From 5cd79d6abd2c142352dead0e3df04e86ee32f5d3 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 4 Oct 2017 16:27:00 -0700 Subject: timer: Remove users of TIMER_DEFERRED_INITIALIZER This removes uses of TIMER_DEFERRED_INITIALIZER and chooses a location to call timer_setup() from before add_timer() or mod_timer() is called. Adjusts callbacks to use from_timer() as needed. Signed-off-by: Kees Cook Signed-off-by: Thomas Gleixner Cc: linux-mips@linux-mips.org Cc: Petr Mladek Cc: Benjamin Herrenschmidt Cc: Lai Jiangshan Cc: Sebastian Reichel Cc: Kalle Valo Cc: Paul Mackerras Cc: Pavel Machek Cc: linux1394-devel@lists.sourceforge.net Cc: Chris Metcalf Cc: linux-s390@vger.kernel.org Cc: linux-wireless@vger.kernel.org Cc: "James E.J. Bottomley" Cc: Wim Van Sebroeck Cc: Michael Ellerman Cc: Ursula Braun Cc: Geert Uytterhoeven Cc: Viresh Kumar Cc: Harish Patil Cc: Stephen Boyd Cc: Guenter Roeck Cc: Manish Chopra Cc: Len Brown Cc: Arnd Bergmann Cc: linux-pm@vger.kernel.org Cc: Heiko Carstens Cc: Martin Schwidefsky Cc: Julian Wiedmann Cc: John Stultz Cc: Mark Gross Cc: linux-watchdog@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: "Martin K. Petersen" Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Oleg Nesterov Cc: Ralf Baechle Cc: Stefan Richter Cc: Michael Reed Cc: netdev@vger.kernel.org Cc: Tejun Heo Cc: Andrew Morton Cc: linuxppc-dev@lists.ozlabs.org Cc: Sudip Mukherjee Link: https://lkml.kernel.org/r/1507159627-127660-7-git-send-email-keescook@chromium.org --- kernel/workqueue.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 64d0edf428f8..a5361fc6215d 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -5390,11 +5390,8 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq) { } */ #ifdef CONFIG_WQ_WATCHDOG -static void wq_watchdog_timer_fn(unsigned long data); - static unsigned long wq_watchdog_thresh = 30; -static struct timer_list wq_watchdog_timer = - TIMER_DEFERRED_INITIALIZER(wq_watchdog_timer_fn, 0, 0); +static struct timer_list wq_watchdog_timer; static unsigned long wq_watchdog_touched = INITIAL_JIFFIES; static DEFINE_PER_CPU(unsigned long, wq_watchdog_touched_cpu) = INITIAL_JIFFIES; @@ -5408,7 +5405,7 @@ static void wq_watchdog_reset_touched(void) per_cpu(wq_watchdog_touched_cpu, cpu) = jiffies; } -static void wq_watchdog_timer_fn(unsigned long data) +static void wq_watchdog_timer_fn(struct timer_list *unused) { unsigned long thresh = READ_ONCE(wq_watchdog_thresh) * HZ; bool lockup_detected = false; @@ -5510,6 +5507,7 @@ module_param_cb(watchdog_thresh, &wq_watchdog_thresh_ops, &wq_watchdog_thresh, static void wq_watchdog_init(void) { + timer_setup(&wq_watchdog_timer, wq_watchdog_timer_fn, TIMER_DEFERRABLE); wq_watchdog_set_thresh(wq_watchdog_thresh); } -- cgit v1.2.3 From 8c20feb60604d91a29cd7fef8ac758bd92d9fd2c Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 4 Oct 2017 16:27:07 -0700 Subject: workqueue: Convert callback to use from_timer() In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch workqueue to use from_timer() and pass the timer pointer explicitly. Signed-off-by: Kees Cook Signed-off-by: Thomas Gleixner Cc: linux-mips@linux-mips.org Cc: Petr Mladek Cc: Benjamin Herrenschmidt Cc: Lai Jiangshan Cc: Sebastian Reichel Cc: Kalle Valo Cc: Paul Mackerras Cc: Pavel Machek Cc: linux1394-devel@lists.sourceforge.net Cc: Chris Metcalf Cc: linux-s390@vger.kernel.org Cc: linux-wireless@vger.kernel.org Cc: "James E.J. Bottomley" Cc: Wim Van Sebroeck Cc: Michael Ellerman Cc: Ursula Braun Cc: Geert Uytterhoeven Cc: Viresh Kumar Cc: Harish Patil Cc: Stephen Boyd Cc: Guenter Roeck Cc: Manish Chopra Cc: Len Brown Cc: Arnd Bergmann Cc: linux-pm@vger.kernel.org Cc: Heiko Carstens Cc: Martin Schwidefsky Cc: Julian Wiedmann Cc: John Stultz Cc: Mark Gross Cc: linux-watchdog@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: "Martin K. Petersen" Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Oleg Nesterov Cc: Ralf Baechle Cc: Stefan Richter Cc: Michael Reed Cc: netdev@vger.kernel.org Cc: Tejun Heo Cc: Andrew Morton Cc: linuxppc-dev@lists.ozlabs.org Cc: Sudip Mukherjee Link: https://lkml.kernel.org/r/1507159627-127660-14-git-send-email-keescook@chromium.org --- include/linux/workqueue.h | 15 ++++++++------- kernel/workqueue.c | 7 +++---- 2 files changed, 11 insertions(+), 11 deletions(-) (limited to 'kernel/workqueue.c') diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index f4960260feaf..f3c47a05fd06 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -17,7 +17,7 @@ struct workqueue_struct; struct work_struct; typedef void (*work_func_t)(struct work_struct *work); -void delayed_work_timer_fn(unsigned long __data); +void delayed_work_timer_fn(struct timer_list *t); /* * The first word is the work queue pointer and the flags rolled into @@ -175,8 +175,8 @@ struct execute_work { #define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \ .work = __WORK_INITIALIZER((n).work, (f)), \ - .timer = __TIMER_INITIALIZER(delayed_work_timer_fn, \ - (unsigned long)&(n), \ + .timer = __TIMER_INITIALIZER((TIMER_FUNC_TYPE)delayed_work_timer_fn,\ + (TIMER_DATA_TYPE)&(n.timer), \ (tflags) | TIMER_IRQSAFE), \ } @@ -241,8 +241,9 @@ static inline unsigned int work_static(struct work_struct *work) { return 0; } #define __INIT_DELAYED_WORK(_work, _func, _tflags) \ do { \ INIT_WORK(&(_work)->work, (_func)); \ - __setup_timer(&(_work)->timer, delayed_work_timer_fn, \ - (unsigned long)(_work), \ + __setup_timer(&(_work)->timer, \ + (TIMER_FUNC_TYPE)delayed_work_timer_fn, \ + (TIMER_DATA_TYPE)&(_work)->timer, \ (_tflags) | TIMER_IRQSAFE); \ } while (0) @@ -250,8 +251,8 @@ static inline unsigned int work_static(struct work_struct *work) { return 0; } do { \ INIT_WORK_ONSTACK(&(_work)->work, (_func)); \ __setup_timer_on_stack(&(_work)->timer, \ - delayed_work_timer_fn, \ - (unsigned long)(_work), \ + (TIMER_FUNC_TYPE)delayed_work_timer_fn,\ + (TIMER_DATA_TYPE)&(_work)->timer,\ (_tflags) | TIMER_IRQSAFE); \ } while (0) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index a5361fc6215d..c77fdf6bf24f 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1492,9 +1492,9 @@ bool queue_work_on(int cpu, struct workqueue_struct *wq, } EXPORT_SYMBOL(queue_work_on); -void delayed_work_timer_fn(unsigned long __data) +void delayed_work_timer_fn(struct timer_list *t) { - struct delayed_work *dwork = (struct delayed_work *)__data; + struct delayed_work *dwork = from_timer(dwork, t, timer); /* should have been called from irqsafe timer with irq already off */ __queue_work(dwork->cpu, dwork->wq, &dwork->work); @@ -1508,8 +1508,7 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq, struct work_struct *work = &dwork->work; WARN_ON_ONCE(!wq); - WARN_ON_ONCE(timer->function != delayed_work_timer_fn || - timer->data != (unsigned long)dwork); + WARN_ON_ONCE(timer->function != (TIMER_FUNC_TYPE)delayed_work_timer_fn); WARN_ON_ONCE(timer_pending(timer)); WARN_ON_ONCE(!list_empty(&work->entry)); -- cgit v1.2.3 From 32a6c7233c41216f5dd41fc7bf100eedb1063dfc Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 16 Oct 2017 15:58:25 -0700 Subject: workqueue: Convert timers to use timer_setup() (part 2) In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. (The prior workqueue patch missed a few timers.) Signed-off-by: Kees Cook Acked-by: Tejun Heo Cc: Lai Jiangshan Link: https://lkml.kernel.org/r/20171016225825.GA99101@beast Signed-off-by: Thomas Gleixner --- kernel/workqueue.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index c77fdf6bf24f..6e5eed58f215 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1831,9 +1831,9 @@ static void destroy_worker(struct worker *worker) wake_up_process(worker->task); } -static void idle_worker_timeout(unsigned long __pool) +static void idle_worker_timeout(struct timer_list *t) { - struct worker_pool *pool = (void *)__pool; + struct worker_pool *pool = from_timer(pool, t, idle_timer); spin_lock_irq(&pool->lock); @@ -1879,9 +1879,9 @@ static void send_mayday(struct work_struct *work) } } -static void pool_mayday_timeout(unsigned long __pool) +static void pool_mayday_timeout(struct timer_list *t) { - struct worker_pool *pool = (void *)__pool; + struct worker_pool *pool = from_timer(pool, t, mayday_timer); struct work_struct *work; spin_lock_irq(&pool->lock); @@ -3241,11 +3241,9 @@ static int init_worker_pool(struct worker_pool *pool) INIT_LIST_HEAD(&pool->idle_list); hash_init(pool->busy_hash); - setup_deferrable_timer(&pool->idle_timer, idle_worker_timeout, - (unsigned long)pool); + timer_setup(&pool->idle_timer, idle_worker_timeout, TIMER_DEFERRABLE); - setup_timer(&pool->mayday_timer, pool_mayday_timeout, - (unsigned long)pool); + timer_setup(&pool->mayday_timer, pool_mayday_timeout, 0); mutex_init(&pool->manager_arb); mutex_init(&pool->attach_mutex); -- cgit v1.2.3 From c95491ed6d6a958743d82bea1d053819988da418 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:22 -0700 Subject: locking/atomics, workqueue: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't handle comments, leaving references to ACCESS_ONCE() instances which have been removed. As a preparatory step, this patch converts the workqueue code and comments to use {READ,WRITE}_ONCE() consistently. ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Acked-by: Tejun Heo Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-12-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- kernel/workqueue.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 64d0edf428f8..39831b2f3c5f 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -4647,7 +4647,7 @@ static void rebind_workers(struct worker_pool *pool) * concurrency management. Note that when or whether * @worker clears REBOUND doesn't affect correctness. * - * ACCESS_ONCE() is necessary because @worker->flags may be + * WRITE_ONCE() is necessary because @worker->flags may be * tested without holding any lock in * wq_worker_waking_up(). Without it, NOT_RUNNING test may * fail incorrectly leading to premature concurrency @@ -4656,7 +4656,7 @@ static void rebind_workers(struct worker_pool *pool) WARN_ON_ONCE(!(worker_flags & WORKER_UNBOUND)); worker_flags |= WORKER_REBOUND; worker_flags &= ~WORKER_UNBOUND; - ACCESS_ONCE(worker->flags) = worker_flags; + WRITE_ONCE(worker->flags, worker_flags); } spin_unlock_irq(&pool->lock); -- cgit v1.2.3 From fd1a5b04dfb899f84ddeb8acdaea6b98283df1e5 Mon Sep 17 00:00:00 2001 From: Byungchul Park Date: Wed, 25 Oct 2017 17:56:04 +0900 Subject: workqueue: Remove now redundant lock acquisitions wrt. workqueue flushes The workqueue code added manual lock acquisition annotations to catch deadlocks. After lockdepcrossrelease was introduced, some of those became redundant, since wait_for_completion() already does the acquisition and tracking. Remove the duplicate annotations. Signed-off-by: Byungchul Park Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-9-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar --- include/linux/workqueue.h | 4 ++-- kernel/workqueue.c | 19 +++---------------- 2 files changed, 5 insertions(+), 18 deletions(-) (limited to 'kernel/workqueue.c') diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 1c49431f3121..c8a572cb49be 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -218,7 +218,7 @@ static inline unsigned int work_static(struct work_struct *work) { return 0; } \ __init_work((_work), _onstack); \ (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \ - lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0); \ + lockdep_init_map(&(_work)->lockdep_map, "(work_completion)"#_work, &__key, 0); \ INIT_LIST_HEAD(&(_work)->entry); \ (_work)->func = (_func); \ } while (0) @@ -398,7 +398,7 @@ __alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active, static struct lock_class_key __key; \ const char *__lock_name; \ \ - __lock_name = #fmt#args; \ + __lock_name = "(wq_completion)"#fmt#args; \ \ __alloc_workqueue_key((fmt), (flags), (max_active), \ &__key, __lock_name, ##args); \ diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 39831b2f3c5f..160fdc6e839a 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2497,15 +2497,8 @@ static void insert_wq_barrier(struct pool_workqueue *pwq, INIT_WORK_ONSTACK(&barr->work, wq_barrier_func); __set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(&barr->work)); - /* - * Explicitly init the crosslock for wq_barrier::done, make its lock - * key a subkey of the corresponding work. As a result we won't - * build a dependency between wq_barrier::done and unrelated work. - */ - lockdep_init_map_crosslock((struct lockdep_map *)&barr->done.map, - "(complete)wq_barr::done", - target->lockdep_map.key, 1); - __init_completion(&barr->done); + init_completion_map(&barr->done, &target->lockdep_map); + barr->task = current; /* @@ -2611,16 +2604,13 @@ void flush_workqueue(struct workqueue_struct *wq) struct wq_flusher this_flusher = { .list = LIST_HEAD_INIT(this_flusher.list), .flush_color = -1, - .done = COMPLETION_INITIALIZER_ONSTACK(this_flusher.done), + .done = COMPLETION_INITIALIZER_ONSTACK_MAP(this_flusher.done, wq->lockdep_map), }; int next_color; if (WARN_ON(!wq_online)) return; - lock_map_acquire(&wq->lockdep_map); - lock_map_release(&wq->lockdep_map); - mutex_lock(&wq->mutex); /* @@ -2883,9 +2873,6 @@ bool flush_work(struct work_struct *work) if (WARN_ON(!wq_online)) return false; - lock_map_acquire(&work->lockdep_map); - lock_map_release(&work->lockdep_map); - if (start_flush_work(work, &barr)) { wait_for_completion(&barr.done); destroy_work_on_stack(&barr.work); -- cgit v1.2.3 From 8e8eb730759f9cfd7a761b0b4ee41d714e720993 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:19 +0100 Subject: workqueue: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Acked-by: Tejun Heo Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1509980490-4285-4-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- kernel/workqueue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 1070b21ba4aa..13f67b5a0a0c 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1376,7 +1376,7 @@ static void __queue_work(int cpu, struct workqueue_struct *wq, * queued or lose PENDING. Grabbing PENDING and queueing should * happen with IRQ disabled. */ - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); debug_work_activate(work); -- cgit v1.2.3