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 big round of FUTEX_UNLOCK_PI improvements, fixes, cleanups and
     general restructuring

   - lockdep updates such as new checks for lock_downgrade()

   - introduce the new atomic_try_cmpxchg() locking API and use it to
     optimize refcount code generation

   - ... plus misc fixes, updates and cleanups"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits)
  MAINTAINERS: Add FUTEX SUBSYSTEM
  futex: Clarify mark_wake_futex memory barrier usage
  futex: Fix small (and harmless looking) inconsistencies
  futex: Avoid freeing an active timer
  rtmutex: Plug preempt count leak in rt_mutex_futex_unlock()
  rtmutex: Fix more prio comparisons
  rtmutex: Fix PI chain order integrity
  sched,tracing: Update trace_sched_pi_setprio()
  sched/rtmutex: Refactor rt_mutex_setprio()
  rtmutex: Clean up
  sched/deadline/rtmutex: Dont miss the dl_runtime/dl_period update
  sched/rtmutex/deadline: Fix a PI crash for deadline tasks
  rtmutex: Deboost before waking up the top waiter
  locking/ww-mutex: Limit stress test to 2 seconds
  locking/atomic: Fix atomic_try_cmpxchg() semantics
  lockdep: Fix per-cpu static objects
  futex: Drop hb->lock before enqueueing on the rtmutex
  futex: Futex_unlock_pi() determinism
  futex: Rework futex_lock_pi() to use rt_mutex_*_proxy_lock()
  futex,rt_mutex: Restructure rt_mutex_finish_proxy_lock()
  ...

1 files changed, 26 insertions, 14 deletions

diff --git a/mm/percpu.c b/mm/percpu.c
index 60a6488e9e6d..e0aa8ae7bde7 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1284,18 +1284,7 @@ void free_percpu(void __percpu *ptr)
 }
 EXPORT_SYMBOL_GPL(free_percpu);
 
-/**
- * is_kernel_percpu_address - test whether address is from static percpu area
- * @addr: address to test
- *
- * Test whether @addr belongs to in-kernel static percpu area.  Module
- * static percpu areas are not considered.  For those, use
- * is_module_percpu_address().
- *
- * RETURNS:
- * %true if @addr is from in-kernel static percpu area, %false otherwise.
- */
-bool is_kernel_percpu_address(unsigned long addr)
+bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr)
 {
 #ifdef CONFIG_SMP
 	const size_t static_size = __per_cpu_end - __per_cpu_start;
@@ -1304,16 +1293,39 @@ bool is_kernel_percpu_address(unsigned long addr)
 
 	for_each_possible_cpu(cpu) {
 		void *start = per_cpu_ptr(base, cpu);
+		void *va = (void *)addr;
 
-		if ((void *)addr >= start && (void *)addr < start + static_size)
+		if (va >= start && va < start + static_size) {
+			if (can_addr) {
+				*can_addr = (unsigned long) (va - start);
+				*can_addr += (unsigned long)
+					per_cpu_ptr(base, get_boot_cpu_id());
+			}
 			return true;
-        }
+		}
+	}
 #endif
 	/* on UP, can't distinguish from other static vars, always false */
 	return false;
 }
 
 /**
+ * is_kernel_percpu_address - test whether address is from static percpu area
+ * @addr: address to test
+ *
+ * Test whether @addr belongs to in-kernel static percpu area.  Module
+ * static percpu areas are not considered.  For those, use
+ * is_module_percpu_address().
+ *
+ * RETURNS:
+ * %true if @addr is from in-kernel static percpu area, %false otherwise.
+ */
+bool is_kernel_percpu_address(unsigned long addr)
+{
+	return __is_kernel_percpu_address(addr, NULL);
+}
+
+/**
  * per_cpu_ptr_to_phys - convert translated percpu address to physical address
  * @addr: the address to be converted to physical address
  *