1 files changed, 47 insertions, 1 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index f1e1927ccd48..98fd8f6df851 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1355,6 +1355,49 @@ static const struct file_operations proc_fault_inject_operations = {
 	.write		= proc_fault_inject_write,
 	.llseek		= generic_file_llseek,
 };
+
+static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
+				   size_t count, loff_t *ppos)
+{
+	struct task_struct *task;
+	int err;
+	unsigned int n;
+
+	err = kstrtouint_from_user(buf, count, 0, &n);
+	if (err)
+		return err;
+
+	task = get_proc_task(file_inode(file));
+	if (!task)
+		return -ESRCH;
+	WRITE_ONCE(task->fail_nth, n);
+	put_task_struct(task);
+
+	return count;
+}
+
+static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
+				  size_t count, loff_t *ppos)
+{
+	struct task_struct *task;
+	char numbuf[PROC_NUMBUF];
+	ssize_t len;
+
+	task = get_proc_task(file_inode(file));
+	if (!task)
+		return -ESRCH;
+	len = snprintf(numbuf, sizeof(numbuf), "%u\n",
+			READ_ONCE(task->fail_nth));
+	len = simple_read_from_buffer(buf, count, ppos, numbuf, len);
+	put_task_struct(task);
+
+	return len;
+}
+
+static const struct file_operations proc_fail_nth_operations = {
+	.read		= proc_fail_nth_read,
+	.write		= proc_fail_nth_write,
+};
 #endif
 
 
@@ -1365,12 +1408,13 @@ static const struct file_operations proc_fault_inject_operations = {
 static int sched_show(struct seq_file *m, void *v)
 {
 	struct inode *inode = m->private;
+	struct pid_namespace *ns = inode->i_sb->s_fs_info;
 	struct task_struct *p;
 
 	p = get_proc_task(inode);
 	if (!p)
 		return -ESRCH;
-	proc_sched_show_task(p, m);
+	proc_sched_show_task(p, ns, m);
 
 	put_task_struct(p);
 
@@ -2919,6 +2963,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 #endif
 #ifdef CONFIG_FAULT_INJECTION
 	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
+	REG("fail-nth", 0644, proc_fail_nth_operations),
 #endif
 #ifdef CONFIG_ELF_CORE
 	REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
@@ -3311,6 +3356,7 @@ static const struct pid_entry tid_base_stuff[] = {
 #endif
 #ifdef CONFIG_FAULT_INJECTION
 	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
+	REG("fail-nth", 0644, proc_fail_nth_operations),
 #endif
 #ifdef CONFIG_TASK_IO_ACCOUNTING
 	ONE("io",	S_IRUSR, proc_tid_io_accounting),