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- Improve some witness_watch operability in code which does perform both

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lock tracking and checks, doing just the former ones.
- Fix a bug where sysctl utility was printing crazy values when setting a
  new value for debug.witness.watch [0]

[0] Reported by:	yongari
This commit is contained in:
Attilio Rao 2008-08-30 13:20:35 +00:00
parent 74bb9e3ad5
commit 988d28340a
1 changed files with 45 additions and 35 deletions
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80
sys/kern/subr_witness.c
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@ -980,7 +980,7 @@ int
witness_defineorder(struct lock_object *lock1, struct lock_object *lock2) witness_defineorder(struct lock_object *lock1, struct lock_object *lock2)
{ {
if (witness_watch < 1 || panicstr != NULL) if (witness_watch == -1 || panicstr != NULL)
return (0); return (0);
/* Require locks that witness knows about. */ /* Require locks that witness knows about. */
@ -995,7 +995,8 @@ witness_defineorder(struct lock_object *lock1, struct lock_object *lock2)
* If we already have either an explicit or implied lock order that * If we already have either an explicit or implied lock order that
* is the other way around, then return an error. * is the other way around, then return an error.
*/ */
if (isitmydescendant(lock2->lo_witness, lock1->lo_witness)) { if (witness_watch &&
isitmydescendant(lock2->lo_witness, lock1->lo_witness)) {
mtx_unlock_spin(&w_mtx); mtx_unlock_spin(&w_mtx);
return (EDOOFUS); return (EDOOFUS);
} }
@ -1356,27 +1357,31 @@ witness_upgrade(struct lock_object *lock, int flags, const char *file, int line)
struct lock_class *class; struct lock_class *class;
KASSERT(witness_cold == 0, ("%s: witness_cold", __func__)); KASSERT(witness_cold == 0, ("%s: witness_cold", __func__));
if (lock->lo_witness == NULL || witness_watch < 1 || panicstr != NULL) if (lock->lo_witness == NULL || witness_watch == -1 || panicstr != NULL)
return; return;
class = LOCK_CLASS(lock); class = LOCK_CLASS(lock);
file = fixup_filename(file); file = fixup_filename(file);
if ((lock->lo_flags & LO_UPGRADABLE) == 0) if (witness_watch) {
panic("upgrade of non-upgradable lock (%s) %s @ %s:%d", if ((lock->lo_flags & LO_UPGRADABLE) == 0)
class->lc_name, lock->lo_name, file, line); panic("upgrade of non-upgradable lock (%s) %s @ %s:%d",
if ((class->lc_flags & LC_SLEEPLOCK) == 0) class->lc_name, lock->lo_name, file, line);
panic("upgrade of non-sleep lock (%s) %s @ %s:%d", if ((class->lc_flags & LC_SLEEPLOCK) == 0)
class->lc_name, lock->lo_name, file, line); panic("upgrade of non-sleep lock (%s) %s @ %s:%d",
class->lc_name, lock->lo_name, file, line);
}
instance = find_instance(curthread->td_sleeplocks, lock); instance = find_instance(curthread->td_sleeplocks, lock);
if (instance == NULL) if (instance == NULL)
panic("upgrade of unlocked lock (%s) %s @ %s:%d", panic("upgrade of unlocked lock (%s) %s @ %s:%d",
class->lc_name, lock->lo_name, file, line); class->lc_name, lock->lo_name, file, line);
if ((instance->li_flags & LI_EXCLUSIVE) != 0) if (witness_watch) {
panic("upgrade of exclusive lock (%s) %s @ %s:%d", if ((instance->li_flags & LI_EXCLUSIVE) != 0)
class->lc_name, lock->lo_name, file, line); panic("upgrade of exclusive lock (%s) %s @ %s:%d",
if ((instance->li_flags & LI_RECURSEMASK) != 0) class->lc_name, lock->lo_name, file, line);
panic("upgrade of recursed lock (%s) %s r=%d @ %s:%d", if ((instance->li_flags & LI_RECURSEMASK) != 0)
class->lc_name, lock->lo_name, panic("upgrade of recursed lock (%s) %s r=%d @ %s:%d",
instance->li_flags & LI_RECURSEMASK, file, line); class->lc_name, lock->lo_name,
instance->li_flags & LI_RECURSEMASK, file, line);
}
instance->li_flags |= LI_EXCLUSIVE; instance->li_flags |= LI_EXCLUSIVE;
} }
@ -1388,27 +1393,31 @@ witness_downgrade(struct lock_object *lock, int flags, const char *file,
struct lock_class *class; struct lock_class *class;
KASSERT(witness_cold == 0, ("%s: witness_cold", __func__)); KASSERT(witness_cold == 0, ("%s: witness_cold", __func__));
if (lock->lo_witness == NULL || witness_watch < 1 || panicstr != NULL) if (lock->lo_witness == NULL || witness_watch == -1 || panicstr != NULL)
return; return;
class = LOCK_CLASS(lock); class = LOCK_CLASS(lock);
file = fixup_filename(file); file = fixup_filename(file);
if ((lock->lo_flags & LO_UPGRADABLE) == 0) if (witness_watch) {
if ((lock->lo_flags & LO_UPGRADABLE) == 0)
panic("downgrade of non-upgradable lock (%s) %s @ %s:%d", panic("downgrade of non-upgradable lock (%s) %s @ %s:%d",
class->lc_name, lock->lo_name, file, line); class->lc_name, lock->lo_name, file, line);
if ((class->lc_flags & LC_SLEEPLOCK) == 0) if ((class->lc_flags & LC_SLEEPLOCK) == 0)
panic("downgrade of non-sleep lock (%s) %s @ %s:%d", panic("downgrade of non-sleep lock (%s) %s @ %s:%d",
class->lc_name, lock->lo_name, file, line); class->lc_name, lock->lo_name, file, line);
}
instance = find_instance(curthread->td_sleeplocks, lock); instance = find_instance(curthread->td_sleeplocks, lock);
if (instance == NULL) if (instance == NULL)
panic("downgrade of unlocked lock (%s) %s @ %s:%d", panic("downgrade of unlocked lock (%s) %s @ %s:%d",
class->lc_name, lock->lo_name, file, line); class->lc_name, lock->lo_name, file, line);
if ((instance->li_flags & LI_EXCLUSIVE) == 0) if (witness_watch) {
panic("downgrade of shared lock (%s) %s @ %s:%d", if ((instance->li_flags & LI_EXCLUSIVE) == 0)
class->lc_name, lock->lo_name, file, line); panic("downgrade of shared lock (%s) %s @ %s:%d",
if ((instance->li_flags & LI_RECURSEMASK) != 0) class->lc_name, lock->lo_name, file, line);
panic("downgrade of recursed lock (%s) %s r=%d @ %s:%d", if ((instance->li_flags & LI_RECURSEMASK) != 0)
class->lc_name, lock->lo_name, panic("downgrade of recursed lock (%s) %s r=%d @ %s:%d",
instance->li_flags & LI_RECURSEMASK, file, line); class->lc_name, lock->lo_name,
instance->li_flags & LI_RECURSEMASK, file, line);
}
instance->li_flags &= ~LI_EXCLUSIVE; instance->li_flags &= ~LI_EXCLUSIVE;
} }
@ -1443,9 +1452,9 @@ witness_unlock(struct lock_object *lock, int flags, const char *file, int line)
/* /*
* When disabling WITNESS through witness_watch we could end up in * When disabling WITNESS through witness_watch we could end up in
* having registered locks in the locks list queue. * having registered locks in the td_sleeplocks queue.
* We have to make sure we flush these queues, so just search for * We have to make sure we flush these queues, so just search for
* eventual registered locks and remove them. * eventual register locks and remove them.
*/ */
if (witness_watch > 0) if (witness_watch > 0)
panic("lock (%s) %s not locked @ %s:%d", class->lc_name, panic("lock (%s) %s not locked @ %s:%d", class->lc_name,
@ -1630,7 +1639,7 @@ enroll(const char *description, struct lock_class *lock_class)
MPASS(description != NULL); MPASS(description != NULL);
if (witness_watch < 1 || panicstr != NULL) if (witness_watch == -1 || panicstr != NULL)
return (NULL); return (NULL);
if ((lock_class->lc_flags & LC_SPINLOCK)) { if ((lock_class->lc_flags & LC_SPINLOCK)) {
if (witness_skipspin) if (witness_skipspin)
@ -1897,7 +1906,7 @@ witness_get(void)
if (witness_cold == 0) if (witness_cold == 0)
mtx_assert(&w_mtx, MA_OWNED); mtx_assert(&w_mtx, MA_OWNED);
if (witness_watch < 1) { if (witness_watch == -1) {
mtx_unlock_spin(&w_mtx); mtx_unlock_spin(&w_mtx);
return (NULL); return (NULL);
} }
@ -2055,7 +2064,7 @@ witness_save(struct lock_object *lock, const char **filep, int *linep)
struct lock_class *class; struct lock_class *class;
KASSERT(witness_cold == 0, ("%s: witness_cold", __func__)); KASSERT(witness_cold == 0, ("%s: witness_cold", __func__));
if (lock->lo_witness == NULL || witness_watch < 1 || panicstr != NULL) if (lock->lo_witness == NULL || witness_watch == -1 || panicstr != NULL)
return; return;
class = LOCK_CLASS(lock); class = LOCK_CLASS(lock);
if (class->lc_flags & LC_SLEEPLOCK) if (class->lc_flags & LC_SLEEPLOCK)
@ -2081,7 +2090,7 @@ witness_restore(struct lock_object *lock, const char *file, int line)
struct lock_class *class; struct lock_class *class;
KASSERT(witness_cold == 0, ("%s: witness_cold", __func__)); KASSERT(witness_cold == 0, ("%s: witness_cold", __func__));
if (lock->lo_witness == NULL || witness_watch < 1 || panicstr != NULL) if (lock->lo_witness == NULL || witness_watch == -1 || panicstr != NULL)
return; return;
class = LOCK_CLASS(lock); class = LOCK_CLASS(lock);
if (class->lc_flags & LC_SLEEPLOCK) if (class->lc_flags & LC_SLEEPLOCK)
@ -2445,6 +2454,7 @@ sysctl_debug_witness_watch(SYSCTL_HANDLER_ARGS)
{ {
int error, value; int error, value;
value = witness_watch;
error = sysctl_handle_int(oidp, &value, 0, req); error = sysctl_handle_int(oidp, &value, 0, req);
if (error != 0 || req->newptr == NULL) if (error != 0 || req->newptr == NULL)
return (error); return (error);