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

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

   - A comprehensive rewrite of the robust/PI futex code's exit handling
     to fix various exit races. (Thomas Gleixner et al)

   - Rework the generic REFCOUNT_FULL implementation using
     atomic_fetch_* operations so that the performance impact of the
     cmpxchg() loops is mitigated for common refcount operations.

     With these performance improvements the generic implementation of
     refcount_t should be good enough for everybody - and this got
     confirmed by performance testing, so remove ARCH_HAS_REFCOUNT and
     REFCOUNT_FULL entirely, leaving the generic implementation enabled
     unconditionally. (Will Deacon)

   - Other misc changes, fixes, cleanups"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
  lkdtm: Remove references to CONFIG_REFCOUNT_FULL
  locking/refcount: Remove unused 'refcount_error_report()' function
  locking/refcount: Consolidate implementations of refcount_t
  locking/refcount: Consolidate REFCOUNT_{MAX,SATURATED} definitions
  locking/refcount: Move saturation warnings out of line
  locking/refcount: Improve performance of generic REFCOUNT_FULL code
  locking/refcount: Move the bulk of the REFCOUNT_FULL implementation into the <linux/refcount.h> header
  locking/refcount: Remove unused refcount_*_checked() variants
  locking/refcount: Ensure integer operands are treated as signed
  locking/refcount: Define constants for saturation and max refcount values
  futex: Prevent exit livelock
  futex: Provide distinct return value when owner is exiting
  futex: Add mutex around futex exit
  futex: Provide state handling for exec() as well
  futex: Sanitize exit state handling
  futex: Mark the begin of futex exit explicitly
  futex: Set task::futex_state to DEAD right after handling futex exit
  futex: Split futex_mm_release() for exit/exec
  exit/exec: Seperate mm_release()
  futex: Replace PF_EXITPIDONE with a state
  ...

7 files changed, 11 insertions, 21 deletions

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 4c766624b20d..4a8b2e5c2af6 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -719,7 +719,7 @@ void drm_connector_list_iter_end(struct drm_connector_list_iter *iter)
 		__drm_connector_put_safe(iter->conn);
 		spin_unlock_irqrestore(&config->connector_list_lock, flags);
 	}
-	lock_release(&connector_list_iter_dep_map, 0, _RET_IP_);
+	lock_release(&connector_list_iter_dep_map, _RET_IP_);
 }
 EXPORT_SYMBOL(drm_connector_list_iter_end);
 
diff --git a/drivers/gpu/drm/i915/Kconfig.debug b/drivers/gpu/drm/i915/Kconfig.debug
index 00786a142ff0..1400fce39c58 100644
--- a/drivers/gpu/drm/i915/Kconfig.debug
+++ b/drivers/gpu/drm/i915/Kconfig.debug
@@ -22,7 +22,6 @@ config DRM_I915_DEBUG
         depends on DRM_I915
         select DEBUG_FS
         select PREEMPT_COUNT
-        select REFCOUNT_FULL
         select I2C_CHARDEV
         select STACKDEPOT
         select DRM_DP_AUX_CHARDEV
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
index edd21d14e64f..1a51b3598d63 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
@@ -509,14 +509,14 @@ void i915_gem_shrinker_taints_mutex(struct drm_i915_private *i915,
 		      I915_MM_SHRINKER, 0, _RET_IP_);
 
 	mutex_acquire(&mutex->dep_map, 0, 0, _RET_IP_);
-	mutex_release(&mutex->dep_map, 0, _RET_IP_);
+	mutex_release(&mutex->dep_map, _RET_IP_);
 
-	mutex_release(&i915->drm.struct_mutex.dep_map, 0, _RET_IP_);
+	mutex_release(&i915->drm.struct_mutex.dep_map, _RET_IP_);
 
 	fs_reclaim_release(GFP_KERNEL);
 
 	if (unlock)
-		mutex_release(&i915->drm.struct_mutex.dep_map, 0, _RET_IP_);
+		mutex_release(&i915->drm.struct_mutex.dep_map, _RET_IP_);
 }
 
 #define obj_to_i915(obj__) to_i915((obj__)->base.dev)
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
index 65b5ca74b394..7f647243b3b9 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
@@ -52,7 +52,7 @@ static inline unsigned long __timeline_mark_lock(struct intel_context *ce)
 static inline void __timeline_mark_unlock(struct intel_context *ce,
 					  unsigned long flags)
 {
-	mutex_release(&ce->timeline->mutex.dep_map, 0, _THIS_IP_);
+	mutex_release(&ce->timeline->mutex.dep_map, _THIS_IP_);
 	local_irq_restore(flags);
 }
 
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 1c5506822dc7..bc828a9ace84 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1495,7 +1495,7 @@ long i915_request_wait(struct i915_request *rq,
 	dma_fence_remove_callback(&rq->fence, &wait.cb);
 
 out:
-	mutex_release(&rq->engine->gt->reset.mutex.dep_map, 0, _THIS_IP_);
+	mutex_release(&rq->engine->gt->reset.mutex.dep_map, _THIS_IP_);
 	trace_i915_request_wait_end(rq);
 	return timeout;
 }
diff --git a/drivers/misc/lkdtm/refcount.c b/drivers/misc/lkdtm/refcount.c
index 0a146b32da13..de7c5ab528d9 100644
--- a/drivers/misc/lkdtm/refcount.c
+++ b/drivers/misc/lkdtm/refcount.c
@@ -6,14 +6,6 @@
 #include "lkdtm.h"
 #include <linux/refcount.h>
 
-#ifdef CONFIG_REFCOUNT_FULL
-#define REFCOUNT_MAX		(UINT_MAX - 1)
-#define REFCOUNT_SATURATED	UINT_MAX
-#else
-#define REFCOUNT_MAX		INT_MAX
-#define REFCOUNT_SATURATED	(INT_MIN / 2)
-#endif
-
 static void overflow_check(refcount_t *ref)
 {
 	switch (refcount_read(ref)) {
@@ -127,7 +119,7 @@ void lkdtm_REFCOUNT_DEC_ZERO(void)
 static void check_negative(refcount_t *ref, int start)
 {
 	/*
-	 * CONFIG_REFCOUNT_FULL refuses to move a refcount at all on an
+	 * refcount_t refuses to move a refcount at all on an
 	 * over-sub, so we have to track our starting position instead of
 	 * looking only at zero-pinning.
 	 */
@@ -210,7 +202,6 @@ static void check_from_zero(refcount_t *ref)
 
 /*
  * A refcount_inc() from zero should pin to zero or saturate and may WARN.
- * Only CONFIG_REFCOUNT_FULL provides this protection currently.
  */
 void lkdtm_REFCOUNT_INC_ZERO(void)
 {
diff --git a/drivers/tty/tty_ldsem.c b/drivers/tty/tty_ldsem.c
index 60ff236a3d63..ce8291053af3 100644
--- a/drivers/tty/tty_ldsem.c
+++ b/drivers/tty/tty_ldsem.c
@@ -303,7 +303,7 @@ static int __ldsem_down_read_nested(struct ld_semaphore *sem,
 	if (count <= 0) {
 		lock_contended(&sem->dep_map, _RET_IP_);
 		if (!down_read_failed(sem, count, timeout)) {
-			rwsem_release(&sem->dep_map, 1, _RET_IP_);
+			rwsem_release(&sem->dep_map, _RET_IP_);
 			return 0;
 		}
 	}
@@ -322,7 +322,7 @@ static int __ldsem_down_write_nested(struct ld_semaphore *sem,
 	if ((count & LDSEM_ACTIVE_MASK) != LDSEM_ACTIVE_BIAS) {
 		lock_contended(&sem->dep_map, _RET_IP_);
 		if (!down_write_failed(sem, count, timeout)) {
-			rwsem_release(&sem->dep_map, 1, _RET_IP_);
+			rwsem_release(&sem->dep_map, _RET_IP_);
 			return 0;
 		}
 	}
@@ -390,7 +390,7 @@ void ldsem_up_read(struct ld_semaphore *sem)
 {
 	long count;
 
-	rwsem_release(&sem->dep_map, 1, _RET_IP_);
+	rwsem_release(&sem->dep_map, _RET_IP_);
 
 	count = atomic_long_add_return(-LDSEM_READ_BIAS, &sem->count);
 	if (count < 0 && (count & LDSEM_ACTIVE_MASK) == 0)
@@ -404,7 +404,7 @@ void ldsem_up_write(struct ld_semaphore *sem)
 {
 	long count;
 
-	rwsem_release(&sem->dep_map, 1, _RET_IP_);
+	rwsem_release(&sem->dep_map, _RET_IP_);
 
 	count = atomic_long_add_return(-LDSEM_WRITE_BIAS, &sem->count);
 	if (count < 0)