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authorLinus Torvalds <torvalds@linux-foundation.org>2019-12-17 11:00:46 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-12-17 11:00:46 -0800
commit9e8a0d5ff8408b1e54be0546df0b2ca9d04264cd (patch)
tree26e1dcee67b1d03fd9309a32424ac176c163e3f8 /kernel
parenta114a18c7dbc2b7ac5a1379a8dcced6095c52ead (diff)
parentc571b72e2b845ca0519670cb7c4b5fe5f56498a5 (diff)
Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar: "Tone down mutex debugging complaints, and annotate/fix spinlock debugging data accesses for KCSAN" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Revert "locking/mutex: Complain upon mutex API misuse in IRQ contexts" locking/spinlock/debug: Fix various data races
Diffstat (limited to 'kernel')
-rw-r--r--kernel/locking/mutex.c4
-rw-r--r--kernel/locking/spinlock_debug.c32
2 files changed, 16 insertions, 20 deletions
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 54cc5f9286e9..5352ce50a97e 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -733,9 +733,6 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
*/
void __sched mutex_unlock(struct mutex *lock)
{
-#ifdef CONFIG_DEBUG_MUTEXES
- WARN_ON(in_interrupt());
-#endif
#ifndef CONFIG_DEBUG_LOCK_ALLOC
if (__mutex_unlock_fast(lock))
return;
@@ -1416,7 +1413,6 @@ int __sched mutex_trylock(struct mutex *lock)
#ifdef CONFIG_DEBUG_MUTEXES
DEBUG_LOCKS_WARN_ON(lock->magic != lock);
- WARN_ON(in_interrupt());
#endif
locked = __mutex_trylock(lock);
diff --git a/kernel/locking/spinlock_debug.c b/kernel/locking/spinlock_debug.c
index 399669f7eba8..472dd462a40c 100644
--- a/kernel/locking/spinlock_debug.c
+++ b/kernel/locking/spinlock_debug.c
@@ -51,19 +51,19 @@ EXPORT_SYMBOL(__rwlock_init);
static void spin_dump(raw_spinlock_t *lock, const char *msg)
{
- struct task_struct *owner = NULL;
+ struct task_struct *owner = READ_ONCE(lock->owner);
- if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT)
- owner = lock->owner;
+ if (owner == SPINLOCK_OWNER_INIT)
+ owner = NULL;
printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n",
msg, raw_smp_processor_id(),
current->comm, task_pid_nr(current));
printk(KERN_EMERG " lock: %pS, .magic: %08x, .owner: %s/%d, "
".owner_cpu: %d\n",
- lock, lock->magic,
+ lock, READ_ONCE(lock->magic),
owner ? owner->comm : "<none>",
owner ? task_pid_nr(owner) : -1,
- lock->owner_cpu);
+ READ_ONCE(lock->owner_cpu));
dump_stack();
}
@@ -80,16 +80,16 @@ static void spin_bug(raw_spinlock_t *lock, const char *msg)
static inline void
debug_spin_lock_before(raw_spinlock_t *lock)
{
- SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic");
- SPIN_BUG_ON(lock->owner == current, lock, "recursion");
- SPIN_BUG_ON(lock->owner_cpu == raw_smp_processor_id(),
+ SPIN_BUG_ON(READ_ONCE(lock->magic) != SPINLOCK_MAGIC, lock, "bad magic");
+ SPIN_BUG_ON(READ_ONCE(lock->owner) == current, lock, "recursion");
+ SPIN_BUG_ON(READ_ONCE(lock->owner_cpu) == raw_smp_processor_id(),
lock, "cpu recursion");
}
static inline void debug_spin_lock_after(raw_spinlock_t *lock)
{
- lock->owner_cpu = raw_smp_processor_id();
- lock->owner = current;
+ WRITE_ONCE(lock->owner_cpu, raw_smp_processor_id());
+ WRITE_ONCE(lock->owner, current);
}
static inline void debug_spin_unlock(raw_spinlock_t *lock)
@@ -99,8 +99,8 @@ static inline void debug_spin_unlock(raw_spinlock_t *lock)
SPIN_BUG_ON(lock->owner != current, lock, "wrong owner");
SPIN_BUG_ON(lock->owner_cpu != raw_smp_processor_id(),
lock, "wrong CPU");
- lock->owner = SPINLOCK_OWNER_INIT;
- lock->owner_cpu = -1;
+ WRITE_ONCE(lock->owner, SPINLOCK_OWNER_INIT);
+ WRITE_ONCE(lock->owner_cpu, -1);
}
/*
@@ -187,8 +187,8 @@ static inline void debug_write_lock_before(rwlock_t *lock)
static inline void debug_write_lock_after(rwlock_t *lock)
{
- lock->owner_cpu = raw_smp_processor_id();
- lock->owner = current;
+ WRITE_ONCE(lock->owner_cpu, raw_smp_processor_id());
+ WRITE_ONCE(lock->owner, current);
}
static inline void debug_write_unlock(rwlock_t *lock)
@@ -197,8 +197,8 @@ static inline void debug_write_unlock(rwlock_t *lock)
RWLOCK_BUG_ON(lock->owner != current, lock, "wrong owner");
RWLOCK_BUG_ON(lock->owner_cpu != raw_smp_processor_id(),
lock, "wrong CPU");
- lock->owner = SPINLOCK_OWNER_INIT;
- lock->owner_cpu = -1;
+ WRITE_ONCE(lock->owner, SPINLOCK_OWNER_INIT);
+ WRITE_ONCE(lock->owner_cpu, -1);
}
void do_raw_write_lock(rwlock_t *lock)