svn commit: r184216 - head/sys/kern

[David Xu]

Author: davidxu
Date: Fri Oct 24 01:03:31 2008
New Revision: 184216
URL: http://svn.freebsd.org/changeset/base/184216

Log:
  partly revert revision 184199, because TDF_NEEDSIGCHK is persitent
  when thread is in kernel mode, it can cause dead loop, now unlock
  process lock after acquired sleep queue lock and thread lock to
  avoid the problem. This means TDF_NEEDSIGCHK and TDF_NEEDSUSPCHK must
  be set with process lock and thread lock being hold at same time.

Modified:
  head/sys/kern/subr_sleepqueue.c

Modified: head/sys/kern/subr_sleepqueue.c
==============================================================================
--- head/sys/kern/subr_sleepqueue.c	Thu Oct 23 21:50:16 2008	(r184215)
+++ head/sys/kern/subr_sleepqueue.c	Fri Oct 24 01:03:31 2008	(r184216)
@@ -396,7 +396,6 @@ sleepq_catch_signals(void *wchan, int pr
 		return (0);
 	}
 
-catch_sig:
 	thread_unlock(td);
 	mtx_unlock_spin(&sc->sc_lock);
 	CTR3(KTR_PROC, "sleepq catching signals: thread %p (pid %ld, %s)",
@@ -416,19 +415,15 @@ catch_sig:
 			ret = ERESTART;
 		mtx_unlock(&ps->ps_mtx);
 	}
-	PROC_UNLOCK(p);
 
 	mtx_lock_spin(&sc->sc_lock);
 	thread_lock(td);
-	if (ret != 0)
-		goto out;
-	if ((td->td_flags & (TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK)) != 0)
-		goto catch_sig;
-
-	sleepq_switch(wchan, pri);
-	return (0);
+	PROC_UNLOCK(p);
+	if (ret == 0) {
+		sleepq_switch(wchan, pri);
+		return (0);
+	}
 
-out:
 	/*
 	 * There were pending signals and this thread is still
 	 * on the sleep queue, remove it from the sleep queue.