diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cpu.c | 9 | ||||
| -rw-r--r-- | kernel/futex.c | 8 | ||||
| -rw-r--r-- | kernel/locking/lockdep.c | 57 | ||||
| -rw-r--r-- | kernel/locking/lockdep_internals.h | 4 | ||||
| -rw-r--r-- | kernel/sched/core.c | 7 |
5 files changed, 38 insertions, 47 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index d1c6d152da89..025f419d16f6 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -313,6 +313,15 @@ void cpus_write_unlock(void) void lockdep_assert_cpus_held(void) { + /* + * We can't have hotplug operations before userspace starts running, + * and some init codepaths will knowingly not take the hotplug lock. + * This is all valid, so mute lockdep until it makes sense to report + * unheld locks. + */ + if (system_state < SYSTEM_RUNNING) + return; + percpu_rwsem_assert_held(&cpu_hotplug_lock); } diff --git a/kernel/futex.c b/kernel/futex.c index fdd312da0992..69e619baf709 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -321,12 +321,8 @@ static int __init fail_futex_debugfs(void) if (IS_ERR(dir)) return PTR_ERR(dir); - if (!debugfs_create_bool("ignore-private", mode, dir, - &fail_futex.ignore_private)) { - debugfs_remove_recursive(dir); - return -ENOMEM; - } - + debugfs_create_bool("ignore-private", mode, dir, + &fail_futex.ignore_private); return 0; } diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 95932333a48b..608f74ed8bb9 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -1624,29 +1624,18 @@ static const char *state_rnames[] = { static inline const char *state_name(enum lock_usage_bit bit) { - return (bit & 1) ? state_rnames[bit >> 2] : state_names[bit >> 2]; + return (bit & LOCK_USAGE_READ_MASK) ? state_rnames[bit >> 2] : state_names[bit >> 2]; } static int exclusive_bit(int new_bit) { - /* - * USED_IN - * USED_IN_READ - * ENABLED - * ENABLED_READ - * - * bit 0 - write/read - * bit 1 - used_in/enabled - * bit 2+ state - */ - - int state = new_bit & ~3; - int dir = new_bit & 2; + int state = new_bit & LOCK_USAGE_STATE_MASK; + int dir = new_bit & LOCK_USAGE_DIR_MASK; /* * keep state, bit flip the direction and strip read. */ - return state | (dir ^ 2); + return state | (dir ^ LOCK_USAGE_DIR_MASK); } static int check_irq_usage(struct task_struct *curr, struct held_lock *prev, @@ -2662,8 +2651,8 @@ mark_lock_irq(struct task_struct *curr, struct held_lock *this, enum lock_usage_bit new_bit) { int excl_bit = exclusive_bit(new_bit); - int read = new_bit & 1; - int dir = new_bit & 2; + int read = new_bit & LOCK_USAGE_READ_MASK; + int dir = new_bit & LOCK_USAGE_DIR_MASK; /* * mark USED_IN has to look forwards -- to ensure no dependency @@ -2687,19 +2676,19 @@ mark_lock_irq(struct task_struct *curr, struct held_lock *this, * states. */ if ((!read || !dir || STRICT_READ_CHECKS) && - !usage(curr, this, excl_bit, state_name(new_bit & ~1))) + !usage(curr, this, excl_bit, state_name(new_bit & ~LOCK_USAGE_READ_MASK))) return 0; /* * Check for read in write conflicts */ if (!read) { - if (!valid_state(curr, this, new_bit, excl_bit + 1)) + if (!valid_state(curr, this, new_bit, excl_bit + LOCK_USAGE_READ_MASK)) return 0; if (STRICT_READ_CHECKS && - !usage(curr, this, excl_bit + 1, - state_name(new_bit + 1))) + !usage(curr, this, excl_bit + LOCK_USAGE_READ_MASK, + state_name(new_bit + LOCK_USAGE_READ_MASK))) return 0; } @@ -2709,35 +2698,28 @@ mark_lock_irq(struct task_struct *curr, struct held_lock *this, return 1; } -enum mark_type { -#define LOCKDEP_STATE(__STATE) __STATE, -#include "lockdep_states.h" -#undef LOCKDEP_STATE -}; - /* * Mark all held locks with a usage bit: */ static int -mark_held_locks(struct task_struct *curr, enum mark_type mark) +mark_held_locks(struct task_struct *curr, enum lock_usage_bit base_bit) { - enum lock_usage_bit usage_bit; struct held_lock *hlock; int i; for (i = 0; i < curr->lockdep_depth; i++) { + enum lock_usage_bit hlock_bit = base_bit; hlock = curr->held_locks + i; - usage_bit = 2 + (mark << 2); /* ENABLED */ if (hlock->read) - usage_bit += 1; /* READ */ + hlock_bit += LOCK_USAGE_READ_MASK; - BUG_ON(usage_bit >= LOCK_USAGE_STATES); + BUG_ON(hlock_bit >= LOCK_USAGE_STATES); if (!hlock->check) continue; - if (!mark_lock(curr, hlock, usage_bit)) + if (!mark_lock(curr, hlock, hlock_bit)) return 0; } @@ -2758,7 +2740,7 @@ static void __trace_hardirqs_on_caller(unsigned long ip) * We are going to turn hardirqs on, so set the * usage bit for all held locks: */ - if (!mark_held_locks(curr, HARDIRQ)) + if (!mark_held_locks(curr, LOCK_ENABLED_HARDIRQ)) return; /* * If we have softirqs enabled, then set the usage @@ -2766,7 +2748,7 @@ static void __trace_hardirqs_on_caller(unsigned long ip) * this bit from being set before) */ if (curr->softirqs_enabled) - if (!mark_held_locks(curr, SOFTIRQ)) + if (!mark_held_locks(curr, LOCK_ENABLED_SOFTIRQ)) return; curr->hardirq_enable_ip = ip; @@ -2880,7 +2862,7 @@ void trace_softirqs_on(unsigned long ip) * enabled too: */ if (curr->hardirqs_enabled) - mark_held_locks(curr, SOFTIRQ); + mark_held_locks(curr, LOCK_ENABLED_SOFTIRQ); current->lockdep_recursion = 0; } @@ -3535,6 +3517,9 @@ static int __lock_downgrade(struct lockdep_map *lock, unsigned long ip) unsigned int depth; int i; + if (unlikely(!debug_locks)) + return 0; + depth = curr->lockdep_depth; /* * This function is about (re)setting the class of a held lock, diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h index 88c847a41c8a..2ebb9d0ea91c 100644 --- a/kernel/locking/lockdep_internals.h +++ b/kernel/locking/lockdep_internals.h @@ -22,6 +22,10 @@ enum lock_usage_bit { LOCK_USAGE_STATES }; +#define LOCK_USAGE_READ_MASK 1 +#define LOCK_USAGE_DIR_MASK 2 +#define LOCK_USAGE_STATE_MASK (~(LOCK_USAGE_READ_MASK | LOCK_USAGE_DIR_MASK)) + /* * Usage-state bitmasks: */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index d8d76a65cfdd..3c8b4dba3d2d 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -421,7 +421,7 @@ void wake_q_add(struct wake_q_head *head, struct task_struct *task) * state, even in the failed case, an explicit smp_mb() must be used. */ smp_mb__before_atomic(); - if (cmpxchg_relaxed(&node->next, NULL, WAKE_Q_TAIL)) + if (unlikely(cmpxchg_relaxed(&node->next, NULL, WAKE_Q_TAIL))) return; get_task_struct(task); @@ -5867,14 +5867,11 @@ void __init sched_init_smp(void) /* * There's no userspace yet to cause hotplug operations; hence all the * CPU masks are stable and all blatant races in the below code cannot - * happen. The hotplug lock is nevertheless taken to satisfy lockdep, - * but there won't be any contention on it. + * happen. */ - cpus_read_lock(); mutex_lock(&sched_domains_mutex); sched_init_domains(cpu_active_mask); mutex_unlock(&sched_domains_mutex); - cpus_read_unlock(); /* Move init over to a non-isolated CPU */ if (set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_FLAG_DOMAIN)) < 0) |