svn commit: r258890 - stable/10/sys/netinet

[Michael Tuexen]

Author: tuexen
Date: Tue Dec  3 20:55:37 2013
New Revision: 258890
URL: http://svnweb.freebsd.org/changeset/base/258890

Log:
  MFC r258574:
  
  Only initialize some mutexes for the default VNET.
  
  In r208160, sctp_it_ctl was made a global variable, across all VNETs.
  However, sctp_init() is called for every VNET that is created.  This results
  in the same global mutexes which are part of sctp_it_ctl being initialized.  This can result
  in crashes if many jails are created.
  
  To reproduce the problem:
    (1)  Take a GENERIC kernel config, and add options for: VIMAGE, WITNESS,
         INVARIANTS.
    (2)  Run this command in a loop:
         jail -l -u root -c path=/ name=foo persist vnet && jexec foo ifconfig lo0 127.0.0.1/8 && jail -r foo
  
         (see http://lists.freebsd.org/pipermail/freebsd-current/2010-November/021280.html )
  
  Witness will warn about the same mutex being initialized.
  
  Fix the problem by only initializing these mutexes in the default VNET.
  
  MFC r258765:
  
  In
  http://svnweb.freebsd.org/changeset/base/258221
  I introduced a bug which initialized global locks
  whenever the SCTP stack initialized. This was fixed in
  http://svnweb.freebsd.org/changeset/base/258574
  by rodrigc at . He just initialized the locks for
  the default vnet. This fix reverts to the old
  behaviour before r258221, which explicitly makes
  sure it is only called once, because this works also on
  other platforms.
  
  Approved by: re@ (gjb)

Modified:
  stable/10/sys/netinet/sctp_bsd_addr.c
  stable/10/sys/netinet/sctp_pcb.c
Directory Properties:
  stable/10/sys/   (props changed)

Modified: stable/10/sys/netinet/sctp_bsd_addr.c
==============================================================================
--- stable/10/sys/netinet/sctp_bsd_addr.c	Tue Dec  3 20:06:58 2013	(r258889)
+++ stable/10/sys/netinet/sctp_bsd_addr.c	Tue Dec  3 20:55:37 2013	(r258890)
@@ -100,6 +100,9 @@ sctp_startup_iterator(void)
 		/* You only get one */
 		return;
 	}
+	/* Initialize global locks here, thus only once. */
+	SCTP_ITERATOR_LOCK_INIT();
+	SCTP_IPI_ITERATOR_WQ_INIT();
 	TAILQ_INIT(&sctp_it_ctl.iteratorhead);
 	kproc_create(sctp_iterator_thread,
 	    (void *)NULL,

Modified: stable/10/sys/netinet/sctp_pcb.c
==============================================================================
--- stable/10/sys/netinet/sctp_pcb.c	Tue Dec  3 20:06:58 2013	(r258889)
+++ stable/10/sys/netinet/sctp_pcb.c	Tue Dec  3 20:55:37 2013	(r258890)
@@ -5864,8 +5864,6 @@ sctp_pcb_init()
 	for (i = 0; i < SCTP_STACK_VTAG_HASH_SIZE; i++) {
 		LIST_INIT(&SCTP_BASE_INFO(vtag_timewait)[i]);
 	}
-	SCTP_ITERATOR_LOCK_INIT();
-	SCTP_IPI_ITERATOR_WQ_INIT();
 	sctp_startup_iterator();
 
 #if defined(__FreeBSD__) && defined(SCTP_MCORE_INPUT) && defined(SMP)