Merge tag 'v3.12' into core/locking to pick up mutex upates

Signed-off-by: Ingo Molnar <mingo@kernel.org>

6 files changed, 30 insertions, 10 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 06344d9..094f315 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -983,7 +983,7 @@ config DEBUG_KOBJECT
 
 config DEBUG_KOBJECT_RELEASE
 	bool "kobject release debugging"
-	depends on DEBUG_KERNEL
+	depends on DEBUG_OBJECTS_TIMERS
 	help
 	  kobjects are reference counted objects.  This means that their
 	  last reference count put is not predictable, and the kobject can
diff --git a/lib/hexdump.c b/lib/hexdump.c
index 3f0494c..8499c81 100644
--- a/lib/hexdump.c
+++ b/lib/hexdump.c
@@ -14,6 +14,8 @@
 
 const char hex_asc[] = "0123456789abcdef";
 EXPORT_SYMBOL(hex_asc);
+const char hex_asc_upper[] = "0123456789ABCDEF";
+EXPORT_SYMBOL(hex_asc_upper);
 
 /**
  * hex_to_bin - convert a hex digit to its real value
diff --git a/lib/kobject.c b/lib/kobject.c
index 9621751..084f7b1 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -592,7 +592,7 @@ static void kobject_release(struct kref *kref)
 {
 	struct kobject *kobj = container_of(kref, struct kobject, kref);
 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
-	pr_debug("kobject: '%s' (%p): %s, parent %p (delayed)\n",
+	pr_info("kobject: '%s' (%p): %s, parent %p (delayed)\n",
 		 kobject_name(kobj), kobj, __func__, kobj->parent);
 	INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup);
 	schedule_delayed_work(&kobj->release, HZ);
@@ -933,10 +933,7 @@ const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
 
 bool kobj_ns_current_may_mount(enum kobj_ns_type type)
 {
-	bool may_mount = false;
-
-	if (type == KOBJ_NS_TYPE_NONE)
-		return true;
+	bool may_mount = true;
 
 	spin_lock(&kobj_ns_type_lock);
 	if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
diff --git a/lib/lockref.c b/lib/lockref.c
index 677d036c..6f9d434 100644
--- a/lib/lockref.c
+++ b/lib/lockref.c
@@ -4,6 +4,22 @@
 #ifdef CONFIG_CMPXCHG_LOCKREF
 
 /*
+ * Allow weakly-ordered memory architectures to provide barrier-less
+ * cmpxchg semantics for lockref updates.
+ */
+#ifndef cmpxchg64_relaxed
+# define cmpxchg64_relaxed cmpxchg64
+#endif
+
+/*
+ * Allow architectures to override the default cpu_relax() within CMPXCHG_LOOP.
+ * This is useful for architectures with an expensive cpu_relax().
+ */
+#ifndef arch_mutex_cpu_relax
+# define arch_mutex_cpu_relax() cpu_relax()
+#endif
+
+/*
  * Note that the "cmpxchg()" reloads the "old" value for the
  * failure case.
  */
@@ -14,12 +30,13 @@
 	while (likely(arch_spin_value_unlocked(old.lock.rlock.raw_lock))) {  	\
 		struct lockref new = old, prev = old;				\
 		CODE								\
-		old.lock_count = cmpxchg64(&lockref->lock_count,		\
-					   old.lock_count, new.lock_count);	\
+		old.lock_count = cmpxchg64_relaxed(&lockref->lock_count,	\
+						   old.lock_count,		\
+						   new.lock_count);		\
 		if (likely(old.lock_count == prev.lock_count)) {		\
 			SUCCESS;						\
 		}								\
-		cpu_relax();							\
+		arch_mutex_cpu_relax();						\
 	}									\
 } while (0)
 
diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c
index 7deeb62..1a53d49 100644
--- a/lib/percpu-refcount.c
+++ b/lib/percpu-refcount.c
@@ -53,6 +53,7 @@ int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release)
 	ref->release = release;
 	return 0;
 }
+EXPORT_SYMBOL_GPL(percpu_ref_init);
 
 /**
  * percpu_ref_cancel_init - cancel percpu_ref_init()
@@ -84,6 +85,7 @@ void percpu_ref_cancel_init(struct percpu_ref *ref)
 		free_percpu(ref->pcpu_count);
 	}
 }
+EXPORT_SYMBOL_GPL(percpu_ref_cancel_init);
 
 static void percpu_ref_kill_rcu(struct rcu_head *rcu)
 {
@@ -156,3 +158,4 @@ void percpu_ref_kill_and_confirm(struct percpu_ref *ref,
 
 	call_rcu_sched(&ref->rcu, percpu_ref_kill_rcu);
 }
+EXPORT_SYMBOL_GPL(percpu_ref_kill_and_confirm);
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index a685c8a..d16fa29 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -577,7 +577,8 @@ void sg_miter_stop(struct sg_mapping_iter *miter)
 		miter->__offset += miter->consumed;
 		miter->__remaining -= miter->consumed;
 
-		if (miter->__flags & SG_MITER_TO_SG)
+		if ((miter->__flags & SG_MITER_TO_SG) &&
+		    !PageSlab(miter->page))
 			flush_kernel_dcache_page(miter->page);
 
 		if (miter->__flags & SG_MITER_ATOMIC) {