diff --git a/Makefile b/Makefile index d277446ee8ee..ed97caf40f71 100644 --- a/Makefile +++ b/Makefile @@ -1,6 +1,6 @@ VERSION = 3 PATCHLEVEL = 4 -SUBLEVEL = 98 +SUBLEVEL = 99 EXTRAVERSION = NAME = Saber-toothed Squirrel diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 02aee03e713c..1eef567f177a 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -472,7 +472,22 @@ static void power_pmu_read(struct perf_event *event) } while (local64_cmpxchg(&event->hw.prev_count, prev, val) != prev); local64_add(delta, &event->count); - local64_sub(delta, &event->hw.period_left); + + /* + * A number of places program the PMC with (0x80000000 - period_left). + * We never want period_left to be less than 1 because we will program + * the PMC with a value >= 0x800000000 and an edge detected PMC will + * roll around to 0 before taking an exception. We have seen this + * on POWER8. + * + * To fix this, clamp the minimum value of period_left to 1. + */ + do { + prev = local64_read(&event->hw.period_left); + val = prev - delta; + if (val < 1) + val = 1; + } while (local64_cmpxchg(&event->hw.period_left, prev, val) != prev); } /* diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index be1ef574ce9a..dec49d34c048 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -50,6 +50,21 @@ int ioremap_change_attr(unsigned long vaddr, unsigned long size, return err; } +static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages, + void *arg) +{ + unsigned long i; + + for (i = 0; i < nr_pages; ++i) + if (pfn_valid(start_pfn + i) && + !PageReserved(pfn_to_page(start_pfn + i))) + return 1; + + WARN_ONCE(1, "ioremap on RAM pfn 0x%lx\n", start_pfn); + + return 0; +} + /* * Remap an arbitrary physical address space into the kernel virtual * address space. Needed when the kernel wants to access high addresses @@ -93,14 +108,11 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, /* * Don't allow anybody to remap normal RAM that we're using.. */ + pfn = phys_addr >> PAGE_SHIFT; last_pfn = last_addr >> PAGE_SHIFT; - for (pfn = phys_addr >> PAGE_SHIFT; pfn <= last_pfn; pfn++) { - int is_ram = page_is_ram(pfn); - - if (is_ram && pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn))) - return NULL; - WARN_ON_ONCE(is_ram); - } + if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL, + __ioremap_check_ram) == 1) + return NULL; /* * Mappings have to be page-aligned diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c index 9bdfcf50a190..93f3034ea85d 100644 --- a/drivers/acpi/battery.c +++ b/drivers/acpi/battery.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #ifdef CONFIG_ACPI_PROCFS_POWER @@ -1055,6 +1056,28 @@ static int battery_notify(struct notifier_block *nb, return 0; } +/* + * Some machines'(E,G Lenovo Z480) ECs are not stable + * during boot up and this causes battery driver fails to be + * probed due to failure of getting battery information + * from EC sometimes. After several retries, the operation + * may work. So add retry code here and 20ms sleep between + * every retries. + */ +static int acpi_battery_update_retry(struct acpi_battery *battery) +{ + int retry, ret; + + for (retry = 5; retry; retry--) { + ret = acpi_battery_update(battery); + if (!ret) + break; + + msleep(20); + } + return ret; +} + static int acpi_battery_add(struct acpi_device *device) { int result = 0; @@ -1074,9 +1097,11 @@ static int acpi_battery_add(struct acpi_device *device) if (ACPI_SUCCESS(acpi_get_handle(battery->device->handle, "_BIX", &handle))) set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags); - result = acpi_battery_update(battery); + + result = acpi_battery_update_retry(battery); if (result) goto fail; + #ifdef CONFIG_ACPI_PROCFS_POWER result = acpi_battery_add_fs(device); #endif diff --git a/drivers/gpu/drm/radeon/rs600.c b/drivers/gpu/drm/radeon/rs600.c index 52480010156d..739eb0d0d12d 100644 --- a/drivers/gpu/drm/radeon/rs600.c +++ b/drivers/gpu/drm/radeon/rs600.c @@ -539,8 +539,10 @@ int rs600_gart_set_page(struct radeon_device *rdev, int i, uint64_t addr) return -EINVAL; } addr = addr & 0xFFFFFFFFFFFFF000ULL; - addr |= R600_PTE_VALID | R600_PTE_SYSTEM | R600_PTE_SNOOPED; - addr |= R600_PTE_READABLE | R600_PTE_WRITEABLE; + if (addr != rdev->dummy_page.addr) + addr |= R600_PTE_VALID | R600_PTE_READABLE | + R600_PTE_WRITEABLE; + addr |= R600_PTE_SYSTEM | R600_PTE_SNOOPED; writeq(addr, ptr + (i * 8)); return 0; } diff --git a/drivers/hwmon/adm1029.c b/drivers/hwmon/adm1029.c index 80cc465d8ac7..f078baef90fe 100644 --- a/drivers/hwmon/adm1029.c +++ b/drivers/hwmon/adm1029.c @@ -231,6 +231,9 @@ static ssize_t set_fan_div(struct device *dev, /* Update the value */ reg = (reg & 0x3F) | (val << 6); + /* Update the cache */ + data->fan_div[attr->index] = reg; + /* Write value */ i2c_smbus_write_byte_data(client, ADM1029_REG_FAN_DIV[attr->index], reg); diff --git a/drivers/hwmon/amc6821.c b/drivers/hwmon/amc6821.c index f600fa1f92e3..1d2bace45287 100644 --- a/drivers/hwmon/amc6821.c +++ b/drivers/hwmon/amc6821.c @@ -715,7 +715,7 @@ static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, get_temp_alarm, NULL, IDX_TEMP1_MAX); static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, get_temp_alarm, NULL, IDX_TEMP1_CRIT); -static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO | S_IWUSR, +static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, get_temp, NULL, IDX_TEMP2_INPUT); static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR, get_temp, set_temp, IDX_TEMP2_MIN); diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c index 3bd9bd49ed9a..ac339570a805 100644 --- a/drivers/usb/serial/cp210x.c +++ b/drivers/usb/serial/cp210x.c @@ -159,6 +159,7 @@ static const struct usb_device_id id_table[] = { { USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */ { USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */ { USB_DEVICE(0x1ADB, 0x0001) }, /* Schweitzer Engineering C662 Cable */ + { USB_DEVICE(0x1B1C, 0x1C00) }, /* Corsair USB Dongle */ { USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */ { USB_DEVICE(0x1E29, 0x0102) }, /* Festo CPX-USB */ { USB_DEVICE(0x1E29, 0x0501) }, /* Festo CMSP */ diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index ed1650fb910d..89b5664aa53b 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -731,7 +731,8 @@ static struct usb_device_id id_table_combined [] = { { USB_DEVICE(FTDI_VID, FTDI_ACG_HFDUAL_PID) }, { USB_DEVICE(FTDI_VID, FTDI_YEI_SERVOCENTER31_PID) }, { USB_DEVICE(FTDI_VID, FTDI_THORLABS_PID) }, - { USB_DEVICE(TESTO_VID, TESTO_USB_INTERFACE_PID) }, + { USB_DEVICE(TESTO_VID, TESTO_1_PID) }, + { USB_DEVICE(TESTO_VID, TESTO_3_PID) }, { USB_DEVICE(FTDI_VID, FTDI_GAMMA_SCOUT_PID) }, { USB_DEVICE(FTDI_VID, FTDI_TACTRIX_OPENPORT_13M_PID) }, { USB_DEVICE(FTDI_VID, FTDI_TACTRIX_OPENPORT_13S_PID) }, diff --git a/drivers/usb/serial/ftdi_sio_ids.h b/drivers/usb/serial/ftdi_sio_ids.h index 500474c48f4b..106cc16cc6ed 100644 --- a/drivers/usb/serial/ftdi_sio_ids.h +++ b/drivers/usb/serial/ftdi_sio_ids.h @@ -798,7 +798,8 @@ * Submitted by Colin Leroy */ #define TESTO_VID 0x128D -#define TESTO_USB_INTERFACE_PID 0x0001 +#define TESTO_1_PID 0x0001 +#define TESTO_3_PID 0x0003 /* * Mobility Electronics products. diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c index 58fcaa5ae548..e1e05bad2be0 100644 --- a/drivers/usb/serial/option.c +++ b/drivers/usb/serial/option.c @@ -1501,6 +1501,8 @@ static const struct usb_device_id option_ids[] = { .driver_info = (kernel_ulong_t)&net_intf2_blacklist }, { USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1426, 0xff, 0xff, 0xff), /* ZTE MF91 */ .driver_info = (kernel_ulong_t)&net_intf2_blacklist }, + { USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1428, 0xff, 0xff, 0xff), /* Telewell TW-LTE 4G v2 */ + .driver_info = (kernel_ulong_t)&net_intf2_blacklist }, { USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1533, 0xff, 0xff, 0xff) }, { USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1534, 0xff, 0xff, 0xff) }, { USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1535, 0xff, 0xff, 0xff) }, diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 0b0c03c878e5..f0e4e46867f7 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2589,10 +2589,11 @@ static void print_daily_error_info(unsigned long arg) es = sbi->s_es; if (es->s_error_count) - ext4_msg(sb, KERN_NOTICE, "error count: %u", + /* fsck newer than v1.41.13 is needed to clean this condition. */ + ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u", le32_to_cpu(es->s_error_count)); if (es->s_first_error_time) { - printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d", + printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d", sb->s_id, le32_to_cpu(es->s_first_error_time), (int) sizeof(es->s_first_error_func), es->s_first_error_func, @@ -2606,7 +2607,7 @@ static void print_daily_error_info(unsigned long arg) printk("\n"); } if (es->s_last_error_time) { - printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d", + printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d", sb->s_id, le32_to_cpu(es->s_last_error_time), (int) sizeof(es->s_last_error_func), es->s_last_error_func, diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 4b843ace285c..9cb82b9aeb73 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1152,7 +1152,13 @@ done: int current_cpuset_is_being_rebound(void) { - return task_cs(current) == cpuset_being_rebound; + int ret; + + rcu_read_lock(); + ret = task_cs(current) == cpuset_being_rebound; + rcu_read_unlock(); + + return ret; } static int update_relax_domain_level(struct cpuset *cs, s64 val) diff --git a/kernel/rtmutex-debug.h b/kernel/rtmutex-debug.h index 14193d596d78..ab29b6a22669 100644 --- a/kernel/rtmutex-debug.h +++ b/kernel/rtmutex-debug.h @@ -31,3 +31,8 @@ static inline int debug_rt_mutex_detect_deadlock(struct rt_mutex_waiter *waiter, { return (waiter != NULL); } + +static inline void rt_mutex_print_deadlock(struct rt_mutex_waiter *w) +{ + debug_rt_mutex_print_deadlock(w); +} diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c index a242e691c993..375ae48479fa 100644 --- a/kernel/rtmutex.c +++ b/kernel/rtmutex.c @@ -81,6 +81,47 @@ static inline void mark_rt_mutex_waiters(struct rt_mutex *lock) owner = *p; } while (cmpxchg(p, owner, owner | RT_MUTEX_HAS_WAITERS) != owner); } + +/* + * Safe fastpath aware unlock: + * 1) Clear the waiters bit + * 2) Drop lock->wait_lock + * 3) Try to unlock the lock with cmpxchg + */ +static inline bool unlock_rt_mutex_safe(struct rt_mutex *lock) + __releases(lock->wait_lock) +{ + struct task_struct *owner = rt_mutex_owner(lock); + + clear_rt_mutex_waiters(lock); + raw_spin_unlock(&lock->wait_lock); + /* + * If a new waiter comes in between the unlock and the cmpxchg + * we have two situations: + * + * unlock(wait_lock); + * lock(wait_lock); + * cmpxchg(p, owner, 0) == owner + * mark_rt_mutex_waiters(lock); + * acquire(lock); + * or: + * + * unlock(wait_lock); + * lock(wait_lock); + * mark_rt_mutex_waiters(lock); + * + * cmpxchg(p, owner, 0) != owner + * enqueue_waiter(); + * unlock(wait_lock); + * lock(wait_lock); + * wake waiter(); + * unlock(wait_lock); + * lock(wait_lock); + * acquire(lock); + */ + return rt_mutex_cmpxchg(lock, owner, NULL); +} + #else # define rt_mutex_cmpxchg(l,c,n) (0) static inline void mark_rt_mutex_waiters(struct rt_mutex *lock) @@ -88,6 +129,17 @@ static inline void mark_rt_mutex_waiters(struct rt_mutex *lock) lock->owner = (struct task_struct *) ((unsigned long)lock->owner | RT_MUTEX_HAS_WAITERS); } + +/* + * Simple slow path only version: lock->owner is protected by lock->wait_lock. + */ +static inline bool unlock_rt_mutex_safe(struct rt_mutex *lock) + __releases(lock->wait_lock) +{ + lock->owner = NULL; + raw_spin_unlock(&lock->wait_lock); + return true; +} #endif /* @@ -141,6 +193,11 @@ static void rt_mutex_adjust_prio(struct task_struct *task) */ int max_lock_depth = 1024; +static inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p) +{ + return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL; +} + /* * Adjust the priority chain. Also used for deadlock detection. * Decreases task's usage by one - may thus free the task. @@ -149,6 +206,7 @@ int max_lock_depth = 1024; static int rt_mutex_adjust_prio_chain(struct task_struct *task, int deadlock_detect, struct rt_mutex *orig_lock, + struct rt_mutex *next_lock, struct rt_mutex_waiter *orig_waiter, struct task_struct *top_task) { @@ -182,7 +240,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, } put_task_struct(task); - return deadlock_detect ? -EDEADLK : 0; + return -EDEADLK; } retry: /* @@ -207,13 +265,32 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, goto out_unlock_pi; /* + * We dropped all locks after taking a refcount on @task, so + * the task might have moved on in the lock chain or even left + * the chain completely and blocks now on an unrelated lock or + * on @orig_lock. + * + * We stored the lock on which @task was blocked in @next_lock, + * so we can detect the chain change. + */ + if (next_lock != waiter->lock) + goto out_unlock_pi; + + /* * Drop out, when the task has no waiters. Note, * top_waiter can be NULL, when we are in the deboosting * mode! */ - if (top_waiter && (!task_has_pi_waiters(task) || - top_waiter != task_top_pi_waiter(task))) - goto out_unlock_pi; + if (top_waiter) { + if (!task_has_pi_waiters(task)) + goto out_unlock_pi; + /* + * If deadlock detection is off, we stop here if we + * are not the top pi waiter of the task. + */ + if (!detect_deadlock && top_waiter != task_top_pi_waiter(task)) + goto out_unlock_pi; + } /* * When deadlock detection is off then we check, if further @@ -229,11 +306,16 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, goto retry; } - /* Deadlock detection */ + /* + * Deadlock detection. If the lock is the same as the original + * lock which caused us to walk the lock chain or if the + * current lock is owned by the task which initiated the chain + * walk, we detected a deadlock. + */ if (lock == orig_lock || rt_mutex_owner(lock) == top_task) { debug_rt_mutex_deadlock(deadlock_detect, orig_waiter, lock); raw_spin_unlock(&lock->wait_lock); - ret = deadlock_detect ? -EDEADLK : 0; + ret = -EDEADLK; goto out_unlock_pi; } @@ -280,11 +362,26 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, __rt_mutex_adjust_prio(task); } + /* + * Check whether the task which owns the current lock is pi + * blocked itself. If yes we store a pointer to the lock for + * the lock chain change detection above. After we dropped + * task->pi_lock next_lock cannot be dereferenced anymore. + */ + next_lock = task_blocked_on_lock(task); + raw_spin_unlock_irqrestore(&task->pi_lock, flags); top_waiter = rt_mutex_top_waiter(lock); raw_spin_unlock(&lock->wait_lock); + /* + * We reached the end of the lock chain. Stop right here. No + * point to go back just to figure that out. + */ + if (!next_lock) + goto out_put_task; + if (!detect_deadlock && waiter != top_waiter) goto out_put_task; @@ -395,8 +492,21 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, { struct task_struct *owner = rt_mutex_owner(lock); struct rt_mutex_waiter *top_waiter = waiter; - unsigned long flags; + struct rt_mutex *next_lock; int chain_walk = 0, res; + unsigned long flags; + + /* + * Early deadlock detection. We really don't want the task to + * enqueue on itself just to untangle the mess later. It's not + * only an optimization. We drop the locks, so another waiter + * can come in before the chain walk detects the deadlock. So + * the other will detect the deadlock and return -EDEADLOCK, + * which is wrong, as the other waiter is not in a deadlock + * situation. + */ + if (owner == task) + return -EDEADLK; raw_spin_lock_irqsave(&task->pi_lock, flags); __rt_mutex_adjust_prio(task); @@ -417,20 +527,28 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, if (!owner) return 0; + raw_spin_lock_irqsave(&owner->pi_lock, flags); if (waiter == rt_mutex_top_waiter(lock)) { - raw_spin_lock_irqsave(&owner->pi_lock, flags); plist_del(&top_waiter->pi_list_entry, &owner->pi_waiters); plist_add(&waiter->pi_list_entry, &owner->pi_waiters); __rt_mutex_adjust_prio(owner); if (owner->pi_blocked_on) chain_walk = 1; - raw_spin_unlock_irqrestore(&owner->pi_lock, flags); - } - else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock)) + } else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock)) { chain_walk = 1; + } + + /* Store the lock on which owner is blocked or NULL */ + next_lock = task_blocked_on_lock(owner); - if (!chain_walk) + raw_spin_unlock_irqrestore(&owner->pi_lock, flags); + /* + * Even if full deadlock detection is on, if the owner is not + * blocked itself, we can avoid finding this out in the chain + * walk. + */ + if (!chain_walk || !next_lock) return 0; /* @@ -442,8 +560,8 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, raw_spin_unlock(&lock->wait_lock); - res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, waiter, - task); + res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, + next_lock, waiter, task); raw_spin_lock(&lock->wait_lock); @@ -453,7 +571,8 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, /* * Wake up the next waiter on the lock. * - * Remove the top waiter from the current tasks waiter list and wake it up. + * Remove the top waiter from the current tasks pi waiter list and + * wake it up. * * Called with lock->wait_lock held. */ @@ -474,10 +593,23 @@ static void wakeup_next_waiter(struct rt_mutex *lock) */ plist_del(&waiter->pi_list_entry, ¤t->pi_waiters); - rt_mutex_set_owner(lock, NULL); + /* + * As we are waking up the top waiter, and the waiter stays + * queued on the lock until it gets the lock, this lock + * obviously has waiters. Just set the bit here and this has + * the added benefit of forcing all new tasks into the + * slow path making sure no task of lower priority than + * the top waiter can steal this lock. + */ + lock->owner = (void *) RT_MUTEX_HAS_WAITERS; raw_spin_unlock_irqrestore(¤t->pi_lock, flags); + /* + * It's safe to dereference waiter as it cannot go away as + * long as we hold lock->wait_lock. The waiter task needs to + * acquire it in order to dequeue the waiter. + */ wake_up_process(waiter->task); } @@ -492,8 +624,8 @@ static void remove_waiter(struct rt_mutex *lock, { int first = (waiter == rt_mutex_top_waiter(lock)); struct task_struct *owner = rt_mutex_owner(lock); + struct rt_mutex *next_lock = NULL; unsigned long flags; - int chain_walk = 0; raw_spin_lock_irqsave(¤t->pi_lock, flags); plist_del(&waiter->list_entry, &lock->wait_list); @@ -517,15 +649,15 @@ static void remove_waiter(struct rt_mutex *lock, } __rt_mutex_adjust_prio(owner); - if (owner->pi_blocked_on) - chain_walk = 1; + /* Store the lock on which owner is blocked or NULL */ + next_lock = task_blocked_on_lock(owner); raw_spin_unlock_irqrestore(&owner->pi_lock, flags); } WARN_ON(!plist_node_empty(&waiter->pi_list_entry)); - if (!chain_walk) + if (!next_lock) return; /* gets dropped in rt_mutex_adjust_prio_chain()! */ @@ -533,7 +665,7 @@ static void remove_waiter(struct rt_mutex *lock, raw_spin_unlock(&lock->wait_lock); - rt_mutex_adjust_prio_chain(owner, 0, lock, NULL, current); + rt_mutex_adjust_prio_chain(owner, 0, lock, next_lock, NULL, current); raw_spin_lock(&lock->wait_lock); } @@ -546,6 +678,7 @@ static void remove_waiter(struct rt_mutex *lock, void rt_mutex_adjust_pi(struct task_struct *task) { struct rt_mutex_waiter *waiter; + struct rt_mutex *next_lock; unsigned long flags; raw_spin_lock_irqsave(&task->pi_lock, flags); @@ -555,12 +688,13 @@ void rt_mutex_adjust_pi(struct task_struct *task) raw_spin_unlock_irqrestore(&task->pi_lock, flags); return; } - + next_lock = waiter->lock; raw_spin_unlock_irqrestore(&task->pi_lock, flags); /* gets dropped in rt_mutex_adjust_prio_chain()! */ get_task_struct(task); - rt_mutex_adjust_prio_chain(task, 0, NULL, NULL, task); + + rt_mutex_adjust_prio_chain(task, 0, NULL, next_lock, NULL, task); } /** @@ -612,6 +746,26 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state, return ret; } +static void rt_mutex_handle_deadlock(int res, int detect_deadlock, + struct rt_mutex_waiter *w) +{ + /* + * If the result is not -EDEADLOCK or the caller requested + * deadlock detection, nothing to do here. + */ + if (res != -EDEADLOCK || detect_deadlock) + return; + + /* + * Yell lowdly and stop the task right here. + */ + rt_mutex_print_deadlock(w); + while (1) { + set_current_state(TASK_INTERRUPTIBLE); + schedule(); + } +} + /* * Slow path lock function: */ @@ -649,8 +803,10 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state, set_current_state(TASK_RUNNING); - if (unlikely(ret)) + if (unlikely(ret)) { remove_waiter(lock, &waiter); + rt_mutex_handle_deadlock(ret, detect_deadlock, &waiter); + } /* * try_to_take_rt_mutex() sets the waiter bit @@ -706,12 +862,49 @@ rt_mutex_slowunlock(struct rt_mutex *lock) rt_mutex_deadlock_account_unlock(current); - if (!rt_mutex_has_waiters(lock)) { - lock->owner = NULL; - raw_spin_unlock(&lock->wait_lock); - return; + /* + * We must be careful here if the fast path is enabled. If we + * have no waiters queued we cannot set owner to NULL here + * because of: + * + * foo->lock->owner = NULL; + * rtmutex_lock(foo->lock); <- fast path + * free = atomic_dec_and_test(foo->refcnt); + * rtmutex_unlock(foo->lock); <- fast path + * if (free) + * kfree(foo); + * raw_spin_unlock(foo->lock->wait_lock); + * + * So for the fastpath enabled kernel: + * + * Nothing can set the waiters bit as long as we hold + * lock->wait_lock. So we do the following sequence: + * + * owner = rt_mutex_owner(lock); + * clear_rt_mutex_waiters(lock); + * raw_spin_unlock(&lock->wait_lock); + * if (cmpxchg(&lock->owner, owner, 0) == owner) + * return; + * goto retry; + * + * The fastpath disabled variant is simple as all access to + * lock->owner is serialized by lock->wait_lock: + * + * lock->owner = NULL; + * raw_spin_unlock(&lock->wait_lock); + */ + while (!rt_mutex_has_waiters(lock)) { + /* Drops lock->wait_lock ! */ + if (unlock_rt_mutex_safe(lock) == true) + return; + /* Relock the rtmutex and try again */ + raw_spin_lock(&lock->wait_lock); } + /* + * The wakeup next waiter path does not suffer from the above + * race. See the comments there. + */ wakeup_next_waiter(lock); raw_spin_unlock(&lock->wait_lock); @@ -958,7 +1151,8 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock, return 1; } - ret = task_blocks_on_rt_mutex(lock, waiter, task, detect_deadlock); + /* We enforce deadlock detection for futexes */ + ret = task_blocks_on_rt_mutex(lock, waiter, task, 1); if (ret && !rt_mutex_owner(lock)) { /* diff --git a/kernel/rtmutex.h b/kernel/rtmutex.h index a1a1dd06421d..f6a1f3c133b1 100644 --- a/kernel/rtmutex.h +++ b/kernel/rtmutex.h @@ -24,3 +24,8 @@ #define debug_rt_mutex_print_deadlock(w) do { } while (0) #define debug_rt_mutex_detect_deadlock(w,d) (d) #define debug_rt_mutex_reset_waiter(w) do { } while (0) + +static inline void rt_mutex_print_deadlock(struct rt_mutex_waiter *w) +{ + WARN(1, "rtmutex deadlock detected\n"); +} diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a494ec317e0a..8897a6f5c408 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1052,7 +1052,6 @@ void tracing_start(void) arch_spin_unlock(&ftrace_max_lock); - ftrace_start(); out: raw_spin_unlock_irqrestore(&tracing_start_lock, flags); } @@ -1068,7 +1067,6 @@ void tracing_stop(void) struct ring_buffer *buffer; unsigned long flags; - ftrace_stop(); raw_spin_lock_irqsave(&tracing_start_lock, flags); if (trace_stop_count++) goto out; diff --git a/mm/mempolicy.c b/mm/mempolicy.c index ee50c256fdc3..5cec36b6e838 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1991,7 +1991,6 @@ struct mempolicy *__mpol_dup(struct mempolicy *old) } else *new = *old; - rcu_read_lock(); if (current_cpuset_is_being_rebound()) { nodemask_t mems = cpuset_mems_allowed(current); if (new->flags & MPOL_F_REBINDING) @@ -1999,7 +1998,6 @@ struct mempolicy *__mpol_dup(struct mempolicy *old) else mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE); } - rcu_read_unlock(); atomic_set(&new->refcnt, 1); return new; }