svn commit: r258574 - head/sys/netinet

[Craig Rodrigues]

Author: rodrigc
Date: Mon Nov 25 18:49:37 2013
New Revision: 258574
URL: http://svnweb.freebsd.org/changeset/base/258574

Log:
  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.

Modified:
  head/sys/netinet/sctp_pcb.c

Modified: head/sys/netinet/sctp_pcb.c
==============================================================================
--- head/sys/netinet/sctp_pcb.c	Mon Nov 25 18:46:08 2013	(r258573)
+++ head/sys/netinet/sctp_pcb.c	Mon Nov 25 18:49:37 2013	(r258574)
@@ -5864,8 +5864,14 @@ 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();
+	/*
+	 * Only initialize non-VNET global mutexes for the
+	 * default instance.
+	 */
+	if (IS_DEFAULT_VNET(curvnet)) {
+		SCTP_ITERATOR_LOCK_INIT();
+		SCTP_IPI_ITERATOR_WQ_INIT();
+	}
 	sctp_startup_iterator();
 
 #if defined(__FreeBSD__) && defined(SCTP_MCORE_INPUT) && defined(SMP)