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Right now, WITNESS just blindly pipes all the output to the

Browse Source 
(TOCONS | TOLOG) mask even when called from DDB points.
That breaks several output, where the most notable is textdump output.
Fix this by having configurable callbacks passed to witness_list_locks()
and witness_display_spinlock() for printing out datas.

Reported by:	several broken textdump outputs
Tested by:	Giovanni Trematerra
		<giovanni dot trematerra at gmail dot com>
MFC after:	7 days
X-MFC:		r207922
This commit is contained in:
Attilio Rao 2010-05-11 18:24:22 +00:00
parent 227901e1a2
commit 98332c8c71
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=207929
4 changed files with 24 additions and 18 deletions
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2
sys/kern/kern_mutex.c
View File

@ -485,7 +485,7 @@ _mtx_lock_spin_failed(struct mtx *m)
printf( "spin lock %p (%s) held by %p (tid %d) too long\n",
m, m->lock_object.lo_name, td, td->td_tid);
#ifdef WITNESS
witness_display_spinlock(&m->lock_object, td);
witness_display_spinlock(&m->lock_object, td, printf);
#endif
panic("spin lock held too long");
}

2
sys/kern/subr_pcpu.c
View File

@ -363,7 +363,7 @@ show_pcpu(struct pcpu *pc)
#ifdef WITNESS
db_printf("spin locks held:\n");
witness_list_locks(&pc->pc_spinlocks);
witness_list_locks(&pc->pc_spinlocks, db_printf);
#endif
}

32
sys/kern/subr_witness.c
View File

@ -367,7 +367,8 @@ static int witness_lock_order_check(struct witness *parent,
static struct witness_lock_order_data *witness_lock_order_get(
struct witness *parent,
struct witness *child);
static void witness_list_lock(struct lock_instance *instance);
static void witness_list_lock(struct lock_instance *instance,
int (*prnt)(const char *fmt, ...));
static void witness_setflag(struct lock_object *lock, int flag, int set);
#ifdef KDB
@ -1597,7 +1598,7 @@ witness_thread_exit(struct thread *td)
printf("Thread %p exiting with the following locks held:\n",
td);
n++;
witness_list_lock(&lle->ll_children[i]);
witness_list_lock(&lle->ll_children[i], printf);
}
panic("Thread %p cannot exit while holding sleeplocks\n", td);
@ -1646,7 +1647,7 @@ witness_warn(int flags, struct lock_object *lock, const char *fmt, ...)
printf(" locks held:\n");
}
n++;
witness_list_lock(lock1);
witness_list_lock(lock1, printf);
}
/*
@ -1677,7 +1678,7 @@ witness_warn(int flags, struct lock_object *lock, const char *fmt, ...)
if (flags & WARN_SLEEPOK)
printf(" non-sleepable");
printf(" locks held:\n");
n += witness_list_locks(&lock_list);
n += witness_list_locks(&lock_list, printf);
} else
sched_unpin();
if (flags & WARN_PANIC && n)
@ -2063,16 +2064,17 @@ find_instance(struct lock_list_entry *list, struct lock_object *lock)
}
static void
witness_list_lock(struct lock_instance *instance)
witness_list_lock(struct lock_instance *instance,
int (*prnt)(const char *fmt, ...))
{
struct lock_object *lock;
lock = instance->li_lock;
printf("%s %s %s", (instance->li_flags & LI_EXCLUSIVE) != 0 ?
prnt("%s %s %s", (instance->li_flags & LI_EXCLUSIVE) != 0 ?
"exclusive" : "shared", LOCK_CLASS(lock)->lc_name, lock->lo_name);
if (lock->lo_witness->w_name != lock->lo_name)
printf(" (%s)", lock->lo_witness->w_name);
printf(" r = %d (%p) locked @ %s:%d\n",
prnt(" (%s)", lock->lo_witness->w_name);
prnt(" r = %d (%p) locked @ %s:%d\n",
instance->li_flags & LI_RECURSEMASK, lock, instance->li_file,
instance->li_line);
}
@ -2101,7 +2103,8 @@ witness_proc_has_locks(struct proc *p)
#endif
int
witness_list_locks(struct lock_list_entry **lock_list)
witness_list_locks(struct lock_list_entry **lock_list,
int (*prnt)(const char *fmt, ...))
{
struct lock_list_entry *lle;
int i, nheld;
@ -2109,7 +2112,7 @@ witness_list_locks(struct lock_list_entry **lock_list)
nheld = 0;
for (lle = *lock_list; lle != NULL; lle = lle->ll_next)
for (i = lle->ll_count - 1; i >= 0; i--) {
witness_list_lock(&lle->ll_children[i]);
witness_list_lock(&lle->ll_children[i], prnt);
nheld++;
}
return (nheld);
@ -2123,7 +2126,8 @@ witness_list_locks(struct lock_list_entry **lock_list)
* see when it was last acquired.
*/
void
witness_display_spinlock(struct lock_object *lock, struct thread *owner)
witness_display_spinlock(struct lock_object *lock, struct thread *owner,
int (*prnt)(const char *fmt, ...))
{
struct lock_instance *instance;
struct pcpu *pc;
@ -2133,7 +2137,7 @@ witness_display_spinlock(struct lock_object *lock, struct thread *owner)
pc = pcpu_find(owner->td_oncpu);
instance = find_instance(pc->pc_spinlocks, lock);
if (instance != NULL)
witness_list_lock(instance);
witness_list_lock(instance, prnt);
}
void
@ -2306,7 +2310,7 @@ witness_ddb_list(struct thread *td)
if (witness_watch < 1)
return;
witness_list_locks(&td->td_sleeplocks);
witness_list_locks(&td->td_sleeplocks, db_printf);
/*
* We only handle spinlocks if td == curthread. This is somewhat broken
@ -2322,7 +2326,7 @@ witness_ddb_list(struct thread *td)
* handle threads on other CPU's for now.
*/
if (td == curthread && PCPU_GET(spinlocks) != NULL)
witness_list_locks(PCPU_PTR(spinlocks));
witness_list_locks(PCPU_PTR(spinlocks), db_printf);
}
DB_SHOW_COMMAND(locks, db_witness_list)

6
sys/sys/lock.h
View File

@ -212,10 +212,12 @@ void witness_downgrade(struct lock_object *, int, const char *, int);
void witness_unlock(struct lock_object *, int, const char *, int);
void witness_save(struct lock_object *, const char **, int *);
void witness_restore(struct lock_object *, const char *, int);
int witness_list_locks(struct lock_list_entry **);
int witness_list_locks(struct lock_list_entry **,
int (*)(const char *, ...));
int witness_warn(int, struct lock_object *, const char *, ...);
void witness_assert(struct lock_object *, int, const char *, int);
void witness_display_spinlock(struct lock_object *, struct thread *);
void witness_display_spinlock(struct lock_object *, struct thread *,
int (*)(const char *, ...));
int witness_line(struct lock_object *);
void witness_norelease(struct lock_object *);
void witness_releaseok(struct lock_object *);