svn commit: r302613 - head/sys/kern

[Konstantin Belousov]

Author: kib
Date: Tue Jul 12 03:52:05 2016
New Revision: 302613
URL: https://svnweb.freebsd.org/changeset/base/302613

Log:
  Add assert to complement r302328.
  
  AST must not execute with TDF_SBDRY or TDF_SEINTR/TDF_SERESTART thread
  flags set, which is asserted in userret(). As the consequence, -1 return
  from cursig() must not be possible.
  
  Tested by:	pho
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week

Modified:
  head/sys/kern/subr_trap.c

Modified: head/sys/kern/subr_trap.c
==============================================================================
--- head/sys/kern/subr_trap.c	Tue Jul 12 03:38:29 2016	(r302612)
+++ head/sys/kern/subr_trap.c	Tue Jul 12 03:52:05 2016	(r302613)
@@ -274,8 +274,10 @@ ast(struct trapframe *framep)
 	    !SIGISEMPTY(p->p_siglist)) {
 		PROC_LOCK(p);
 		mtx_lock(&p->p_sigacts->ps_mtx);
-		while ((sig = cursig(td)) != 0)
+		while ((sig = cursig(td)) != 0) {
+			KASSERT(sig >= 0, ("sig %d", sig));
 			postsig(sig);
+		}
 		mtx_unlock(&p->p_sigacts->ps_mtx);
 		PROC_UNLOCK(p);
 	}