From 24150d37d3bdc035a19da4d59c33043aa4ad006d Mon Sep 17 00:00:00 2001 From: John Baldwin Date: Mon, 3 Jun 2013 17:41:11 +0000 Subject: [PATCH] - Fix a couple of inverted panic messages for shared/exclusive mismatches of a lock within a single thread. - Fix handling of interlocks in WITNESS by properly requiring the interlock to be held exactly once if it is specified. --- sys/kern/kern_lock.c | 8 +++++--- sys/kern/subr_witness.c | 28 +++++++++++++++++++++------- 2 files changed, 26 insertions(+), 10 deletions(-) diff --git a/sys/kern/kern_lock.c b/sys/kern/kern_lock.c index 849f583cf23c..f0eedd8d1ce0 100644 --- a/sys/kern/kern_lock.c +++ b/sys/kern/kern_lock.c @@ -511,7 +511,7 @@ __lockmgr_args(struct lock *lk, u_int flags, struct lock_object *ilk, case LK_SHARED: if (LK_CAN_WITNESS(flags)) WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER, - file, line, ilk); + file, line, flags & LK_INTERLOCK ? ilk : NULL); for (;;) { x = lk->lk_lock; @@ -723,7 +723,8 @@ __lockmgr_args(struct lock *lk, u_int flags, struct lock_object *ilk, case LK_EXCLUSIVE: if (LK_CAN_WITNESS(flags)) WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER | - LOP_EXCLUSIVE, file, line, ilk); + LOP_EXCLUSIVE, file, line, flags & LK_INTERLOCK ? + ilk : NULL); /* * If curthread already holds the lock and this one is @@ -1072,7 +1073,8 @@ __lockmgr_args(struct lock *lk, u_int flags, struct lock_object *ilk, case LK_DRAIN: if (LK_CAN_WITNESS(flags)) WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER | - LOP_EXCLUSIVE, file, line, ilk); + LOP_EXCLUSIVE, file, line, flags & LK_INTERLOCK ? + ilk : NULL); /* * Trying to drain a lock we already own will result in a diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c index ac7636ae9203..bf28a88865f6 100644 --- a/sys/kern/subr_witness.c +++ b/sys/kern/subr_witness.c @@ -1053,7 +1053,7 @@ witness_checkorder(struct lock_object *lock, int flags, const char *file, { struct lock_list_entry *lock_list, *lle; struct lock_instance *lock1, *lock2, *plock; - struct lock_class *class; + struct lock_class *class, *iclass; struct witness *w, *w1; struct thread *td; int i, j; @@ -1119,7 +1119,7 @@ witness_checkorder(struct lock_object *lock, int flags, const char *file, fixup_filename(file), line); printf("while exclusively locked from %s:%d\n", fixup_filename(lock1->li_file), lock1->li_line); - kassert_panic("share->excl"); + kassert_panic("excl->share"); } if ((lock1->li_flags & LI_EXCLUSIVE) == 0 && (flags & LOP_EXCLUSIVE) != 0) { @@ -1128,11 +1128,27 @@ witness_checkorder(struct lock_object *lock, int flags, const char *file, fixup_filename(file), line); printf("while share locked from %s:%d\n", fixup_filename(lock1->li_file), lock1->li_line); - kassert_panic("excl->share"); + kassert_panic("share->excl"); } return; } + /* Warn if the interlock is not locked exactly once. */ + if (interlock != NULL) { + iclass = LOCK_CLASS(interlock); + lock1 = find_instance(lock_list, interlock); + if (lock1 == NULL) + kassert_panic("interlock (%s) %s not locked @ %s:%d", + iclass->lc_name, interlock->lo_name, + flags & LOP_EXCLUSIVE ? "exclusive" : "shared", + fixup_filename(file), line); + else if ((lock1->li_flags & LI_RECURSEMASK) != 0) + kassert_panic("interlock (%s) %s recursed @ %s:%d", + iclass->lc_name, interlock->lo_name, + flags & LOP_EXCLUSIVE ? "exclusive" : "shared", + fixup_filename(file), line); + } + /* * Find the previously acquired lock, but ignore interlocks. */ @@ -1205,12 +1221,10 @@ witness_checkorder(struct lock_object *lock, int flags, const char *file, lock1 = &lle->ll_children[i]; /* - * Ignore the interlock the first time we see it. + * Ignore the interlock. */ - if (interlock != NULL && interlock == lock1->li_lock) { - interlock = NULL; + if (interlock == lock1->li_lock) continue; - } /* * If this lock doesn't undergo witness checking,