Author: mjg
Date: Thu Mar 16 07:10:08 2017
New Revision: 315386
URL: https://svnweb.freebsd.org/changeset/base/315386
Log:
MFC r313853,r313859:
locks: remove SCHEDULER_STOPPED checks from primitives for modules
They all fallback to the slow path if necessary and the check is there.
This means a panicked kernel executing code from modules will be able to
succeed doing actual lock/unlock, but this was already the case for core code
which has said primitives inlined.
==
Introduce SCHEDULER_STOPPED_TD for use when the thread pointer was already
read
Sprinkle in few places.
Modified:
stable/11/sys/kern/kern_condvar.c
stable/11/sys/kern/kern_mutex.c
stable/11/sys/kern/kern_rwlock.c
stable/11/sys/kern/kern_sx.c
stable/11/sys/kern/kern_synch.c
stable/11/sys/sys/systm.h
Directory Properties:
stable/11/ (props changed)
Modified: stable/11/sys/kern/kern_condvar.c
==============================================================================
--- stable/11/sys/kern/kern_condvar.c Thu Mar 16 07:09:47 2017
(r315385)
+++ stable/11/sys/kern/kern_condvar.c Thu Mar 16 07:10:08 2017
(r315386)
@@ -122,7 +122,7 @@ _cv_wait(struct cv *cvp, struct lock_obj
"Waiting on \"%s\"", cvp->cv_description);
class = LOCK_CLASS(lock);
- if (SCHEDULER_STOPPED())
+ if (SCHEDULER_STOPPED_TD(td))
return;
sleepq_lock(cvp);
@@ -176,7 +176,7 @@ _cv_wait_unlock(struct cv *cvp, struct l
("cv_wait_unlock cannot be used with Giant"));
class = LOCK_CLASS(lock);
- if (SCHEDULER_STOPPED()) {
+ if (SCHEDULER_STOPPED_TD(td)) {
class->lc_unlock(lock);
return;
}
@@ -227,7 +227,7 @@ _cv_wait_sig(struct cv *cvp, struct lock
"Waiting on \"%s\"", cvp->cv_description);
class = LOCK_CLASS(lock);
- if (SCHEDULER_STOPPED())
+ if (SCHEDULER_STOPPED_TD(td))
return (0);
sleepq_lock(cvp);
@@ -287,7 +287,7 @@ _cv_timedwait_sbt(struct cv *cvp, struct
"Waiting on \"%s\"", cvp->cv_description);
class = LOCK_CLASS(lock);
- if (SCHEDULER_STOPPED())
+ if (SCHEDULER_STOPPED_TD(td))
return (0);
sleepq_lock(cvp);
@@ -349,7 +349,7 @@ _cv_timedwait_sig_sbt(struct cv *cvp, st
"Waiting on \"%s\"", cvp->cv_description);
class = LOCK_CLASS(lock);
- if (SCHEDULER_STOPPED())
+ if (SCHEDULER_STOPPED_TD(td))
return (0);
sleepq_lock(cvp);
Modified: stable/11/sys/kern/kern_mutex.c
==============================================================================
--- stable/11/sys/kern/kern_mutex.c Thu Mar 16 07:09:47 2017
(r315385)
+++ stable/11/sys/kern/kern_mutex.c Thu Mar 16 07:10:08 2017
(r315386)
@@ -228,9 +228,6 @@ __mtx_lock_flags(volatile uintptr_t *c,
struct mtx *m;
uintptr_t tid, v;
- if (SCHEDULER_STOPPED())
- return;
-
m = mtxlock2mtx(c);
KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
@@ -263,9 +260,6 @@ __mtx_unlock_flags(volatile uintptr_t *c
{
struct mtx *m;
- if (SCHEDULER_STOPPED())
- return;
-
m = mtxlock2mtx(c);
KASSERT(m->mtx_lock != MTX_DESTROYED,
Modified: stable/11/sys/kern/kern_rwlock.c
==============================================================================
--- stable/11/sys/kern/kern_rwlock.c Thu Mar 16 07:09:47 2017
(r315385)
+++ stable/11/sys/kern/kern_rwlock.c Thu Mar 16 07:10:08 2017
(r315386)
@@ -267,9 +267,6 @@ _rw_wlock_cookie(volatile uintptr_t *c,
struct rwlock *rw;
uintptr_t tid, v;
- if (SCHEDULER_STOPPED())
- return;
-
rw = rwlock2rw(c);
KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
@@ -335,9 +332,6 @@ _rw_wunlock_cookie(volatile uintptr_t *c
{
struct rwlock *rw;
- if (SCHEDULER_STOPPED())
- return;
-
rw = rwlock2rw(c);
KASSERT(rw->rw_lock != RW_DESTROYED,
Modified: stable/11/sys/kern/kern_sx.c
==============================================================================
--- stable/11/sys/kern/kern_sx.c Thu Mar 16 07:09:47 2017
(r315385)
+++ stable/11/sys/kern/kern_sx.c Thu Mar 16 07:10:08 2017
(r315386)
@@ -293,8 +293,6 @@ _sx_xlock(struct sx *sx, int opts, const
uintptr_t tid, x;
int error = 0;
- if (SCHEDULER_STOPPED())
- return (0);
KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
("sx_xlock() by idle thread %p on sx %s @ %s:%d",
curthread, sx->lock_object.lo_name, file, line));
@@ -358,8 +356,6 @@ void
_sx_xunlock(struct sx *sx, const char *file, int line)
{
- if (SCHEDULER_STOPPED())
- return;
KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
("sx_xunlock() of destroyed sx @ %s:%d", file, line));
_sx_assert(sx, SA_XLOCKED, file, line);
Modified: stable/11/sys/kern/kern_synch.c
==============================================================================
--- stable/11/sys/kern/kern_synch.c Thu Mar 16 07:09:47 2017
(r315385)
+++ stable/11/sys/kern/kern_synch.c Thu Mar 16 07:10:08 2017
(r315386)
@@ -162,7 +162,7 @@ _sleep(void *ident, struct lock_object *
else
class = NULL;
- if (SCHEDULER_STOPPED()) {
+ if (SCHEDULER_STOPPED_TD(td)) {
if (lock != NULL && priority & PDROP)
class->lc_unlock(lock);
return (0);
@@ -250,7 +250,7 @@ msleep_spin_sbt(void *ident, struct mtx
KASSERT(p != NULL, ("msleep1"));
KASSERT(ident != NULL && TD_IS_RUNNING(td), ("msleep"));
- if (SCHEDULER_STOPPED())
+ if (SCHEDULER_STOPPED_TD(td))
return (0);
sleepq_lock(ident);
@@ -411,7 +411,7 @@ mi_switch(int flags, struct thread *newt
*/
if (kdb_active)
kdb_switch();
- if (SCHEDULER_STOPPED())
+ if (SCHEDULER_STOPPED_TD(td))
return;
if (flags & SW_VOL) {
td->td_ru.ru_nvcsw++;
Modified: stable/11/sys/sys/systm.h
==============================================================================
--- stable/11/sys/sys/systm.h Thu Mar 16 07:09:47 2017 (r315385)
+++ stable/11/sys/sys/systm.h Thu Mar 16 07:10:08 2017 (r315386)
@@ -128,7 +128,11 @@ void kassert_panic(const char *fmt, ...)
* Otherwise, the kernel will deadlock since the scheduler isn't
* going to run the thread that holds any lock we need.
*/
-#define SCHEDULER_STOPPED() __predict_false(curthread->td_stopsched)
+#define SCHEDULER_STOPPED_TD(td) ({
\
+ MPASS((td) == curthread); \
+ __predict_false((td)->td_stopsched); \
+})
+#define SCHEDULER_STOPPED() SCHEDULER_STOPPED_TD(curthread)
/*
* Align variables.
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