user/sven/linux.git/include/linux/lockdep.h, branch v3.10.97

Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2013-02-23T03:25:09Z

Pull core locking changes from Ingo Molnar: "The biggest change is the rwsem lock-steal improvements, both to the assembly optimized and the spinlock based variants. The other notable change is the clean up of the seqlock implementation to be based on the seqcount infrastructure. The rest is assorted smaller debuggability, cleanup and continued -rt locking changes." * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rwsem-spinlock: Implement writer lock-stealing for better scalability futex: Revert "futex: Mark get_robust_list as deprecated" generic: Use raw local irq variant for generic cmpxchg lockdep: Selftest: convert spinlock to raw spinlock seqlock: Use seqcount infrastructure seqlock: Remove unused functions ntp: Make ntp_lock raw intel_idle: Convert i7300_idle_lock to raw_spinlock locking: Various static lock initializer fixes lockdep: Print more info when MAX_LOCK_DEPTH is exceeded rwsem: Implement writer lock-stealing for better scalability lockdep: Silence warning if CONFIG_LOCKDEP isn't set watchdog: Use local_clock for get_timestamp() lockdep: Rename print_unlock_inbalance_bug() to print_unlock_imbalance_bug() locking/stat: Fix a typo

lockdep: make lockdep_assert_held() not have a return value

2013-02-22T01:22:19Z

I recently made the mistake of writing: foo = lockdep_dereference_protected(..., lockdep_assert_held(...)); which is clearly bogus. If lockdep is disabled in the config this would cause a compile failure, if it is enabled then it compiles and causes a puzzling warning about dereferencing without the correct protection. Wrap the macro in "do { ... } while (0)" to also fail compile for this when lockdep is enabled. Signed-off-by: Johannes Berg Cc: Peter Zijlstra Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lockdep: Silence warning if CONFIG_LOCKDEP isn't set

2013-02-19T07:42:41Z

Since commit c9a4962881929df7f1ef6e63e1b9da304faca4dd ("nfsd: make client_lock per net") compiling nfs4state.o without CONFIG_LOCKDEP set, triggers this GCC warning: fs/nfsd/nfs4state.c: In function ‘free_client’: fs/nfsd/nfs4state.c:1051:19: warning: unused variable ‘nn’ [-Wunused-variable] The cause of that warning is that lockdep_assert_held() compiles away if CONFIG_LOCKDEP is not set. Silence this warning by using the argument to lockdep_assert_held() as a nop if CONFIG_LOCKDEP is not set. Signed-off-by: Paul Bolle Cc: Peter Zijlstra Cc: Stanislav Kinsbursky Cc: J. Bruce Fields Link: http://lkml.kernel.org/r/1359060797.1325.33.camel@x61.thuisdomein Signed-off-by: Ingo Molnar -- include/linux/lockdep.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

lockdep, rwsem: provide down_write_nest_lock()

2013-01-11T22:54:55Z

down_write_nest_lock() provides a means to annotate locking scenario where an outer lock is guaranteed to serialize the order nested locks are being acquired. This is analogoue to already existing mutex_lock_nest_lock() and spin_lock_nest_lock(). Signed-off-by: Jiri Kosina Cc: Rik van Riel Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Mel Gorman Tested-by: Sedat Dilek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lockdep: fix oops in processing workqueue

2012-05-15T15:08:31Z

Under memory load, on x86_64, with lockdep enabled, the workqueue's process_one_work() has been seen to oops in __lock_acquire(), barfing on a 0xffffffff00000000 pointer in the lockdep_map's class_cache[]. Because it's permissible to free a work_struct from its callout function, the map used is an onstack copy of the map given in the work_struct: and that copy is made without any locking. Surprisingly, gcc (4.5.1 in Hugh's case) uses "rep movsl" rather than "rep movsq" for that structure copy: which might race with a workqueue user's wait_on_work() doing lock_map_acquire() on the source of the copy, putting a pointer into the class_cache[], but only in time for the top half of that pointer to be copied to the destination map. Boom when process_one_work() subsequently does lock_map_acquire() on its onstack copy of the lockdep_map. Fix this, and a similar instance in call_timer_fn(), with a lockdep_copy_map() function which additionally NULLs the class_cache[]. Note: this oops was actually seen on 3.4-next, where flush_work() newly does the racing lock_map_acquire(); but Tejun points out that 3.4 and earlier are already vulnerable to the same through wait_on_work(). * Patch orginally from Peter. Hugh modified it a bit and wrote the description. Signed-off-by: Peter Zijlstra Reported-by: Hugh Dickins LKML-Reference: Signed-off-by: Tejun Heo

printk, lockdep: Disable lock debugging on zap_locks()

2011-11-14T12:35:16Z

zap_locks() is used by printk() in a last ditch effort to get data out, clearly we cannot trust lock state after this so make it disable lock debugging. Also don't treat printk recursion through lockdep as a normal recursion bug but try hard to get the lockdep splat out. Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-kqxwmo4xz37e1s8w0xopvr0q@git.kernel.org Signed-off-by: Ingo Molnar

rcu: Restore checks for blocking in RCU read-side critical sections

2011-09-29T04:36:37Z

Long ago, using TREE_RCU with PREEMPT would result in "scheduling while atomic" diagnostics if you blocked in an RCU read-side critical section. However, PREEMPT now implies TREE_PREEMPT_RCU, which defeats this diagnostic. This commit therefore adds a replacement diagnostic based on PROVE_RCU. Because rcu_lockdep_assert() and lockdep_rcu_dereference() are now being used for things that have nothing to do with rcu_dereference(), rename lockdep_rcu_dereference() to lockdep_rcu_suspicious() and add a third argument that is a string indicating what is suspicious. This third argument is passed in from a new third argument to rcu_lockdep_assert(). Update all calls to rcu_lockdep_assert() to add an informative third argument. Also, add a pair of rcu_lockdep_assert() calls from within rcu_note_context_switch(), one complaining if a context switch occurs in an RCU-bh read-side critical section and another complaining if a context switch occurs in an RCU-sched read-side critical section. These are present only if the PROVE_RCU kernel parameter is enabled. Finally, fix some checkpatch whitespace complaints in lockdep.c. Again, you must enable PROVE_RCU to see these new diagnostics. But you are enabling PROVE_RCU to check out new RCU uses in any case, aren't you? Signed-off-by: Paul E. McKenney

lockdep, mutex: provide mutex_lock_nest_lock

2011-05-25T15:39:17Z

In order to convert i_mmap_lock to a mutex we need a mutex equivalent to spin_lock_nest_lock(), thus provide the mutex_lock_nest_lock() annotation. As with spin_lock_nest_lock(), mutex_lock_nest_lock() allows annotation of the locking pattern where an outer lock serializes the acquisition order of nested locks. That is, if every time you lock multiple locks A, say A1 and A2 you first acquire N, the order of acquiring A1 and A2 is irrelevant. Signed-off-by: Peter Zijlstra Cc: Benjamin Herrenschmidt Cc: David Miller Cc: Martin Schwidefsky Cc: Russell King Cc: Paul Mundt Cc: Jeff Dike Cc: Richard Weinberger Cc: Tony Luck Cc: KAMEZAWA Hiroyuki Cc: Hugh Dickins Cc: Mel Gorman Cc: KOSAKI Motohiro Cc: Nick Piggin Cc: Namhyung Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'fixes-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

2011-01-21T21:38:57Z

* 'fixes-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: note the nested NOT_RUNNING test in worker_clr_flags() isn't a noop workqueue: relax lockdep annotation on flush_work()

lockdep: Move early boot local IRQ enable/disable status to init/main.c

2011-01-20T12:32:33Z

During early boot, local IRQ is disabled until IRQ subsystem is properly initialized. During this time, no one should enable local IRQ and some operations which usually are not allowed with IRQ disabled, e.g. operations which might sleep or require communications with other processors, are allowed. lockdep tracked this with early_boot_irqs_off/on() callbacks. As other subsystems need this information too, move it to init/main.c and make it generally available. While at it, toggle the boolean to early_boot_irqs_disabled instead of enabled so that it can be initialized with %false and %true indicates the exceptional condition. Signed-off-by: Tejun Heo Acked-by: Peter Zijlstra Acked-by: Pekka Enberg Cc: Linus Torvalds LKML-Reference: <20110120110635.GB6036@htj.dyndns.org> Signed-off-by: Ingo Molnar