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- Split out the functionality of displaying the contents of a single lock

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list into a public witness_list_locks() function.  Call this function
  twice in witness_list() instead of using an evil goto.
- Adjust the 'show locks' command to take an optional parameter which
  specifies the pid of a process to list the locks of.  By default the
  locks held by the current process are displayed.
This commit is contained in:
jhb 2001-04-06 21:37:52 +00:00
parent 8c75c79c0f
commit dd676bb0ec
2 changed files with 53 additions and 21 deletions
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73
sys/kern/subr_witness.c
View File

@ -1081,27 +1081,14 @@ witness_lock_list_free(struct lock_list_entry *lle)
mtx_unlock_spin(&w_mtx);
}
/*
* Calling this on p != curproc is bad unless we are in ddb.
*/
int
witness_list(struct proc *p)
witness_list_locks(struct lock_list_entry **lock_list)
{
struct lock_list_entry **lock_list, *lle;
struct lock_list_entry *lle;
struct lock_object *lock;
critical_t savecrit;
int i, nheld;
KASSERT(p == curproc || db_active,
("%s: p != curproc and we aren't in the debugger", __func__));
KASSERT(!witness_cold, ("%s: witness_cold", __func__));
nheld = 0;
/*
* Preemption bad because we need PCPU_PTR(spinlocks) to not change.
*/
savecrit = critical_enter();
lock_list = &p->p_sleeplocks;
again:
for (lle = *lock_list; lle != NULL; lle = lle->ll_next)
for (i = lle->ll_count - 1; i >= 0; i--) {
lock = lle->ll_children[i];
@ -1110,16 +1097,40 @@ witness_list(struct proc *p)
lock->lo_file, lock->lo_line);
nheld++;
}
return (nheld);
}
/*
* Calling this on p != curproc is bad unless we are in ddb.
*/
int
witness_list(struct proc *p)
{
critical_t savecrit;
int nheld;
KASSERT(p == curproc || db_active,
("%s: p != curproc and we aren't in the debugger", __func__));
KASSERT(!witness_cold, ("%s: witness_cold", __func__));
nheld = witness_list_locks(&p->p_sleeplocks);
/*
* We only handle spinlocks if p == curproc. This is somewhat broken
* if p is currently executing on some other CPU and holds spin locks
* as we won't display those locks.
* as we won't display those locks. If we had a MI way of getting
* the per-cpu data for a given cpu then we could use p->p_oncpu to
* get the list of spinlocks for this process and "fix" this.
*/
if (lock_list == &p->p_sleeplocks && p == curproc) {
lock_list = PCPU_PTR(spinlocks);
goto again;
if (p == curproc) {
/*
* Preemption bad because we need PCPU_PTR(spinlocks) to not
* change.
*/
savecrit = critical_enter();
nheld += witness_list_locks(PCPU_PTR(spinlocks));
critical_exit(savecrit);
}
critical_exit(savecrit);
return (nheld);
}
@ -1154,8 +1165,28 @@ witness_restore(struct lock_object *lock, const char *file, int line)
DB_SHOW_COMMAND(locks, db_witness_list)
{
struct proc *p;
pid_t pid;
witness_list(curproc);
if (have_addr) {
pid = (addr % 16) + ((addr >> 4) % 16) * 10 +
((addr >> 8) % 16) * 100 + ((addr >> 12) % 16) * 1000 +
((addr >> 16) % 16) * 10000;
/* sx_slock(&allproc_lock); */
LIST_FOREACH(p, &allproc, p_list) {
if (p->p_pid == pid)
break;
}
/* sx_sunlock(&allproc_lock); */
if (p == NULL) {
db_printf("pid %d not found\n", pid);
return;
}
} else
p = curproc;
witness_list(p);
}
DB_SHOW_COMMAND(witness, db_witness_display)

1
sys/sys/lock.h
View File

@ -164,6 +164,7 @@ void witness_lock(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(struct proc *);
int witness_sleep(int, struct lock_object *, const char *, int);