/*- * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Berkeley Software Design Inc's name may not be used to endorse or * promote products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from BSDI $Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp Exp $ * $FreeBSD$ */ #ifndef _SYS_LOCK_H_ #define _SYS_LOCK_H_ #include #include struct thread; /* * Lock classes. Each lock has a class which describes characteristics * common to all types of locks of a given class. * * Spin locks in general must always protect against preemption, as it is * an error to perform any type of context switch while holding a spin lock. * Also, for an individual lock to be recursable, its class must allow * recursion and the lock itself must explicitly allow recursion. */ struct lock_class { const char *lc_name; u_int lc_flags; }; #define LC_SLEEPLOCK 0x00000001 /* Sleep lock. */ #define LC_SPINLOCK 0x00000002 /* Spin lock. */ #define LC_SLEEPABLE 0x00000004 /* Sleeping allowed with this lock. */ #define LC_RECURSABLE 0x00000008 /* Locks of this type may recurse. */ #define LC_UPGRADABLE 0x00000010 /* Upgrades and downgrades permitted. */ #define LO_CLASSFLAGS 0x0000ffff /* Class specific flags. */ #define LO_INITIALIZED 0x00010000 /* Lock has been initialized. */ #define LO_WITNESS 0x00020000 /* Should witness monitor this lock. */ #define LO_QUIET 0x00040000 /* Don't log locking operations. */ #define LO_RECURSABLE 0x00080000 /* Lock may recurse. */ #define LO_SLEEPABLE 0x00100000 /* Lock may be held while sleeping. */ #define LO_UPGRADABLE 0x00200000 /* Lock may be upgraded/downgraded. */ #define LO_DUPOK 0x00400000 /* Don't check for duplicate acquires */ #define LI_RECURSEMASK 0x0000ffff /* Recursion depth of lock instance. */ #define LI_SLEPT 0x00010000 /* Lock instance has been slept with. */ #define LI_EXCLUSIVE 0x00020000 /* Exclusive lock instance. */ /* * Option flags passed to lock operations that witness also needs to know * about or that are generic across all locks. */ #define LOP_QUIET 0x00000002 /* Don't log locking operations. */ #define LOP_TRYLOCK 0x00000004 /* Don't check lock order. */ #define LOP_EXCLUSIVE 0x00000008 /* Exclusive lock. */ /* Flags passed to witness_assert. */ #define LA_UNLOCKED 0x00000000 /* Lock is unlocked. */ #define LA_LOCKED 0x00000001 /* Lock is at least share locked. */ #define LA_SLOCKED 0x00000002 /* Lock is exactly share locked. */ #define LA_XLOCKED 0x00000004 /* Lock is exclusively locked. */ #define LA_RECURSED 0x00000008 /* Lock is recursed. */ #define LA_NOTRECURSED 0x00000010 /* Lock is not recursed. */ #ifdef _KERNEL /* * Lock instances. A lock instance is the data associated with a lock while * it is held by witness. For example, a lock instance will hold the * recursion count of a lock. Lock instances are held in lists. Spin locks * are held in a per-cpu list while sleep locks are held in per-process list. */ struct lock_instance { struct lock_object *li_lock; const char *li_file; /* File and line of last acquire. */ int li_line; u_int li_flags; /* Recursion count and LI_* flags. */ }; /* * A simple list type used to build the list of locks held by a process * or CPU. We can't simply embed the list in struct lock_object since a * lock may be held by more than one process if it is a shared lock. Locks * are added to the head of the list, so we fill up each list entry from * "the back" logically. To ease some of the arithmetic, we actually fill * in each list entry the normal way (childer[0] then children[1], etc.) but * when we traverse the list we read children[count-1] as the first entry * down to children[0] as the final entry. */ #define LOCK_NCHILDREN 3 struct lock_list_entry { struct lock_list_entry *ll_next; struct lock_instance ll_children[LOCK_NCHILDREN]; u_int ll_count; }; /* * If any of WITNESS, INVARIANTS, or KTR_LOCK KTR tracing has been enabled, * then turn on LOCK_DEBUG. When this option is on, extra debugging * facilities such as tracking the file and line number of lock operations * are enabled. Also, mutex locking operations are not inlined to avoid * bloat from all the extra debugging code. We also have to turn on all the * calling conventions for this debugging code in modules so that modules can * work with both debug and non-debug kernels. */ #if defined(KLD_MODULE) || defined(WITNESS) || defined(INVARIANTS) || defined(INVARIANT_SUPPORT) || defined(KTR) #define LOCK_DEBUG 1 #else #define LOCK_DEBUG 0 #endif /* * In the LOCK_DEBUG case, use the filename and line numbers for debugging * operations. Otherwise, use default values to avoid the unneeded bloat. */ #if LOCK_DEBUG > 0 #define LOCK_FILE __FILE__ #define LOCK_LINE __LINE__ #else #define LOCK_FILE NULL #define LOCK_LINE 0 #endif /* * Macros for KTR_LOCK tracing. * * opname - name of this operation (LOCK/UNLOCK/SLOCK, etc.) * lo - struct lock_object * for this lock * flags - flags passed to the lock operation * recurse - this locks recursion level (or 0 if class is not recursable) * result - result of a try lock operation * file - file name * line - line number */ #define LOCK_LOG_TEST(lo, flags) \ (((flags) & LOP_QUIET) == 0 && ((lo)->lo_flags & LO_QUIET) == 0) #define LOCK_LOG_LOCK(opname, lo, flags, recurse, file, line) do { \ if (LOCK_LOG_TEST((lo), (flags))) \ CTR5(KTR_LOCK, opname " (%s) %s r = %d at %s:%d", \ (lo)->lo_class->lc_name, (lo)->lo_name, \ (u_int)(recurse), (file), (line)); \ } while (0) #define LOCK_LOG_TRY(opname, lo, flags, result, file, line) do { \ if (LOCK_LOG_TEST((lo), (flags))) \ CTR5(KTR_LOCK, "TRY_" opname " (%s) %s result=%d at %s:%d",\ (lo)->lo_class->lc_name, (lo)->lo_name, \ (u_int)(result), (file), (line)); \ } while (0) #define LOCK_LOG_INIT(lo, flags) do { \ if (LOCK_LOG_TEST((lo), (flags))) \ CTR4(KTR_LOCK, "%s: %p (%s) %s", __func__, (lo), \ (lo)->lo_class->lc_name, (lo)->lo_name); \ } while (0) #define LOCK_LOG_DESTROY(lo, flags) LOCK_LOG_INIT(lo, flags) /* * Helpful macros for quickly coming up with assertions with informative * panic messages. */ #define MPASS(ex) MPASS4(ex, #ex, __FILE__, __LINE__) #define MPASS2(ex, what) MPASS4(ex, what, __FILE__, __LINE__) #define MPASS3(ex, file, line) MPASS4(ex, #ex, file, line) #define MPASS4(ex, what, file, line) \ KASSERT((ex), ("Assertion %s failed at %s:%d", what, file, line)) extern struct lock_class lock_class_mtx_sleep; extern struct lock_class lock_class_mtx_spin; extern struct lock_class lock_class_sx; void witness_init(struct lock_object *); void witness_destroy(struct lock_object *); void witness_lock(struct lock_object *, int, const char *, int); void witness_upgrade(struct lock_object *, int, const char *, int); 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(struct thread *); int witness_sleep(int, struct lock_object *, const char *, int); void witness_assert(struct lock_object *, int, const char *, int); int witness_line(struct lock_object *); const char *witness_file(struct lock_object *); #ifdef WITNESS #define WITNESS_INIT(lock) \ witness_init((lock)) #define WITNESS_DESTROY(lock) \ witness_destroy(lock) #define WITNESS_LOCK(lock, flags, file, line) \ witness_lock((lock), (flags), (file), (line)) #define WITNESS_UPGRADE(lock, flags, file, line) \ witness_upgrade((lock), (flags), (file), (line)) #define WITNESS_DOWNGRADE(lock, flags, file, line) \ witness_downgrade((lock), (flags), (file), (line)) #define WITNESS_UNLOCK(lock, flags, file, line) \ witness_unlock((lock), (flags), (file), (line)) #define WITNESS_SLEEP(check, lock) \ witness_sleep((check), (lock), __FILE__, __LINE__) #define WITNESS_SAVE_DECL(n) \ const char * __CONCAT(n, __wf); \ int __CONCAT(n, __wl) #define WITNESS_SAVE(lock, n) \ witness_save((lock), &__CONCAT(n, __wf), &__CONCAT(n, __wl)) #define WITNESS_RESTORE(lock, n) \ witness_restore((lock), __CONCAT(n, __wf), __CONCAT(n, __wl)) #define WITNESS_FILE(lock) \ witness_file(lock) #define WITNESS_LINE(lock) \ witness_line(lock) #else /* WITNESS */ #define WITNESS_INIT(lock) ((lock)->lo_flags |= LO_INITIALIZED) #define WITNESS_DESTROY(lock) ((lock)->lo_flags &= ~LO_INITIALIZED) #define WITNESS_LOCK(lock, flags, file, line) #define WITNESS_UPGRADE(lock, flags, file, line) #define WITNESS_DOWNGRADE(lock, flags, file, line) #define WITNESS_UNLOCK(lock, flags, file, line) #define WITNESS_SLEEP(check, lock) #define WITNESS_SAVE_DECL(n) #define WITNESS_SAVE(lock, n) #define WITNESS_RESTORE(lock, n) #define WITNESS_FILE(lock) ("?") #define WITNESS_LINE(lock) (0) #endif /* WITNESS */ #endif /* _KERNEL */ #endif /* _SYS_LOCK_H_ */