Merge branch 'linux-linaro-lsk-v3.10' into linux-linaro-lsk-v3.10-android

8 files changed, 56 insertions, 14 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index e646e870ec5f..fcf0aeff45b4 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -984,7 +984,7 @@ static void cgroup_d_remove_dir(struct dentry *dentry)
 	parent = dentry->d_parent;
 	spin_lock(&parent->d_lock);
 	spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
-	list_del_init(&dentry->d_u.d_child);
+	list_del_init(&dentry->d_child);
 	spin_unlock(&dentry->d_lock);
 	spin_unlock(&parent->d_lock);
 	remove_dir(dentry);
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 7d4755634d32..f1cfa7367a92 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -27,18 +27,23 @@
 static DEFINE_MUTEX(cpu_add_remove_lock);
 
 /*
- * The following two API's must be used when attempting
- * to serialize the updates to cpu_online_mask, cpu_present_mask.
+ * The following two APIs (cpu_maps_update_begin/done) must be used when
+ * attempting to serialize the updates to cpu_online_mask & cpu_present_mask.
+ * The APIs cpu_notifier_register_begin/done() must be used to protect CPU
+ * hotplug callback (un)registration performed using __register_cpu_notifier()
+ * or __unregister_cpu_notifier().
  */
 void cpu_maps_update_begin(void)
 {
 	mutex_lock(&cpu_add_remove_lock);
 }
+EXPORT_SYMBOL(cpu_notifier_register_begin);
 
 void cpu_maps_update_done(void)
 {
 	mutex_unlock(&cpu_add_remove_lock);
 }
+EXPORT_SYMBOL(cpu_notifier_register_done);
 
 static RAW_NOTIFIER_HEAD(cpu_chain);
 
@@ -169,6 +174,11 @@ int __ref register_cpu_notifier(struct notifier_block *nb)
 	return ret;
 }
 
+int __ref __register_cpu_notifier(struct notifier_block *nb)
+{
+	return raw_notifier_chain_register(&cpu_chain, nb);
+}
+
 static int __cpu_notify(unsigned long val, void *v, int nr_to_call,
 			int *nr_calls)
 {
@@ -192,6 +202,7 @@ static void cpu_notify_nofail(unsigned long val, void *v)
 	BUG_ON(cpu_notify(val, v));
 }
 EXPORT_SYMBOL(register_cpu_notifier);
+EXPORT_SYMBOL(__register_cpu_notifier);
 
 void __ref unregister_cpu_notifier(struct notifier_block *nb)
 {
@@ -201,6 +212,12 @@ void __ref unregister_cpu_notifier(struct notifier_block *nb)
 }
 EXPORT_SYMBOL(unregister_cpu_notifier);
 
+void __ref __unregister_cpu_notifier(struct notifier_block *nb)
+{
+	raw_notifier_chain_unregister(&cpu_chain, nb);
+}
+EXPORT_SYMBOL(__unregister_cpu_notifier);
+
 /**
  * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU
  * @cpu: a CPU id
diff --git a/kernel/printk.c b/kernel/printk.c
index f7aff4bd5454..fd0154a57d6e 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -107,7 +107,7 @@ static struct console *exclusive_console;
  */
 struct console_cmdline
 {
-	char	name[8];			/* Name of the driver	    */
+	char	name[16];			/* Name of the driver	    */
 	int	index;				/* Minor dev. to use	    */
 	char	*options;			/* Options for the driver   */
 #ifdef CONFIG_A11Y_BRAILLE_CONSOLE
@@ -2290,6 +2290,8 @@ void register_console(struct console *newcon)
 	 */
 	for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0];
 			i++) {
+		BUILD_BUG_ON(sizeof(console_cmdline[i].name) !=
+			     sizeof(newcon->name));
 		if (strcmp(console_cmdline[i].name, newcon->name) != 0)
 			continue;
 		if (newcon->index >= 0 &&
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index afadcf7b4a22..118323bc8529 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -720,6 +720,8 @@ static int ptrace_peek_siginfo(struct task_struct *child,
 static int ptrace_resume(struct task_struct *child, long request,
 			 unsigned long data)
 {
+	bool need_siglock;
+
 	if (!valid_signal(data))
 		return -EIO;
 
@@ -747,8 +749,26 @@ static int ptrace_resume(struct task_struct *child, long request,
 		user_disable_single_step(child);
 	}
 
+	/*
+	 * Change ->exit_code and ->state under siglock to avoid the race
+	 * with wait_task_stopped() in between; a non-zero ->exit_code will
+	 * wrongly look like another report from tracee.
+	 *
+	 * Note that we need siglock even if ->exit_code == data and/or this
+	 * status was not reported yet, the new status must not be cleared by
+	 * wait_task_stopped() after resume.
+	 *
+	 * If data == 0 we do not care if wait_task_stopped() reports the old
+	 * status and clears the code too; this can't race with the tracee, it
+	 * takes siglock after resume.
+	 */
+	need_siglock = data && !thread_group_empty(current);
+	if (need_siglock)
+		spin_lock_irq(&child->sighand->siglock);
 	child->exit_code = data;
 	wake_up_state(child, __TASK_TRACED);
+	if (need_siglock)
+		spin_unlock_irq(&child->sighand->siglock);
 
 	return 0;
 }
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 787b3a032429..21956f00cb51 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -774,9 +774,13 @@ static void run_ksoftirqd(unsigned int cpu)
 	local_irq_disable();
 	if (local_softirq_pending()) {
 		__do_softirq();
-		rcu_note_context_switch(cpu);
 		local_irq_enable();
 		cond_resched();
+
+		preempt_disable();
+		rcu_note_context_switch(cpu);
+		preempt_enable();
+
 		return;
 	}
 	local_irq_enable();
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 3d9fee3a80b3..ab21b8c66535 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2650,7 +2650,7 @@ static DEFINE_PER_CPU(unsigned int, current_context);
 
 static __always_inline int trace_recursive_lock(void)
 {
-	unsigned int val = this_cpu_read(current_context);
+	unsigned int val = __this_cpu_read(current_context);
 	int bit;
 
 	if (in_interrupt()) {
@@ -2667,18 +2667,17 @@ static __always_inline int trace_recursive_lock(void)
 		return 1;
 
 	val |= (1 << bit);
-	this_cpu_write(current_context, val);
+	__this_cpu_write(current_context, val);
 
 	return 0;
 }
 
 static __always_inline void trace_recursive_unlock(void)
 {
-	unsigned int val = this_cpu_read(current_context);
+	unsigned int val = __this_cpu_read(current_context);
 
-	val--;
-	val &= this_cpu_read(current_context);
-	this_cpu_write(current_context, val);
+	val &= val & (val - 1);
+	__this_cpu_write(current_context, val);
 }
 
 #else
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 88e8f9057d1a..249e32b5aa0d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -6154,7 +6154,7 @@ static int instance_mkdir (struct inode *inode, struct dentry *dentry, umode_t m
 	int ret;
 
 	/* Paranoid: Make sure the parent is the "instances" directory */
-	parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias);
+	parent = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias);
 	if (WARN_ON_ONCE(parent != trace_instance_dir))
 		return -ENOENT;
 
@@ -6181,7 +6181,7 @@ static int instance_rmdir(struct inode *inode, struct dentry *dentry)
 	int ret;
 
 	/* Paranoid: Make sure the parent is the "instances" directory */
-	parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias);
+	parent = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias);
 	if (WARN_ON_ONCE(parent != trace_instance_dir))
 		return -ENOENT;
 
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 001b349af939..5a898f15bfc6 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -425,7 +425,7 @@ static void remove_event_file_dir(struct ftrace_event_file *file)
 
 	if (dir) {
 		spin_lock(&dir->d_lock);	/* probably unneeded */
-		list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
+		list_for_each_entry(child, &dir->d_subdirs, d_child) {
 			if (child->d_inode)	/* probably unneeded */
 				child->d_inode->i_private = NULL;
 		}