[src/netbsd-1-5]: src/sys/kern Pull up revision 1.67 (via patch, requested by...

[he <he%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/73fb1fdb825d
branches:  netbsd-1-5
changeset: 493128:73fb1fdb825d
user:      he <he%NetBSD.org@localhost>
date:      Wed Jun 12 20:41:45 2002 +0000

description:
Pull up revision 1.67 (via patch, requested by he):
  Make sure to preserve atomicity of receive operation when instructed
  to do so.  Make sure to drop rest of partial record if an error
  occurs.  Fixes PR#16990.

diffstat:

 sys/kern/uipc_socket.c |  23 +++++++++++++++++++++--
 1 files changed, 21 insertions(+), 2 deletions(-)

diffs (59 lines):

diff -r 6edae4841253 -r 73fb1fdb825d sys/kern/uipc_socket.c
--- a/sys/kern/uipc_socket.c    Thu Jun 06 22:00:07 2002 +0000
+++ b/sys/kern/uipc_socket.c    Wed Jun 12 20:41:45 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uipc_socket.c,v 1.50.4.3 2001/10/08 19:47:51 he Exp $  */
+/*     $NetBSD: uipc_socket.c,v 1.50.4.4 2002/06/12 20:41:45 he Exp $  */
 
 /*
  * Copyright (c) 1982, 1986, 1988, 1990, 1993
@@ -569,6 +569,7 @@
        struct mbuf *nextrecord;
        int moff, type = 0;
        int orig_resid = uio->uio_resid;
+       int mbuf_removed = 0;
 
        mp = mp0;
        if (paddr)
@@ -683,6 +684,7 @@
                        m = m->m_next;
                } else {
                        sbfree(&so->so_rcv, m);
+                       mbuf_removed = 1;
                        if (paddr) {
                                *paddr = m;
                                so->so_rcv.sb_mb = m->m_next;
@@ -701,6 +703,7 @@
                        m = m->m_next;
                } else {
                        sbfree(&so->so_rcv, m);
+                       mbuf_removed = 1;
                        if (controlp) {
                                if (pr->pr_domain->dom_externalize &&
                                    mtod(m, struct cmsghdr *)->cmsg_type ==
@@ -757,8 +760,24 @@
                        splx(s);
                        error = uiomove(mtod(m, caddr_t) + moff, (int)len, uio);
                        s = splsoftnet();
-                       if (error)
+                       if (error) {
+                               /*
+                                * If any part of the record has been removed
+                                * (such as the MT_SONAME mbuf, which will
+                                * happen when PR_ADDR, and thus also
+                                * PR_ATOMIC, is set), then drop the entire
+                                * record to maintain the atomicity of the
+                                * receive operation.
+                                *
+                                * This avoids a later panic("receive 1a")
+                                * when compiled with DIAGNOSTIC.
+                                */
+                               if (m && mbuf_removed
+                                   && (pr->pr_flags & PR_ATOMIC))
+                                       (void) sbdroprecord(&so->so_rcv);
+
                                goto release;
+                       }
                } else
                        uio->uio_resid -= len;
                if (len == m->m_len - moff) {