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

Pull core locking updates from Ingo Molnar:
 "The main changes in this cycle are:

   - Another attempt at enabling cross-release lockdep dependency
     tracking (automatically part of CONFIG_PROVE_LOCKING=y), this time
     with better performance and fewer false positives. (Byungchul Park)

   - Introduce lockdep_assert_irqs_enabled()/disabled() and convert
     open-coded equivalents to lockdep variants. (Frederic Weisbecker)

   - Add down_read_killable() and use it in the VFS's iterate_dir()
     method. (Kirill Tkhai)

   - Convert remaining uses of ACCESS_ONCE() to
     READ_ONCE()/WRITE_ONCE(). Most of the conversion was Coccinelle
     driven. (Mark Rutland, Paul E. McKenney)

   - Get rid of lockless_dereference(), by strengthening Alpha atomics,
     strengthening READ_ONCE() with smp_read_barrier_depends() and thus
     being able to convert users of lockless_dereference() to
     READ_ONCE(). (Will Deacon)

   - Various micro-optimizations:

        - better PV qspinlocks (Waiman Long),
        - better x86 barriers (Michael S. Tsirkin)
        - better x86 refcounts (Kees Cook)

   - ... plus other fixes and enhancements. (Borislav Petkov, Juergen
     Gross, Miguel Bernal Marin)"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
  locking/x86: Use LOCK ADD for smp_mb() instead of MFENCE
  rcu: Use lockdep to assert IRQs are disabled/enabled
  netpoll: Use lockdep to assert IRQs are disabled/enabled
  timers/posix-cpu-timers: Use lockdep to assert IRQs are disabled/enabled
  sched/clock, sched/cputime: Use lockdep to assert IRQs are disabled/enabled
  irq_work: Use lockdep to assert IRQs are disabled/enabled
  irq/timings: Use lockdep to assert IRQs are disabled/enabled
  perf/core: Use lockdep to assert IRQs are disabled/enabled
  x86: Use lockdep to assert IRQs are disabled/enabled
  smp/core: Use lockdep to assert IRQs are disabled/enabled
  timers/hrtimer: Use lockdep to assert IRQs are disabled/enabled
  timers/nohz: Use lockdep to assert IRQs are disabled/enabled
  workqueue: Use lockdep to assert IRQs are disabled/enabled
  irq/softirqs: Use lockdep to assert IRQs are disabled/enabled
  locking/lockdep: Add IRQs disabled/enabled assertion APIs: lockdep_assert_irqs_enabled()/disabled()
  locking/pvqspinlock: Implement hybrid PV queued/unfair locks
  locking/rwlocks: Fix comments
  x86/paravirt: Set up the virt_spin_lock_key after static keys get initialized
  block, locking/lockdep: Assign a lock_class per gendisk used for wait_for_completion()
  workqueue: Remove now redundant lock acquisitions wrt. workqueue flushes
  ...
This commit is contained in:
Linus Torvalds
2017-11-13 12:38:26 -08:00
307 changed files with 1252 additions and 1672 deletions

View File

@@ -1092,8 +1092,8 @@ config PROVE_LOCKING
select DEBUG_MUTEXES
select DEBUG_RT_MUTEXES if RT_MUTEXES
select DEBUG_LOCK_ALLOC
select LOCKDEP_CROSSRELEASE if BROKEN
select LOCKDEP_COMPLETIONS if BROKEN
select LOCKDEP_CROSSRELEASE
select LOCKDEP_COMPLETIONS
select TRACE_IRQFLAGS
default n
help
@@ -1179,6 +1179,21 @@ config LOCKDEP_COMPLETIONS
A deadlock caused by wait_for_completion() and complete() can be
detected by lockdep using crossrelease feature.
config BOOTPARAM_LOCKDEP_CROSSRELEASE_FULLSTACK
bool "Enable the boot parameter, crossrelease_fullstack"
depends on LOCKDEP_CROSSRELEASE
default n
help
The lockdep "cross-release" feature needs to record stack traces
(of calling functions) for all acquisitions, for eventual later
use during analysis. By default only a single caller is recorded,
because the unwind operation can be very expensive with deeper
stack chains.
However a boot parameter, crossrelease_fullstack, was
introduced since sometimes deeper traces are required for full
analysis. This option turns on the boot parameter.
config DEBUG_LOCKDEP
bool "Lock dependency engine debugging"
depends on DEBUG_KERNEL && LOCKDEP

View File

@@ -39,7 +39,7 @@ begin_node:
/* Descend through a shortcut */
shortcut = assoc_array_ptr_to_shortcut(cursor);
smp_read_barrier_depends();
cursor = ACCESS_ONCE(shortcut->next_node);
cursor = READ_ONCE(shortcut->next_node);
}
node = assoc_array_ptr_to_node(cursor);
@@ -55,7 +55,7 @@ begin_node:
*/
has_meta = 0;
for (; slot < ASSOC_ARRAY_FAN_OUT; slot++) {
ptr = ACCESS_ONCE(node->slots[slot]);
ptr = READ_ONCE(node->slots[slot]);
has_meta |= (unsigned long)ptr;
if (ptr && assoc_array_ptr_is_leaf(ptr)) {
/* We need a barrier between the read of the pointer
@@ -89,7 +89,7 @@ continue_node:
smp_read_barrier_depends();
for (; slot < ASSOC_ARRAY_FAN_OUT; slot++) {
ptr = ACCESS_ONCE(node->slots[slot]);
ptr = READ_ONCE(node->slots[slot]);
if (assoc_array_ptr_is_meta(ptr)) {
cursor = ptr;
goto begin_node;
@@ -98,7 +98,7 @@ continue_node:
finished_node:
/* Move up to the parent (may need to skip back over a shortcut) */
parent = ACCESS_ONCE(node->back_pointer);
parent = READ_ONCE(node->back_pointer);
slot = node->parent_slot;
if (parent == stop)
return 0;
@@ -107,7 +107,7 @@ finished_node:
shortcut = assoc_array_ptr_to_shortcut(parent);
smp_read_barrier_depends();
cursor = parent;
parent = ACCESS_ONCE(shortcut->back_pointer);
parent = READ_ONCE(shortcut->back_pointer);
slot = shortcut->parent_slot;
if (parent == stop)
return 0;
@@ -147,7 +147,7 @@ int assoc_array_iterate(const struct assoc_array *array,
void *iterator_data),
void *iterator_data)
{
struct assoc_array_ptr *root = ACCESS_ONCE(array->root);
struct assoc_array_ptr *root = READ_ONCE(array->root);
if (!root)
return 0;
@@ -194,7 +194,7 @@ assoc_array_walk(const struct assoc_array *array,
pr_devel("-->%s()\n", __func__);
cursor = ACCESS_ONCE(array->root);
cursor = READ_ONCE(array->root);
if (!cursor)
return assoc_array_walk_tree_empty;
@@ -220,7 +220,7 @@ consider_node:
slot = segments >> (level & ASSOC_ARRAY_KEY_CHUNK_MASK);
slot &= ASSOC_ARRAY_FAN_MASK;
ptr = ACCESS_ONCE(node->slots[slot]);
ptr = READ_ONCE(node->slots[slot]);
pr_devel("consider slot %x [ix=%d type=%lu]\n",
slot, level, (unsigned long)ptr & 3);
@@ -294,7 +294,7 @@ follow_shortcut:
} while (sc_level < shortcut->skip_to_level);
/* The shortcut matches the leaf's index to this point. */
cursor = ACCESS_ONCE(shortcut->next_node);
cursor = READ_ONCE(shortcut->next_node);
if (((level ^ sc_level) & ~ASSOC_ARRAY_KEY_CHUNK_MASK) != 0) {
level = sc_level;
goto jumped;
@@ -337,7 +337,7 @@ void *assoc_array_find(const struct assoc_array *array,
* the terminal node.
*/
for (slot = 0; slot < ASSOC_ARRAY_FAN_OUT; slot++) {
ptr = ACCESS_ONCE(node->slots[slot]);
ptr = READ_ONCE(node->slots[slot]);
if (ptr && assoc_array_ptr_is_leaf(ptr)) {
/* We need a barrier between the read of the pointer
* and dereferencing the pointer - but only if we are

View File

@@ -21,7 +21,7 @@ void dql_completed(struct dql *dql, unsigned int count)
unsigned int ovlimit, completed, num_queued;
bool all_prev_completed;
num_queued = ACCESS_ONCE(dql->num_queued);
num_queued = READ_ONCE(dql->num_queued);
/* Can't complete more than what's in queue */
BUG_ON(count > num_queued - dql->num_completed);

View File

@@ -41,7 +41,7 @@ bool llist_add_batch(struct llist_node *new_first, struct llist_node *new_last,
struct llist_node *first;
do {
new_last->next = first = ACCESS_ONCE(head->first);
new_last->next = first = READ_ONCE(head->first);
} while (cmpxchg(&head->first, first, new_first) != first);
return !first;

View File

@@ -620,8 +620,8 @@ char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_sp
rcu_read_lock();
for (i = 0; i < depth; i++, d = p) {
p = ACCESS_ONCE(d->d_parent);
array[i] = ACCESS_ONCE(d->d_name.name);
p = READ_ONCE(d->d_parent);
array[i] = READ_ONCE(d->d_name.name);
if (p == d) {
if (i)
array[i] = "";