN(nlh) ((nlh)->nlmsg_len - ND_IFINDEX_LEN) > > That does not, correct? > Could you please clarify why this doesn't make sense? If, for some reason I calculate by hand the pointer address and call this macro like: ND_NLMSG_R_LEN(nlh + sizeof(*nlh)), then it would expand like nlh + sizeof(*nlh)->nlmsg_len - ND_IFINDEX_LEN which looks wrong in my pov, no? Please, let me know if I misunderstood anything. Thanks _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
