Re: suprious reboot on netbsd-6:i386 with PAE

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

On Thu, Dec 05, 2013 at 11:20:16PM +1100, matthew green wrote:
> breaking binary compat like this is really unacceptable.
> can someone please file a PR about it.  we should not have
> to patch and rebuild apps!

Attached is a patch that seems to solve the problem at mine. Dovecot
works again and kdump does not dumps core anymore. 

I am not sure I did the (nam->m_len > MLEN && !ext) case correctly, though.
And we now report the path length including the trailing zero, I do not
know if it is right or nor.

-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost

Index: sys/kern/uipc_usrreq.c
===================================================================
RCS file: /cvsroot/src/sys/kern/uipc_usrreq.c,v
retrieving revision 1.148
diff -U8 -r1.148 uipc_usrreq.c
--- sys/kern/uipc_usrreq.c      29 Oct 2013 09:53:51 -0000      1.148
+++ sys/kern/uipc_usrreq.c      5 Dec 2013 14:01:58 -0000
@@ -343,27 +343,31 @@
                        if (unp->unp_conn && unp->unp_conn->unp_addr)
                                sun = unp->unp_conn->unp_addr;
                } else {
                        if (unp->unp_addr)
                                sun = unp->unp_addr;
                }
                if (sun == NULL)
                        sun = &sun_noname;
-               nam->m_len = sun->sun_len;
+
+               nam->m_len = sun->sun_len + 1;  /* +1 for trailin \0 */
+
                if (nam->m_len > MLEN && !ext) {
                        sounlock(so);
                        MEXTMALLOC(nam, MAXPATHLEN * 2, M_WAITOK);
                        solock(so);
                        ext = true;
                } else {
                        KASSERT(nam->m_len <= MAXPATHLEN * 2);
                        memcpy(mtod(nam, void *), sun, (size_t)nam->m_len);
                        break;
                }
+
+               mtod(nam, char *)[nam->m_len] = '\0'; /* trailin \0 */
        }
 }
 
 /*ARGSUSED*/
 int
 uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam,
        struct mbuf *control, struct lwp *l)
 {