On Thu, Mar 05, 2020 at 07:19:59PM +0100, Dimitry Andric wrote: > On 5 Mar 2020, at 18:44, Gleb Smirnoff <gleb...@freebsd.org> wrote: > > > > On Thu, Mar 05, 2020 at 08:35:15PM +0300, Slawa Olhovchenkov wrote: > > S> > > D> sbin/mount_nfs/mount_nfs.c:549:10: error: cast from 'char *' to > > 'struct > > S> > > D> if_msghdr *' increases required alignment from 1 to 4 > > S> > > D> [-Werror,-Wcast-align] > > S> > > D> ifm = (struct if_msghdr *)buf; > > S> > > D> ^~~~~~~~~~~~~~~~~~~~~~~ > > S> > > D> 1 error generated. > > S> > > D> > > S> > > D> In practice I don't think the buffer can ever get misaligned, so > > can you > > S> > > D> please add a NO_WCAST_ALIGN= to the Makefile? > > S> > > > > S> > > route(8) handles the same problem via intermediate (void *) cast. > > What is > > S> > > preferred way to solve the problem? Change compiler flags file wide, > > or > > S> > > just through (void *) cast? > > S> > > > S> > Copy to aligned buffer or got SIGBUS on some architectures? > > S> > > S> char buf[2048] __aligned(__alignof(struct if_msghdr)); > > S> > > S> resolve this watning. > > > > Thanks, Slawa! I think this is the most elegant solution. > > Why don't just declare the buffer as: > > struct if_msghdr buf; > > and then do: > > nread = read(s, &buf, sizeof buf); > > ? You are never reading more than one if_msghdr anyway, and then there > is no need to cast anything.
My inspiration: route socket can return other messages (man 4 route) _______________________________________________ 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"
