svn commit: r320124 - head/sys/kern

[Mark Johnston]

Author: markj
Date: Mon Jun 19 21:09:50 2017
New Revision: 320124
URL: https://svnweb.freebsd.org/changeset/base/320124

Log:
  Fix the !TD_IS_IDLETHREAD(curthread) locking assertions.
  
  Most of the lock slowpaths assert that the calling thread isn't an idle
  thread. However, this may not be true if the system has panicked, and in
  some cases the assertion appears before a SCHEDULER_STOPPED() check.
  
  MFC after:	3 days
  Sponsored by:	Dell EMC Isilon

Modified:
  head/sys/kern/kern_mutex.c
  head/sys/kern/kern_rwlock.c
  head/sys/kern/kern_sx.c

Modified: head/sys/kern/kern_mutex.c
==============================================================================
--- head/sys/kern/kern_mutex.c	Mon Jun 19 20:48:00 2017	(r320123)
+++ head/sys/kern/kern_mutex.c	Mon Jun 19 21:09:50 2017	(r320124)
@@ -233,7 +233,8 @@ __mtx_lock_flags(volatile uintptr_t *c, int opts, cons
 
 	m = mtxlock2mtx(c);
 
-	KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
+	KASSERT(kdb_active != 0 || SCHEDULER_STOPPED() ||
+	    !TD_IS_IDLETHREAD(curthread),
 	    ("mtx_lock() by idle thread %p on sleep mutex %s @ %s:%d",
 	    curthread, m->lock_object.lo_name, file, line));
 	KASSERT(m->mtx_lock != MTX_DESTROYED,
@@ -390,7 +391,7 @@ _mtx_trylock_flags_(volatile uintptr_t *c, int opts, c
 
 	m = mtxlock2mtx(c);
 
-	KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
+	KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(td),
 	    ("mtx_trylock() by idle thread %p on sleep mutex %s @ %s:%d",
 	    curthread, m->lock_object.lo_name, file, line));
 	KASSERT(m->mtx_lock != MTX_DESTROYED,

Modified: head/sys/kern/kern_rwlock.c
==============================================================================
--- head/sys/kern/kern_rwlock.c	Mon Jun 19 20:48:00 2017	(r320123)
+++ head/sys/kern/kern_rwlock.c	Mon Jun 19 21:09:50 2017	(r320124)
@@ -269,7 +269,8 @@ _rw_wlock_cookie(volatile uintptr_t *c, const char *fi
 
 	rw = rwlock2rw(c);
 
-	KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
+	KASSERT(kdb_active != 0 || SCHEDULER_STOPPED() ||
+	    !TD_IS_IDLETHREAD(curthread),
 	    ("rw_wlock() by idle thread %p on rwlock %s @ %s:%d",
 	    curthread, rw->lock_object.lo_name, file, line));
 	KASSERT(rw->rw_lock != RW_DESTROYED,
@@ -305,7 +306,7 @@ __rw_try_wlock(volatile uintptr_t *c, const char *file
 
 	rw = rwlock2rw(c);
 
-	KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
+	KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(td),
 	    ("rw_try_wlock() by idle thread %p on rwlock %s @ %s:%d",
 	    curthread, rw->lock_object.lo_name, file, line));
 	KASSERT(rw->rw_lock != RW_DESTROYED,
@@ -615,7 +616,8 @@ __rw_rlock(volatile uintptr_t *c, const char *file, in
 	td = curthread;
 	rw = rwlock2rw(c);
 
-	KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(td),
+	KASSERT(kdb_active != 0 || SCHEDULER_STOPPED_TD(td) ||
+	    !TD_IS_IDLETHREAD(td),
 	    ("rw_rlock() by idle thread %p on rwlock %s @ %s:%d",
 	    td, rw->lock_object.lo_name, file, line));
 	KASSERT(rw->rw_lock != RW_DESTROYED,
@@ -815,7 +817,6 @@ _rw_runlock_cookie(volatile uintptr_t *c, const char *
 
 	TD_LOCKS_DEC(curthread);
 }
-
 
 /*
  * This function is called when we are unable to obtain a write lock on the

Modified: head/sys/kern/kern_sx.c
==============================================================================
--- head/sys/kern/kern_sx.c	Mon Jun 19 20:48:00 2017	(r320123)
+++ head/sys/kern/kern_sx.c	Mon Jun 19 21:09:50 2017	(r320124)
@@ -295,7 +295,8 @@ _sx_xlock(struct sx *sx, int opts, const char *file, i
 	uintptr_t tid, x;
 	int error = 0;
 
-	KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
+	KASSERT(kdb_active != 0 || SCHEDULER_STOPPED() ||
+	    !TD_IS_IDLETHREAD(curthread),
 	    ("sx_xlock() by idle thread %p on sx %s @ %s:%d",
 	    curthread, sx->lock_object.lo_name, file, line));
 	KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
@@ -332,7 +333,7 @@ sx_try_xlock_(struct sx *sx, const char *file, int lin
 	if (SCHEDULER_STOPPED_TD(td))
 		return (1);
 
-	KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
+	KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(td),
 	    ("sx_try_xlock() by idle thread %p on sx %s @ %s:%d",
 	    curthread, sx->lock_object.lo_name, file, line));
 	KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
@@ -1030,7 +1031,8 @@ _sx_slock(struct sx *sx, int opts, const char *file, i
 	uintptr_t x;
 	int error;
 
-	KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
+	KASSERT(kdb_active != 0 || SCHEDULER_STOPPED() ||
+	    !TD_IS_IDLETHREAD(curthread),
 	    ("sx_slock() by idle thread %p on sx %s @ %s:%d",
 	    curthread, sx->lock_object.lo_name, file, line));
 	KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,