Merge tag 'v3.11' into for_next

Update Xtensa tree to Linux 3.11 (merging)

40 files changed, 1008 insertions, 631 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index 470839d1a30e..35ef1185e359 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -2,7 +2,7 @@
 # Makefile for the linux kernel.
 #
 
-obj-y     = fork.o exec_domain.o panic.o printk.o \
+obj-y     = fork.o exec_domain.o panic.o \
             cpu.o exit.o itimer.o time.o softirq.o resource.o \
             sysctl.o sysctl_binary.o capability.o ptrace.o timer.o user.o \
             signal.o sys.o kmod.o workqueue.o pid.o task_work.o \
@@ -24,6 +24,7 @@ endif
 
 obj-y += sched/
 obj-y += power/
+obj-y += printk/
 obj-y += cpu/
 
 obj-$(CONFIG_CHECKPOINT_RESTORE) += kcmp.o
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 0e0b20b8c5db..e91963302c0d 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1845,36 +1845,43 @@ out:
 EXPORT_SYMBOL_GPL(cgroup_path);
 
 /**
- * task_cgroup_path_from_hierarchy - cgroup path of a task on a hierarchy
+ * task_cgroup_path - cgroup path of a task in the first cgroup hierarchy
  * @task: target task
- * @hierarchy_id: the hierarchy to look up @task's cgroup from
  * @buf: the buffer to write the path into
  * @buflen: the length of the buffer
  *
- * Determine @task's cgroup on the hierarchy specified by @hierarchy_id and
- * copy its path into @buf.  This function grabs cgroup_mutex and shouldn't
- * be used inside locks used by cgroup controller callbacks.
+ * Determine @task's cgroup on the first (the one with the lowest non-zero
+ * hierarchy_id) cgroup hierarchy and copy its path into @buf.  This
+ * function grabs cgroup_mutex and shouldn't be used inside locks used by
+ * cgroup controller callbacks.
+ *
+ * Returns 0 on success, fails with -%ENAMETOOLONG if @buflen is too short.
  */
-int task_cgroup_path_from_hierarchy(struct task_struct *task, int hierarchy_id,
-                                    char *buf, size_t buflen)
+int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
 {
         struct cgroupfs_root *root;
-        struct cgroup *cgrp = NULL;
-        int ret = -ENOENT;
+        struct cgroup *cgrp;
+        int hierarchy_id = 1, ret = 0;
+
+        if (buflen < 2)
+                return -ENAMETOOLONG;
 
         mutex_lock(&cgroup_mutex);
 
-        root = idr_find(&cgroup_hierarchy_idr, hierarchy_id);
+        root = idr_get_next(&cgroup_hierarchy_idr, &hierarchy_id);
+
         if (root) {
                 cgrp = task_cgroup_from_root(task, root);
                 ret = cgroup_path(cgrp, buf, buflen);
+        } else {
+                /* if no hierarchy exists, everyone is in "/" */
+                memcpy(buf, "/", 2);
         }
 
         mutex_unlock(&cgroup_mutex);
-
         return ret;
 }
-EXPORT_SYMBOL_GPL(task_cgroup_path_from_hierarchy);
+EXPORT_SYMBOL_GPL(task_cgroup_path);
 
 /*
  * Control Group taskset
@@ -4328,8 +4335,10 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
                 }
 
                 err = percpu_ref_init(&css->refcnt, css_release);
-                if (err)
+                if (err) {
+                        ss->css_free(cgrp);
                         goto err_free_all;
+                }
 
                 init_cgroup_css(css, ss, cgrp);
 
@@ -4471,6 +4480,7 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
         struct dentry *d = cgrp->dentry;
         struct cgroup_event *event, *tmp;
         struct cgroup_subsys *ss;
+        struct cgroup *child;
         bool empty;
 
         lockdep_assert_held(&d->d_inode->i_mutex);
@@ -4481,12 +4491,28 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
          * @cgrp from being removed while __put_css_set() is in progress.
          */
         read_lock(&css_set_lock);
-        empty = list_empty(&cgrp->cset_links) && list_empty(&cgrp->children);
+        empty = list_empty(&cgrp->cset_links);
         read_unlock(&css_set_lock);
         if (!empty)
                 return -EBUSY;
 
         /*
+         * Make sure there's no live children.  We can't test ->children
+         * emptiness as dead children linger on it while being destroyed;
+         * otherwise, "rmdir parent/child parent" may fail with -EBUSY.
+         */
+        empty = true;
+        rcu_read_lock();
+        list_for_each_entry_rcu(child, &cgrp->children, sibling) {
+                empty = cgroup_is_dead(child);
+                if (!empty)
+                        break;
+        }
+        rcu_read_unlock();
+        if (!empty)
+                return -EBUSY;
+
+        /*
          * Block new css_tryget() by killing css refcnts.  cgroup core
          * guarantees that, by the time ->css_offline() is invoked, no new
          * css reference will be given out via css_tryget().  We can't
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index e5657788fedd..ea1966db34f2 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -475,13 +475,17 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial)
 
         /*
          * Cpusets with tasks - existing or newly being attached - can't
-         * have empty cpus_allowed or mems_allowed.
+         * be changed to have empty cpus_allowed or mems_allowed.
          */
         ret = -ENOSPC;
-        if ((cgroup_task_count(cur->css.cgroup) || cur->attach_in_progress) &&
-            (cpumask_empty(trial->cpus_allowed) &&
-             nodes_empty(trial->mems_allowed)))
-                goto out;
+        if ((cgroup_task_count(cur->css.cgroup) || cur->attach_in_progress)) {
+                if (!cpumask_empty(cur->cpus_allowed) &&
+                    cpumask_empty(trial->cpus_allowed))
+                        goto out;
+                if (!nodes_empty(cur->mems_allowed) &&
+                    nodes_empty(trial->mems_allowed))
+                        goto out;
+        }
 
         ret = 0;
 out:
@@ -1608,11 +1612,13 @@ static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val)
 {
         struct cpuset *cs = cgroup_cs(cgrp);
         cpuset_filetype_t type = cft->private;
-        int retval = -ENODEV;
+        int retval = 0;
 
         mutex_lock(&cpuset_mutex);
-        if (!is_cpuset_online(cs))
+        if (!is_cpuset_online(cs)) {
+                retval = -ENODEV;
                 goto out_unlock;
+        }
 
         switch (type) {
         case FILE_CPU_EXCLUSIVE:
diff --git a/kernel/fork.c b/kernel/fork.c
index 403d2bb8a968..bf46287c91a4 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1177,7 +1177,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
          * don't allow the creation of threads.
          */
         if ((clone_flags & (CLONE_VM|CLONE_NEWPID)) &&
-            (task_active_pid_ns(current) != current->nsproxy->pid_ns))
+            (task_active_pid_ns(current) !=
+             current->nsproxy->pid_ns_for_children))
                 return ERR_PTR(-EINVAL);
 
         retval = security_task_create(clone_flags);
@@ -1351,7 +1352,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 
         if (pid != &init_struct_pid) {
                 retval = -ENOMEM;
-                pid = alloc_pid(p->nsproxy->pid_ns);
+                pid = alloc_pid(p->nsproxy->pid_ns_for_children);
                 if (!pid)
                         goto bad_fork_cleanup_io;
         }
@@ -1679,6 +1680,12 @@ SYSCALL_DEFINE5(clone, unsigned long, newsp, unsigned long, clone_flags,
                  int __user *, parent_tidptr,
                  int __user *, child_tidptr,
                  int, tls_val)
+#elif defined(CONFIG_CLONE_BACKWARDS3)
+SYSCALL_DEFINE6(clone, unsigned long, clone_flags, unsigned long, newsp,
+                int, stack_size,
+                int __user *, parent_tidptr,
+                int __user *, child_tidptr,
+                int, tls_val)
 #else
 SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
                  int __user *, parent_tidptr,
diff --git a/kernel/freezer.c b/kernel/freezer.c
index 8b2afc1c9df0..b462fa197517 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -33,7 +33,7 @@ static DEFINE_SPINLOCK(freezer_lock);
  */
 bool freezing_slow_path(struct task_struct *p)
 {
-        if (p->flags & PF_NOFREEZE)
+        if (p->flags & (PF_NOFREEZE | PF_SUSPEND_TASK))
                 return false;
 
         if (pm_nosig_freezing || cgroup_freezing(p))
diff --git a/kernel/mutex.c b/kernel/mutex.c
index ff05f4bd86eb..a52ee7bb830d 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -686,7 +686,7 @@ __ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
         might_sleep();
         ret =  __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE,
                                    0, &ctx->dep_map, _RET_IP_, ctx);
-        if (!ret && ctx->acquired > 0)
+        if (!ret && ctx->acquired > 1)
                 return ww_mutex_deadlock_injection(lock, ctx);
 
         return ret;
@@ -702,7 +702,7 @@ __ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
         ret = __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE,
                                   0, &ctx->dep_map, _RET_IP_, ctx);
 
-        if (!ret && ctx->acquired > 0)
+        if (!ret && ctx->acquired > 1)
                 return ww_mutex_deadlock_injection(lock, ctx);
 
         return ret;
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 364ceab15f0c..997cbb951a3b 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -29,15 +29,15 @@
 static struct kmem_cache *nsproxy_cachep;
 
 struct nsproxy init_nsproxy = {
-        .count  = ATOMIC_INIT(1),
-        .uts_ns = &init_uts_ns,
+        .count                  = ATOMIC_INIT(1),
+        .uts_ns                 = &init_uts_ns,
 #if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC)
-        .ipc_ns = &init_ipc_ns,
+        .ipc_ns                 = &init_ipc_ns,
 #endif
-        .mnt_ns = NULL,
-        .pid_ns = &init_pid_ns,
+        .mnt_ns                 = NULL,
+        .pid_ns_for_children    = &init_pid_ns,
 #ifdef CONFIG_NET
-        .net_ns = &init_net,
+        .net_ns                 = &init_net,
 #endif
 };
 
@@ -85,9 +85,10 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
                 goto out_ipc;
         }
 
-        new_nsp->pid_ns = copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns);
-        if (IS_ERR(new_nsp->pid_ns)) {
-                err = PTR_ERR(new_nsp->pid_ns);
+        new_nsp->pid_ns_for_children =
+                copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns_for_children);
+        if (IS_ERR(new_nsp->pid_ns_for_children)) {
+                err = PTR_ERR(new_nsp->pid_ns_for_children);
                 goto out_pid;
         }
 
@@ -100,8 +101,8 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
         return new_nsp;
 
 out_net:
-        if (new_nsp->pid_ns)
-                put_pid_ns(new_nsp->pid_ns);
+        if (new_nsp->pid_ns_for_children)
+                put_pid_ns(new_nsp->pid_ns_for_children);
 out_pid:
         if (new_nsp->ipc_ns)
                 put_ipc_ns(new_nsp->ipc_ns);
@@ -174,8 +175,8 @@ void free_nsproxy(struct nsproxy *ns)
                 put_uts_ns(ns->uts_ns);
         if (ns->ipc_ns)
                 put_ipc_ns(ns->ipc_ns);
-        if (ns->pid_ns)
-                put_pid_ns(ns->pid_ns);
+        if (ns->pid_ns_for_children)
+                put_pid_ns(ns->pid_ns_for_children);
         put_net(ns->net_ns);
         kmem_cache_free(nsproxy_cachep, ns);
 }
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 6917e8edb48e..601bb361c235 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -349,8 +349,8 @@ static int pidns_install(struct nsproxy *nsproxy, void *ns)
         if (ancestor != active)
                 return -EINVAL;
 
-        put_pid_ns(nsproxy->pid_ns);
-        nsproxy->pid_ns = get_pid_ns(new);
+        put_pid_ns(nsproxy->pid_ns_for_children);
+        nsproxy->pid_ns_for_children = get_pid_ns(new);
         return 0;
 }
 
diff --git a/kernel/power/process.c b/kernel/power/process.c
index fc0df8486449..06ec8869dbf1 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -109,6 +109,8 @@ static int try_to_freeze_tasks(bool user_only)
 
 /**
  * freeze_processes - Signal user space processes to enter the refrigerator.
+ * The current thread will not be frozen.  The same process that calls
+ * freeze_processes must later call thaw_processes.
  *
  * On success, returns 0.  On failure, -errno and system is fully thawed.
  */
@@ -120,6 +122,9 @@ int freeze_processes(void)
         if (error)
                 return error;
 
+        /* Make sure this task doesn't get frozen */
+        current->flags |= PF_SUSPEND_TASK;
+
         if (!pm_freezing)
                 atomic_inc(&system_freezing_cnt);
 
@@ -168,6 +173,7 @@ int freeze_kernel_threads(void)
 void thaw_processes(void)
 {
         struct task_struct *g, *p;
+        struct task_struct *curr = current;
 
         if (pm_freezing)
                 atomic_dec(&system_freezing_cnt);
@@ -182,10 +188,15 @@ void thaw_processes(void)
 
         read_lock(&tasklist_lock);
         do_each_thread(g, p) {
+                /* No other threads should have PF_SUSPEND_TASK set */
+                WARN_ON((p != curr) && (p->flags & PF_SUSPEND_TASK));
                 __thaw_task(p);
         } while_each_thread(g, p);
         read_unlock(&tasklist_lock);
 
+        WARN_ON(!(curr->flags & PF_SUSPEND_TASK));
+        curr->flags &= ~PF_SUSPEND_TASK;
+
         usermodehelper_enable();
 
         schedule();
diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index 06fe28589e9c..a394297f8b2f 100644
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -296,6 +296,17 @@ int pm_qos_request_active(struct pm_qos_request *req)
 }
 EXPORT_SYMBOL_GPL(pm_qos_request_active);
 
+static void __pm_qos_update_request(struct pm_qos_request *req,
+                           s32 new_value)
+{
+        trace_pm_qos_update_request(req->pm_qos_class, new_value);
+
+        if (new_value != req->node.prio)
+                pm_qos_update_target(
+                        pm_qos_array[req->pm_qos_class]->constraints,
+                        &req->node, PM_QOS_UPDATE_REQ, new_value);
+}
+
 /**
  * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout
  * @work: work struct for the delayed work (timeout)
@@ -308,7 +319,7 @@ static void pm_qos_work_fn(struct work_struct *work)
                                                   struct pm_qos_request,
                                                   work);
 
-        pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE);
+        __pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE);
 }
 
 /**
@@ -364,12 +375,7 @@ void pm_qos_update_request(struct pm_qos_request *req,
         }
 
         cancel_delayed_work_sync(&req->work);
-
-        trace_pm_qos_update_request(req->pm_qos_class, new_value);
-        if (new_value != req->node.prio)
-                pm_qos_update_target(
-                        pm_qos_array[req->pm_qos_class]->constraints,
-                        &req->node, PM_QOS_UPDATE_REQ, new_value);
+        __pm_qos_update_request(req, new_value);
 }
 EXPORT_SYMBOL_GPL(pm_qos_update_request);
 
diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile
new file mode 100644
index 000000000000..85405bdcf2b3
--- /dev/null
+++ b/kernel/printk/Makefile
@@ -0,0 +1,2 @@
+obj-y   = printk.o
+obj-$(CONFIG_A11Y_BRAILLE_CONSOLE)      += braille.o
diff --git a/kernel/printk/braille.c b/kernel/printk/braille.c
new file mode 100644
index 000000000000..276762f3a460
--- /dev/null
+++ b/kernel/printk/braille.c
@@ -0,0 +1,49 @@
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/console.h>
+#include <linux/string.h>
+
+#include "console_cmdline.h"
+#include "braille.h"
+
+char *_braille_console_setup(char **str, char **brl_options)
+{
+        if (!memcmp(*str, "brl,", 4)) {
+                *brl_options = "";
+                *str += 4;
+        } else if (!memcmp(str, "brl=", 4)) {
+                *brl_options = *str + 4;
+                *str = strchr(*brl_options, ',');
+                if (!*str)
+                        pr_err("need port name after brl=\n");
+                else
+                        *((*str)++) = 0;
+        } else
+                return NULL;
+
+        return *str;
+}
+
+int
+_braille_register_console(struct console *console, struct console_cmdline *c)
+{
+        int rtn = 0;
+
+        if (c->brl_options) {
+                console->flags |= CON_BRL;
+                rtn = braille_register_console(console, c->index, c->options,
+                                               c->brl_options);
+        }
+
+        return rtn;
+}
+
+int
+_braille_unregister_console(struct console *console)
+{
+        if (console->flags & CON_BRL)
+                return braille_unregister_console(console);
+
+        return 0;
+}
diff --git a/kernel/printk/braille.h b/kernel/printk/braille.h
new file mode 100644
index 000000000000..769d771145c8
--- /dev/null
+++ b/kernel/printk/braille.h
@@ -0,0 +1,48 @@
+#ifndef _PRINTK_BRAILLE_H
+#define _PRINTK_BRAILLE_H
+
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+
+static inline void
+braille_set_options(struct console_cmdline *c, char *brl_options)
+{
+        c->brl_options = brl_options;
+}
+
+char *
+_braille_console_setup(char **str, char **brl_options);
+
+int
+_braille_register_console(struct console *console, struct console_cmdline *c);
+
+int
+_braille_unregister_console(struct console *console);
+
+#else
+
+static inline void
+braille_set_options(struct console_cmdline *c, char *brl_options)
+{
+}
+
+static inline char *
+_braille_console_setup(char **str, char **brl_options)
+{
+        return NULL;
+}
+
+static inline int
+_braille_register_console(struct console *console, struct console_cmdline *c)
+{
+        return 0;
+}
+
+static inline int
+_braille_unregister_console(struct console *console)
+{
+        return 0;
+}
+
+#endif
+
+#endif
diff --git a/kernel/printk/console_cmdline.h b/kernel/printk/console_cmdline.h
new file mode 100644
index 000000000000..cbd69d842341
--- /dev/null
+++ b/kernel/printk/console_cmdline.h
@@ -0,0 +1,14 @@
+#ifndef _CONSOLE_CMDLINE_H
+#define _CONSOLE_CMDLINE_H
+
+struct console_cmdline
+{
+        char    name[8];                        /* Name of the driver       */
+        int     index;                          /* Minor dev. to use        */
+        char    *options;                       /* Options for the driver   */
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+        char    *brl_options;                   /* Options for braille driver */
+#endif
+};
+
+#endif
diff --git a/kernel/printk.c b/kernel/printk/printk.c
index 69b0890ed7e5..5b5a7080e2a5 100644
--- a/kernel/printk.c
+++ b/kernel/printk/printk.c
@@ -51,6 +51,9 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/printk.h>
 
+#include "console_cmdline.h"
+#include "braille.h"
+
 /* printk's without a loglevel use this.. */
 #define DEFAULT_MESSAGE_LOGLEVEL CONFIG_DEFAULT_MESSAGE_LOGLEVEL
 
@@ -105,19 +108,11 @@ static struct console *exclusive_console;
 /*
  *      Array of consoles built from command line options (console=)
  */
-struct console_cmdline
-{
-        char    name[8];                        /* Name of the driver       */
-        int     index;                          /* Minor dev. to use        */
-        char    *options;                       /* Options for the driver   */
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
-        char    *brl_options;                   /* Options for braille driver */
-#endif
-};
 
 #define MAX_CMDLINECONSOLES 8
 
 static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES];
+
 static int selected_console = -1;
 static int preferred_console = -1;
 int console_set_on_cmdline;
@@ -178,7 +173,7 @@ static int console_may_schedule;
  *         67                           "g"
  *   0032     00 00 00                  padding to next message header
  *
- * The 'struct log' buffer header must never be directly exported to
+ * The 'struct printk_log' buffer header must never be directly exported to
  * userspace, it is a kernel-private implementation detail that might
  * need to be changed in the future, when the requirements change.
  *
@@ -200,7 +195,7 @@ enum log_flags {
         LOG_CONT        = 8,    /* text is a fragment of a continuation line */
 };
 
-struct log {
+struct printk_log {
         u64 ts_nsec;            /* timestamp in nanoseconds */
         u16 len;                /* length of entire record */
         u16 text_len;           /* length of text buffer */
@@ -248,7 +243,7 @@ static u32 clear_idx;
 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 #define LOG_ALIGN 4
 #else
-#define LOG_ALIGN __alignof__(struct log)
+#define LOG_ALIGN __alignof__(struct printk_log)
 #endif
 #define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
 static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
@@ -259,35 +254,35 @@ static u32 log_buf_len = __LOG_BUF_LEN;
 static volatile unsigned int logbuf_cpu = UINT_MAX;
 
 /* human readable text of the record */
-static char *log_text(const struct log *msg)
+static char *log_text(const struct printk_log *msg)
 {
-        return (char *)msg + sizeof(struct log);
+        return (char *)msg + sizeof(struct printk_log);
 }
 
 /* optional key/value pair dictionary attached to the record */
-static char *log_dict(const struct log *msg)
+static char *log_dict(const struct printk_log *msg)
 {
-        return (char *)msg + sizeof(struct log) + msg->text_len;
+        return (char *)msg + sizeof(struct printk_log) + msg->text_len;
 }
 
 /* get record by index; idx must point to valid msg */
-static struct log *log_from_idx(u32 idx)
+static struct printk_log *log_from_idx(u32 idx)
 {
-        struct log *msg = (struct log *)(log_buf + idx);
+        struct printk_log *msg = (struct printk_log *)(log_buf + idx);
 
         /*
          * A length == 0 record is the end of buffer marker. Wrap around and
          * read the message at the start of the buffer.
          */
         if (!msg->len)
-                return (struct log *)log_buf;
+                return (struct printk_log *)log_buf;
         return msg;
 }
 
 /* get next record; idx must point to valid msg */
 static u32 log_next(u32 idx)
 {
-        struct log *msg = (struct log *)(log_buf + idx);
+        struct printk_log *msg = (struct printk_log *)(log_buf + idx);
 
         /* length == 0 indicates the end of the buffer; wrap */
         /*
@@ -296,7 +291,7 @@ static u32 log_next(u32 idx)
          * return the one after that.
          */
         if (!msg->len) {
-                msg = (struct log *)log_buf;
+                msg = (struct printk_log *)log_buf;
                 return msg->len;
         }
         return idx + msg->len;
@@ -308,11 +303,11 @@ static void log_store(int facility, int level,
                       const char *dict, u16 dict_len,
                       const char *text, u16 text_len)
 {
-        struct log *msg;
+        struct printk_log *msg;
         u32 size, pad_len;
 
         /* number of '\0' padding bytes to next message */
-        size = sizeof(struct log) + text_len + dict_len;
+        size = sizeof(struct printk_log) + text_len + dict_len;
         pad_len = (-size) & (LOG_ALIGN - 1);
         size += pad_len;
 
@@ -324,7 +319,7 @@ static void log_store(int facility, int level,
                 else
                         free = log_first_idx - log_next_idx;
 
-                if (free > size + sizeof(struct log))
+                if (free > size + sizeof(struct printk_log))
                         break;
 
                 /* drop old messages until we have enough contiuous space */
@@ -332,18 +327,18 @@ static void log_store(int facility, int level,
                 log_first_seq++;
         }
 
-        if (log_next_idx + size + sizeof(struct log) >= log_buf_len) {
+        if (log_next_idx + size + sizeof(struct printk_log) >= log_buf_len) {
                 /*
                  * This message + an additional empty header does not fit
                  * at the end of the buffer. Add an empty header with len == 0
                  * to signify a wrap around.
                  */
-                memset(log_buf + log_next_idx, 0, sizeof(struct log));
+                memset(log_buf + log_next_idx, 0, sizeof(struct printk_log));
                 log_next_idx = 0;
         }
 
         /* fill message */
-        msg = (struct log *)(log_buf + log_next_idx);
+        msg = (struct printk_log *)(log_buf + log_next_idx);
         memcpy(log_text(msg), text, text_len);
         msg->text_len = text_len;
         memcpy(log_dict(msg), dict, dict_len);
@@ -356,7 +351,7 @@ static void log_store(int facility, int level,
         else
                 msg->ts_nsec = local_clock();
         memset(log_dict(msg) + dict_len, 0, pad_len);
-        msg->len = sizeof(struct log) + text_len + dict_len + pad_len;
+        msg->len = sizeof(struct printk_log) + text_len + dict_len + pad_len;
 
         /* insert message */
         log_next_idx += msg->len;
@@ -479,7 +474,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
                             size_t count, loff_t *ppos)
 {
         struct devkmsg_user *user = file->private_data;
-        struct log *msg;
+        struct printk_log *msg;
         u64 ts_usec;
         size_t i;
         char cont = '-';
@@ -724,14 +719,14 @@ void log_buf_kexec_setup(void)
         VMCOREINFO_SYMBOL(log_first_idx);
         VMCOREINFO_SYMBOL(log_next_idx);
         /*
-         * Export struct log size and field offsets. User space tools can
+         * Export struct printk_log size and field offsets. User space tools can
          * parse it and detect any changes to structure down the line.
          */
-        VMCOREINFO_STRUCT_SIZE(log);
-        VMCOREINFO_OFFSET(log, ts_nsec);
-        VMCOREINFO_OFFSET(log, len);
-        VMCOREINFO_OFFSET(log, text_len);
-        VMCOREINFO_OFFSET(log, dict_len);
+        VMCOREINFO_STRUCT_SIZE(printk_log);
+        VMCOREINFO_OFFSET(printk_log, ts_nsec);
+        VMCOREINFO_OFFSET(printk_log, len);
+        VMCOREINFO_OFFSET(printk_log, text_len);
+        VMCOREINFO_OFFSET(printk_log, dict_len);
 }
 #endif
 
@@ -884,7 +879,7 @@ static size_t print_time(u64 ts, char *buf)
                        (unsigned long)ts, rem_nsec / 1000);
 }
 
-static size_t print_prefix(const struct log *msg, bool syslog, char *buf)
+static size_t print_prefix(const struct printk_log *msg, bool syslog, char *buf)
 {
         size_t len = 0;
         unsigned int prefix = (msg->facility << 3) | msg->level;
@@ -907,7 +902,7 @@ static size_t print_prefix(const struct log *msg, bool syslog, char *buf)
         return len;
 }
 
-static size_t msg_print_text(const struct log *msg, enum log_flags prev,
+static size_t msg_print_text(const struct printk_log *msg, enum log_flags prev,
                              bool syslog, char *buf, size_t size)
 {
         const char *text = log_text(msg);
@@ -969,7 +964,7 @@ static size_t msg_print_text(const struct log *msg, enum log_flags prev,
 static int syslog_print(char __user *buf, int size)
 {
         char *text;
-        struct log *msg;
+        struct printk_log *msg;
         int len = 0;
 
         text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
@@ -1060,7 +1055,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
                 idx = clear_idx;
                 prev = 0;
                 while (seq < log_next_seq) {
-                        struct log *msg = log_from_idx(idx);
+                        struct printk_log *msg = log_from_idx(idx);
 
                         len += msg_print_text(msg, prev, true, NULL, 0);
                         prev = msg->flags;
@@ -1073,7 +1068,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
                 idx = clear_idx;
                 prev = 0;
                 while (len > size && seq < log_next_seq) {
-                        struct log *msg = log_from_idx(idx);
+                        struct printk_log *msg = log_from_idx(idx);
 
                         len -= msg_print_text(msg, prev, true, NULL, 0);
                         prev = msg->flags;
@@ -1087,7 +1082,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
                 len = 0;
                 prev = 0;
                 while (len >= 0 && seq < next_seq) {
-                        struct log *msg = log_from_idx(idx);
+                        struct printk_log *msg = log_from_idx(idx);
                         int textlen;
 
                         textlen = msg_print_text(msg, prev, true, text,
@@ -1233,7 +1228,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
 
                         error = 0;
                         while (seq < log_next_seq) {
-                                struct log *msg = log_from_idx(idx);
+                                struct printk_log *msg = log_from_idx(idx);
 
                                 error += msg_print_text(msg, prev, true, NULL, 0);
                                 idx = log_next(idx);
@@ -1719,10 +1714,10 @@ static struct cont {
         u8 level;
         bool flushed:1;
 } cont;
-static struct log *log_from_idx(u32 idx) { return NULL; }
+static struct printk_log *log_from_idx(u32 idx) { return NULL; }
 static u32 log_next(u32 idx) { return 0; }
 static void call_console_drivers(int level, const char *text, size_t len) {}
-static size_t msg_print_text(const struct log *msg, enum log_flags prev,
+static size_t msg_print_text(const struct printk_log *msg, enum log_flags prev,
                              bool syslog, char *buf, size_t size) { return 0; }
 static size_t cont_print_text(char *text, size_t size) { return 0; }
 
@@ -1761,23 +1756,23 @@ static int __add_preferred_console(char *name, int idx, char *options,
          *      See if this tty is not yet registered, and
          *      if we have a slot free.
          */
-        for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0]; i++)
-                if (strcmp(console_cmdline[i].name, name) == 0 &&
-                          console_cmdline[i].index == idx) {
-                                if (!brl_options)
-                                        selected_console = i;
-                                return 0;
+        for (i = 0, c = console_cmdline;
+             i < MAX_CMDLINECONSOLES && c->name[0];
+             i++, c++) {
+                if (strcmp(c->name, name) == 0 && c->index == idx) {
+                        if (!brl_options)
+                                selected_console = i;
+                        return 0;
                 }
+        }
         if (i == MAX_CMDLINECONSOLES)
                 return -E2BIG;
         if (!brl_options)
                 selected_console = i;
-        c = &console_cmdline[i];
         strlcpy(c->name, name, sizeof(c->name));
         c->options = options;
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
-        c->brl_options = brl_options;
-#endif
+        braille_set_options(c, brl_options);
+
         c->index = idx;
         return 0;
 }
@@ -1790,20 +1785,8 @@ static int __init console_setup(char *str)
         char *s, *options, *brl_options = NULL;
         int idx;
 
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
-        if (!memcmp(str, "brl,", 4)) {
-                brl_options = "";
-                str += 4;
-        } else if (!memcmp(str, "brl=", 4)) {
-                brl_options = str + 4;
-                str = strchr(brl_options, ',');
-                if (!str) {
-                        printk(KERN_ERR "need port name after brl=\n");
-                        return 1;
-                }
-                *(str++) = 0;
-        }
-#endif
+        if (_braille_console_setup(&str, &brl_options))
+                return 1;
 
         /*
          * Decode str into name, index, options.
@@ -1858,15 +1841,15 @@ int update_console_cmdline(char *name, int idx, char *name_new, int idx_new, cha
         struct console_cmdline *c;
         int i;
 
-        for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0]; i++)
-                if (strcmp(console_cmdline[i].name, name) == 0 &&
-                          console_cmdline[i].index == idx) {
-                                c = &console_cmdline[i];
-                                strlcpy(c->name, name_new, sizeof(c->name));
-                                c->name[sizeof(c->name) - 1] = 0;
-                                c->options = options;
-                                c->index = idx_new;
-                                return i;
+        for (i = 0, c = console_cmdline;
+             i < MAX_CMDLINECONSOLES && c->name[0];
+             i++, c++)
+                if (strcmp(c->name, name) == 0 && c->index == idx) {
+                        strlcpy(c->name, name_new, sizeof(c->name));
+                        c->name[sizeof(c->name) - 1] = 0;
+                        c->options = options;
+                        c->index = idx_new;
+                        return i;
                 }
         /* not found */
         return -1;
@@ -2046,7 +2029,7 @@ void console_unlock(void)
         console_cont_flush(text, sizeof(text));
 again:
         for (;;) {
-                struct log *msg;
+                struct printk_log *msg;
                 size_t len;
                 int level;
 
@@ -2241,6 +2224,7 @@ void register_console(struct console *newcon)
         int i;
         unsigned long flags;
         struct console *bcon = NULL;
+        struct console_cmdline *c;
 
         /*
          * before we register a new CON_BOOT console, make sure we don't
@@ -2288,30 +2272,25 @@ void register_console(struct console *newcon)
          *      See if this console matches one we selected on
          *      the command line.
          */
-        for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0];
-                        i++) {
-                if (strcmp(console_cmdline[i].name, newcon->name) != 0)
+        for (i = 0, c = console_cmdline;
+             i < MAX_CMDLINECONSOLES && c->name[0];
+             i++, c++) {
+                if (strcmp(c->name, newcon->name) != 0)
                         continue;
                 if (newcon->index >= 0 &&
-                    newcon->index != console_cmdline[i].index)
+                    newcon->index != c->index)
                         continue;
                 if (newcon->index < 0)
-                        newcon->index = console_cmdline[i].index;
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
-                if (console_cmdline[i].brl_options) {
-                        newcon->flags |= CON_BRL;
-                        braille_register_console(newcon,
-                                        console_cmdline[i].index,
-                                        console_cmdline[i].options,
-                                        console_cmdline[i].brl_options);
+                        newcon->index = c->index;
+
+                if (_braille_register_console(newcon, c))
                         return;
-                }
-#endif
+
                 if (newcon->setup &&
                     newcon->setup(newcon, console_cmdline[i].options) != 0)
                         break;
                 newcon->flags |= CON_ENABLED;
-                newcon->index = console_cmdline[i].index;
+                newcon->index = c->index;
                 if (i == selected_console) {
                         newcon->flags |= CON_CONSDEV;
                         preferred_console = selected_console;
@@ -2394,13 +2373,13 @@ EXPORT_SYMBOL(register_console);
 int unregister_console(struct console *console)
 {
         struct console *a, *b;
-        int res = 1;
+        int res;
 
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
-        if (console->flags & CON_BRL)
-                return braille_unregister_console(console);
-#endif
+        res = _braille_unregister_console(console);
+        if (res)
+                return res;
 
+        res = 1;
         console_lock();
         if (console_drivers == console) {
                 console_drivers=console->next;
@@ -2666,7 +2645,7 @@ void kmsg_dump(enum kmsg_dump_reason reason)
 bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
                                char *line, size_t size, size_t *len)
 {
-        struct log *msg;
+        struct printk_log *msg;
         size_t l = 0;
         bool ret = false;
 
@@ -2778,7 +2757,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
         idx = dumper->cur_idx;
         prev = 0;
         while (seq < dumper->next_seq) {
-                struct log *msg = log_from_idx(idx);
+                struct printk_log *msg = log_from_idx(idx);
 
                 l += msg_print_text(msg, prev, true, NULL, 0);
                 idx = log_next(idx);
@@ -2791,7 +2770,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
         idx = dumper->cur_idx;
         prev = 0;
         while (l > size && seq < dumper->next_seq) {
-                struct log *msg = log_from_idx(idx);
+                struct printk_log *msg = log_from_idx(idx);
 
                 l -= msg_print_text(msg, prev, true, NULL, 0);
                 idx = log_next(idx);
@@ -2806,7 +2785,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
         l = 0;
         prev = 0;
         while (seq < dumper->next_seq) {
-                struct log *msg = log_from_idx(idx);
+                struct printk_log *msg = log_from_idx(idx);
 
                 l += msg_print_text(msg, prev, syslog, buf + l, size - l);
                 idx = log_next(idx);
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 4041f5747e73..a146ee327f6a 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -469,7 +469,6 @@ static int ptrace_detach(struct task_struct *child, unsigned int data)
         /* Architecture-specific hardware disable .. */
         ptrace_disable(child);
         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-        flush_ptrace_hw_breakpoint(child);
 
         write_lock_irq(&tasklist_lock);
         /*
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b7c32cb7bfeb..05c39f030314 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -933,6 +933,8 @@ static int effective_prio(struct task_struct *p)
 /**
  * task_curr - is this task currently executing on a CPU?
  * @p: the task in question.
+ *
+ * Return: 1 if the task is currently executing. 0 otherwise.
  */
 inline int task_curr(const struct task_struct *p)
 {
@@ -1482,7 +1484,7 @@ static void ttwu_queue(struct task_struct *p, int cpu)
  * the simpler "current->state = TASK_RUNNING" to mark yourself
  * runnable without the overhead of this.
  *
- * Returns %true if @p was woken up, %false if it was already running
+ * Return: %true if @p was woken up, %false if it was already running.
  * or @state didn't match @p's state.
  */
 static int
@@ -1491,7 +1493,13 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
         unsigned long flags;
         int cpu, success = 0;
 
-        smp_wmb();
+        /*
+         * If we are going to wake up a thread waiting for CONDITION we
+         * need to ensure that CONDITION=1 done by the caller can not be
+         * reordered with p->state check below. This pairs with mb() in
+         * set_current_state() the waiting thread does.
+         */
+        smp_mb__before_spinlock();
         raw_spin_lock_irqsave(&p->pi_lock, flags);
         if (!(p->state & state))
                 goto out;
@@ -1577,8 +1585,9 @@ out:
  * @p: The process to be woken up.
  *
  * Attempt to wake up the nominated process and move it to the set of runnable
- * processes.  Returns 1 if the process was woken up, 0 if it was already
- * running.
+ * processes.
+ *
+ * Return: 1 if the process was woken up, 0 if it was already running.
  *
  * It may be assumed that this function implies a write memory barrier before
  * changing the task state if and only if any tasks are woken up.
@@ -2191,6 +2200,8 @@ void scheduler_tick(void)
  * This makes sure that uptime, CFS vruntime, load
  * balancing, etc... continue to move forward, even
  * with a very low granularity.
+ *
+ * Return: Maximum deferment in nanoseconds.
  */
 u64 scheduler_tick_max_deferment(void)
 {
@@ -2394,6 +2405,12 @@ need_resched:
         if (sched_feat(HRTICK))
                 hrtick_clear(rq);
 
+        /*
+         * Make sure that signal_pending_state()->signal_pending() below
+         * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE)
+         * done by the caller to avoid the race with signal_wake_up().
+         */
+        smp_mb__before_spinlock();
         raw_spin_lock_irq(&rq->lock);
 
         switch_count = &prev->nivcsw;
@@ -2796,8 +2813,8 @@ EXPORT_SYMBOL(wait_for_completion);
  * specified timeout to expire. The timeout is in jiffies. It is not
  * interruptible.
  *
- * The return value is 0 if timed out, and positive (at least 1, or number of
- * jiffies left till timeout) if completed.
+ * Return: 0 if timed out, and positive (at least 1, or number of jiffies left
+ * till timeout) if completed.
  */
 unsigned long __sched
 wait_for_completion_timeout(struct completion *x, unsigned long timeout)
@@ -2829,8 +2846,8 @@ EXPORT_SYMBOL(wait_for_completion_io);
  * specified timeout to expire. The timeout is in jiffies. It is not
  * interruptible. The caller is accounted as waiting for IO.
  *
- * The return value is 0 if timed out, and positive (at least 1, or number of
- * jiffies left till timeout) if completed.
+ * Return: 0 if timed out, and positive (at least 1, or number of jiffies left
+ * till timeout) if completed.
  */
 unsigned long __sched
 wait_for_completion_io_timeout(struct completion *x, unsigned long timeout)
@@ -2846,7 +2863,7 @@ EXPORT_SYMBOL(wait_for_completion_io_timeout);
  * This waits for completion of a specific task to be signaled. It is
  * interruptible.
  *
- * The return value is -ERESTARTSYS if interrupted, 0 if completed.
+ * Return: -ERESTARTSYS if interrupted, 0 if completed.
  */
 int __sched wait_for_completion_interruptible(struct completion *x)
 {
@@ -2865,8 +2882,8 @@ EXPORT_SYMBOL(wait_for_completion_interruptible);
  * This waits for either a completion of a specific task to be signaled or for a
  * specified timeout to expire. It is interruptible. The timeout is in jiffies.
  *
- * The return value is -ERESTARTSYS if interrupted, 0 if timed out,
- * positive (at least 1, or number of jiffies left till timeout) if completed.
+ * Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1,
+ * or number of jiffies left till timeout) if completed.
  */
 long __sched
 wait_for_completion_interruptible_timeout(struct completion *x,
@@ -2883,7 +2900,7 @@ EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
  * This waits to be signaled for completion of a specific task. It can be
  * interrupted by a kill signal.
  *
- * The return value is -ERESTARTSYS if interrupted, 0 if completed.
+ * Return: -ERESTARTSYS if interrupted, 0 if completed.
  */
 int __sched wait_for_completion_killable(struct completion *x)
 {
@@ -2903,8 +2920,8 @@ EXPORT_SYMBOL(wait_for_completion_killable);
  * signaled or for a specified timeout to expire. It can be
  * interrupted by a kill signal. The timeout is in jiffies.
  *
- * The return value is -ERESTARTSYS if interrupted, 0 if timed out,
- * positive (at least 1, or number of jiffies left till timeout) if completed.
+ * Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1,
+ * or number of jiffies left till timeout) if completed.
  */
 long __sched
 wait_for_completion_killable_timeout(struct completion *x,
@@ -2918,7 +2935,7 @@ EXPORT_SYMBOL(wait_for_completion_killable_timeout);
  *      try_wait_for_completion - try to decrement a completion without blocking
  *      @x:     completion structure
  *
- *      Returns: 0 if a decrement cannot be done without blocking
+ *      Return: 0 if a decrement cannot be done without blocking
  *               1 if a decrement succeeded.
  *
  *      If a completion is being used as a counting completion,
@@ -2945,7 +2962,7 @@ EXPORT_SYMBOL(try_wait_for_completion);
  *      completion_done - Test to see if a completion has any waiters
  *      @x:     completion structure
  *
- *      Returns: 0 if there are waiters (wait_for_completion() in progress)
+ *      Return: 0 if there are waiters (wait_for_completion() in progress)
  *               1 if there are no waiters.
  *
  */
@@ -3182,7 +3199,7 @@ SYSCALL_DEFINE1(nice, int, increment)
  * task_prio - return the priority value of a given task.
  * @p: the task in question.
  *
- * This is the priority value as seen by users in /proc.
+ * Return: The priority value as seen by users in /proc.
  * RT tasks are offset by -200. Normal tasks are centered
  * around 0, value goes from -16 to +15.
  */
@@ -3194,6 +3211,8 @@ int task_prio(const struct task_struct *p)
 /**
  * task_nice - return the nice value of a given task.
  * @p: the task in question.
+ *
+ * Return: The nice value [ -20 ... 0 ... 19 ].
  */
 int task_nice(const struct task_struct *p)
 {
@@ -3204,6 +3223,8 @@ EXPORT_SYMBOL(task_nice);
 /**
  * idle_cpu - is a given cpu idle currently?
  * @cpu: the processor in question.
+ *
+ * Return: 1 if the CPU is currently idle. 0 otherwise.
  */
 int idle_cpu(int cpu)
 {
@@ -3226,6 +3247,8 @@ int idle_cpu(int cpu)
 /**
  * idle_task - return the idle task for a given cpu.
  * @cpu: the processor in question.
+ *
+ * Return: The idle task for the cpu @cpu.
  */
 struct task_struct *idle_task(int cpu)
 {
@@ -3235,6 +3258,8 @@ struct task_struct *idle_task(int cpu)
 /**
  * find_process_by_pid - find a process with a matching PID value.
  * @pid: the pid in question.
+ *
+ * The task of @pid, if found. %NULL otherwise.
  */
 static struct task_struct *find_process_by_pid(pid_t pid)
 {
@@ -3432,6 +3457,8 @@ recheck:
  * @policy: new policy.
  * @param: structure containing the new RT priority.
  *
+ * Return: 0 on success. An error code otherwise.
+ *
  * NOTE that the task may be already dead.
  */
 int sched_setscheduler(struct task_struct *p, int policy,
@@ -3451,6 +3478,8 @@ EXPORT_SYMBOL_GPL(sched_setscheduler);
  * current context has permission.  For example, this is needed in
  * stop_machine(): we create temporary high priority worker threads,
  * but our caller might not have that capability.
+ *
+ * Return: 0 on success. An error code otherwise.
  */
 int sched_setscheduler_nocheck(struct task_struct *p, int policy,
                                const struct sched_param *param)
@@ -3485,6 +3514,8 @@ do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
  * @pid: the pid in question.
  * @policy: new policy.
  * @param: structure containing the new RT priority.
+ *
+ * Return: 0 on success. An error code otherwise.
  */
 SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy,
                 struct sched_param __user *, param)
@@ -3500,6 +3531,8 @@ SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy,
  * sys_sched_setparam - set/change the RT priority of a thread
  * @pid: the pid in question.
  * @param: structure containing the new RT priority.
+ *
+ * Return: 0 on success. An error code otherwise.
  */
 SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
 {
@@ -3509,6 +3542,9 @@ SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
 /**
  * sys_sched_getscheduler - get the policy (scheduling class) of a thread
  * @pid: the pid in question.
+ *
+ * Return: On success, the policy of the thread. Otherwise, a negative error
+ * code.
  */
 SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
 {
@@ -3535,6 +3571,9 @@ SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
  * sys_sched_getparam - get the RT priority of a thread
  * @pid: the pid in question.
  * @param: structure containing the RT priority.
+ *
+ * Return: On success, 0 and the RT priority is in @param. Otherwise, an error
+ * code.
  */
 SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
 {
@@ -3659,6 +3698,8 @@ static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len,
  * @pid: pid of the process
  * @len: length in bytes of the bitmask pointed to by user_mask_ptr
  * @user_mask_ptr: user-space pointer to the new cpu mask
+ *
+ * Return: 0 on success. An error code otherwise.
  */
 SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len,
                 unsigned long __user *, user_mask_ptr)
@@ -3710,6 +3751,8 @@ out_unlock:
  * @pid: pid of the process
  * @len: length in bytes of the bitmask pointed to by user_mask_ptr
  * @user_mask_ptr: user-space pointer to hold the current cpu mask
+ *
+ * Return: 0 on success. An error code otherwise.
  */
 SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
                 unsigned long __user *, user_mask_ptr)
@@ -3744,6 +3787,8 @@ SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
  *
  * This function yields the current CPU to other tasks. If there are no
  * other threads running on this CPU then this function will return.
+ *
+ * Return: 0.
  */
 SYSCALL_DEFINE0(sched_yield)
 {
@@ -3869,7 +3914,7 @@ EXPORT_SYMBOL(yield);
  * It's the caller's job to ensure that the target task struct
  * can't go away on us before we can do any checks.
  *
- * Returns:
+ * Return:
  *      true (>0) if we indeed boosted the target task.
  *      false (0) if we failed to boost the target.
  *      -ESRCH if there's no task to yield to.
@@ -3972,8 +4017,9 @@ long __sched io_schedule_timeout(long timeout)
  * sys_sched_get_priority_max - return maximum RT priority.
  * @policy: scheduling class.
  *
- * this syscall returns the maximum rt_priority that can be used
- * by a given scheduling class.
+ * Return: On success, this syscall returns the maximum
+ * rt_priority that can be used by a given scheduling class.
+ * On failure, a negative error code is returned.
  */
 SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
 {
@@ -3997,8 +4043,9 @@ SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
  * sys_sched_get_priority_min - return minimum RT priority.
  * @policy: scheduling class.
  *
- * this syscall returns the minimum rt_priority that can be used
- * by a given scheduling class.
+ * Return: On success, this syscall returns the minimum
+ * rt_priority that can be used by a given scheduling class.
+ * On failure, a negative error code is returned.
  */
 SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
 {
@@ -4024,6 +4071,9 @@ SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
  *
  * this syscall writes the default timeslice value of a given process
  * into the user-space timespec buffer. A value of '0' means infinity.
+ *
+ * Return: On success, 0 and the timeslice is in @interval. Otherwise,
+ * an error code.
  */
 SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
                 struct timespec __user *, interval)
@@ -6632,6 +6682,8 @@ void normalize_rt_tasks(void)
  * @cpu: the processor in question.
  *
  * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
+ *
+ * Return: The current task for @cpu.
  */
 struct task_struct *curr_task(int cpu)
 {
diff --git a/kernel/sched/cpupri.c b/kernel/sched/cpupri.c
index 1095e878a46f..8b836b376d91 100644
--- a/kernel/sched/cpupri.c
+++ b/kernel/sched/cpupri.c
@@ -62,7 +62,7 @@ static int convert_prio(int prio)
  * any discrepancies created by racing against the uncertainty of the current
  * priority configuration.
  *
- * Returns: (int)bool - CPUs were found
+ * Return: (int)bool - CPUs were found
  */
 int cpupri_find(struct cpupri *cp, struct task_struct *p,
                 struct cpumask *lowest_mask)
@@ -203,7 +203,7 @@ void cpupri_set(struct cpupri *cp, int cpu, int newpri)
  * cpupri_init - initialize the cpupri structure
  * @cp: The cpupri context
  *
- * Returns: -ENOMEM if memory fails.
+ * Return: -ENOMEM on memory allocation failure.
  */
 int cpupri_init(struct cpupri *cp)
 {
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index bb456f44b7b1..68f1609ca149 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -851,7 +851,7 @@ void task_numa_fault(int node, int pages, bool migrated)
 {
         struct task_struct *p = current;
 
-        if (!sched_feat_numa(NUMA))
+        if (!numabalancing_enabled)
                 return;
 
         /* FIXME: Allocate task-specific structure for placement policy here */
@@ -2032,6 +2032,7 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
          */
         update_entity_load_avg(curr, 1);
         update_cfs_rq_blocked_load(cfs_rq, 1);
+        update_cfs_shares(cfs_rq);
 
 #ifdef CONFIG_SCHED_HRTICK
         /*
@@ -4280,6 +4281,8 @@ struct sg_lb_stats {
  * get_sd_load_idx - Obtain the load index for a given sched domain.
  * @sd: The sched_domain whose load_idx is to be obtained.
  * @idle: The Idle status of the CPU for whose sd load_icx is obtained.
+ *
+ * Return: The load index.
  */
 static inline int get_sd_load_idx(struct sched_domain *sd,
                                         enum cpu_idle_type idle)
@@ -4574,6 +4577,9 @@ static inline void update_sg_lb_stats(struct lb_env *env,
  *
  * Determine if @sg is a busier group than the previously selected
  * busiest group.
+ *
+ * Return: %true if @sg is a busier group than the previously selected
+ * busiest group. %false otherwise.
  */
 static bool update_sd_pick_busiest(struct lb_env *env,
                                    struct sd_lb_stats *sds,
@@ -4691,7 +4697,7 @@ static inline void update_sd_lb_stats(struct lb_env *env,
  * assuming lower CPU number will be equivalent to lower a SMT thread
  * number.
  *
- * Returns 1 when packing is required and a task should be moved to
+ * Return: 1 when packing is required and a task should be moved to
  * this CPU.  The amount of the imbalance is returned in *imbalance.
  *
  * @env: The load balancing environment.
@@ -4869,7 +4875,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
  * @balance: Pointer to a variable indicating if this_cpu
  *      is the appropriate cpu to perform load balancing at this_level.
  *
- * Returns:     - the busiest group if imbalance exists.
+ * Return:      - The busiest group if imbalance exists.
  *              - If no imbalance and user has opted for power-savings balance,
  *                 return the least loaded group whose CPUs can be
  *                 put to idle by rebalancing its tasks onto our group.
@@ -5786,7 +5792,7 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
                 entity_tick(cfs_rq, se, queued);
         }
 
-        if (sched_feat_numa(NUMA))
+        if (numabalancing_enabled)
                 task_tick_numa(rq, curr);
 
         update_rq_runnable_avg(rq, 1);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index ac09d98490aa..07f6fc468e17 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2346,7 +2346,11 @@ static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
                                             int write, void *data)
 {
         if (write) {
-                *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
+                unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
+
+                if (jif > INT_MAX)
+                        return 1;
+                *valp = (int)jif;
         } else {
                 int val = *valp;
                 unsigned long lval;
diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
index a326f27d7f09..0b479a6a22bb 100644
--- a/kernel/time/sched_clock.c
+++ b/kernel/time/sched_clock.c
@@ -121,7 +121,7 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate)
         BUG_ON(bits > 32);
         WARN_ON(!irqs_disabled());
         read_sched_clock = read;
-        sched_clock_mask = (1 << bits) - 1;
+        sched_clock_mask = (1ULL << bits) - 1;
         cd.rate = rate;
 
         /* calculate the mult/shift to convert counter ticks to ns. */
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index e80183f4a6c4..e8a1516cc0a3 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -182,7 +182,8 @@ static bool can_stop_full_tick(void)
                  * Don't allow the user to think they can get
                  * full NO_HZ with this machine.
                  */
-                WARN_ONCE(1, "NO_HZ FULL will not work with unstable sched clock");
+                WARN_ONCE(have_nohz_full_mask,
+                          "NO_HZ FULL will not work with unstable sched clock");
                 return false;
         }
 #endif
@@ -343,8 +344,6 @@ static int tick_nohz_init_all(void)
 
 void __init tick_nohz_init(void)
 {
-        int cpu;
-
         if (!have_nohz_full_mask) {
                 if (tick_nohz_init_all() < 0)
                         return;
@@ -827,13 +826,10 @@ void tick_nohz_irq_exit(void)
 {
         struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
 
-        if (ts->inidle) {
-                /* Cancel the timer because CPU already waken up from the C-states*/
-                menu_hrtimer_cancel();
+        if (ts->inidle)
                 __tick_nohz_idle_enter(ts);
-        } else {
+        else
                 tick_nohz_full_stop_tick(ts);
-        }
 }
 
 /**
@@ -931,8 +927,6 @@ void tick_nohz_idle_exit(void)
 
         ts->inidle = 0;
 
-        /* Cancel the timer because CPU already waken up from the C-states*/
-        menu_hrtimer_cancel();
         if (ts->idle_active || ts->tick_stopped)
                 now = ktime_get();
 
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index 3bdf28323012..61ed862cdd37 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -265,10 +265,9 @@ static inline void timer_list_header(struct seq_file *m, u64 now)
 static int timer_list_show(struct seq_file *m, void *v)
 {
         struct timer_list_iter *iter = v;
-        u64 now = ktime_to_ns(ktime_get());
 
         if (iter->cpu == -1 && !iter->second_pass)
-                timer_list_header(m, now);
+                timer_list_header(m, iter->now);
         else if (!iter->second_pass)
                 print_cpu(m, iter->cpu, iter->now);
 #ifdef CONFIG_GENERIC_CLOCKEVENTS
@@ -298,33 +297,41 @@ void sysrq_timer_list_show(void)
         return;
 }
 
-static void *timer_list_start(struct seq_file *file, loff_t *offset)
+static void *move_iter(struct timer_list_iter *iter, loff_t offset)
 {
-        struct timer_list_iter *iter = file->private;
-
-        if (!*offset) {
-                iter->cpu = -1;
-                iter->now = ktime_to_ns(ktime_get());
-        } else if (iter->cpu >= nr_cpu_ids) {
+        for (; offset; offset--) {
+                iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
+                if (iter->cpu >= nr_cpu_ids) {
 #ifdef CONFIG_GENERIC_CLOCKEVENTS
-                if (!iter->second_pass) {
-                        iter->cpu = -1;
-                        iter->second_pass = true;
-                } else
-                        return NULL;
+                        if (!iter->second_pass) {
+                                iter->cpu = -1;
+                                iter->second_pass = true;
+                        } else
+                                return NULL;
 #else
-                return NULL;
+                        return NULL;
 #endif
+                }
         }
         return iter;
 }
 
+static void *timer_list_start(struct seq_file *file, loff_t *offset)
+{
+        struct timer_list_iter *iter = file->private;
+
+        if (!*offset)
+                iter->now = ktime_to_ns(ktime_get());
+        iter->cpu = -1;
+        iter->second_pass = false;
+        return move_iter(iter, *offset);
+}
+
 static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset)
 {
         struct timer_list_iter *iter = file->private;
-        iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
         ++*offset;
-        return timer_list_start(file, offset);
+        return move_iter(iter, 1);
 }
 
 static void timer_list_stop(struct seq_file *seq, void *v)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 67708f46baae..a6d098c6df3f 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1441,12 +1441,22 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable,
  * the hashes are freed with call_rcu_sched().
  */
 static int
-ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
+ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
 {
         struct ftrace_hash *filter_hash;
         struct ftrace_hash *notrace_hash;
         int ret;
 
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+        /*
+         * There's a small race when adding ops that the ftrace handler
+         * that wants regs, may be called without them. We can not
+         * allow that handler to be called if regs is NULL.
+         */
+        if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
+                return 0;
+#endif
+
         filter_hash = rcu_dereference_raw_notrace(ops->filter_hash);
         notrace_hash = rcu_dereference_raw_notrace(ops->notrace_hash);
 
@@ -2159,12 +2169,57 @@ static cycle_t		ftrace_update_time;
 static unsigned long    ftrace_update_cnt;
 unsigned long           ftrace_update_tot_cnt;
 
-static int ops_traces_mod(struct ftrace_ops *ops)
+static inline int ops_traces_mod(struct ftrace_ops *ops)
 {
-        struct ftrace_hash *hash;
+        /*
+         * Filter_hash being empty will default to trace module.
+         * But notrace hash requires a test of individual module functions.
+         */
+        return ftrace_hash_empty(ops->filter_hash) &&
+                ftrace_hash_empty(ops->notrace_hash);
+}
+
+/*
+ * Check if the current ops references the record.
+ *
+ * If the ops traces all functions, then it was already accounted for.
+ * If the ops does not trace the current record function, skip it.
+ * If the ops ignores the function via notrace filter, skip it.
+ */
+static inline bool
+ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
+{
+        /* If ops isn't enabled, ignore it */
+        if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+                return 0;
+
+        /* If ops traces all mods, we already accounted for it */
+        if (ops_traces_mod(ops))
+                return 0;
+
+        /* The function must be in the filter */
+        if (!ftrace_hash_empty(ops->filter_hash) &&
+            !ftrace_lookup_ip(ops->filter_hash, rec->ip))
+                return 0;
+
+        /* If in notrace hash, we ignore it too */
+        if (ftrace_lookup_ip(ops->notrace_hash, rec->ip))
+                return 0;
 
-        hash = ops->filter_hash;
-        return ftrace_hash_empty(hash);
+        return 1;
+}
+
+static int referenced_filters(struct dyn_ftrace *rec)
+{
+        struct ftrace_ops *ops;
+        int cnt = 0;
+
+        for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
+                if (ops_references_rec(ops, rec))
+                    cnt++;
+        }
+
+        return cnt;
 }
 
 static int ftrace_update_code(struct module *mod)
@@ -2173,6 +2228,7 @@ static int ftrace_update_code(struct module *mod)
         struct dyn_ftrace *p;
         cycle_t start, stop;
         unsigned long ref = 0;
+        bool test = false;
         int i;
 
         /*
@@ -2186,9 +2242,12 @@ static int ftrace_update_code(struct module *mod)
 
                 for (ops = ftrace_ops_list;
                      ops != &ftrace_list_end; ops = ops->next) {
-                        if (ops->flags & FTRACE_OPS_FL_ENABLED &&
-                            ops_traces_mod(ops))
-                                ref++;
+                        if (ops->flags & FTRACE_OPS_FL_ENABLED) {
+                                if (ops_traces_mod(ops))
+                                        ref++;
+                                else
+                                        test = true;
+                        }
                 }
         }
 
@@ -2198,12 +2257,16 @@ static int ftrace_update_code(struct module *mod)
         for (pg = ftrace_new_pgs; pg; pg = pg->next) {
 
                 for (i = 0; i < pg->index; i++) {
+                        int cnt = ref;
+
                         /* If something went wrong, bail without enabling anything */
                         if (unlikely(ftrace_disabled))
                                 return -1;
 
                         p = &pg->records[i];
-                        p->flags = ref;
+                        if (test)
+                                cnt += referenced_filters(p);
+                        p->flags = cnt;
 
                         /*
                          * Do the initial record conversion from mcount jump
@@ -2223,7 +2286,7 @@ static int ftrace_update_code(struct module *mod)
                          * conversion puts the module to the correct state, thus
                          * passing the ftrace_make_call check.
                          */
-                        if (ftrace_start_up && ref) {
+                        if (ftrace_start_up && cnt) {
                                 int failed = __ftrace_replace_code(p, 1);
                                 if (failed)
                                         ftrace_bug(failed, p->ip);
@@ -3374,6 +3437,12 @@ ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
         return add_hash_entry(hash, ip);
 }
 
+static void ftrace_ops_update_code(struct ftrace_ops *ops)
+{
+        if (ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled)
+                ftrace_run_update_code(FTRACE_UPDATE_CALLS);
+}
+
 static int
 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
                 unsigned long ip, int remove, int reset, int enable)
@@ -3416,9 +3485,8 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
 
         mutex_lock(&ftrace_lock);
         ret = ftrace_hash_move(ops, enable, orig_hash, hash);
-        if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED
-            && ftrace_enabled)
-                ftrace_run_update_code(FTRACE_UPDATE_CALLS);
+        if (!ret)
+                ftrace_ops_update_code(ops);
 
         mutex_unlock(&ftrace_lock);
 
@@ -3645,9 +3713,8 @@ int ftrace_regex_release(struct inode *inode, struct file *file)
                 mutex_lock(&ftrace_lock);
                 ret = ftrace_hash_move(iter->ops, filter_hash,
                                        orig_hash, iter->hash);
-                if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED)
-                    && ftrace_enabled)
-                        ftrace_run_update_code(FTRACE_UPDATE_CALLS);
+                if (!ret)
+                        ftrace_ops_update_code(iter->ops);
 
                 mutex_unlock(&ftrace_lock);
         }
@@ -4218,7 +4285,7 @@ static inline void ftrace_startup_enable(int command) { }
 # define ftrace_shutdown_sysctl()       do { } while (0)
 
 static inline int
-ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
+ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
 {
         return 1;
 }
@@ -4241,7 +4308,7 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
         do_for_each_ftrace_op(op, ftrace_control_list) {
                 if (!(op->flags & FTRACE_OPS_FL_STUB) &&
                     !ftrace_function_local_disabled(op) &&
-                    ftrace_ops_test(op, ip))
+                    ftrace_ops_test(op, ip, regs))
                         op->func(ip, parent_ip, op, regs);
         } while_for_each_ftrace_op(op);
         trace_recursion_clear(TRACE_CONTROL_BIT);
@@ -4274,7 +4341,7 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
          */
         preempt_disable_notrace();
         do_for_each_ftrace_op(op, ftrace_ops_list) {
-                if (ftrace_ops_test(op, ip))
+                if (ftrace_ops_test(op, ip, regs))
                         op->func(ip, parent_ip, op, regs);
         } while_for_each_ftrace_op(op);
         preempt_enable_notrace();
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index e444ff88f0a4..cc2f66f68dc5 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -36,11 +36,11 @@ int ring_buffer_print_entry_header(struct trace_seq *s)
 {
         int ret;
 
-        ret = trace_seq_printf(s, "# compressed entry header\n");
-        ret = trace_seq_printf(s, "\ttype_len    :    5 bits\n");
-        ret = trace_seq_printf(s, "\ttime_delta  :   27 bits\n");
-        ret = trace_seq_printf(s, "\tarray       :   32 bits\n");
-        ret = trace_seq_printf(s, "\n");
+        ret = trace_seq_puts(s, "# compressed entry header\n");
+        ret = trace_seq_puts(s, "\ttype_len    :    5 bits\n");
+        ret = trace_seq_puts(s, "\ttime_delta  :   27 bits\n");
+        ret = trace_seq_puts(s, "\tarray       :   32 bits\n");
+        ret = trace_seq_putc(s, '\n');
         ret = trace_seq_printf(s, "\tpadding     : type == %d\n",
                                RINGBUF_TYPE_PADDING);
         ret = trace_seq_printf(s, "\ttime_extend : type == %d\n",
@@ -1066,7 +1066,7 @@ static int rb_check_list(struct ring_buffer_per_cpu *cpu_buffer,
 }
 
 /**
- * check_pages - integrity check of buffer pages
+ * rb_check_pages - integrity check of buffer pages
  * @cpu_buffer: CPU buffer with pages to test
  *
  * As a safety measure we check to make sure the data pages have not
@@ -1258,7 +1258,7 @@ static int rb_cpu_notify(struct notifier_block *self,
 #endif
 
 /**
- * ring_buffer_alloc - allocate a new ring_buffer
+ * __ring_buffer_alloc - allocate a new ring_buffer
  * @size: the size in bytes per cpu that is needed.
  * @flags: attributes to set for the ring buffer.
  *
@@ -1607,6 +1607,7 @@ static void update_pages_handler(struct work_struct *work)
  * ring_buffer_resize - resize the ring buffer
  * @buffer: the buffer to resize.
  * @size: the new size.
+ * @cpu_id: the cpu buffer to resize
  *
  * Minimum size is 2 * BUF_PAGE_SIZE.
  *
@@ -3956,11 +3957,11 @@ EXPORT_SYMBOL_GPL(ring_buffer_consume);
  * expected.
  *
  * After a sequence of ring_buffer_read_prepare calls, the user is
- * expected to make at least one call to ring_buffer_prepare_sync.
+ * expected to make at least one call to ring_buffer_read_prepare_sync.
  * Afterwards, ring_buffer_read_start is invoked to get things going
  * for real.
  *
- * This overall must be paired with ring_buffer_finish.
+ * This overall must be paired with ring_buffer_read_finish.
  */
 struct ring_buffer_iter *
 ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu)
@@ -4009,7 +4010,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_read_prepare_sync);
  * an intervening ring_buffer_read_prepare_sync must have been
  * performed.
  *
- * Must be paired with ring_buffer_finish.
+ * Must be paired with ring_buffer_read_finish.
  */
 void
 ring_buffer_read_start(struct ring_buffer_iter *iter)
@@ -4031,7 +4032,7 @@ ring_buffer_read_start(struct ring_buffer_iter *iter)
 EXPORT_SYMBOL_GPL(ring_buffer_read_start);
 
 /**
- * ring_buffer_finish - finish reading the iterator of the buffer
+ * ring_buffer_read_finish - finish reading the iterator of the buffer
  * @iter: The iterator retrieved by ring_buffer_start
  *
  * This re-enables the recording to the buffer, and frees the
@@ -4346,6 +4347,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_swap_cpu);
 /**
  * ring_buffer_alloc_read_page - allocate a page to read from buffer
  * @buffer: the buffer to allocate for.
+ * @cpu: the cpu buffer to allocate.
  *
  * This function is used in conjunction with ring_buffer_read_page.
  * When reading a full page from the ring buffer, these functions
@@ -4403,7 +4405,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_free_read_page);
  * to swap with a page in the ring buffer.
  *
  * for example:
- *      rpage = ring_buffer_alloc_read_page(buffer);
+ *      rpage = ring_buffer_alloc_read_page(buffer, cpu);
  *      if (!rpage)
  *              return error;
  *      ret = ring_buffer_read_page(buffer, &rpage, len, cpu, 0);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 0cd500bffd9b..496f94d57698 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -243,20 +243,25 @@ int filter_current_check_discard(struct ring_buffer *buffer,
 }
 EXPORT_SYMBOL_GPL(filter_current_check_discard);
 
-cycle_t ftrace_now(int cpu)
+cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu)
 {
         u64 ts;
 
         /* Early boot up does not have a buffer yet */
-        if (!global_trace.trace_buffer.buffer)
+        if (!buf->buffer)
                 return trace_clock_local();
 
-        ts = ring_buffer_time_stamp(global_trace.trace_buffer.buffer, cpu);
-        ring_buffer_normalize_time_stamp(global_trace.trace_buffer.buffer, cpu, &ts);
+        ts = ring_buffer_time_stamp(buf->buffer, cpu);
+        ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts);
 
         return ts;
 }
 
+cycle_t ftrace_now(int cpu)
+{
+        return buffer_ftrace_now(&global_trace.trace_buffer, cpu);
+}
+
 /**
  * tracing_is_enabled - Show if global_trace has been disabled
  *
@@ -1211,7 +1216,7 @@ void tracing_reset_online_cpus(struct trace_buffer *buf)
         /* Make sure all commits have finished */
         synchronize_sched();
 
-        buf->time_start = ftrace_now(buf->cpu);
+        buf->time_start = buffer_ftrace_now(buf, buf->cpu);
 
         for_each_online_cpu(cpu)
                 ring_buffer_reset_cpu(buffer, cpu);
@@ -1219,23 +1224,17 @@ void tracing_reset_online_cpus(struct trace_buffer *buf)
         ring_buffer_record_enable(buffer);
 }
 
-void tracing_reset_current(int cpu)
-{
-        tracing_reset(&global_trace.trace_buffer, cpu);
-}
-
+/* Must have trace_types_lock held */
 void tracing_reset_all_online_cpus(void)
 {
         struct trace_array *tr;
 
-        mutex_lock(&trace_types_lock);
         list_for_each_entry(tr, &ftrace_trace_arrays, list) {
                 tracing_reset_online_cpus(&tr->trace_buffer);
 #ifdef CONFIG_TRACER_MAX_TRACE
                 tracing_reset_online_cpus(&tr->max_buffer);
 #endif
         }
-        mutex_unlock(&trace_types_lock);
 }
 
 #define SAVED_CMDLINES 128
@@ -2843,6 +2842,17 @@ static int s_show(struct seq_file *m, void *v)
         return 0;
 }
 
+/*
+ * Should be used after trace_array_get(), trace_types_lock
+ * ensures that i_cdev was already initialized.
+ */
+static inline int tracing_get_cpu(struct inode *inode)
+{
+        if (inode->i_cdev) /* See trace_create_cpu_file() */
+                return (long)inode->i_cdev - 1;
+        return RING_BUFFER_ALL_CPUS;
+}
+
 static const struct seq_operations tracer_seq_ops = {
         .start          = s_start,
         .next           = s_next,
@@ -2851,9 +2861,9 @@ static const struct seq_operations tracer_seq_ops = {
 };
 
 static struct trace_iterator *
-__tracing_open(struct trace_array *tr, struct trace_cpu *tc,
-               struct inode *inode, struct file *file, bool snapshot)
+__tracing_open(struct inode *inode, struct file *file, bool snapshot)
 {
+        struct trace_array *tr = inode->i_private;
         struct trace_iterator *iter;
         int cpu;
 
@@ -2894,8 +2904,8 @@ __tracing_open(struct trace_array *tr, struct trace_cpu *tc,
                 iter->trace_buffer = &tr->trace_buffer;
         iter->snapshot = snapshot;
         iter->pos = -1;
+        iter->cpu_file = tracing_get_cpu(inode);
         mutex_init(&iter->mutex);
-        iter->cpu_file = tc->cpu;
 
         /* Notify the tracer early; before we stop tracing. */
         if (iter->trace && iter->trace->open)
@@ -2971,45 +2981,22 @@ static int tracing_open_generic_tr(struct inode *inode, struct file *filp)
         filp->private_data = inode->i_private;
 
         return 0;
-        
-}
-
-static int tracing_open_generic_tc(struct inode *inode, struct file *filp)
-{
-        struct trace_cpu *tc = inode->i_private;
-        struct trace_array *tr = tc->tr;
-
-        if (tracing_disabled)
-                return -ENODEV;
-
-        if (trace_array_get(tr) < 0)
-                return -ENODEV;
-
-        filp->private_data = inode->i_private;
-
-        return 0;
-        
 }
 
 static int tracing_release(struct inode *inode, struct file *file)
 {
+        struct trace_array *tr = inode->i_private;
         struct seq_file *m = file->private_data;
         struct trace_iterator *iter;
-        struct trace_array *tr;
         int cpu;
 
-        /* Writes do not use seq_file, need to grab tr from inode */
         if (!(file->f_mode & FMODE_READ)) {
-                struct trace_cpu *tc = inode->i_private;
-
-                trace_array_put(tc->tr);
+                trace_array_put(tr);
                 return 0;
         }
 
+        /* Writes do not use seq_file */
         iter = m->private;
-        tr = iter->tr;
-        trace_array_put(tr);
-
         mutex_lock(&trace_types_lock);
 
         for_each_tracing_cpu(cpu) {
@@ -3023,6 +3010,9 @@ static int tracing_release(struct inode *inode, struct file *file)
         if (!iter->snapshot)
                 /* reenable tracing if it was previously enabled */
                 tracing_start_tr(tr);
+
+        __trace_array_put(tr);
+
         mutex_unlock(&trace_types_lock);
 
         mutex_destroy(&iter->mutex);
@@ -3042,15 +3032,6 @@ static int tracing_release_generic_tr(struct inode *inode, struct file *file)
         return 0;
 }
 
-static int tracing_release_generic_tc(struct inode *inode, struct file *file)
-{
-        struct trace_cpu *tc = inode->i_private;
-        struct trace_array *tr = tc->tr;
-
-        trace_array_put(tr);
-        return 0;
-}
-
 static int tracing_single_release_tr(struct inode *inode, struct file *file)
 {
         struct trace_array *tr = inode->i_private;
@@ -3062,8 +3043,7 @@ static int tracing_single_release_tr(struct inode *inode, struct file *file)
 
 static int tracing_open(struct inode *inode, struct file *file)
 {
-        struct trace_cpu *tc = inode->i_private;
-        struct trace_array *tr = tc->tr;
+        struct trace_array *tr = inode->i_private;
         struct trace_iterator *iter;
         int ret = 0;
 
@@ -3071,16 +3051,17 @@ static int tracing_open(struct inode *inode, struct file *file)
                 return -ENODEV;
 
         /* If this file was open for write, then erase contents */
-        if ((file->f_mode & FMODE_WRITE) &&
-            (file->f_flags & O_TRUNC)) {
-                if (tc->cpu == RING_BUFFER_ALL_CPUS)
+        if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
+                int cpu = tracing_get_cpu(inode);
+
+                if (cpu == RING_BUFFER_ALL_CPUS)
                         tracing_reset_online_cpus(&tr->trace_buffer);
                 else
-                        tracing_reset(&tr->trace_buffer, tc->cpu);
+                        tracing_reset(&tr->trace_buffer, cpu);
         }
 
         if (file->f_mode & FMODE_READ) {
-                iter = __tracing_open(tr, tc, inode, file, false);
+                iter = __tracing_open(inode, file, false);
                 if (IS_ERR(iter))
                         ret = PTR_ERR(iter);
                 else if (trace_flags & TRACE_ITER_LATENCY_FMT)
@@ -3447,6 +3428,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
 static int tracing_trace_options_open(struct inode *inode, struct file *file)
 {
         struct trace_array *tr = inode->i_private;
+        int ret;
 
         if (tracing_disabled)
                 return -ENODEV;
@@ -3454,7 +3436,11 @@ static int tracing_trace_options_open(struct inode *inode, struct file *file)
         if (trace_array_get(tr) < 0)
                 return -ENODEV;
 
-        return single_open(file, tracing_trace_options_show, inode->i_private);
+        ret = single_open(file, tracing_trace_options_show, inode->i_private);
+        if (ret < 0)
+                trace_array_put(tr);
+
+        return ret;
 }
 
 static const struct file_operations tracing_iter_fops = {
@@ -3537,14 +3523,14 @@ static const char readme_msg[] =
         "\n  snapshot\t\t- Like 'trace' but shows the content of the static snapshot buffer\n"
         "\t\t\t  Read the contents for more information\n"
 #endif
-#ifdef CONFIG_STACKTRACE
+#ifdef CONFIG_STACK_TRACER
         "  stack_trace\t\t- Shows the max stack trace when active\n"
         "  stack_max_size\t- Shows current max stack size that was traced\n"
         "\t\t\t  Write into this file to reset the max size (trigger a new trace)\n"
 #ifdef CONFIG_DYNAMIC_FTRACE
         "  stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace traces\n"
 #endif
-#endif /* CONFIG_STACKTRACE */
+#endif /* CONFIG_STACK_TRACER */
 ;
 
 static ssize_t
@@ -3941,8 +3927,7 @@ tracing_max_lat_write(struct file *filp, const char __user *ubuf,
 
 static int tracing_open_pipe(struct inode *inode, struct file *filp)
 {
-        struct trace_cpu *tc = inode->i_private;
-        struct trace_array *tr = tc->tr;
+        struct trace_array *tr = inode->i_private;
         struct trace_iterator *iter;
         int ret = 0;
 
@@ -3958,6 +3943,7 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
         iter = kzalloc(sizeof(*iter), GFP_KERNEL);
         if (!iter) {
                 ret = -ENOMEM;
+                __trace_array_put(tr);
                 goto out;
         }
 
@@ -3987,9 +3973,9 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
         if (trace_clocks[tr->clock_id].in_ns)
                 iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
 
-        iter->cpu_file = tc->cpu;
-        iter->tr = tc->tr;
-        iter->trace_buffer = &tc->tr->trace_buffer;
+        iter->tr = tr;
+        iter->trace_buffer = &tr->trace_buffer;
+        iter->cpu_file = tracing_get_cpu(inode);
         mutex_init(&iter->mutex);
         filp->private_data = iter;
 
@@ -4012,8 +3998,7 @@ fail:
 static int tracing_release_pipe(struct inode *inode, struct file *file)
 {
         struct trace_iterator *iter = file->private_data;
-        struct trace_cpu *tc = inode->i_private;
-        struct trace_array *tr = tc->tr;
+        struct trace_array *tr = inode->i_private;
 
         mutex_lock(&trace_types_lock);
 
@@ -4166,6 +4151,7 @@ waitagain:
         memset(&iter->seq, 0,
                sizeof(struct trace_iterator) -
                offsetof(struct trace_iterator, seq));
+        cpumask_clear(iter->started);
         iter->pos = -1;
 
         trace_event_read_lock();
@@ -4366,15 +4352,16 @@ static ssize_t
 tracing_entries_read(struct file *filp, char __user *ubuf,
                      size_t cnt, loff_t *ppos)
 {
-        struct trace_cpu *tc = filp->private_data;
-        struct trace_array *tr = tc->tr;
+        struct inode *inode = file_inode(filp);
+        struct trace_array *tr = inode->i_private;
+        int cpu = tracing_get_cpu(inode);
         char buf[64];
         int r = 0;
         ssize_t ret;
 
         mutex_lock(&trace_types_lock);
 
-        if (tc->cpu == RING_BUFFER_ALL_CPUS) {
+        if (cpu == RING_BUFFER_ALL_CPUS) {
                 int cpu, buf_size_same;
                 unsigned long size;
 
@@ -4401,7 +4388,7 @@ tracing_entries_read(struct file *filp, char __user *ubuf,
                 } else
                         r = sprintf(buf, "X\n");
         } else
-                r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, tc->cpu)->entries >> 10);
+                r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10);
 
         mutex_unlock(&trace_types_lock);
 
@@ -4413,7 +4400,8 @@ static ssize_t
 tracing_entries_write(struct file *filp, const char __user *ubuf,
                       size_t cnt, loff_t *ppos)
 {
-        struct trace_cpu *tc = filp->private_data;
+        struct inode *inode = file_inode(filp);
+        struct trace_array *tr = inode->i_private;
         unsigned long val;
         int ret;
 
@@ -4427,8 +4415,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 
         /* value is in KB */
         val <<= 10;
-
-        ret = tracing_resize_ring_buffer(tc->tr, val, tc->cpu);
+        ret = tracing_resize_ring_buffer(tr, val, tracing_get_cpu(inode));
         if (ret < 0)
                 return ret;
 
@@ -4482,7 +4469,7 @@ tracing_free_buffer_release(struct inode *inode, struct file *filp)
 
         /* disable tracing ? */
         if (trace_flags & TRACE_ITER_STOP_ON_FREE)
-                tracing_off();
+                tracer_tracing_off(tr);
         /* resize the ring buffer to 0 */
         tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS);
 
@@ -4647,12 +4634,12 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
          * New clock may not be consistent with the previous clock.
          * Reset the buffer so that it doesn't have incomparable timestamps.
          */
-        tracing_reset_online_cpus(&global_trace.trace_buffer);
+        tracing_reset_online_cpus(&tr->trace_buffer);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
         if (tr->flags & TRACE_ARRAY_FL_GLOBAL && tr->max_buffer.buffer)
                 ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func);
-        tracing_reset_online_cpus(&global_trace.max_buffer);
+        tracing_reset_online_cpus(&tr->max_buffer);
 #endif
 
         mutex_unlock(&trace_types_lock);
@@ -4689,8 +4676,7 @@ struct ftrace_buffer_info {
 #ifdef CONFIG_TRACER_SNAPSHOT
 static int tracing_snapshot_open(struct inode *inode, struct file *file)
 {
-        struct trace_cpu *tc = inode->i_private;
-        struct trace_array *tr = tc->tr;
+        struct trace_array *tr = inode->i_private;
         struct trace_iterator *iter;
         struct seq_file *m;
         int ret = 0;
@@ -4699,26 +4685,29 @@ static int tracing_snapshot_open(struct inode *inode, struct file *file)
                 return -ENODEV;
 
         if (file->f_mode & FMODE_READ) {
-                iter = __tracing_open(tr, tc, inode, file, true);
+                iter = __tracing_open(inode, file, true);
                 if (IS_ERR(iter))
                         ret = PTR_ERR(iter);
         } else {
                 /* Writes still need the seq_file to hold the private data */
+                ret = -ENOMEM;
                 m = kzalloc(sizeof(*m), GFP_KERNEL);
                 if (!m)
-                        return -ENOMEM;
+                        goto out;
                 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
                 if (!iter) {
                         kfree(m);
-                        return -ENOMEM;
+                        goto out;
                 }
+                ret = 0;
+
                 iter->tr = tr;
-                iter->trace_buffer = &tc->tr->max_buffer;
-                iter->cpu_file = tc->cpu;
+                iter->trace_buffer = &tr->max_buffer;
+                iter->cpu_file = tracing_get_cpu(inode);
                 m->private = iter;
                 file->private_data = m;
         }
-
+out:
         if (ret < 0)
                 trace_array_put(tr);
 
@@ -4873,11 +4862,11 @@ static const struct file_operations tracing_pipe_fops = {
 };
 
 static const struct file_operations tracing_entries_fops = {
-        .open           = tracing_open_generic_tc,
+        .open           = tracing_open_generic_tr,
         .read           = tracing_entries_read,
         .write          = tracing_entries_write,
         .llseek         = generic_file_llseek,
-        .release        = tracing_release_generic_tc,
+        .release        = tracing_release_generic_tr,
 };
 
 static const struct file_operations tracing_total_entries_fops = {
@@ -4929,8 +4918,7 @@ static const struct file_operations snapshot_raw_fops = {
 
 static int tracing_buffers_open(struct inode *inode, struct file *filp)
 {
-        struct trace_cpu *tc = inode->i_private;
-        struct trace_array *tr = tc->tr;
+        struct trace_array *tr = inode->i_private;
         struct ftrace_buffer_info *info;
         int ret;
 
@@ -4948,10 +4936,8 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp)
 
         mutex_lock(&trace_types_lock);
 
-        tr->ref++;
-
         info->iter.tr           = tr;
-        info->iter.cpu_file     = tc->cpu;
+        info->iter.cpu_file     = tracing_get_cpu(inode);
         info->iter.trace        = tr->current_trace;
         info->iter.trace_buffer = &tr->trace_buffer;
         info->spare             = NULL;
@@ -5268,14 +5254,14 @@ static ssize_t
 tracing_stats_read(struct file *filp, char __user *ubuf,
                    size_t count, loff_t *ppos)
 {
-        struct trace_cpu *tc = filp->private_data;
-        struct trace_array *tr = tc->tr;
+        struct inode *inode = file_inode(filp);
+        struct trace_array *tr = inode->i_private;
         struct trace_buffer *trace_buf = &tr->trace_buffer;
+        int cpu = tracing_get_cpu(inode);
         struct trace_seq *s;
         unsigned long cnt;
         unsigned long long t;
         unsigned long usec_rem;
-        int cpu = tc->cpu;
 
         s = kmalloc(sizeof(*s), GFP_KERNEL);
         if (!s)
@@ -5328,9 +5314,10 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
 }
 
 static const struct file_operations tracing_stats_fops = {
-        .open           = tracing_open_generic,
+        .open           = tracing_open_generic_tr,
         .read           = tracing_stats_read,
         .llseek         = generic_file_llseek,
+        .release        = tracing_release_generic_tr,
 };
 
 #ifdef CONFIG_DYNAMIC_FTRACE
@@ -5519,10 +5506,20 @@ static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu)
         return tr->percpu_dir;
 }
 
+static struct dentry *
+trace_create_cpu_file(const char *name, umode_t mode, struct dentry *parent,
+                      void *data, long cpu, const struct file_operations *fops)
+{
+        struct dentry *ret = trace_create_file(name, mode, parent, data, fops);
+
+        if (ret) /* See tracing_get_cpu() */
+                ret->d_inode->i_cdev = (void *)(cpu + 1);
+        return ret;
+}
+
 static void
 tracing_init_debugfs_percpu(struct trace_array *tr, long cpu)
 {
-        struct trace_array_cpu *data = per_cpu_ptr(tr->trace_buffer.data, cpu);
         struct dentry *d_percpu = tracing_dentry_percpu(tr, cpu);
         struct dentry *d_cpu;
         char cpu_dir[30]; /* 30 characters should be more than enough */
@@ -5538,28 +5535,28 @@ tracing_init_debugfs_percpu(struct trace_array *tr, long cpu)
         }
 
         /* per cpu trace_pipe */
-        trace_create_file("trace_pipe", 0444, d_cpu,
-                        (void *)&data->trace_cpu, &tracing_pipe_fops);
+        trace_create_cpu_file("trace_pipe", 0444, d_cpu,
+                                tr, cpu, &tracing_pipe_fops);
 
         /* per cpu trace */
-        trace_create_file("trace", 0644, d_cpu,
-                        (void *)&data->trace_cpu, &tracing_fops);
+        trace_create_cpu_file("trace", 0644, d_cpu,
+                                tr, cpu, &tracing_fops);
 
-        trace_create_file("trace_pipe_raw", 0444, d_cpu,
-                        (void *)&data->trace_cpu, &tracing_buffers_fops);
+        trace_create_cpu_file("trace_pipe_raw", 0444, d_cpu,
+                                tr, cpu, &tracing_buffers_fops);
 
-        trace_create_file("stats", 0444, d_cpu,
-                        (void *)&data->trace_cpu, &tracing_stats_fops);
+        trace_create_cpu_file("stats", 0444, d_cpu,
+                                tr, cpu, &tracing_stats_fops);
 
-        trace_create_file("buffer_size_kb", 0444, d_cpu,
-                        (void *)&data->trace_cpu, &tracing_entries_fops);
+        trace_create_cpu_file("buffer_size_kb", 0444, d_cpu,
+                                tr, cpu, &tracing_entries_fops);
 
 #ifdef CONFIG_TRACER_SNAPSHOT
-        trace_create_file("snapshot", 0644, d_cpu,
-                          (void *)&data->trace_cpu, &snapshot_fops);
+        trace_create_cpu_file("snapshot", 0644, d_cpu,
+                                tr, cpu, &snapshot_fops);
 
-        trace_create_file("snapshot_raw", 0444, d_cpu,
-                        (void *)&data->trace_cpu, &snapshot_raw_fops);
+        trace_create_cpu_file("snapshot_raw", 0444, d_cpu,
+                                tr, cpu, &snapshot_raw_fops);
 #endif
 }
 
@@ -5868,17 +5865,6 @@ struct dentry *trace_instance_dir;
 static void
 init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer);
 
-static void init_trace_buffers(struct trace_array *tr, struct trace_buffer *buf)
-{
-        int cpu;
-
-        for_each_tracing_cpu(cpu) {
-                memset(per_cpu_ptr(buf->data, cpu), 0, sizeof(struct trace_array_cpu));
-                per_cpu_ptr(buf->data, cpu)->trace_cpu.cpu = cpu;
-                per_cpu_ptr(buf->data, cpu)->trace_cpu.tr = tr;
-        }
-}
-
 static int
 allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size)
 {
@@ -5896,8 +5882,6 @@ allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size
                 return -ENOMEM;
         }
 
-        init_trace_buffers(tr, buf);
-
         /* Allocate the first page for all buffers */
         set_buffer_entries(&tr->trace_buffer,
                            ring_buffer_size(tr->trace_buffer.buffer, 0));
@@ -5964,17 +5948,15 @@ static int new_instance_create(const char *name)
         if (allocate_trace_buffers(tr, trace_buf_size) < 0)
                 goto out_free_tr;
 
-        /* Holder for file callbacks */
-        tr->trace_cpu.cpu = RING_BUFFER_ALL_CPUS;
-        tr->trace_cpu.tr = tr;
-
         tr->dir = debugfs_create_dir(name, trace_instance_dir);
         if (!tr->dir)
                 goto out_free_tr;
 
         ret = event_trace_add_tracer(tr->dir, tr);
-        if (ret)
+        if (ret) {
+                debugfs_remove_recursive(tr->dir);
                 goto out_free_tr;
+        }
 
         init_tracer_debugfs(tr, tr->dir);
 
@@ -6120,13 +6102,13 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
                           tr, &tracing_iter_fops);
 
         trace_create_file("trace", 0644, d_tracer,
-                        (void *)&tr->trace_cpu, &tracing_fops);
+                          tr, &tracing_fops);
 
         trace_create_file("trace_pipe", 0444, d_tracer,
-                        (void *)&tr->trace_cpu, &tracing_pipe_fops);
+                          tr, &tracing_pipe_fops);
 
         trace_create_file("buffer_size_kb", 0644, d_tracer,
-                        (void *)&tr->trace_cpu, &tracing_entries_fops);
+                          tr, &tracing_entries_fops);
 
         trace_create_file("buffer_total_size_kb", 0444, d_tracer,
                           tr, &tracing_total_entries_fops);
@@ -6141,11 +6123,11 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
                           &trace_clock_fops);
 
         trace_create_file("tracing_on", 0644, d_tracer,
-                            tr, &rb_simple_fops);
+                          tr, &rb_simple_fops);
 
 #ifdef CONFIG_TRACER_SNAPSHOT
         trace_create_file("snapshot", 0644, d_tracer,
-                          (void *)&tr->trace_cpu, &snapshot_fops);
+                          tr, &snapshot_fops);
 #endif
 
         for_each_tracing_cpu(cpu)
@@ -6439,10 +6421,6 @@ __init static int tracer_alloc_buffers(void)
 
         global_trace.flags = TRACE_ARRAY_FL_GLOBAL;
 
-        /* Holder for file callbacks */
-        global_trace.trace_cpu.cpu = RING_BUFFER_ALL_CPUS;
-        global_trace.trace_cpu.tr = &global_trace;
-
         INIT_LIST_HEAD(&global_trace.systems);
         INIT_LIST_HEAD(&global_trace.events);
         list_add(&global_trace.list, &ftrace_trace_arrays);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 4a4f6e1828b6..afaae41b0a02 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -130,19 +130,12 @@ enum trace_flag_type {
 
 struct trace_array;
 
-struct trace_cpu {
-        struct trace_array      *tr;
-        struct dentry           *dir;
-        int                     cpu;
-};
-
 /*
  * The CPU trace array - it consists of thousands of trace entries
  * plus some other descriptor data: (for example which task started
  * the trace, etc.)
  */
 struct trace_array_cpu {
-        struct trace_cpu        trace_cpu;
         atomic_t                disabled;
         void                    *buffer_page;   /* ring buffer spare */
 
@@ -196,7 +189,6 @@ struct trace_array {
         bool                    allocated_snapshot;
 #endif
         int                     buffer_disabled;
-        struct trace_cpu        trace_cpu;      /* place holder */
 #ifdef CONFIG_FTRACE_SYSCALLS
         int                     sys_refcount_enter;
         int                     sys_refcount_exit;
@@ -214,7 +206,6 @@ struct trace_array {
         struct dentry           *event_dir;
         struct list_head        systems;
         struct list_head        events;
-        struct task_struct      *waiter;
         int                     ref;
 };
 
@@ -680,6 +671,15 @@ extern int trace_selftest_startup_sched_switch(struct tracer *trace,
                                                struct trace_array *tr);
 extern int trace_selftest_startup_branch(struct tracer *trace,
                                          struct trace_array *tr);
+/*
+ * Tracer data references selftest functions that only occur
+ * on boot up. These can be __init functions. Thus, when selftests
+ * are enabled, then the tracers need to reference __init functions.
+ */
+#define __tracer_data           __refdata
+#else
+/* Tracers are seldom changed. Optimize when selftests are disabled. */
+#define __tracer_data           __read_mostly
 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 
 extern void *head_page(struct trace_array_cpu *data);
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 84b1e045faba..80c36bcf66e8 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -236,6 +236,10 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type,
 
         BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long));
 
+        if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
+                        "perf buffer not large enough"))
+                return NULL;
+
         pc = preempt_count();
 
         *rctxp = perf_swevent_get_recursion_context();
@@ -266,6 +270,10 @@ perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip,
         struct pt_regs regs;
         int rctx;
 
+        head = this_cpu_ptr(event_function.perf_events);
+        if (hlist_empty(head))
+                return;
+
 #define ENTRY_SIZE (ALIGN(sizeof(struct ftrace_entry) + sizeof(u32), \
                     sizeof(u64)) - sizeof(u32))
 
@@ -279,8 +287,6 @@ perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip,
 
         entry->ip = ip;
         entry->parent_ip = parent_ip;
-
-        head = this_cpu_ptr(event_function.perf_events);
         perf_trace_buf_submit(entry, ENTRY_SIZE, rctx, 0,
                               1, &regs, head, NULL);
 
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 7d854290bf81..29a7ebcfb426 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -409,33 +409,42 @@ static void put_system(struct ftrace_subsystem_dir *dir)
         mutex_unlock(&event_mutex);
 }
 
-/*
- * Open and update trace_array ref count.
- * Must have the current trace_array passed to it.
- */
-static int tracing_open_generic_file(struct inode *inode, struct file *filp)
+static void remove_subsystem(struct ftrace_subsystem_dir *dir)
 {
-        struct ftrace_event_file *file = inode->i_private;
-        struct trace_array *tr = file->tr;
-        int ret;
+        if (!dir)
+                return;
 
-        if (trace_array_get(tr) < 0)
-                return -ENODEV;
+        if (!--dir->nr_events) {
+                debugfs_remove_recursive(dir->entry);
+                list_del(&dir->list);
+                __put_system_dir(dir);
+        }
+}
 
-        ret = tracing_open_generic(inode, filp);
-        if (ret < 0)
-                trace_array_put(tr);
-        return ret;
+static void *event_file_data(struct file *filp)
+{
+        return ACCESS_ONCE(file_inode(filp)->i_private);
 }
 
-static int tracing_release_generic_file(struct inode *inode, struct file *filp)
+static void remove_event_file_dir(struct ftrace_event_file *file)
 {
-        struct ftrace_event_file *file = inode->i_private;
-        struct trace_array *tr = file->tr;
+        struct dentry *dir = file->dir;
+        struct dentry *child;
 
-        trace_array_put(tr);
+        if (dir) {
+                spin_lock(&dir->d_lock);        /* probably unneeded */
+                list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
+                        if (child->d_inode)     /* probably unneeded */
+                                child->d_inode->i_private = NULL;
+                }
+                spin_unlock(&dir->d_lock);
 
-        return 0;
+                debugfs_remove_recursive(dir);
+        }
+
+        list_del(&file->list);
+        remove_subsystem(file->system);
+        kmem_cache_free(file_cachep, file);
 }
 
 /*
@@ -679,15 +688,25 @@ static ssize_t
 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
                   loff_t *ppos)
 {
-        struct ftrace_event_file *file = filp->private_data;
+        struct ftrace_event_file *file;
+        unsigned long flags;
         char buf[4] = "0";
 
-        if (file->flags & FTRACE_EVENT_FL_ENABLED &&
-            !(file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
+        mutex_lock(&event_mutex);
+        file = event_file_data(filp);
+        if (likely(file))
+                flags = file->flags;
+        mutex_unlock(&event_mutex);
+
+        if (!file)
+                return -ENODEV;
+
+        if (flags & FTRACE_EVENT_FL_ENABLED &&
+            !(flags & FTRACE_EVENT_FL_SOFT_DISABLED))
                 strcpy(buf, "1");
 
-        if (file->flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
-            file->flags & FTRACE_EVENT_FL_SOFT_MODE)
+        if (flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
+            flags & FTRACE_EVENT_FL_SOFT_MODE)
                 strcat(buf, "*");
 
         strcat(buf, "\n");
@@ -699,13 +718,10 @@ static ssize_t
 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
                    loff_t *ppos)
 {
-        struct ftrace_event_file *file = filp->private_data;
+        struct ftrace_event_file *file;
         unsigned long val;
         int ret;
 
-        if (!file)
-                return -EINVAL;
-
         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
         if (ret)
                 return ret;
@@ -717,8 +733,11 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
         switch (val) {
         case 0:
         case 1:
+                ret = -ENODEV;
                 mutex_lock(&event_mutex);
-                ret = ftrace_event_enable_disable(file, val);
+                file = event_file_data(filp);
+                if (likely(file))
+                        ret = ftrace_event_enable_disable(file, val);
                 mutex_unlock(&event_mutex);
                 break;
 
@@ -825,65 +844,39 @@ enum {
 
 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
 {
-        struct ftrace_event_call *call = m->private;
-        struct ftrace_event_field *field;
+        struct ftrace_event_call *call = event_file_data(m->private);
         struct list_head *common_head = &ftrace_common_fields;
         struct list_head *head = trace_get_fields(call);
+        struct list_head *node = v;
 
         (*pos)++;
 
         switch ((unsigned long)v) {
         case FORMAT_HEADER:
-                if (unlikely(list_empty(common_head)))
-                        return NULL;
-
-                field = list_entry(common_head->prev,
-                                   struct ftrace_event_field, link);
-                return field;
+                node = common_head;
+                break;
 
         case FORMAT_FIELD_SEPERATOR:
-                if (unlikely(list_empty(head)))
-                        return NULL;
-
-                field = list_entry(head->prev, struct ftrace_event_field, link);
-                return field;
+                node = head;
+                break;
 
         case FORMAT_PRINTFMT:
                 /* all done */
                 return NULL;
         }
 
-        field = v;
-        if (field->link.prev == common_head)
+        node = node->prev;
+        if (node == common_head)
                 return (void *)FORMAT_FIELD_SEPERATOR;
-        else if (field->link.prev == head)
+        else if (node == head)
                 return (void *)FORMAT_PRINTFMT;
-
-        field = list_entry(field->link.prev, struct ftrace_event_field, link);
-
-        return field;
-}
-
-static void *f_start(struct seq_file *m, loff_t *pos)
-{
-        loff_t l = 0;
-        void *p;
-
-        /* Start by showing the header */
-        if (!*pos)
-                return (void *)FORMAT_HEADER;
-
-        p = (void *)FORMAT_HEADER;
-        do {
-                p = f_next(m, p, &l);
-        } while (p && l < *pos);
-
-        return p;
+        else
+                return node;
 }
 
 static int f_show(struct seq_file *m, void *v)
 {
-        struct ftrace_event_call *call = m->private;
+        struct ftrace_event_call *call = event_file_data(m->private);
         struct ftrace_event_field *field;
         const char *array_descriptor;
 
@@ -904,8 +897,7 @@ static int f_show(struct seq_file *m, void *v)
                 return 0;
         }
 
-        field = v;
-
+        field = list_entry(v, struct ftrace_event_field, link);
         /*
          * Smartly shows the array type(except dynamic array).
          * Normal:
@@ -932,8 +924,25 @@ static int f_show(struct seq_file *m, void *v)
         return 0;
 }
 
+static void *f_start(struct seq_file *m, loff_t *pos)
+{
+        void *p = (void *)FORMAT_HEADER;
+        loff_t l = 0;
+
+        /* ->stop() is called even if ->start() fails */
+        mutex_lock(&event_mutex);
+        if (!event_file_data(m->private))
+                return ERR_PTR(-ENODEV);
+
+        while (l < *pos && p)
+                p = f_next(m, p, &l);
+
+        return p;
+}
+
 static void f_stop(struct seq_file *m, void *p)
 {
+        mutex_unlock(&event_mutex);
 }
 
 static const struct seq_operations trace_format_seq_ops = {
@@ -945,7 +954,6 @@ static const struct seq_operations trace_format_seq_ops = {
 
 static int trace_format_open(struct inode *inode, struct file *file)
 {
-        struct ftrace_event_call *call = inode->i_private;
         struct seq_file *m;
         int ret;
 
@@ -954,7 +962,7 @@ static int trace_format_open(struct inode *inode, struct file *file)
                 return ret;
 
         m = file->private_data;
-        m->private = call;
+        m->private = file;
 
         return 0;
 }
@@ -962,45 +970,47 @@ static int trace_format_open(struct inode *inode, struct file *file)
 static ssize_t
 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 {
-        struct ftrace_event_call *call = filp->private_data;
-        struct trace_seq *s;
-        int r;
+        int id = (long)event_file_data(filp);
+        char buf[32];
+        int len;
 
         if (*ppos)
                 return 0;
 
-        s = kmalloc(sizeof(*s), GFP_KERNEL);
-        if (!s)
-                return -ENOMEM;
+        if (unlikely(!id))
+                return -ENODEV;
 
-        trace_seq_init(s);
-        trace_seq_printf(s, "%d\n", call->event.type);
+        len = sprintf(buf, "%d\n", id);
 
-        r = simple_read_from_buffer(ubuf, cnt, ppos,
-                                    s->buffer, s->len);
-        kfree(s);
-        return r;
+        return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
 }
 
 static ssize_t
 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
                   loff_t *ppos)
 {
-        struct ftrace_event_call *call = filp->private_data;
+        struct ftrace_event_call *call;
         struct trace_seq *s;
-        int r;
+        int r = -ENODEV;
 
         if (*ppos)
                 return 0;
 
         s = kmalloc(sizeof(*s), GFP_KERNEL);
+
         if (!s)
                 return -ENOMEM;
 
         trace_seq_init(s);
 
-        print_event_filter(call, s);
-        r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
+        mutex_lock(&event_mutex);
+        call = event_file_data(filp);
+        if (call)
+                print_event_filter(call, s);
+        mutex_unlock(&event_mutex);
+
+        if (call)
+                r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 
         kfree(s);
 
@@ -1011,9 +1021,9 @@ static ssize_t
 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
                    loff_t *ppos)
 {
-        struct ftrace_event_call *call = filp->private_data;
+        struct ftrace_event_call *call;
         char *buf;
-        int err;
+        int err = -ENODEV;
 
         if (cnt >= PAGE_SIZE)
                 return -EINVAL;
@@ -1028,7 +1038,12 @@ event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
         }
         buf[cnt] = '\0';
 
-        err = apply_event_filter(call, buf);
+        mutex_lock(&event_mutex);
+        call = event_file_data(filp);
+        if (call)
+                err = apply_event_filter(call, buf);
+        mutex_unlock(&event_mutex);
+
         free_page((unsigned long) buf);
         if (err < 0)
                 return err;
@@ -1218,6 +1233,7 @@ show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 
 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
 static int ftrace_event_set_open(struct inode *inode, struct file *file);
+static int ftrace_event_release(struct inode *inode, struct file *file);
 
 static const struct seq_operations show_event_seq_ops = {
         .start = t_start,
@@ -1245,14 +1261,13 @@ static const struct file_operations ftrace_set_event_fops = {
         .read = seq_read,
         .write = ftrace_event_write,
         .llseek = seq_lseek,
-        .release = seq_release,
+        .release = ftrace_event_release,
 };
 
 static const struct file_operations ftrace_enable_fops = {
-        .open = tracing_open_generic_file,
+        .open = tracing_open_generic,
         .read = event_enable_read,
         .write = event_enable_write,
-        .release = tracing_release_generic_file,
         .llseek = default_llseek,
 };
 
@@ -1264,7 +1279,6 @@ static const struct file_operations ftrace_event_format_fops = {
 };
 
 static const struct file_operations ftrace_event_id_fops = {
-        .open = tracing_open_generic,
         .read = event_id_read,
         .llseek = default_llseek,
 };
@@ -1323,6 +1337,15 @@ ftrace_event_open(struct inode *inode, struct file *file,
         return ret;
 }
 
+static int ftrace_event_release(struct inode *inode, struct file *file)
+{
+        struct trace_array *tr = inode->i_private;
+
+        trace_array_put(tr);
+
+        return seq_release(inode, file);
+}
+
 static int
 ftrace_event_avail_open(struct inode *inode, struct file *file)
 {
@@ -1336,12 +1359,19 @@ ftrace_event_set_open(struct inode *inode, struct file *file)
 {
         const struct seq_operations *seq_ops = &show_set_event_seq_ops;
         struct trace_array *tr = inode->i_private;
+        int ret;
+
+        if (trace_array_get(tr) < 0)
+                return -ENODEV;
 
         if ((file->f_mode & FMODE_WRITE) &&
             (file->f_flags & O_TRUNC))
                 ftrace_clear_events(tr);
 
-        return ftrace_event_open(inode, file, seq_ops);
+        ret = ftrace_event_open(inode, file, seq_ops);
+        if (ret < 0)
+                trace_array_put(tr);
+        return ret;
 }
 
 static struct event_subsystem *
@@ -1496,8 +1526,8 @@ event_create_dir(struct dentry *parent,
 
 #ifdef CONFIG_PERF_EVENTS
         if (call->event.type && call->class->reg)
-                trace_create_file("id", 0444, file->dir, call,
-                                  id);
+                trace_create_file("id", 0444, file->dir,
+                                  (void *)(long)call->event.type, id);
 #endif
 
         /*
@@ -1522,33 +1552,16 @@ event_create_dir(struct dentry *parent,
         return 0;
 }
 
-static void remove_subsystem(struct ftrace_subsystem_dir *dir)
-{
-        if (!dir)
-                return;
-
-        if (!--dir->nr_events) {
-                debugfs_remove_recursive(dir->entry);
-                list_del(&dir->list);
-                __put_system_dir(dir);
-        }
-}
-
 static void remove_event_from_tracers(struct ftrace_event_call *call)
 {
         struct ftrace_event_file *file;
         struct trace_array *tr;
 
         do_for_each_event_file_safe(tr, file) {
-
                 if (file->event_call != call)
                         continue;
 
-                list_del(&file->list);
-                debugfs_remove_recursive(file->dir);
-                remove_subsystem(file->system);
-                kmem_cache_free(file_cachep, file);
-
+                remove_event_file_dir(file);
                 /*
                  * The do_for_each_event_file_safe() is
                  * a double loop. After finding the call for this
@@ -1700,16 +1713,53 @@ static void __trace_remove_event_call(struct ftrace_event_call *call)
         destroy_preds(call);
 }
 
+static int probe_remove_event_call(struct ftrace_event_call *call)
+{
+        struct trace_array *tr;
+        struct ftrace_event_file *file;
+
+#ifdef CONFIG_PERF_EVENTS
+        if (call->perf_refcount)
+                return -EBUSY;
+#endif
+        do_for_each_event_file(tr, file) {
+                if (file->event_call != call)
+                        continue;
+                /*
+                 * We can't rely on ftrace_event_enable_disable(enable => 0)
+                 * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
+                 * TRACE_REG_UNREGISTER.
+                 */
+                if (file->flags & FTRACE_EVENT_FL_ENABLED)
+                        return -EBUSY;
+                /*
+                 * The do_for_each_event_file_safe() is
+                 * a double loop. After finding the call for this
+                 * trace_array, we use break to jump to the next
+                 * trace_array.
+                 */
+                break;
+        } while_for_each_event_file();
+
+        __trace_remove_event_call(call);
+
+        return 0;
+}
+
 /* Remove an event_call */
-void trace_remove_event_call(struct ftrace_event_call *call)
+int trace_remove_event_call(struct ftrace_event_call *call)
 {
+        int ret;
+
         mutex_lock(&trace_types_lock);
         mutex_lock(&event_mutex);
         down_write(&trace_event_sem);
-        __trace_remove_event_call(call);
+        ret = probe_remove_event_call(call);
         up_write(&trace_event_sem);
         mutex_unlock(&event_mutex);
         mutex_unlock(&trace_types_lock);
+
+        return ret;
 }
 
 #define for_each_event(event, start, end)                       \
@@ -2278,12 +2328,8 @@ __trace_remove_event_dirs(struct trace_array *tr)
 {
         struct ftrace_event_file *file, *next;
 
-        list_for_each_entry_safe(file, next, &tr->events, list) {
-                list_del(&file->list);
-                debugfs_remove_recursive(file->dir);
-                remove_subsystem(file->system);
-                kmem_cache_free(file_cachep, file);
-        }
+        list_for_each_entry_safe(file, next, &tr->events, list)
+                remove_event_file_dir(file);
 }
 
 static void
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 0d883dc057d6..97daa8cf958d 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -637,17 +637,15 @@ static void append_filter_err(struct filter_parse_state *ps,
         free_page((unsigned long) buf);
 }
 
+/* caller must hold event_mutex */
 void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s)
 {
-        struct event_filter *filter;
+        struct event_filter *filter = call->filter;
 
-        mutex_lock(&event_mutex);
-        filter = call->filter;
         if (filter && filter->filter_string)
                 trace_seq_printf(s, "%s\n", filter->filter_string);
         else
-                trace_seq_printf(s, "none\n");
-        mutex_unlock(&event_mutex);
+                trace_seq_puts(s, "none\n");
 }
 
 void print_subsystem_event_filter(struct event_subsystem *system,
@@ -660,7 +658,7 @@ void print_subsystem_event_filter(struct event_subsystem *system,
         if (filter && filter->filter_string)
                 trace_seq_printf(s, "%s\n", filter->filter_string);
         else
-                trace_seq_printf(s, DEFAULT_SYS_FILTER_MESSAGE "\n");
+                trace_seq_puts(s, DEFAULT_SYS_FILTER_MESSAGE "\n");
         mutex_unlock(&event_mutex);
 }
 
@@ -1841,23 +1839,22 @@ static int create_system_filter(struct event_subsystem *system,
         return err;
 }
 
+/* caller must hold event_mutex */
 int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
 {
         struct event_filter *filter;
-        int err = 0;
-
-        mutex_lock(&event_mutex);
+        int err;
 
         if (!strcmp(strstrip(filter_string), "0")) {
                 filter_disable(call);
                 filter = call->filter;
                 if (!filter)
-                        goto out_unlock;
+                        return 0;
                 RCU_INIT_POINTER(call->filter, NULL);
                 /* Make sure the filter is not being used */
                 synchronize_sched();
                 __free_filter(filter);
-                goto out_unlock;
+                return 0;
         }
 
         err = create_filter(call, filter_string, true, &filter);
@@ -1884,8 +1881,6 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
                         __free_filter(tmp);
                 }
         }
-out_unlock:
-        mutex_unlock(&event_mutex);
 
         return err;
 }
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index b863f93b30f3..38fe1483c508 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -199,7 +199,7 @@ static int func_set_flag(u32 old_flags, u32 bit, int set)
         return 0;
 }
 
-static struct tracer function_trace __read_mostly =
+static struct tracer function_trace __tracer_data =
 {
         .name           = "function",
         .init           = function_trace_init,
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 8388bc99f2ee..b5c09242683d 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -446,7 +446,7 @@ print_graph_proc(struct trace_seq *s, pid_t pid)
 
         /* First spaces to align center */
         for (i = 0; i < spaces / 2; i++) {
-                ret = trace_seq_printf(s, " ");
+                ret = trace_seq_putc(s, ' ');
                 if (!ret)
                         return TRACE_TYPE_PARTIAL_LINE;
         }
@@ -457,7 +457,7 @@ print_graph_proc(struct trace_seq *s, pid_t pid)
 
         /* Last spaces to align center */
         for (i = 0; i < spaces - (spaces / 2); i++) {
-                ret = trace_seq_printf(s, " ");
+                ret = trace_seq_putc(s, ' ');
                 if (!ret)
                         return TRACE_TYPE_PARTIAL_LINE;
         }
@@ -503,7 +503,7 @@ verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
  ------------------------------------------
 
  */
-        ret = trace_seq_printf(s,
+        ret = trace_seq_puts(s,
                 " ------------------------------------------\n");
         if (!ret)
                 return TRACE_TYPE_PARTIAL_LINE;
@@ -516,7 +516,7 @@ verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
         if (ret == TRACE_TYPE_PARTIAL_LINE)
                 return TRACE_TYPE_PARTIAL_LINE;
 
-        ret = trace_seq_printf(s, " => ");
+        ret = trace_seq_puts(s, " => ");
         if (!ret)
                 return TRACE_TYPE_PARTIAL_LINE;
 
@@ -524,7 +524,7 @@ verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
         if (ret == TRACE_TYPE_PARTIAL_LINE)
                 return TRACE_TYPE_PARTIAL_LINE;
 
-        ret = trace_seq_printf(s,
+        ret = trace_seq_puts(s,
                 "\n ------------------------------------------\n\n");
         if (!ret)
                 return TRACE_TYPE_PARTIAL_LINE;
@@ -645,7 +645,7 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr,
                         ret = print_graph_proc(s, pid);
                         if (ret == TRACE_TYPE_PARTIAL_LINE)
                                 return TRACE_TYPE_PARTIAL_LINE;
-                        ret = trace_seq_printf(s, " | ");
+                        ret = trace_seq_puts(s, " | ");
                         if (!ret)
                                 return TRACE_TYPE_PARTIAL_LINE;
                 }
@@ -657,9 +657,9 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr,
                 return ret;
 
         if (type == TRACE_GRAPH_ENT)
-                ret = trace_seq_printf(s, "==========>");
+                ret = trace_seq_puts(s, "==========>");
         else
-                ret = trace_seq_printf(s, "<==========");
+                ret = trace_seq_puts(s, "<==========");
 
         if (!ret)
                 return TRACE_TYPE_PARTIAL_LINE;
@@ -668,7 +668,7 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr,
         if (ret != TRACE_TYPE_HANDLED)
                 return ret;
 
-        ret = trace_seq_printf(s, "\n");
+        ret = trace_seq_putc(s, '\n');
 
         if (!ret)
                 return TRACE_TYPE_PARTIAL_LINE;
@@ -705,13 +705,13 @@ trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
                 len += strlen(nsecs_str);
         }
 
-        ret = trace_seq_printf(s, " us ");
+        ret = trace_seq_puts(s, " us ");
         if (!ret)
                 return TRACE_TYPE_PARTIAL_LINE;
 
         /* Print remaining spaces to fit the row's width */
         for (i = len; i < 7; i++) {
-                ret = trace_seq_printf(s, " ");
+                ret = trace_seq_putc(s, ' ');
                 if (!ret)
                         return TRACE_TYPE_PARTIAL_LINE;
         }
@@ -731,13 +731,13 @@ print_graph_duration(unsigned long long duration, struct trace_seq *s,
         /* No real adata, just filling the column with spaces */
         switch (duration) {
         case DURATION_FILL_FULL:
-                ret = trace_seq_printf(s, "              |  ");
+                ret = trace_seq_puts(s, "              |  ");
                 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
         case DURATION_FILL_START:
-                ret = trace_seq_printf(s, "  ");
+                ret = trace_seq_puts(s, "  ");
                 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
         case DURATION_FILL_END:
-                ret = trace_seq_printf(s, " |");
+                ret = trace_seq_puts(s, " |");
                 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
         }
 
@@ -745,10 +745,10 @@ print_graph_duration(unsigned long long duration, struct trace_seq *s,
         if (flags & TRACE_GRAPH_PRINT_OVERHEAD) {
                 /* Duration exceeded 100 msecs */
                 if (duration > 100000ULL)
-                        ret = trace_seq_printf(s, "! ");
+                        ret = trace_seq_puts(s, "! ");
                 /* Duration exceeded 10 msecs */
                 else if (duration > 10000ULL)
-                        ret = trace_seq_printf(s, "+ ");
+                        ret = trace_seq_puts(s, "+ ");
         }
 
         /*
@@ -757,7 +757,7 @@ print_graph_duration(unsigned long long duration, struct trace_seq *s,
          * to fill out the space.
          */
         if (ret == -1)
-                ret = trace_seq_printf(s, "  ");
+                ret = trace_seq_puts(s, "  ");
 
         /* Catching here any failure happenned above */
         if (!ret)
@@ -767,7 +767,7 @@ print_graph_duration(unsigned long long duration, struct trace_seq *s,
         if (ret != TRACE_TYPE_HANDLED)
                 return ret;
 
-        ret = trace_seq_printf(s, "|  ");
+        ret = trace_seq_puts(s, "|  ");
         if (!ret)
                 return TRACE_TYPE_PARTIAL_LINE;
 
@@ -817,7 +817,7 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 
         /* Function */
         for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
-                ret = trace_seq_printf(s, " ");
+                ret = trace_seq_putc(s, ' ');
                 if (!ret)
                         return TRACE_TYPE_PARTIAL_LINE;
         }
@@ -858,7 +858,7 @@ print_graph_entry_nested(struct trace_iterator *iter,
 
         /* Function */
         for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
-                ret = trace_seq_printf(s, " ");
+                ret = trace_seq_putc(s, ' ');
                 if (!ret)
                         return TRACE_TYPE_PARTIAL_LINE;
         }
@@ -917,7 +917,7 @@ print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
                 if (ret == TRACE_TYPE_PARTIAL_LINE)
                         return TRACE_TYPE_PARTIAL_LINE;
 
-                ret = trace_seq_printf(s, " | ");
+                ret = trace_seq_puts(s, " | ");
                 if (!ret)
                         return TRACE_TYPE_PARTIAL_LINE;
         }
@@ -1117,7 +1117,7 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
 
         /* Closing brace */
         for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
-                ret = trace_seq_printf(s, " ");
+                ret = trace_seq_putc(s, ' ');
                 if (!ret)
                         return TRACE_TYPE_PARTIAL_LINE;
         }
@@ -1129,7 +1129,7 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
          * belongs to, write out the function name.
          */
         if (func_match) {
-                ret = trace_seq_printf(s, "}\n");
+                ret = trace_seq_puts(s, "}\n");
                 if (!ret)
                         return TRACE_TYPE_PARTIAL_LINE;
         } else {
@@ -1179,13 +1179,13 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
         /* Indentation */
         if (depth > 0)
                 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) {
-                        ret = trace_seq_printf(s, " ");
+                        ret = trace_seq_putc(s, ' ');
                         if (!ret)
                                 return TRACE_TYPE_PARTIAL_LINE;
                 }
 
         /* The comment */
-        ret = trace_seq_printf(s, "/* ");
+        ret = trace_seq_puts(s, "/* ");
         if (!ret)
                 return TRACE_TYPE_PARTIAL_LINE;
 
@@ -1216,7 +1216,7 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
                 s->len--;
         }
 
-        ret = trace_seq_printf(s, " */\n");
+        ret = trace_seq_puts(s, " */\n");
         if (!ret)
                 return TRACE_TYPE_PARTIAL_LINE;
 
@@ -1448,7 +1448,7 @@ static struct trace_event graph_trace_ret_event = {
         .funcs          = &graph_functions
 };
 
-static struct tracer graph_trace __read_mostly = {
+static struct tracer graph_trace __tracer_data = {
         .name           = "function_graph",
         .open           = graph_trace_open,
         .pipe_open      = graph_trace_open,
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 7ed6976493c8..243f6834d026 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -95,7 +95,7 @@ static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp)
 }
 
 static int register_probe_event(struct trace_probe *tp);
-static void unregister_probe_event(struct trace_probe *tp);
+static int unregister_probe_event(struct trace_probe *tp);
 
 static DEFINE_MUTEX(probe_lock);
 static LIST_HEAD(probe_list);
@@ -243,11 +243,11 @@ find_event_file_link(struct trace_probe *tp, struct ftrace_event_file *file)
 static int
 disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file)
 {
+        struct event_file_link *link = NULL;
+        int wait = 0;
         int ret = 0;
 
         if (file) {
-                struct event_file_link *link;
-
                 link = find_event_file_link(tp, file);
                 if (!link) {
                         ret = -EINVAL;
@@ -255,10 +255,7 @@ disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file)
                 }
 
                 list_del_rcu(&link->list);
-                /* synchronize with kprobe_trace_func/kretprobe_trace_func */
-                synchronize_sched();
-                kfree(link);
-
+                wait = 1;
                 if (!list_empty(&tp->files))
                         goto out;
 
@@ -271,8 +268,22 @@ disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file)
                         disable_kretprobe(&tp->rp);
                 else
                         disable_kprobe(&tp->rp.kp);
+                wait = 1;
         }
  out:
+        if (wait) {
+                /*
+                 * Synchronize with kprobe_trace_func/kretprobe_trace_func
+                 * to ensure disabled (all running handlers are finished).
+                 * This is not only for kfree(), but also the caller,
+                 * trace_remove_event_call() supposes it for releasing
+                 * event_call related objects, which will be accessed in
+                 * the kprobe_trace_func/kretprobe_trace_func.
+                 */
+                synchronize_sched();
+                kfree(link);    /* Ignored if link == NULL */
+        }
+
         return ret;
 }
 
@@ -340,9 +351,12 @@ static int unregister_trace_probe(struct trace_probe *tp)
         if (trace_probe_is_enabled(tp))
                 return -EBUSY;
 
+        /* Will fail if probe is being used by ftrace or perf */
+        if (unregister_probe_event(tp))
+                return -EBUSY;
+
         __unregister_trace_probe(tp);
         list_del(&tp->list);
-        unregister_probe_event(tp);
 
         return 0;
 }
@@ -621,7 +635,9 @@ static int release_all_trace_probes(void)
         /* TODO: Use batch unregistration */
         while (!list_empty(&probe_list)) {
                 tp = list_entry(probe_list.next, struct trace_probe, list);
-                unregister_trace_probe(tp);
+                ret = unregister_trace_probe(tp);
+                if (ret)
+                        goto end;
                 free_trace_probe(tp);
         }
 
@@ -1087,9 +1103,6 @@ kprobe_perf_func(struct trace_probe *tp, struct pt_regs *regs)
         __size = sizeof(*entry) + tp->size + dsize;
         size = ALIGN(__size + sizeof(u32), sizeof(u64));
         size -= sizeof(u32);
-        if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
-                     "profile buffer not large enough"))
-                return;
 
         entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
         if (!entry)
@@ -1120,9 +1133,6 @@ kretprobe_perf_func(struct trace_probe *tp, struct kretprobe_instance *ri,
         __size = sizeof(*entry) + tp->size + dsize;
         size = ALIGN(__size + sizeof(u32), sizeof(u64));
         size -= sizeof(u32);
-        if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
-                     "profile buffer not large enough"))
-                return;
 
         entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
         if (!entry)
@@ -1242,11 +1252,15 @@ static int register_probe_event(struct trace_probe *tp)
         return ret;
 }
 
-static void unregister_probe_event(struct trace_probe *tp)
+static int unregister_probe_event(struct trace_probe *tp)
 {
+        int ret;
+
         /* tp->event is unregistered in trace_remove_event_call() */
-        trace_remove_event_call(&tp->call);
-        kfree(tp->call.print_fmt);
+        ret = trace_remove_event_call(&tp->call);
+        if (!ret)
+                kfree(tp->call.print_fmt);
+        return ret;
 }
 
 /* Make a debugfs interface for controlling probe points */
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index a5e8f4878bfa..b3dcfb2f0fef 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -90,7 +90,7 @@ static int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev)
         if (drv)
                 ret += trace_seq_printf(s, " %s\n", drv->name);
         else
-                ret += trace_seq_printf(s, " \n");
+                ret += trace_seq_puts(s, " \n");
         return ret;
 }
 
@@ -107,7 +107,7 @@ static void mmio_pipe_open(struct trace_iterator *iter)
         struct header_iter *hiter;
         struct trace_seq *s = &iter->seq;
 
-        trace_seq_printf(s, "VERSION 20070824\n");
+        trace_seq_puts(s, "VERSION 20070824\n");
 
         hiter = kzalloc(sizeof(*hiter), GFP_KERNEL);
         if (!hiter)
@@ -209,7 +209,7 @@ static enum print_line_t mmio_print_rw(struct trace_iterator *iter)
                         (rw->value >> 0) & 0xff, rw->pc, 0);
                 break;
         default:
-                ret = trace_seq_printf(s, "rw what?\n");
+                ret = trace_seq_puts(s, "rw what?\n");
                 break;
         }
         if (ret)
@@ -245,7 +245,7 @@ static enum print_line_t mmio_print_map(struct trace_iterator *iter)
                         secs, usec_rem, m->map_id, 0UL, 0);
                 break;
         default:
-                ret = trace_seq_printf(s, "map what?\n");
+                ret = trace_seq_puts(s, "map what?\n");
                 break;
         }
         if (ret)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index bb922d9ee51b..34e7cbac0c9c 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -78,7 +78,7 @@ enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
 
         trace_assign_type(field, entry);
 
-        ret = trace_seq_printf(s, "%s", field->buf);
+        ret = trace_seq_puts(s, field->buf);
         if (!ret)
                 return TRACE_TYPE_PARTIAL_LINE;
 
@@ -558,14 +558,14 @@ seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
                         if (ret)
                                 ret = trace_seq_puts(s, "??");
                         if (ret)
-                                ret = trace_seq_puts(s, "\n");
+                                ret = trace_seq_putc(s, '\n');
                         continue;
                 }
                 if (!ret)
                         break;
                 if (ret)
                         ret = seq_print_user_ip(s, mm, ip, sym_flags);
-                ret = trace_seq_puts(s, "\n");
+                ret = trace_seq_putc(s, '\n');
         }
 
         if (mm)
@@ -579,7 +579,7 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
         int ret;
 
         if (!ip)
-                return trace_seq_printf(s, "0");
+                return trace_seq_putc(s, '0');
 
         if (sym_flags & TRACE_ITER_SYM_OFFSET)
                 ret = seq_print_sym_offset(s, "%s", ip);
@@ -964,14 +964,14 @@ static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
                 goto partial;
 
         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
-                if (!trace_seq_printf(s, " <-"))
+                if (!trace_seq_puts(s, " <-"))
                         goto partial;
                 if (!seq_print_ip_sym(s,
                                       field->parent_ip,
                                       flags))
                         goto partial;
         }
-        if (!trace_seq_printf(s, "\n"))
+        if (!trace_seq_putc(s, '\n'))
                 goto partial;
 
         return TRACE_TYPE_HANDLED;
@@ -1210,7 +1210,7 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter,
 
                 if (!seq_print_ip_sym(s, *p, flags))
                         goto partial;
-                if (!trace_seq_puts(s, "\n"))
+                if (!trace_seq_putc(s, '\n'))
                         goto partial;
         }
 
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 322e16461072..8fd03657bc7d 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -175,7 +175,7 @@ print_syscall_exit(struct trace_iterator *iter, int flags,
         entry = syscall_nr_to_meta(syscall);
 
         if (!entry) {
-                trace_seq_printf(s, "\n");
+                trace_seq_putc(s, '\n');
                 return TRACE_TYPE_HANDLED;
         }
 
@@ -566,15 +566,15 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
         if (!sys_data)
                 return;
 
+        head = this_cpu_ptr(sys_data->enter_event->perf_events);
+        if (hlist_empty(head))
+                return;
+
         /* get the size after alignment with the u32 buffer size field */
         size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec);
         size = ALIGN(size + sizeof(u32), sizeof(u64));
         size -= sizeof(u32);
 
-        if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
-                      "perf buffer not large enough"))
-                return;
-
         rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size,
                                 sys_data->enter_event->event.type, regs, &rctx);
         if (!rec)
@@ -583,8 +583,6 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
         rec->nr = syscall_nr;
         syscall_get_arguments(current, regs, 0, sys_data->nb_args,
                                (unsigned long *)&rec->args);
-
-        head = this_cpu_ptr(sys_data->enter_event->perf_events);
         perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
 }
 
@@ -642,18 +640,14 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
         if (!sys_data)
                 return;
 
+        head = this_cpu_ptr(sys_data->exit_event->perf_events);
+        if (hlist_empty(head))
+                return;
+
         /* We can probably do that at build time */
         size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64));
         size -= sizeof(u32);
 
-        /*
-         * Impossible, but be paranoid with the future
-         * How to put this check outside runtime?
-         */
-        if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
-                "exit event has grown above perf buffer size"))
-                return;
-
         rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size,
                                 sys_data->exit_event->event.type, regs, &rctx);
         if (!rec)
@@ -661,8 +655,6 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
 
         rec->nr = syscall_nr;
         rec->ret = syscall_get_return_value(current, regs);
-
-        head = this_cpu_ptr(sys_data->exit_event->perf_events);
         perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
 }
 
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index d5d0cd368a56..272261b5f94f 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -70,7 +70,7 @@ struct trace_uprobe {
         (sizeof(struct probe_arg) * (n)))
 
 static int register_uprobe_event(struct trace_uprobe *tu);
-static void unregister_uprobe_event(struct trace_uprobe *tu);
+static int unregister_uprobe_event(struct trace_uprobe *tu);
 
 static DEFINE_MUTEX(uprobe_lock);
 static LIST_HEAD(uprobe_list);
@@ -164,11 +164,17 @@ static struct trace_uprobe *find_probe_event(const char *event, const char *grou
 }
 
 /* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */
-static void unregister_trace_uprobe(struct trace_uprobe *tu)
+static int unregister_trace_uprobe(struct trace_uprobe *tu)
 {
+        int ret;
+
+        ret = unregister_uprobe_event(tu);
+        if (ret)
+                return ret;
+
         list_del(&tu->list);
-        unregister_uprobe_event(tu);
         free_trace_uprobe(tu);
+        return 0;
 }
 
 /* Register a trace_uprobe and probe_event */
@@ -181,9 +187,12 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
 
         /* register as an event */
         old_tp = find_probe_event(tu->call.name, tu->call.class->system);
-        if (old_tp)
+        if (old_tp) {
                 /* delete old event */
-                unregister_trace_uprobe(old_tp);
+                ret = unregister_trace_uprobe(old_tp);
+                if (ret)
+                        goto end;
+        }
 
         ret = register_uprobe_event(tu);
         if (ret) {
@@ -256,6 +265,8 @@ static int create_trace_uprobe(int argc, char **argv)
                 group = UPROBE_EVENT_SYSTEM;
 
         if (is_delete) {
+                int ret;
+
                 if (!event) {
                         pr_info("Delete command needs an event name.\n");
                         return -EINVAL;
@@ -269,9 +280,9 @@ static int create_trace_uprobe(int argc, char **argv)
                         return -ENOENT;
                 }
                 /* delete an event */
-                unregister_trace_uprobe(tu);
+                ret = unregister_trace_uprobe(tu);
                 mutex_unlock(&uprobe_lock);
-                return 0;
+                return ret;
         }
 
         if (argc < 2) {
@@ -408,16 +419,20 @@ fail_address_parse:
         return ret;
 }
 
-static void cleanup_all_probes(void)
+static int cleanup_all_probes(void)
 {
         struct trace_uprobe *tu;
+        int ret = 0;
 
         mutex_lock(&uprobe_lock);
         while (!list_empty(&uprobe_list)) {
                 tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
-                unregister_trace_uprobe(tu);
+                ret = unregister_trace_uprobe(tu);
+                if (ret)
+                        break;
         }
         mutex_unlock(&uprobe_lock);
+        return ret;
 }
 
 /* Probes listing interfaces */
@@ -462,8 +477,13 @@ static const struct seq_operations probes_seq_op = {
 
 static int probes_open(struct inode *inode, struct file *file)
 {
-        if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC))
-                cleanup_all_probes();
+        int ret;
+
+        if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
+                ret = cleanup_all_probes();
+                if (ret)
+                        return ret;
+        }
 
         return seq_open(file, &probes_seq_op);
 }
@@ -818,8 +838,6 @@ static void uprobe_perf_print(struct trace_uprobe *tu,
 
         size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
         size = ALIGN(size + tu->size + sizeof(u32), sizeof(u64)) - sizeof(u32);
-        if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
-                return;
 
         preempt_disable();
         head = this_cpu_ptr(call->perf_events);
@@ -970,12 +988,17 @@ static int register_uprobe_event(struct trace_uprobe *tu)
         return ret;
 }
 
-static void unregister_uprobe_event(struct trace_uprobe *tu)
+static int unregister_uprobe_event(struct trace_uprobe *tu)
 {
+        int ret;
+
         /* tu->event is unregistered in trace_remove_event_call() */
-        trace_remove_event_call(&tu->call);
+        ret = trace_remove_event_call(&tu->call);
+        if (ret)
+                return ret;
         kfree(tu->call.print_fmt);
         tu->call.print_fmt = NULL;
+        return 0;
 }
 
 /* Make a trace interface for controling probe points */
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index d8c30db06c5b..9064b919a406 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -62,6 +62,9 @@ int create_user_ns(struct cred *new)
         kgid_t group = new->egid;
         int ret;
 
+        if (parent_ns->level > 32)
+                return -EUSERS;
+
         /*
          * Verify that we can not violate the policy of which files
          * may be accessed that is specified by the root directory,
@@ -92,6 +95,7 @@ int create_user_ns(struct cred *new)
         atomic_set(&ns->count, 1);
         /* Leave the new->user_ns reference with the new user namespace. */
         ns->parent = parent_ns;
+        ns->level = parent_ns->level + 1;
         ns->owner = owner;
         ns->group = group;
 
@@ -105,16 +109,21 @@ int create_user_ns(struct cred *new)
 int unshare_userns(unsigned long unshare_flags, struct cred **new_cred)
 {
         struct cred *cred;
+        int err = -ENOMEM;
 
         if (!(unshare_flags & CLONE_NEWUSER))
                 return 0;
 
         cred = prepare_creds();
-        if (!cred)
-                return -ENOMEM;
+        if (cred) {
+                err = create_user_ns(cred);
+                if (err)
+                        put_cred(cred);
+                else
+                        *new_cred = cred;
+        }
 
-        *new_cred = cred;
-        return create_user_ns(cred);
+        return err;
 }
 
 void free_user_ns(struct user_namespace *ns)
diff --git a/kernel/wait.c b/kernel/wait.c
index ce0daa320a26..d550920e040c 100644
--- a/kernel/wait.c
+++ b/kernel/wait.c
@@ -333,7 +333,8 @@ int __wait_on_atomic_t(wait_queue_head_t *wq, struct wait_bit_queue *q,
                 prepare_to_wait(wq, &q->wait, mode);
                 val = q->key.flags;
                 if (atomic_read(val) == 0)
-                        ret = (*action)(val);
+                        break;
+                ret = (*action)(val);
         } while (!ret && atomic_read(val) != 0);
         finish_wait(wq, &q->wait);
         return ret;
@@ -362,8 +363,7 @@ EXPORT_SYMBOL(out_of_line_wait_on_atomic_t);
 
 /**
  * wake_up_atomic_t - Wake up a waiter on a atomic_t
- * @word: The word being waited on, a kernel virtual address
- * @bit: The bit of the word being waited on
+ * @p: The atomic_t being waited on, a kernel virtual address
  *
  * Wake up anyone waiting for the atomic_t to go to zero.
  *
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 0b72e816b8d0..e93f7b9067d8 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2201,6 +2201,15 @@ __acquires(&pool->lock)
                 dump_stack();
         }
 
+        /*
+         * The following prevents a kworker from hogging CPU on !PREEMPT
+         * kernels, where a requeueing work item waiting for something to
+         * happen could deadlock with stop_machine as such work item could
+         * indefinitely requeue itself while all other CPUs are trapped in
+         * stop_machine.
+         */
+        cond_resched();
+
         spin_lock_irq(&pool->lock);
 
         /* clear cpu intensive status */
@@ -2817,6 +2826,19 @@ already_gone:
         return false;
 }
 
+static bool __flush_work(struct work_struct *work)
+{
+        struct wq_barrier barr;
+
+        if (start_flush_work(work, &barr)) {
+                wait_for_completion(&barr.done);
+                destroy_work_on_stack(&barr.work);
+                return true;
+        } else {
+                return false;
+        }
+}
+
 /**
  * flush_work - wait for a work to finish executing the last queueing instance
  * @work: the work to flush
@@ -2830,18 +2852,10 @@ already_gone:
  */
 bool flush_work(struct work_struct *work)
 {
-        struct wq_barrier barr;
-
         lock_map_acquire(&work->lockdep_map);
         lock_map_release(&work->lockdep_map);
 
-        if (start_flush_work(work, &barr)) {
-                wait_for_completion(&barr.done);
-                destroy_work_on_stack(&barr.work);
-                return true;
-        } else {
-                return false;
-        }
+        return __flush_work(work);
 }
 EXPORT_SYMBOL_GPL(flush_work);
 
@@ -3411,6 +3425,12 @@ static void copy_workqueue_attrs(struct workqueue_attrs *to,
 {
         to->nice = from->nice;
         cpumask_copy(to->cpumask, from->cpumask);
+        /*
+         * Unlike hash and equality test, this function doesn't ignore
+         * ->no_numa as it is used for both pool and wq attrs.  Instead,
+         * get_unbound_pool() explicitly clears ->no_numa after copying.
+         */
+        to->no_numa = from->no_numa;
 }
 
 /* hash value of the content of @attr */
@@ -3578,6 +3598,12 @@ static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs)
         lockdep_set_subclass(&pool->lock, 1);   /* see put_pwq() */
         copy_workqueue_attrs(pool->attrs, attrs);
 
+        /*
+         * no_numa isn't a worker_pool attribute, always clear it.  See
+         * 'struct workqueue_attrs' comments for detail.
+         */
+        pool->attrs->no_numa = false;
+
         /* if cpumask is contained inside a NUMA node, we belong to that node */
         if (wq_numa_enabled) {
                 for_each_node(node) {
@@ -4756,7 +4782,14 @@ long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
 
         INIT_WORK_ONSTACK(&wfc.work, work_for_cpu_fn);
         schedule_work_on(cpu, &wfc.work);
-        flush_work(&wfc.work);
+
+        /*
+         * The work item is on-stack and can't lead to deadlock through
+         * flushing.  Use __flush_work() to avoid spurious lockdep warnings
+         * when work_on_cpu()s are nested.
+         */
+        __flush_work(&wfc.work);
+
         return wfc.ret;
 }
 EXPORT_SYMBOL_GPL(work_on_cpu);