On Thu, Mar 05, 2020 at 09:30:41PM +0300, Slawa Olhovchenkov wrote: S> > > On Thu, Mar 05, 2020 at 08:35:15PM +0300, Slawa Olhovchenkov wrote: S> > > S> > > D> sbin/mount_nfs/mount_nfs.c:549:10: error: cast from 'char *' to 'struct S> > > S> > > D> if_msghdr *' increases required alignment from 1 to 4 S> > > S> > > D> [-Werror,-Wcast-align] S> > > S> > > D> ifm = (struct if_msghdr *)buf; S> > > S> > > D> ^~~~~~~~~~~~~~~~~~~~~~~ S> > > S> > > D> 1 error generated. S> > > S> > > D> S> > > S> > > D> In practice I don't think the buffer can ever get misaligned, so can you S> > > S> > > D> please add a NO_WCAST_ALIGN= to the Makefile? S> > > S> > > S> > > S> > > route(8) handles the same problem via intermediate (void *) cast. What is S> > > S> > > preferred way to solve the problem? Change compiler flags file wide, or S> > > S> > > just through (void *) cast? S> > > S> > S> > > S> > Copy to aligned buffer or got SIGBUS on some architectures? S> > > S> S> > > S> char buf[2048] __aligned(__alignof(struct if_msghdr)); S> > > S> S> > > S> resolve this watning. S> > > S> > > Thanks, Slawa! I think this is the most elegant solution. S> > S> > Why don't just declare the buffer as: S> > S> > struct if_msghdr buf; S> > S> > and then do: S> > S> > nread = read(s, &buf, sizeof buf); S> > S> > ? You are never reading more than one if_msghdr anyway, and then there S> > is no need to cast anything. S> S> My inspiration: route socket can return other messages (man 4 route)
Yes, exactly. We don't know what size next datagram is going to be. -- Gleb Smirnoff _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
