svn commit: r349994 - head/sys/kern

[Konstantin Belousov]

Author: kib
Date: Mon Jul 15 08:38:01 2019
New Revision: 349994
URL: https://svnweb.freebsd.org/changeset/base/349994

Log:
  Correctly check for casueword(9) success in do_set_ceiling().
  
  After r349951, the return code must be checked instead of old == new
  comparision.
  
  Reviewed by:	markj
  Tested by:	pho
  Sponsored by:	The FreeBSD Foundation
  MFC after:	12 days
  Differential revision:	https://reviews.freebsd.org/D20949

Modified:
  head/sys/kern/kern_umtx.c

Modified: head/sys/kern/kern_umtx.c
==============================================================================
--- head/sys/kern/kern_umtx.c	Mon Jul 15 08:21:49 2019	(r349993)
+++ head/sys/kern/kern_umtx.c	Mon Jul 15 08:38:01 2019	(r349994)
@@ -2456,7 +2456,8 @@ do_set_ceiling(struct thread *td, struct umutex *m, ui
 			break;
 		}
 
-		if (owner == UMUTEX_CONTESTED) {
+		if (rv == 0) {
+			MPASS(owner == UMUTEX_CONTESTED);
 			rv = suword32(&m->m_ceilings[0], ceiling);
 			rv1 = suword32(&m->m_owner, UMUTEX_CONTESTED);
 			error = (rv == 0 && rv1 == 0) ? 0: EFAULT;