On Sat, Mar 17 2018, Justin Skists wrote: > Fix sparse warning: > > CHECK drivers/staging//lustre/lnet/lnet/acceptor.c > drivers/staging//lustre/lnet/lnet/acceptor.c:243:30: warning: cast to > restricted __le32 > > LNET_PROTO_TCP_MAGIC, as a define, is already CPU byte-ordered when > compared to 'magic', so no need for a cast. > > Signed-off-by: Justin Skists <j.skists@xxxxxxxxx> > --- > drivers/staging/lustre/lnet/lnet/acceptor.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/staging/lustre/lnet/lnet/acceptor.c b/drivers/staging/lustre/lnet/lnet/acceptor.c > index fb478e20e204..13e981781b9a 100644 > --- a/drivers/staging/lustre/lnet/lnet/acceptor.c > +++ b/drivers/staging/lustre/lnet/lnet/acceptor.c > @@ -240,7 +240,7 @@ lnet_accept(struct socket *sock, __u32 magic) > return -EPROTO; > } > > - if (magic == le32_to_cpu(LNET_PROTO_TCP_MAGIC)) > + if (magic == LNET_PROTO_TCP_MAGIC) > str = "'old' socknal/tcpnal"; > else > str = "unrecognised"; This code is almost completely irrelevant (it just choose which error message to use when failing), but we may as well get it right and I cannot see why your change is a fix. "magic" was passed as an argument from lnet_acceptor() to lnet_accept(), and lnet_acceptor() got it by reading bytes off the network with lnet_sock_read(). My knowledge is far from complete, but from what I've seen, lustre sends data in host-byte-order on the sender, and expects the receiver to determine which byte-order that is (often by looking at a "magic" word like this) and do any byte-swap that is necessary. While I agree that LNET_PROTO_TCP_MAGIC is in host-byte-order so calling le32_to_cpu() on it makes no sense, I don't agree that "magic" is also host byte-ordered. I suspect a more correct fix would be to use lnet_accept_magic(magic, LNET_PROTO_TCP_MAGIC) as the condition of the if(). This is consistent with other code that tests magic, and it is consistent with the general understanding that "magic" should be in host-byte-order for the peer which sent the message. Could you resubmit with that change? Thanks, NeilBrown
Attachment:
signature.asc
Description: PGP signature
_______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
