Merge branch 'tracing/core' into auto-tracing-next

21 files changed, 1720 insertions, 811 deletions

diff --git a/kernel/kmod.c b/kernel/kmod.c
index 385c31a1bdbf..a92280870e30 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -37,6 +37,8 @@
 #include <linux/suspend.h>
 #include <asm/uaccess.h>
 
+#include <trace/events/module.h>
+
 extern int max_threads;
 
 static struct workqueue_struct *khelper_wq;
@@ -108,6 +110,8 @@ int __request_module(bool wait, const char *fmt, ...)
 		return -ENOMEM;
 	}
 
+	trace_module_request(module_name, wait, _RET_IP_);
+
 	ret = call_usermodehelper(modprobe_path, argv, envp,
 			wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC);
 	atomic_dec(&kmod_concurrent);
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 0540948e29ab..ef177d653b2c 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -103,7 +103,7 @@ static struct kprobe_blackpoint kprobe_blacklist[] = {
 #define INSNS_PER_PAGE	(PAGE_SIZE/(MAX_INSN_SIZE * sizeof(kprobe_opcode_t)))
 
 struct kprobe_insn_page {
-	struct hlist_node hlist;
+	struct list_head list;
 	kprobe_opcode_t *insns;		/* Page of instruction slots */
 	char slot_used[INSNS_PER_PAGE];
 	int nused;
@@ -117,7 +117,7 @@ enum kprobe_slot_state {
 };
 
 static DEFINE_MUTEX(kprobe_insn_mutex);	/* Protects kprobe_insn_pages */
-static struct hlist_head kprobe_insn_pages;
+static LIST_HEAD(kprobe_insn_pages);
 static int kprobe_garbage_slots;
 static int collect_garbage_slots(void);
 
@@ -152,10 +152,9 @@ loop_end:
 static kprobe_opcode_t __kprobes *__get_insn_slot(void)
 {
 	struct kprobe_insn_page *kip;
-	struct hlist_node *pos;
 
  retry:
-	hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) {
+	list_for_each_entry(kip, &kprobe_insn_pages, list) {
 		if (kip->nused < INSNS_PER_PAGE) {
 			int i;
 			for (i = 0; i < INSNS_PER_PAGE; i++) {
@@ -189,8 +188,8 @@ static kprobe_opcode_t __kprobes *__get_insn_slot(void)
 		kfree(kip);
 		return NULL;
 	}
-	INIT_HLIST_NODE(&kip->hlist);
-	hlist_add_head(&kip->hlist, &kprobe_insn_pages);
+	INIT_LIST_HEAD(&kip->list);
+	list_add(&kip->list, &kprobe_insn_pages);
 	memset(kip->slot_used, SLOT_CLEAN, INSNS_PER_PAGE);
 	kip->slot_used[0] = SLOT_USED;
 	kip->nused = 1;
@@ -219,12 +218,8 @@ static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx)
 		 * so as not to have to set it up again the
 		 * next time somebody inserts a probe.
 		 */
-		hlist_del(&kip->hlist);
-		if (hlist_empty(&kprobe_insn_pages)) {
-			INIT_HLIST_NODE(&kip->hlist);
-			hlist_add_head(&kip->hlist,
-				       &kprobe_insn_pages);
-		} else {
+		if (!list_is_singular(&kprobe_insn_pages)) {
+			list_del(&kip->list);
 			module_free(NULL, kip->insns);
 			kfree(kip);
 		}
@@ -235,14 +230,13 @@ static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx)
 
 static int __kprobes collect_garbage_slots(void)
 {
-	struct kprobe_insn_page *kip;
-	struct hlist_node *pos, *next;
+	struct kprobe_insn_page *kip, *next;
 
 	/* Ensure no-one is preepmted on the garbages */
 	if (check_safety())
 		return -EAGAIN;
 
-	hlist_for_each_entry_safe(kip, pos, next, &kprobe_insn_pages, hlist) {
+	list_for_each_entry_safe(kip, next, &kprobe_insn_pages, list) {
 		int i;
 		if (kip->ngarbage == 0)
 			continue;
@@ -260,19 +254,17 @@ static int __kprobes collect_garbage_slots(void)
 void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty)
 {
 	struct kprobe_insn_page *kip;
-	struct hlist_node *pos;
 
 	mutex_lock(&kprobe_insn_mutex);
-	hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) {
+	list_for_each_entry(kip, &kprobe_insn_pages, list) {
 		if (kip->insns <= slot &&
 		    slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) {
 			int i = (slot - kip->insns) / MAX_INSN_SIZE;
 			if (dirty) {
 				kip->slot_used[i] = SLOT_DIRTY;
 				kip->ngarbage++;
-			} else {
+			} else
 				collect_one_slot(kip, i);
-			}
 			break;
 		}
 	}
diff --git a/kernel/module.c b/kernel/module.c
index fd1411403558..b1821438694e 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -55,6 +55,11 @@
 #include <linux/percpu.h>
 #include <linux/kmemleak.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/module.h>
+
+EXPORT_TRACEPOINT_SYMBOL(module_get);
+
 #if 0
 #define DEBUGP printk
 #else
@@ -940,6 +945,8 @@ void module_put(struct module *module)
 	if (module) {
 		unsigned int cpu = get_cpu();
 		local_dec(__module_ref_addr(module, cpu));
+		trace_module_put(module, _RET_IP_,
+				 local_read(__module_ref_addr(module, cpu)));
 		/* Maybe they're waiting for us to drop reference? */
 		if (unlikely(!module_is_live(module)))
 			wake_up_process(module->waiter);
@@ -1491,6 +1498,8 @@ static int __unlink_module(void *_mod)
 /* Free a module, remove from lists, etc (must hold module_mutex). */
 static void free_module(struct module *mod)
 {
+	trace_module_free(mod);
+
 	/* Delete from various lists */
 	stop_machine(__unlink_module, mod, NULL);
 	remove_notes_attrs(mod);
@@ -2358,6 +2367,8 @@ static noinline struct module *load_module(void __user *umod,
 	/* Get rid of temporary copy */
 	vfree(hdr);
 
+	trace_module_load(mod);
+
 	/* Done! */
 	return mod;
 
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1e1d23c26308..1993b7186cdb 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1016,71 +1016,35 @@ static int
 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
 {
 	unsigned long ftrace_addr;
-	unsigned long ip, fl;
+	unsigned long flag = 0UL;
 
 	ftrace_addr = (unsigned long)FTRACE_ADDR;
 
-	ip = rec->ip;
-
 	/*
-	 * If this record is not to be traced and
-	 * it is not enabled then do nothing.
+	 * If this record is not to be traced or we want to disable it,
+	 * then disable it.
 	 *
-	 * If this record is not to be traced and
-	 * it is enabled then disable it.
+	 * If we want to enable it and filtering is off, then enable it.
 	 *
+	 * If we want to enable it and filtering is on, enable it only if
+	 * it's filtered
 	 */
-	if (rec->flags & FTRACE_FL_NOTRACE) {
-		if (rec->flags & FTRACE_FL_ENABLED)
-			rec->flags &= ~FTRACE_FL_ENABLED;
-		else
-			return 0;
-
-	} else if (ftrace_filtered && enable) {
-		/*
-		 * Filtering is on:
-		 */
-
-		fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
-
-		/* Record is filtered and enabled, do nothing */
-		if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
-			return 0;
-
-		/* Record is not filtered or enabled, do nothing */
-		if (!fl)
-			return 0;
-
-		/* Record is not filtered but enabled, disable it */
-		if (fl == FTRACE_FL_ENABLED)
-			rec->flags &= ~FTRACE_FL_ENABLED;
-		else
-		/* Otherwise record is filtered but not enabled, enable it */
-			rec->flags |= FTRACE_FL_ENABLED;
-	} else {
-		/* Disable or not filtered */
-
-		if (enable) {
-			/* if record is enabled, do nothing */
-			if (rec->flags & FTRACE_FL_ENABLED)
-				return 0;
-
-			rec->flags |= FTRACE_FL_ENABLED;
-
-		} else {
+	if (enable && !(rec->flags & FTRACE_FL_NOTRACE)) {
+		if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER))
+			flag = FTRACE_FL_ENABLED;
+	}
 
-			/* if record is not enabled, do nothing */
-			if (!(rec->flags & FTRACE_FL_ENABLED))
-				return 0;
+	/* If the state of this record hasn't changed, then do nothing */
+	if ((rec->flags & FTRACE_FL_ENABLED) == flag)
+		return 0;
 
-			rec->flags &= ~FTRACE_FL_ENABLED;
-		}
+	if (flag) {
+		rec->flags |= FTRACE_FL_ENABLED;
+		return ftrace_make_call(rec, ftrace_addr);
 	}
 
-	if (rec->flags & FTRACE_FL_ENABLED)
-		return ftrace_make_call(rec, ftrace_addr);
-	else
-		return ftrace_make_nop(NULL, rec, ftrace_addr);
+	rec->flags &= ~FTRACE_FL_ENABLED;
+	return ftrace_make_nop(NULL, rec, ftrace_addr);
 }
 
 static void ftrace_replace_code(int enable)
@@ -1375,7 +1339,6 @@ struct ftrace_iterator {
 	unsigned		flags;
 	unsigned char		buffer[FTRACE_BUFF_MAX+1];
 	unsigned		buffer_idx;
-	unsigned		filtered;
 };
 
 static void *
@@ -1438,18 +1401,13 @@ static int t_hash_show(struct seq_file *m, void *v)
 {
 	struct ftrace_func_probe *rec;
 	struct hlist_node *hnd = v;
-	char str[KSYM_SYMBOL_LEN];
 
 	rec = hlist_entry(hnd, struct ftrace_func_probe, node);
 
 	if (rec->ops->print)
 		return rec->ops->print(m, rec->ip, rec->ops, rec->data);
 
-	kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
-	seq_printf(m, "%s:", str);
-
-	kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str);
-	seq_printf(m, "%s", str);
+	seq_printf(m, "%pf:%pf", (void *)rec->ip, (void *)rec->ops->func);
 
 	if (rec->data)
 		seq_printf(m, ":%p", rec->data);
@@ -1547,7 +1505,6 @@ static int t_show(struct seq_file *m, void *v)
 {
 	struct ftrace_iterator *iter = m->private;
 	struct dyn_ftrace *rec = v;
-	char str[KSYM_SYMBOL_LEN];
 
 	if (iter->flags & FTRACE_ITER_HASH)
 		return t_hash_show(m, v);
@@ -1560,9 +1517,7 @@ static int t_show(struct seq_file *m, void *v)
 	if (!rec)
 		return 0;
 
-	kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
-
-	seq_printf(m, "%s\n", str);
+	seq_printf(m, "%pf\n", (void *)rec->ip);
 
 	return 0;
 }
@@ -1601,17 +1556,6 @@ ftrace_avail_open(struct inode *inode, struct file *file)
 	return ret;
 }
 
-int ftrace_avail_release(struct inode *inode, struct file *file)
-{
-	struct seq_file *m = (struct seq_file *)file->private_data;
-	struct ftrace_iterator *iter = m->private;
-
-	seq_release(inode, file);
-	kfree(iter);
-
-	return 0;
-}
-
 static int
 ftrace_failures_open(struct inode *inode, struct file *file)
 {
@@ -2312,7 +2256,6 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
 	}
 
 	if (isspace(ch)) {
-		iter->filtered++;
 		iter->buffer[iter->buffer_idx] = 0;
 		ret = ftrace_process_regex(iter->buffer,
 					   iter->buffer_idx, enable);
@@ -2443,7 +2386,6 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
 		iter = file->private_data;
 
 	if (iter->buffer_idx) {
-		iter->filtered++;
 		iter->buffer[iter->buffer_idx] = 0;
 		ftrace_match_records(iter->buffer, iter->buffer_idx, enable);
 	}
@@ -2474,14 +2416,14 @@ static const struct file_operations ftrace_avail_fops = {
 	.open = ftrace_avail_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
-	.release = ftrace_avail_release,
+	.release = seq_release_private,
 };
 
 static const struct file_operations ftrace_failures_fops = {
 	.open = ftrace_failures_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
-	.release = ftrace_avail_release,
+	.release = seq_release_private,
 };
 
 static const struct file_operations ftrace_filter_fops = {
@@ -2543,7 +2485,6 @@ static void g_stop(struct seq_file *m, void *p)
 static int g_show(struct seq_file *m, void *v)
 {
 	unsigned long *ptr = v;
-	char str[KSYM_SYMBOL_LEN];
 
 	if (!ptr)
 		return 0;
@@ -2553,9 +2494,7 @@ static int g_show(struct seq_file *m, void *v)
 		return 0;
 	}
 
-	kallsyms_lookup(*ptr, NULL, NULL, NULL, str);
-
-	seq_printf(m, "%s\n", str);
+	seq_printf(m, "%pf\n", v);
 
 	return 0;
 }
diff --git a/kernel/trace/kmemtrace.c b/kernel/trace/kmemtrace.c
index 1edaa9516e81..dda53ccf749b 100644
--- a/kernel/trace/kmemtrace.c
+++ b/kernel/trace/kmemtrace.c
@@ -239,12 +239,52 @@ struct kmemtrace_user_event_alloc {
 };
 
 static enum print_line_t
-kmemtrace_print_alloc_user(struct trace_iterator *iter,
-			   struct kmemtrace_alloc_entry *entry)
+kmemtrace_print_alloc(struct trace_iterator *iter, int flags)
 {
-	struct kmemtrace_user_event_alloc *ev_alloc;
 	struct trace_seq *s = &iter->seq;
+	struct kmemtrace_alloc_entry *entry;
+	int ret;
+
+	trace_assign_type(entry, iter->ent);
+
+	ret = trace_seq_printf(s, "type_id %d call_site %pF ptr %lu "
+	    "bytes_req %lu bytes_alloc %lu gfp_flags %lu node %d\n",
+	    entry->type_id, (void *)entry->call_site, (unsigned long)entry->ptr,
+	    (unsigned long)entry->bytes_req, (unsigned long)entry->bytes_alloc,
+	    (unsigned long)entry->gfp_flags, entry->node);
+
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+	return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t
+kmemtrace_print_free(struct trace_iterator *iter, int flags)
+{
+	struct trace_seq *s = &iter->seq;
+	struct kmemtrace_free_entry *entry;
+	int ret;
+
+	trace_assign_type(entry, iter->ent);
+
+	ret = trace_seq_printf(s, "type_id %d call_site %pF ptr %lu\n",
+			       entry->type_id, (void *)entry->call_site,
+			       (unsigned long)entry->ptr);
+
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+	return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t
+kmemtrace_print_alloc_user(struct trace_iterator *iter, int flags)
+{
+	struct trace_seq *s = &iter->seq;
+	struct kmemtrace_alloc_entry *entry;
 	struct kmemtrace_user_event *ev;
+	struct kmemtrace_user_event_alloc *ev_alloc;
+
+	trace_assign_type(entry, iter->ent);
 
 	ev = trace_seq_reserve(s, sizeof(*ev));
 	if (!ev)
@@ -271,12 +311,14 @@ kmemtrace_print_alloc_user(struct trace_iterator *iter,
 }
 
 static enum print_line_t
-kmemtrace_print_free_user(struct trace_iterator *iter,
-			  struct kmemtrace_free_entry *entry)
+kmemtrace_print_free_user(struct trace_iterator *iter, int flags)
 {
 	struct trace_seq *s = &iter->seq;
+	struct kmemtrace_free_entry *entry;
 	struct kmemtrace_user_event *ev;
 
+	trace_assign_type(entry, iter->ent);
+
 	ev = trace_seq_reserve(s, sizeof(*ev));
 	if (!ev)
 		return TRACE_TYPE_PARTIAL_LINE;
@@ -294,12 +336,14 @@ kmemtrace_print_free_user(struct trace_iterator *iter,
 
 /* The two other following provide a more minimalistic output */
 static enum print_line_t
-kmemtrace_print_alloc_compress(struct trace_iterator *iter,
-					struct kmemtrace_alloc_entry *entry)
+kmemtrace_print_alloc_compress(struct trace_iterator *iter)
 {
+	struct kmemtrace_alloc_entry *entry;
 	struct trace_seq *s = &iter->seq;
 	int ret;
 
+	trace_assign_type(entry, iter->ent);
+
 	/* Alloc entry */
 	ret = trace_seq_printf(s, "  +      ");
 	if (!ret)
@@ -345,29 +389,24 @@ kmemtrace_print_alloc_compress(struct trace_iterator *iter,
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	/* Node */
-	ret = trace_seq_printf(s, "%4d   ", entry->node);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	/* Call site */
-	ret = seq_print_ip_sym(s, entry->call_site, 0);
+	/* Node and call site*/
+	ret = trace_seq_printf(s, "%4d   %pf\n", entry->node,
+						 (void *)entry->call_site);
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	if (!trace_seq_printf(s, "\n"))
-		return TRACE_TYPE_PARTIAL_LINE;
-
 	return TRACE_TYPE_HANDLED;
 }
 
 static enum print_line_t
-kmemtrace_print_free_compress(struct trace_iterator *iter,
-			      struct kmemtrace_free_entry *entry)
+kmemtrace_print_free_compress(struct trace_iterator *iter)
 {
+	struct kmemtrace_free_entry *entry;
 	struct trace_seq *s = &iter->seq;
 	int ret;
 
+	trace_assign_type(entry, iter->ent);
+
 	/* Free entry */
 	ret = trace_seq_printf(s, "  -      ");
 	if (!ret)
@@ -401,19 +440,11 @@ kmemtrace_print_free_compress(struct trace_iterator *iter,
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	/* Skip node */
-	ret = trace_seq_printf(s, "       ");
+	/* Skip node and print call site*/
+	ret = trace_seq_printf(s, "       %pf\n", (void *)entry->call_site);
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	/* Call site */
-	ret = seq_print_ip_sym(s, entry->call_site, 0);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	if (!trace_seq_printf(s, "\n"))
-		return TRACE_TYPE_PARTIAL_LINE;
-
 	return TRACE_TYPE_HANDLED;
 }
 
@@ -421,32 +452,31 @@ static enum print_line_t kmemtrace_print_line(struct trace_iterator *iter)
 {
 	struct trace_entry *entry = iter->ent;
 
-	switch (entry->type) {
-	case TRACE_KMEM_ALLOC: {
-		struct kmemtrace_alloc_entry *field;
-
-		trace_assign_type(field, entry);
-		if (kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL)
-			return kmemtrace_print_alloc_compress(iter, field);
-		else
-			return kmemtrace_print_alloc_user(iter, field);
-	}
-
-	case TRACE_KMEM_FREE: {
-		struct kmemtrace_free_entry *field;
-
-		trace_assign_type(field, entry);
-		if (kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL)
-			return kmemtrace_print_free_compress(iter, field);
-		else
-			return kmemtrace_print_free_user(iter, field);
-	}
+	if (!(kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL))
+		return TRACE_TYPE_UNHANDLED;
 
+	switch (entry->type) {
+	case TRACE_KMEM_ALLOC:
+		return kmemtrace_print_alloc_compress(iter);
+	case TRACE_KMEM_FREE:
+		return kmemtrace_print_free_compress(iter);
 	default:
 		return TRACE_TYPE_UNHANDLED;
 	}
 }
 
+static struct trace_event kmem_trace_alloc = {
+	.type			= TRACE_KMEM_ALLOC,
+	.trace			= kmemtrace_print_alloc,
+	.binary			= kmemtrace_print_alloc_user,
+};
+
+static struct trace_event kmem_trace_free = {
+	.type			= TRACE_KMEM_FREE,
+	.trace			= kmemtrace_print_free,
+	.binary			= kmemtrace_print_free_user,
+};
+
 static struct tracer kmem_tracer __read_mostly = {
 	.name			= "kmemtrace",
 	.init			= kmem_trace_init,
@@ -463,6 +493,21 @@ void kmemtrace_init(void)
 
 static int __init init_kmem_tracer(void)
 {
-	return register_tracer(&kmem_tracer);
+	if (!register_ftrace_event(&kmem_trace_alloc)) {
+		pr_warning("Warning: could not register kmem events\n");
+		return 1;
+	}
+
+	if (!register_ftrace_event(&kmem_trace_free)) {
+		pr_warning("Warning: could not register kmem events\n");
+		return 1;
+	}
+
+	if (!register_tracer(&kmem_tracer)) {
+		pr_warning("Warning: could not register the kmem tracer\n");
+		return 1;
+	}
+
+	return 0;
 }
 device_initcall(init_kmem_tracer);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index a330513d96ce..da2c59d8f486 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -322,6 +322,14 @@ struct buffer_data_page {
 	unsigned char	 data[];	/* data of buffer page */
 };
 
+/*
+ * Note, the buffer_page list must be first. The buffer pages
+ * are allocated in cache lines, which means that each buffer
+ * page will be at the beginning of a cache line, and thus
+ * the least significant bits will be zero. We use this to
+ * add flags in the list struct pointers, to make the ring buffer
+ * lockless.
+ */
 struct buffer_page {
 	struct list_head list;		/* list of buffer pages */
 	local_t		 write;		/* index for next write */
@@ -330,6 +338,21 @@ struct buffer_page {
 	struct buffer_data_page *page;	/* Actual data page */
 };
 
+/*
+ * The buffer page counters, write and entries, must be reset
+ * atomically when crossing page boundaries. To synchronize this
+ * update, two counters are inserted into the number. One is
+ * the actual counter for the write position or count on the page.
+ *
+ * The other is a counter of updaters. Before an update happens
+ * the update partition of the counter is incremented. This will
+ * allow the updater to update the counter atomically.
+ *
+ * The counter is 20 bits, and the state data is 12.
+ */
+#define RB_WRITE_MASK		0xfffff
+#define RB_WRITE_INTCNT		(1 << 20)
+
 static void rb_init_page(struct buffer_data_page *bpage)
 {
 	local_set(&bpage->commit, 0);
@@ -403,21 +426,20 @@ int ring_buffer_print_page_header(struct trace_seq *s)
 struct ring_buffer_per_cpu {
 	int				cpu;
 	struct ring_buffer		*buffer;
-	spinlock_t			reader_lock; /* serialize readers */
+	spinlock_t			reader_lock;	/* serialize readers */
 	raw_spinlock_t			lock;
 	struct lock_class_key		lock_key;
-	struct list_head		pages;
+	struct list_head		*pages;
 	struct buffer_page		*head_page;	/* read from head */
 	struct buffer_page		*tail_page;	/* write to tail */
 	struct buffer_page		*commit_page;	/* committed pages */
 	struct buffer_page		*reader_page;
-	unsigned long			nmi_dropped;
-	unsigned long			commit_overrun;
-	unsigned long			overrun;
-	unsigned long			read;
+	local_t				commit_overrun;
+	local_t				overrun;
 	local_t				entries;
 	local_t				committing;
 	local_t				commits;
+	unsigned long			read;
 	u64				write_stamp;
 	u64				read_stamp;
 	atomic_t			record_disabled;
@@ -489,6 +511,390 @@ void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer,
 }
 EXPORT_SYMBOL_GPL(ring_buffer_normalize_time_stamp);
 
+/*
+ * Making the ring buffer lockless makes things tricky.
+ * Although writes only happen on the CPU that they are on,
+ * and they only need to worry about interrupts. Reads can
+ * happen on any CPU.
+ *
+ * The reader page is always off the ring buffer, but when the
+ * reader finishes with a page, it needs to swap its page with
+ * a new one from the buffer. The reader needs to take from
+ * the head (writes go to the tail). But if a writer is in overwrite
+ * mode and wraps, it must push the head page forward.
+ *
+ * Here lies the problem.
+ *
+ * The reader must be careful to replace only the head page, and
+ * not another one. As described at the top of the file in the
+ * ASCII art, the reader sets its old page to point to the next
+ * page after head. It then sets the page after head to point to
+ * the old reader page. But if the writer moves the head page
+ * during this operation, the reader could end up with the tail.
+ *
+ * We use cmpxchg to help prevent this race. We also do something
+ * special with the page before head. We set the LSB to 1.
+ *
+ * When the writer must push the page forward, it will clear the
+ * bit that points to the head page, move the head, and then set
+ * the bit that points to the new head page.
+ *
+ * We also don't want an interrupt coming in and moving the head
+ * page on another writer. Thus we use the second LSB to catch
+ * that too. Thus:
+ *
+ * head->list->prev->next        bit 1          bit 0
+ *                              -------        -------
+ * Normal page                     0              0
+ * Points to head page             0              1
+ * New head page                   1              0
+ *
+ * Note we can not trust the prev pointer of the head page, because:
+ *
+ * +----+       +-----+        +-----+
+ * |    |------>|  T  |---X--->|  N  |
+ * |    |<------|     |        |     |
+ * +----+       +-----+        +-----+
+ *   ^                           ^ |
+ *   |          +-----+          | |
+ *   +----------|  R  |----------+ |
+ *              |     |<-----------+
+ *              +-----+
+ *
+ * Key:  ---X-->  HEAD flag set in pointer
+ *         T      Tail page
+ *         R      Reader page
+ *         N      Next page
+ *
+ * (see __rb_reserve_next() to see where this happens)
+ *
+ *  What the above shows is that the reader just swapped out
+ *  the reader page with a page in the buffer, but before it
+ *  could make the new header point back to the new page added
+ *  it was preempted by a writer. The writer moved forward onto
+ *  the new page added by the reader and is about to move forward
+ *  again.
+ *
+ *  You can see, it is legitimate for the previous pointer of
+ *  the head (or any page) not to point back to itself. But only
+ *  temporarially.
+ */
+
+#define RB_PAGE_NORMAL		0UL
+#define RB_PAGE_HEAD		1UL
+#define RB_PAGE_UPDATE		2UL
+
+
+#define RB_FLAG_MASK		3UL
+
+/* PAGE_MOVED is not part of the mask */
+#define RB_PAGE_MOVED		4UL
+
+/*
+ * rb_list_head - remove any bit
+ */
+static struct list_head *rb_list_head(struct list_head *list)
+{
+	unsigned long val = (unsigned long)list;
+
+	return (struct list_head *)(val & ~RB_FLAG_MASK);
+}
+
+/*
+ * rb_is_head_page - test if the give page is the head page
+ *
+ * Because the reader may move the head_page pointer, we can
+ * not trust what the head page is (it may be pointing to
+ * the reader page). But if the next page is a header page,
+ * its flags will be non zero.
+ */
+static int inline
+rb_is_head_page(struct ring_buffer_per_cpu *cpu_buffer,
+		struct buffer_page *page, struct list_head *list)
+{
+	unsigned long val;
+
+	val = (unsigned long)list->next;
+
+	if ((val & ~RB_FLAG_MASK) != (unsigned long)&page->list)
+		return RB_PAGE_MOVED;
+
+	return val & RB_FLAG_MASK;
+}
+
+/*
+ * rb_is_reader_page
+ *
+ * The unique thing about the reader page, is that, if the
+ * writer is ever on it, the previous pointer never points
+ * back to the reader page.
+ */
+static int rb_is_reader_page(struct buffer_page *page)
+{
+	struct list_head *list = page->list.prev;
+
+	return rb_list_head(list->next) != &page->list;
+}
+
+/*
+ * rb_set_list_to_head - set a list_head to be pointing to head.
+ */
+static void rb_set_list_to_head(struct ring_buffer_per_cpu *cpu_buffer,
+				struct list_head *list)
+{
+	unsigned long *ptr;
+
+	ptr = (unsigned long *)&list->next;
+	*ptr |= RB_PAGE_HEAD;
+	*ptr &= ~RB_PAGE_UPDATE;
+}
+
+/*
+ * rb_head_page_activate - sets up head page
+ */
+static void rb_head_page_activate(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	struct buffer_page *head;
+
+	head = cpu_buffer->head_page;
+	if (!head)
+		return;
+
+	/*
+	 * Set the previous list pointer to have the HEAD flag.
+	 */
+	rb_set_list_to_head(cpu_buffer, head->list.prev);
+}
+
+static void rb_list_head_clear(struct list_head *list)
+{
+	unsigned long *ptr = (unsigned long *)&list->next;
+
+	*ptr &= ~RB_FLAG_MASK;
+}
+
+/*
+ * rb_head_page_dactivate - clears head page ptr (for free list)
+ */
+static void
+rb_head_page_deactivate(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	struct list_head *hd;
+
+	/* Go through the whole list and clear any pointers found. */
+	rb_list_head_clear(cpu_buffer->pages);
+
+	list_for_each(hd, cpu_buffer->pages)
+		rb_list_head_clear(hd);
+}
+
+static int rb_head_page_set(struct ring_buffer_per_cpu *cpu_buffer,
+			    struct buffer_page *head,
+			    struct buffer_page *prev,
+			    int old_flag, int new_flag)
+{
+	struct list_head *list;
+	unsigned long val = (unsigned long)&head->list;
+	unsigned long ret;
+
+	list = &prev->list;
+
+	val &= ~RB_FLAG_MASK;
+
+	ret = (unsigned long)cmpxchg(&list->next,
+				     val | old_flag, val | new_flag);
+
+	/* check if the reader took the page */
+	if ((ret & ~RB_FLAG_MASK) != val)
+		return RB_PAGE_MOVED;
+
+	return ret & RB_FLAG_MASK;
+}
+
+static int rb_head_page_set_update(struct ring_buffer_per_cpu *cpu_buffer,
+				   struct buffer_page *head,
+				   struct buffer_page *prev,
+				   int old_flag)
+{
+	return rb_head_page_set(cpu_buffer, head, prev,
+				old_flag, RB_PAGE_UPDATE);
+}
+
+static int rb_head_page_set_head(struct ring_buffer_per_cpu *cpu_buffer,
+				 struct buffer_page *head,
+				 struct buffer_page *prev,
+				 int old_flag)
+{
+	return rb_head_page_set(cpu_buffer, head, prev,
+				old_flag, RB_PAGE_HEAD);
+}
+
+static int rb_head_page_set_normal(struct ring_buffer_per_cpu *cpu_buffer,
+				   struct buffer_page *head,
+				   struct buffer_page *prev,
+				   int old_flag)
+{
+	return rb_head_page_set(cpu_buffer, head, prev,
+				old_flag, RB_PAGE_NORMAL);
+}
+
+static inline void rb_inc_page(struct ring_buffer_per_cpu *cpu_buffer,
+			       struct buffer_page **bpage)
+{
+	struct list_head *p = rb_list_head((*bpage)->list.next);
+
+	*bpage = list_entry(p, struct buffer_page, list);
+}
+
+static struct buffer_page *
+rb_set_head_page(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	struct buffer_page *head;
+	struct buffer_page *page;
+	struct list_head *list;
+	int i;
+
+	if (RB_WARN_ON(cpu_buffer, !cpu_buffer->head_page))
+		return NULL;
+
+	/* sanity check */
+	list = cpu_buffer->pages;
+	if (RB_WARN_ON(cpu_buffer, rb_list_head(list->prev->next) != list))
+		return NULL;
+
+	page = head = cpu_buffer->head_page;
+	/*
+	 * It is possible that the writer moves the header behind
+	 * where we started, and we miss in one loop.
+	 * A second loop should grab the header, but we'll do
+	 * three loops just because I'm paranoid.
+	 */
+	for (i = 0; i < 3; i++) {
+		do {
+			if (rb_is_head_page(cpu_buffer, page, page->list.prev)) {
+				cpu_buffer->head_page = page;
+				return page;
+			}
+			rb_inc_page(cpu_buffer, &page);
+		} while (page != head);
+	}
+
+	RB_WARN_ON(cpu_buffer, 1);
+
+	return NULL;
+}
+
+static int rb_head_page_replace(struct buffer_page *old,
+				struct buffer_page *new)
+{
+	unsigned long *ptr = (unsigned long *)&old->list.prev->next;
+	unsigned long val;
+	unsigned long ret;
+
+	val = *ptr & ~RB_FLAG_MASK;
+	val |= RB_PAGE_HEAD;
+
+	ret = cmpxchg(ptr, val, &new->list);
+
+	return ret == val;
+}
+
+/*
+ * rb_tail_page_update - move the tail page forward
+ *
+ * Returns 1 if moved tail page, 0 if someone else did.
+ */
+static int rb_tail_page_update(struct ring_buffer_per_cpu *cpu_buffer,
+			       struct buffer_page *tail_page,
+			       struct buffer_page *next_page)
+{
+	struct buffer_page *old_tail;
+	unsigned long old_entries;
+	unsigned long old_write;
+	int ret = 0;
+
+	/*
+	 * The tail page now needs to be moved forward.
+	 *
+	 * We need to reset the tail page, but without messing
+	 * with possible erasing of data brought in by interrupts
+	 * that have moved the tail page and are currently on it.
+	 *
+	 * We add a counter to the write field to denote this.
+	 */
+	old_write = local_add_return(RB_WRITE_INTCNT, &next_page->write);
+	old_entries = local_add_return(RB_WRITE_INTCNT, &next_page->entries);
+
+	/*
+	 * Just make sure we have seen our old_write and synchronize
+	 * with any interrupts that come in.
+	 */
+	barrier();
+
+	/*
+	 * If the tail page is still the same as what we think
+	 * it is, then it is up to us to update the tail
+	 * pointer.
+	 */
+	if (tail_page == cpu_buffer->tail_page) {
+		/* Zero the write counter */
+		unsigned long val = old_write & ~RB_WRITE_MASK;
+		unsigned long eval = old_entries & ~RB_WRITE_MASK;
+
+		/*
+		 * This will only succeed if an interrupt did
+		 * not come in and change it. In which case, we
+		 * do not want to modify it.
+		 *
+		 * We add (void) to let the compiler know that we do not care
+		 * about the return value of these functions. We use the
+		 * cmpxchg to only update if an interrupt did not already
+		 * do it for us. If the cmpxchg fails, we don't care.
+		 */
+		(void)local_cmpxchg(&next_page->write, old_write, val);
+		(void)local_cmpxchg(&next_page->entries, old_entries, eval);
+
+		/*
+		 * No need to worry about races with clearing out the commit.
+		 * it only can increment when a commit takes place. But that
+		 * only happens in the outer most nested commit.
+		 */
+		local_set(&next_page->page->commit, 0);
+
+		old_tail = cmpxchg(&cpu_buffer->tail_page,
+				   tail_page, next_page);
+
+		if (old_tail == tail_page)
+			ret = 1;
+	}
+
+	return ret;
+}
+
+static int rb_check_bpage(struct ring_buffer_per_cpu *cpu_buffer,
+			  struct buffer_page *bpage)
+{
+	unsigned long val = (unsigned long)bpage;
+
+	if (RB_WARN_ON(cpu_buffer, val & RB_FLAG_MASK))
+		return 1;
+
+	return 0;
+}
+
+/**
+ * rb_check_list - make sure a pointer to a list has the last bits zero
+ */
+static int rb_check_list(struct ring_buffer_per_cpu *cpu_buffer,
+			 struct list_head *list)
+{
+	if (RB_WARN_ON(cpu_buffer, rb_list_head(list->prev) != list->prev))
+		return 1;
+	if (RB_WARN_ON(cpu_buffer, rb_list_head(list->next) != list->next))
+		return 1;
+	return 0;
+}
+
 /**
  * check_pages - integrity check of buffer pages
  * @cpu_buffer: CPU buffer with pages to test
@@ -498,14 +904,19 @@ EXPORT_SYMBOL_GPL(ring_buffer_normalize_time_stamp);
  */
 static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer)
 {
-	struct list_head *head = &cpu_buffer->pages;
+	struct list_head *head = cpu_buffer->pages;
 	struct buffer_page *bpage, *tmp;
 
+	rb_head_page_deactivate(cpu_buffer);
+
 	if (RB_WARN_ON(cpu_buffer, head->next->prev != head))
 		return -1;
 	if (RB_WARN_ON(cpu_buffer, head->prev->next != head))
 		return -1;
 
+	if (rb_check_list(cpu_buffer, head))
+		return -1;
+
 	list_for_each_entry_safe(bpage, tmp, head, list) {
 		if (RB_WARN_ON(cpu_buffer,
 			       bpage->list.next->prev != &bpage->list))
@@ -513,25 +924,33 @@ static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer)
 		if (RB_WARN_ON(cpu_buffer,
 			       bpage->list.prev->next != &bpage->list))
 			return -1;
+		if (rb_check_list(cpu_buffer, &bpage->list))
+			return -1;
 	}
 
+	rb_head_page_activate(cpu_buffer);
+
 	return 0;
 }
 
 static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
 			     unsigned nr_pages)
 {
-	struct list_head *head = &cpu_buffer->pages;
 	struct buffer_page *bpage, *tmp;
 	unsigned long addr;
 	LIST_HEAD(pages);
 	unsigned i;
 
+	WARN_ON(!nr_pages);
+
 	for (i = 0; i < nr_pages; i++) {
 		bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()),
 				    GFP_KERNEL, cpu_to_node(cpu_buffer->cpu));
 		if (!bpage)
 			goto free_pages;
+
+		rb_check_bpage(cpu_buffer, bpage);
+
 		list_add(&bpage->list, &pages);
 
 		addr = __get_free_page(GFP_KERNEL);
@@ -541,7 +960,13 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
 		rb_init_page(bpage->page);
 	}
 
-	list_splice(&pages, head);
+	/*
+	 * The ring buffer page list is a circular list that does not
+	 * start and end with a list head. All page list items point to
+	 * other pages.
+	 */
+	cpu_buffer->pages = pages.next;
+	list_del(&pages);
 
 	rb_check_pages(cpu_buffer);
 
@@ -573,13 +998,14 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
 	spin_lock_init(&cpu_buffer->reader_lock);
 	lockdep_set_class(&cpu_buffer->reader_lock, buffer->reader_lock_key);
 	cpu_buffer->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
-	INIT_LIST_HEAD(&cpu_buffer->pages);
 
 	bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()),
 			    GFP_KERNEL, cpu_to_node(cpu));
 	if (!bpage)
 		goto fail_free_buffer;
 
+	rb_check_bpage(cpu_buffer, bpage);
+
 	cpu_buffer->reader_page = bpage;
 	addr = __get_free_page(GFP_KERNEL);
 	if (!addr)
@@ -594,9 +1020,11 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
 		goto fail_free_reader;
 
 	cpu_buffer->head_page
-		= list_entry(cpu_buffer->pages.next, struct buffer_page, list);
+		= list_entry(cpu_buffer->pages, struct buffer_page, list);
 	cpu_buffer->tail_page = cpu_buffer->commit_page = cpu_buffer->head_page;
 
+	rb_head_page_activate(cpu_buffer);
+
 	return cpu_buffer;
 
  fail_free_reader:
@@ -609,15 +1037,22 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
 
 static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer)
 {
-	struct list_head *head = &cpu_buffer->pages;
+	struct list_head *head = cpu_buffer->pages;
 	struct buffer_page *bpage, *tmp;
 
 	free_buffer_page(cpu_buffer->reader_page);
 
-	list_for_each_entry_safe(bpage, tmp, head, list) {
-		list_del_init(&bpage->list);
+	rb_head_page_deactivate(cpu_buffer);
+
+	if (head) {
+		list_for_each_entry_safe(bpage, tmp, head, list) {
+			list_del_init(&bpage->list);
+			free_buffer_page(bpage);
+		}
+		bpage = list_entry(head, struct buffer_page, list);
 		free_buffer_page(bpage);
 	}
+
 	kfree(cpu_buffer);
 }
 
@@ -760,15 +1195,17 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
 	atomic_inc(&cpu_buffer->record_disabled);
 	synchronize_sched();
 
+	rb_head_page_deactivate(cpu_buffer);
+
 	for (i = 0; i < nr_pages; i++) {
-		if (RB_WARN_ON(cpu_buffer, list_empty(&cpu_buffer->pages)))
+		if (RB_WARN_ON(cpu_buffer, list_empty(cpu_buffer->pages)))
 			return;
-		p = cpu_buffer->pages.next;
+		p = cpu_buffer->pages->next;
 		bpage = list_entry(p, struct buffer_page, list);
 		list_del_init(&bpage->list);
 		free_buffer_page(bpage);
 	}
-	if (RB_WARN_ON(cpu_buffer, list_empty(&cpu_buffer->pages)))
+	if (RB_WARN_ON(cpu_buffer, list_empty(cpu_buffer->pages)))
 		return;
 
 	rb_reset_cpu(cpu_buffer);
@@ -790,15 +1227,19 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
 	atomic_inc(&cpu_buffer->record_disabled);
 	synchronize_sched();
 
+	spin_lock_irq(&cpu_buffer->reader_lock);
+	rb_head_page_deactivate(cpu_buffer);
+
 	for (i = 0; i < nr_pages; i++) {
 		if (RB_WARN_ON(cpu_buffer, list_empty(pages)))
 			return;
 		p = pages->next;
 		bpage = list_entry(p, struct buffer_page, list);
 		list_del_init(&bpage->list);
-		list_add_tail(&bpage->list, &cpu_buffer->pages);
+		list_add_tail(&bpage->list, cpu_buffer->pages);
 	}
 	rb_reset_cpu(cpu_buffer);
+	spin_unlock_irq(&cpu_buffer->reader_lock);
 
 	rb_check_pages(cpu_buffer);
 
@@ -949,21 +1390,14 @@ rb_reader_event(struct ring_buffer_per_cpu *cpu_buffer)
 }
 
 static inline struct ring_buffer_event *
-rb_head_event(struct ring_buffer_per_cpu *cpu_buffer)
-{
-	return __rb_page_index(cpu_buffer->head_page,
-			       cpu_buffer->head_page->read);
-}
-
-static inline struct ring_buffer_event *
 rb_iter_head_event(struct ring_buffer_iter *iter)
 {
 	return __rb_page_index(iter->head_page, iter->head);
 }
 
-static inline unsigned rb_page_write(struct buffer_page *bpage)
+static inline unsigned long rb_page_write(struct buffer_page *bpage)
 {
-	return local_read(&bpage->write);
+	return local_read(&bpage->write) & RB_WRITE_MASK;
 }
 
 static inline unsigned rb_page_commit(struct buffer_page *bpage)
@@ -971,6 +1405,11 @@ static inline unsigned rb_page_commit(struct buffer_page *bpage)
 	return local_read(&bpage->page->commit);
 }
 
+static inline unsigned long rb_page_entries(struct buffer_page *bpage)
+{
+	return local_read(&bpage->entries) & RB_WRITE_MASK;
+}
+
 /* Size is determined by what has been commited */
 static inline unsigned rb_page_size(struct buffer_page *bpage)
 {
@@ -983,22 +1422,6 @@ rb_commit_index(struct ring_buffer_per_cpu *cpu_buffer)
 	return rb_page_commit(cpu_buffer->commit_page);
 }
 
-static inline unsigned rb_head_size(struct ring_buffer_per_cpu *cpu_buffer)
-{
-	return rb_page_commit(cpu_buffer->head_page);
-}
-
-static inline void rb_inc_page(struct ring_buffer_per_cpu *cpu_buffer,
-			       struct buffer_page **bpage)
-{
-	struct list_head *p = (*bpage)->list.next;
-
-	if (p == &cpu_buffer->pages)
-		p = p->next;
-
-	*bpage = list_entry(p, struct buffer_page, list);
-}
-
 static inline unsigned
 rb_event_index(struct ring_buffer_event *event)
 {
@@ -1024,6 +1447,8 @@ rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
 static void
 rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
 {
+	unsigned long max_count;
+
 	/*
 	 * We only race with interrupts and NMIs on this CPU.
 	 * If we own the commit event, then we can commit
@@ -1033,9 +1458,16 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
 	 * assign the commit to the tail.
 	 */
  again:
+	max_count = cpu_buffer->buffer->pages * 100;
+
 	while (cpu_buffer->commit_page != cpu_buffer->tail_page) {
-		cpu_buffer->commit_page->page->commit =
-			cpu_buffer->commit_page->write;
+		if (RB_WARN_ON(cpu_buffer, !(--max_count)))
+			return;
+		if (RB_WARN_ON(cpu_buffer,
+			       rb_is_reader_page(cpu_buffer->tail_page)))
+			return;
+		local_set(&cpu_buffer->commit_page->page->commit,
+			  rb_page_write(cpu_buffer->commit_page));
 		rb_inc_page(cpu_buffer, &cpu_buffer->commit_page);
 		cpu_buffer->write_stamp =
 			cpu_buffer->commit_page->page->time_stamp;
@@ -1044,8 +1476,12 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
 	}
 	while (rb_commit_index(cpu_buffer) !=
 	       rb_page_write(cpu_buffer->commit_page)) {
-		cpu_buffer->commit_page->page->commit =
-			cpu_buffer->commit_page->write;
+
+		local_set(&cpu_buffer->commit_page->page->commit,
+			  rb_page_write(cpu_buffer->commit_page));
+		RB_WARN_ON(cpu_buffer,
+			   local_read(&cpu_buffer->commit_page->page->commit) &
+			   ~RB_WRITE_MASK);
 		barrier();
 	}
 
@@ -1078,7 +1514,7 @@ static void rb_inc_iter(struct ring_buffer_iter *iter)
 	 * to the head page instead of next.
 	 */
 	if (iter->head_page == cpu_buffer->reader_page)
-		iter->head_page = cpu_buffer->head_page;
+		iter->head_page = rb_set_head_page(cpu_buffer);
 	else
 		rb_inc_page(cpu_buffer, &iter->head_page);
 
@@ -1122,6 +1558,163 @@ rb_update_event(struct ring_buffer_event *event,
 	}
 }
 
+/*
+ * rb_handle_head_page - writer hit the head page
+ *
+ * Returns: +1 to retry page
+ *           0 to continue
+ *          -1 on error
+ */
+static int
+rb_handle_head_page(struct ring_buffer_per_cpu *cpu_buffer,
+		    struct buffer_page *tail_page,
+		    struct buffer_page *next_page)
+{
+	struct buffer_page *new_head;
+	int entries;
+	int type;
+	int ret;
+
+	entries = rb_page_entries(next_page);
+
+	/*
+	 * The hard part is here. We need to move the head
+	 * forward, and protect against both readers on
+	 * other CPUs and writers coming in via interrupts.
+	 */
+	type = rb_head_page_set_update(cpu_buffer, next_page, tail_page,
+				       RB_PAGE_HEAD);
+
+	/*
+	 * type can be one of four:
+	 *  NORMAL - an interrupt already moved it for us
+	 *  HEAD   - we are the first to get here.
+	 *  UPDATE - we are the interrupt interrupting
+	 *           a current move.
+	 *  MOVED  - a reader on another CPU moved the next
+	 *           pointer to its reader page. Give up
+	 *           and try again.
+	 */
+
+	switch (type) {
+	case RB_PAGE_HEAD:
+		/*
+		 * We changed the head to UPDATE, thus
+		 * it is our responsibility to update
+		 * the counters.
+		 */
+		local_add(entries, &cpu_buffer->overrun);
+
+		/*
+		 * The entries will be zeroed out when we move the
+		 * tail page.
+		 */
+
+		/* still more to do */
+		break;
+
+	case RB_PAGE_UPDATE:
+		/*
+		 * This is an interrupt that interrupt the
+		 * previous update. Still more to do.
+		 */
+		break;
+	case RB_PAGE_NORMAL:
+		/*
+		 * An interrupt came in before the update
+		 * and processed this for us.
+		 * Nothing left to do.
+		 */
+		return 1;
+	case RB_PAGE_MOVED:
+		/*
+		 * The reader is on another CPU and just did
+		 * a swap with our next_page.
+		 * Try again.
+		 */
+		return 1;
+	default:
+		RB_WARN_ON(cpu_buffer, 1); /* WTF??? */
+		return -1;
+	}
+
+	/*
+	 * Now that we are here, the old head pointer is
+	 * set to UPDATE. This will keep the reader from
+	 * swapping the head page with the reader page.
+	 * The reader (on another CPU) will spin till
+	 * we are finished.
+	 *
+	 * We just need to protect against interrupts
+	 * doing the job. We will set the next pointer
+	 * to HEAD. After that, we set the old pointer
+	 * to NORMAL, but only if it was HEAD before.
+	 * otherwise we are an interrupt, and only
+	 * want the outer most commit to reset it.
+	 */
+	new_head = next_page;
+	rb_inc_page(cpu_buffer, &new_head);
+
+	ret = rb_head_page_set_head(cpu_buffer, new_head, next_page,
+				    RB_PAGE_NORMAL);
+
+	/*
+	 * Valid returns are:
+	 *  HEAD   - an interrupt came in and already set it.
+	 *  NORMAL - One of two things:
+	 *            1) We really set it.
+	 *            2) A bunch of interrupts came in and moved
+	 *               the page forward again.
+	 */
+	switch (ret) {
+	case RB_PAGE_HEAD:
+	case RB_PAGE_NORMAL:
+		/* OK */
+		break;
+	default:
+		RB_WARN_ON(cpu_buffer, 1);
+		return -1;
+	}
+
+	/*
+	 * It is possible that an interrupt came in,
+	 * set the head up, then more interrupts came in
+	 * and moved it again. When we get back here,
+	 * the page would have been set to NORMAL but we
+	 * just set it back to HEAD.
+	 *
+	 * How do you detect this? Well, if that happened
+	 * the tail page would have moved.
+	 */
+	if (ret == RB_PAGE_NORMAL) {
+		/*
+		 * If the tail had moved passed next, then we need
+		 * to reset the pointer.
+		 */
+		if (cpu_buffer->tail_page != tail_page &&
+		    cpu_buffer->tail_page != next_page)
+			rb_head_page_set_normal(cpu_buffer, new_head,
+						next_page,
+						RB_PAGE_HEAD);
+	}
+
+	/*
+	 * If this was the outer most commit (the one that
+	 * changed the original pointer from HEAD to UPDATE),
+	 * then it is up to us to reset it to NORMAL.
+	 */
+	if (type == RB_PAGE_HEAD) {
+		ret = rb_head_page_set_normal(cpu_buffer, next_page,
+					      tail_page,
+					      RB_PAGE_UPDATE);
+		if (RB_WARN_ON(cpu_buffer,
+			       ret != RB_PAGE_UPDATE))
+			return -1;
+	}
+
+	return 0;
+}
+
 static unsigned rb_calculate_event_length(unsigned length)
 {
 	struct ring_buffer_event event; /* Used only for sizeof array */
@@ -1200,96 +1793,93 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
 	     struct buffer_page *commit_page,
 	     struct buffer_page *tail_page, u64 *ts)
 {
-	struct buffer_page *next_page, *head_page, *reader_page;
 	struct ring_buffer *buffer = cpu_buffer->buffer;
-	bool lock_taken = false;
-	unsigned long flags;
+	struct buffer_page *next_page;
+	int ret;
 
 	next_page = tail_page;
 
-	local_irq_save(flags);
-	/*
-	 * Since the write to the buffer is still not
-	 * fully lockless, we must be careful with NMIs.
-	 * The locks in the writers are taken when a write
-	 * crosses to a new page. The locks protect against
-	 * races with the readers (this will soon be fixed
-	 * with a lockless solution).
-	 *
-	 * Because we can not protect against NMIs, and we
-	 * want to keep traces reentrant, we need to manage
-	 * what happens when we are in an NMI.
-	 *
-	 * NMIs can happen after we take the lock.
-	 * If we are in an NMI, only take the lock
-	 * if it is not already taken. Otherwise
-	 * simply fail.
-	 */
-	if (unlikely(in_nmi())) {
-		if (!__raw_spin_trylock(&cpu_buffer->lock)) {
-			cpu_buffer->nmi_dropped++;
-			goto out_reset;
-		}
-	} else
-		__raw_spin_lock(&cpu_buffer->lock);
-
-	lock_taken = true;
-
 	rb_inc_page(cpu_buffer, &next_page);
 
-	head_page = cpu_buffer->head_page;
-	reader_page = cpu_buffer->reader_page;
-
-	/* we grabbed the lock before incrementing */
-	if (RB_WARN_ON(cpu_buffer, next_page == reader_page))
-		goto out_reset;
-
 	/*
 	 * If for some reason, we had an interrupt storm that made
 	 * it all the way around the buffer, bail, and warn
 	 * about it.
 	 */
 	if (unlikely(next_page == commit_page)) {
-		cpu_buffer->commit_overrun++;
+		local_inc(&cpu_buffer->commit_overrun);
 		goto out_reset;
 	}
 
-	if (next_page == head_page) {
-		if (!(buffer->flags & RB_FL_OVERWRITE))
-			goto out_reset;
-
-		/* tail_page has not moved yet? */
-		if (tail_page == cpu_buffer->tail_page) {
-			/* count overflows */
-			cpu_buffer->overrun +=
-				local_read(&head_page->entries);
+	/*
+	 * This is where the fun begins!
+	 *
+	 * We are fighting against races between a reader that
+	 * could be on another CPU trying to swap its reader
+	 * page with the buffer head.
+	 *
+	 * We are also fighting against interrupts coming in and
+	 * moving the head or tail on us as well.
+	 *
+	 * If the next page is the head page then we have filled
+	 * the buffer, unless the commit page is still on the
+	 * reader page.
+	 */
+	if (rb_is_head_page(cpu_buffer, next_page, &tail_page->list)) {
 
-			rb_inc_page(cpu_buffer, &head_page);
-			cpu_buffer->head_page = head_page;
-			cpu_buffer->head_page->read = 0;
+		/*
+		 * If the commit is not on the reader page, then
+		 * move the header page.
+		 */
+		if (!rb_is_reader_page(cpu_buffer->commit_page)) {
+			/*
+			 * If we are not in overwrite mode,
+			 * this is easy, just stop here.
+			 */
+			if (!(buffer->flags & RB_FL_OVERWRITE))
+				goto out_reset;
+
+			ret = rb_handle_head_page(cpu_buffer,
+						  tail_page,
+						  next_page);
+			if (ret < 0)
+				goto out_reset;
+			if (ret)
+				goto out_again;
+		} else {
+			/*
+			 * We need to be careful here too. The
+			 * commit page could still be on the reader
+			 * page. We could have a small buffer, and
+			 * have filled up the buffer with events
+			 * from interrupts and such, and wrapped.
+			 *
+			 * Note, if the tail page is also the on the
+			 * reader_page, we let it move out.
+			 */
+			if (unlikely((cpu_buffer->commit_page !=
+				      cpu_buffer->tail_page) &&
+				     (cpu_buffer->commit_page ==
+				      cpu_buffer->reader_page))) {
+				local_inc(&cpu_buffer->commit_overrun);
+				goto out_reset;
+			}
 		}
 	}
 
-	/*
-	 * If the tail page is still the same as what we think
-	 * it is, then it is up to us to update the tail
-	 * pointer.
-	 */
-	if (tail_page == cpu_buffer->tail_page) {
-		local_set(&next_page->write, 0);
-		local_set(&next_page->entries, 0);
-		local_set(&next_page->page->commit, 0);
-		cpu_buffer->tail_page = next_page;
-
-		/* reread the time stamp */
+	ret = rb_tail_page_update(cpu_buffer, tail_page, next_page);
+	if (ret) {
+		/*
+		 * Nested commits always have zero deltas, so
+		 * just reread the time stamp
+		 */
 		*ts = rb_time_stamp(buffer, cpu_buffer->cpu);
-		cpu_buffer->tail_page->page->time_stamp = *ts;
+		next_page->page->time_stamp = *ts;
 	}
 
-	rb_reset_tail(cpu_buffer, tail_page, tail, length);
+ out_again:
 
-	__raw_spin_unlock(&cpu_buffer->lock);
-	local_irq_restore(flags);
+	rb_reset_tail(cpu_buffer, tail_page, tail, length);
 
 	/* fail and let the caller try again */
 	return ERR_PTR(-EAGAIN);
@@ -1298,9 +1888,6 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
 	/* reset write */
 	rb_reset_tail(cpu_buffer, tail_page, tail, length);
 
-	if (likely(lock_taken))
-		__raw_spin_unlock(&cpu_buffer->lock);
-	local_irq_restore(flags);
 	return NULL;
 }
 
@@ -1317,6 +1904,9 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
 	barrier();
 	tail_page = cpu_buffer->tail_page;
 	write = local_add_return(length, &tail_page->write);
+
+	/* set write to only the index of the write */
+	write &= RB_WRITE_MASK;
 	tail = write - length;
 
 	/* See if we shot pass the end of this buffer page */
@@ -1361,12 +1951,16 @@ rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer,
 	bpage = cpu_buffer->tail_page;
 
 	if (bpage->page == (void *)addr && rb_page_write(bpage) == old_index) {
+		unsigned long write_mask =
+			local_read(&bpage->write) & ~RB_WRITE_MASK;
 		/*
 		 * This is on the tail page. It is possible that
 		 * a write could come in and move the tail page
 		 * and write to the next page. That is fine
 		 * because we just shorten what is on this page.
 		 */
+		old_index += write_mask;
+		new_index += write_mask;
 		index = local_cmpxchg(&bpage->write, old_index, new_index);
 		if (index == old_index)
 			return 1;
@@ -1875,9 +2469,13 @@ EXPORT_SYMBOL_GPL(ring_buffer_write);
 static int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
 {
 	struct buffer_page *reader = cpu_buffer->reader_page;
-	struct buffer_page *head = cpu_buffer->head_page;
+	struct buffer_page *head = rb_set_head_page(cpu_buffer);
 	struct buffer_page *commit = cpu_buffer->commit_page;
 
+	/* In case of error, head will be NULL */
+	if (unlikely(!head))
+		return 1;
+
 	return reader->read == rb_page_commit(reader) &&
 		(commit == reader ||
 		 (commit == head &&
@@ -1968,7 +2566,7 @@ unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu)
 		return 0;
 
 	cpu_buffer = buffer->buffers[cpu];
-	ret = (local_read(&cpu_buffer->entries) - cpu_buffer->overrun)
+	ret = (local_read(&cpu_buffer->entries) - local_read(&cpu_buffer->overrun))
 		- cpu_buffer->read;
 
 	return ret;
@@ -1989,33 +2587,13 @@ unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu)
 		return 0;
 
 	cpu_buffer = buffer->buffers[cpu];
-	ret = cpu_buffer->overrun;
+	ret = local_read(&cpu_buffer->overrun);
 
 	return ret;
 }
 EXPORT_SYMBOL_GPL(ring_buffer_overrun_cpu);
 
 /**
- * ring_buffer_nmi_dropped_cpu - get the number of nmis that were dropped
- * @buffer: The ring buffer
- * @cpu: The per CPU buffer to get the number of overruns from
- */
-unsigned long ring_buffer_nmi_dropped_cpu(struct ring_buffer *buffer, int cpu)
-{
-	struct ring_buffer_per_cpu *cpu_buffer;
-	unsigned long ret;
-
-	if (!cpumask_test_cpu(cpu, buffer->cpumask))
-		return 0;
-
-	cpu_buffer = buffer->buffers[cpu];
-	ret = cpu_buffer->nmi_dropped;
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(ring_buffer_nmi_dropped_cpu);
-
-/**
  * ring_buffer_commit_overrun_cpu - get the number of overruns caused by commits
  * @buffer: The ring buffer
  * @cpu: The per CPU buffer to get the number of overruns from
@@ -2030,7 +2608,7 @@ ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu)
 		return 0;
 
 	cpu_buffer = buffer->buffers[cpu];
-	ret = cpu_buffer->commit_overrun;
+	ret = local_read(&cpu_buffer->commit_overrun);
 
 	return ret;
 }
@@ -2053,7 +2631,7 @@ unsigned long ring_buffer_entries(struct ring_buffer *buffer)
 	for_each_buffer_cpu(buffer, cpu) {
 		cpu_buffer = buffer->buffers[cpu];
 		entries += (local_read(&cpu_buffer->entries) -
-			    cpu_buffer->overrun) - cpu_buffer->read;
+			    local_read(&cpu_buffer->overrun)) - cpu_buffer->read;
 	}
 
 	return entries;
@@ -2076,7 +2654,7 @@ unsigned long ring_buffer_overruns(struct ring_buffer *buffer)
 	/* if you care about this being correct, lock the buffer */
 	for_each_buffer_cpu(buffer, cpu) {
 		cpu_buffer = buffer->buffers[cpu];
-		overruns += cpu_buffer->overrun;
+		overruns += local_read(&cpu_buffer->overrun);
 	}
 
 	return overruns;
@@ -2089,8 +2667,10 @@ static void rb_iter_reset(struct ring_buffer_iter *iter)
 
 	/* Iterator usage is expected to have record disabled */
 	if (list_empty(&cpu_buffer->reader_page->list)) {
-		iter->head_page = cpu_buffer->head_page;
-		iter->head = cpu_buffer->head_page->read;
+		iter->head_page = rb_set_head_page(cpu_buffer);
+		if (unlikely(!iter->head_page))
+			return;
+		iter->head = iter->head_page->read;
 	} else {
 		iter->head_page = cpu_buffer->reader_page;
 		iter->head = cpu_buffer->reader_page->read;
@@ -2207,6 +2787,7 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 	struct buffer_page *reader = NULL;
 	unsigned long flags;
 	int nr_loops = 0;
+	int ret;
 
 	local_irq_save(flags);
 	__raw_spin_lock(&cpu_buffer->lock);
@@ -2240,30 +2821,56 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 		goto out;
 
 	/*
-	 * Splice the empty reader page into the list around the head.
 	 * Reset the reader page to size zero.
 	 */
+	local_set(&cpu_buffer->reader_page->write, 0);
+	local_set(&cpu_buffer->reader_page->entries, 0);
+	local_set(&cpu_buffer->reader_page->page->commit, 0);
 
-	reader = cpu_buffer->head_page;
+ spin:
+	/*
+	 * Splice the empty reader page into the list around the head.
+	 */
+	reader = rb_set_head_page(cpu_buffer);
 	cpu_buffer->reader_page->list.next = reader->list.next;
 	cpu_buffer->reader_page->list.prev = reader->list.prev;
 
-	local_set(&cpu_buffer->reader_page->write, 0);
-	local_set(&cpu_buffer->reader_page->entries, 0);
-	local_set(&cpu_buffer->reader_page->page->commit, 0);
+	/*
+	 * cpu_buffer->pages just needs to point to the buffer, it
+	 *  has no specific buffer page to point to. Lets move it out
+	 *  of our way so we don't accidently swap it.
+	 */
+	cpu_buffer->pages = reader->list.prev;
 
-	/* Make the reader page now replace the head */
-	reader->list.prev->next = &cpu_buffer->reader_page->list;
-	reader->list.next->prev = &cpu_buffer->reader_page->list;
+	/* The reader page will be pointing to the new head */
+	rb_set_list_to_head(cpu_buffer, &cpu_buffer->reader_page->list);
+
+	/*
+	 * Here's the tricky part.
+	 *
+	 * We need to move the pointer past the header page.
+	 * But we can only do that if a writer is not currently
+	 * moving it. The page before the header page has the
+	 * flag bit '1' set if it is pointing to the page we want.
+	 * but if the writer is in the process of moving it
+	 * than it will be '2' or already moved '0'.
+	 */
+
+	ret = rb_head_page_replace(reader, cpu_buffer->reader_page);
 
 	/*
-	 * If the tail is on the reader, then we must set the head
-	 * to the inserted page, otherwise we set it one before.
+	 * If we did not convert it, then we must try again.
 	 */
-	cpu_buffer->head_page = cpu_buffer->reader_page;
+	if (!ret)
+		goto spin;
 
-	if (cpu_buffer->commit_page != reader)
-		rb_inc_page(cpu_buffer, &cpu_buffer->head_page);
+	/*
+	 * Yeah! We succeeded in replacing the page.
+	 *
+	 * Now make the new head point back to the reader page.
+	 */
+	reader->list.next->prev = &cpu_buffer->reader_page->list;
+	rb_inc_page(cpu_buffer, &cpu_buffer->head_page);
 
 	/* Finally update the reader page to the new head */
 	cpu_buffer->reader_page = reader;
@@ -2717,8 +3324,10 @@ EXPORT_SYMBOL_GPL(ring_buffer_size);
 static void
 rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
 {
+	rb_head_page_deactivate(cpu_buffer);
+
 	cpu_buffer->head_page
-		= list_entry(cpu_buffer->pages.next, struct buffer_page, list);
+		= list_entry(cpu_buffer->pages, struct buffer_page, list);
 	local_set(&cpu_buffer->head_page->write, 0);
 	local_set(&cpu_buffer->head_page->entries, 0);
 	local_set(&cpu_buffer->head_page->page->commit, 0);
@@ -2734,16 +3343,17 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
 	local_set(&cpu_buffer->reader_page->page->commit, 0);
 	cpu_buffer->reader_page->read = 0;
 
-	cpu_buffer->nmi_dropped = 0;
-	cpu_buffer->commit_overrun = 0;
-	cpu_buffer->overrun = 0;
-	cpu_buffer->read = 0;
+	local_set(&cpu_buffer->commit_overrun, 0);
+	local_set(&cpu_buffer->overrun, 0);
 	local_set(&cpu_buffer->entries, 0);
 	local_set(&cpu_buffer->committing, 0);
 	local_set(&cpu_buffer->commits, 0);
+	cpu_buffer->read = 0;
 
 	cpu_buffer->write_stamp = 0;
 	cpu_buffer->read_stamp = 0;
+
+	rb_head_page_activate(cpu_buffer);
 }
 
 /**
@@ -3091,7 +3701,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
 		read = 0;
 	} else {
 		/* update the entry counter */
-		cpu_buffer->read += local_read(&reader->entries);
+		cpu_buffer->read += rb_page_entries(reader);
 
 		/* swap the pages */
 		rb_init_page(bpage);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c22b40f8f576..8ac204360a39 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -50,7 +50,7 @@ unsigned long __read_mostly	tracing_thresh;
  * On boot up, the ring buffer is set to the minimum size, so that
  * we do not waste memory on systems that are not using tracing.
  */
-static int ring_buffer_expanded;
+int ring_buffer_expanded;
 
 /*
  * We need to change this state when a selftest is running.
@@ -64,7 +64,7 @@ static bool __read_mostly tracing_selftest_running;
 /*
  * If a tracer is running, we do not want to run SELFTEST.
  */
-static bool __read_mostly tracing_selftest_disabled;
+bool __read_mostly tracing_selftest_disabled;
 
 /* For tracers that don't implement custom flags */
 static struct tracer_opt dummy_tracer_opt[] = {
@@ -89,7 +89,7 @@ static int dummy_set_flag(u32 old_flags, u32 bit, int set)
  */
 static int tracing_disabled = 1;
 
-static DEFINE_PER_CPU(local_t, ftrace_cpu_disabled);
+DEFINE_PER_CPU(local_t, ftrace_cpu_disabled);
 
 static inline void ftrace_disable_cpu(void)
 {
@@ -867,10 +867,6 @@ struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
 
 	return event;
 }
-static void ftrace_trace_stack(struct trace_array *tr,
-			       unsigned long flags, int skip, int pc);
-static void ftrace_trace_userstack(struct trace_array *tr,
-				   unsigned long flags, int pc);
 
 static inline void __trace_buffer_unlock_commit(struct trace_array *tr,
 					struct ring_buffer_event *event,
@@ -947,54 +943,6 @@ trace_function(struct trace_array *tr,
 		ring_buffer_unlock_commit(tr->buffer, event);
 }
 
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-static int __trace_graph_entry(struct trace_array *tr,
-				struct ftrace_graph_ent *trace,
-				unsigned long flags,
-				int pc)
-{
-	struct ftrace_event_call *call = &event_funcgraph_entry;
-	struct ring_buffer_event *event;
-	struct ftrace_graph_ent_entry *entry;
-
-	if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
-		return 0;
-
-	event = trace_buffer_lock_reserve(&global_trace, TRACE_GRAPH_ENT,
-					  sizeof(*entry), flags, pc);
-	if (!event)
-		return 0;
-	entry	= ring_buffer_event_data(event);
-	entry->graph_ent			= *trace;
-	if (!filter_current_check_discard(call, entry, event))
-		ring_buffer_unlock_commit(global_trace.buffer, event);
-
-	return 1;
-}
-
-static void __trace_graph_return(struct trace_array *tr,
-				struct ftrace_graph_ret *trace,
-				unsigned long flags,
-				int pc)
-{
-	struct ftrace_event_call *call = &event_funcgraph_exit;
-	struct ring_buffer_event *event;
-	struct ftrace_graph_ret_entry *entry;
-
-	if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
-		return;
-
-	event = trace_buffer_lock_reserve(&global_trace, TRACE_GRAPH_RET,
-					  sizeof(*entry), flags, pc);
-	if (!event)
-		return;
-	entry	= ring_buffer_event_data(event);
-	entry->ret				= *trace;
-	if (!filter_current_check_discard(call, entry, event))
-		ring_buffer_unlock_commit(global_trace.buffer, event);
-}
-#endif
-
 void
 ftrace(struct trace_array *tr, struct trace_array_cpu *data,
        unsigned long ip, unsigned long parent_ip, unsigned long flags,
@@ -1004,11 +952,11 @@ ftrace(struct trace_array *tr, struct trace_array_cpu *data,
 		trace_function(tr, ip, parent_ip, flags, pc);
 }
 
+#ifdef CONFIG_STACKTRACE
 static void __ftrace_trace_stack(struct trace_array *tr,
 				 unsigned long flags,
 				 int skip, int pc)
 {
-#ifdef CONFIG_STACKTRACE
 	struct ftrace_event_call *call = &event_kernel_stack;
 	struct ring_buffer_event *event;
 	struct stack_entry *entry;
@@ -1029,12 +977,10 @@ static void __ftrace_trace_stack(struct trace_array *tr,
 	save_stack_trace(&trace);
 	if (!filter_check_discard(call, entry, tr->buffer, event))
 		ring_buffer_unlock_commit(tr->buffer, event);
-#endif
 }
 
-static void ftrace_trace_stack(struct trace_array *tr,
-			       unsigned long flags,
-			       int skip, int pc)
+void ftrace_trace_stack(struct trace_array *tr, unsigned long flags, int skip,
+			int pc)
 {
 	if (!(trace_flags & TRACE_ITER_STACKTRACE))
 		return;
@@ -1042,17 +988,14 @@ static void ftrace_trace_stack(struct trace_array *tr,
 	__ftrace_trace_stack(tr, flags, skip, pc);
 }
 
-void __trace_stack(struct trace_array *tr,
-		   unsigned long flags,
-		   int skip, int pc)
+void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
+		   int pc)
 {
 	__ftrace_trace_stack(tr, flags, skip, pc);
 }
 
-static void ftrace_trace_userstack(struct trace_array *tr,
-				   unsigned long flags, int pc)
+void ftrace_trace_userstack(struct trace_array *tr, unsigned long flags, int pc)
 {
-#ifdef CONFIG_STACKTRACE
 	struct ftrace_event_call *call = &event_user_stack;
 	struct ring_buffer_event *event;
 	struct userstack_entry *entry;
@@ -1077,7 +1020,6 @@ static void ftrace_trace_userstack(struct trace_array *tr,
 	save_stack_trace_user(&trace);
 	if (!filter_check_discard(call, entry, tr->buffer, event))
 		ring_buffer_unlock_commit(tr->buffer, event);
-#endif
 }
 
 #ifdef UNUSED
@@ -1087,6 +1029,8 @@ static void __trace_userstack(struct trace_array *tr, unsigned long flags)
 }
 #endif /* UNUSED */
 
+#endif /* CONFIG_STACKTRACE */
+
 static void
 ftrace_trace_special(void *__tr,
 		     unsigned long arg1, unsigned long arg2, unsigned long arg3,
@@ -1115,62 +1059,6 @@ __trace_special(void *__tr, void *__data,
 }
 
 void
-tracing_sched_switch_trace(struct trace_array *tr,
-			   struct task_struct *prev,
-			   struct task_struct *next,
-			   unsigned long flags, int pc)
-{
-	struct ftrace_event_call *call = &event_context_switch;
-	struct ring_buffer_event *event;
-	struct ctx_switch_entry *entry;
-
-	event = trace_buffer_lock_reserve(tr, TRACE_CTX,
-					  sizeof(*entry), flags, pc);
-	if (!event)
-		return;
-	entry	= ring_buffer_event_data(event);
-	entry->prev_pid			= prev->pid;
-	entry->prev_prio		= prev->prio;
-	entry->prev_state		= prev->state;
-	entry->next_pid			= next->pid;
-	entry->next_prio		= next->prio;
-	entry->next_state		= next->state;
-	entry->next_cpu	= task_cpu(next);
-
-	if (!filter_check_discard(call, entry, tr->buffer, event))
-		trace_buffer_unlock_commit(tr, event, flags, pc);
-}
-
-void
-tracing_sched_wakeup_trace(struct trace_array *tr,
-			   struct task_struct *wakee,
-			   struct task_struct *curr,
-			   unsigned long flags, int pc)
-{
-	struct ftrace_event_call *call = &event_wakeup;
-	struct ring_buffer_event *event;
-	struct ctx_switch_entry *entry;
-
-	event = trace_buffer_lock_reserve(tr, TRACE_WAKE,
-					  sizeof(*entry), flags, pc);
-	if (!event)
-		return;
-	entry	= ring_buffer_event_data(event);
-	entry->prev_pid			= curr->pid;
-	entry->prev_prio		= curr->prio;
-	entry->prev_state		= curr->state;
-	entry->next_pid			= wakee->pid;
-	entry->next_prio		= wakee->prio;
-	entry->next_state		= wakee->state;
-	entry->next_cpu			= task_cpu(wakee);
-
-	if (!filter_check_discard(call, entry, tr->buffer, event))
-		ring_buffer_unlock_commit(tr->buffer, event);
-	ftrace_trace_stack(tr, flags, 6, pc);
-	ftrace_trace_userstack(tr, flags, pc);
-}
-
-void
 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
 {
 	struct trace_array *tr = &global_trace;
@@ -1194,68 +1082,6 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
 	local_irq_restore(flags);
 }
 
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-int trace_graph_entry(struct ftrace_graph_ent *trace)
-{
-	struct trace_array *tr = &global_trace;
-	struct trace_array_cpu *data;
-	unsigned long flags;
-	long disabled;
-	int ret;
-	int cpu;
-	int pc;
-
-	if (!ftrace_trace_task(current))
-		return 0;
-
-	if (!ftrace_graph_addr(trace->func))
-		return 0;
-
-	local_irq_save(flags);
-	cpu = raw_smp_processor_id();
-	data = tr->data[cpu];
-	disabled = atomic_inc_return(&data->disabled);
-	if (likely(disabled == 1)) {
-		pc = preempt_count();
-		ret = __trace_graph_entry(tr, trace, flags, pc);
-	} else {
-		ret = 0;
-	}
-	/* Only do the atomic if it is not already set */
-	if (!test_tsk_trace_graph(current))
-		set_tsk_trace_graph(current);
-
-	atomic_dec(&data->disabled);
-	local_irq_restore(flags);
-
-	return ret;
-}
-
-void trace_graph_return(struct ftrace_graph_ret *trace)
-{
-	struct trace_array *tr = &global_trace;
-	struct trace_array_cpu *data;
-	unsigned long flags;
-	long disabled;
-	int cpu;
-	int pc;
-
-	local_irq_save(flags);
-	cpu = raw_smp_processor_id();
-	data = tr->data[cpu];
-	disabled = atomic_inc_return(&data->disabled);
-	if (likely(disabled == 1)) {
-		pc = preempt_count();
-		__trace_graph_return(tr, trace, flags, pc);
-	}
-	if (!trace->depth)
-		clear_tsk_trace_graph(current);
-	atomic_dec(&data->disabled);
-	local_irq_restore(flags);
-}
-#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
-
-
 /**
  * trace_vbprintk - write binary msg to tracing buffer
  *
@@ -2257,8 +2083,8 @@ tracing_trace_options_read(struct file *filp, char __user *ubuf,
 		len += 3; /* "no" and newline */
 	}
 
-	/* +2 for \n and \0 */
-	buf = kmalloc(len + 2, GFP_KERNEL);
+	/* +1 for \0 */
+	buf = kmalloc(len + 1, GFP_KERNEL);
 	if (!buf) {
 		mutex_unlock(&trace_types_lock);
 		return -ENOMEM;
@@ -2281,7 +2107,7 @@ tracing_trace_options_read(struct file *filp, char __user *ubuf,
 	}
 	mutex_unlock(&trace_types_lock);
 
-	WARN_ON(r >= len + 2);
+	WARN_ON(r >= len + 1);
 
 	r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 
@@ -2292,23 +2118,23 @@ tracing_trace_options_read(struct file *filp, char __user *ubuf,
 /* Try to assign a tracer specific option */
 static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
 {
-	struct tracer_flags *trace_flags = trace->flags;
+	struct tracer_flags *tracer_flags = trace->flags;
 	struct tracer_opt *opts = NULL;
 	int ret = 0, i = 0;
 	int len;
 
-	for (i = 0; trace_flags->opts[i].name; i++) {
-		opts = &trace_flags->opts[i];
+	for (i = 0; tracer_flags->opts[i].name; i++) {
+		opts = &tracer_flags->opts[i];
 		len = strlen(opts->name);
 
 		if (strncmp(cmp, opts->name, len) == 0) {
-			ret = trace->set_flag(trace_flags->val,
+			ret = trace->set_flag(tracer_flags->val,
 				opts->bit, !neg);
 			break;
 		}
 	}
 	/* Not found */
-	if (!trace_flags->opts[i].name)
+	if (!tracer_flags->opts[i].name)
 		return -EINVAL;
 
 	/* Refused to handle */
@@ -2316,9 +2142,9 @@ static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
 		return ret;
 
 	if (neg)
-		trace_flags->val &= ~opts->bit;
+		tracer_flags->val &= ~opts->bit;
 	else
-		trace_flags->val |= opts->bit;
+		tracer_flags->val |= opts->bit;
 
 	return 0;
 }
@@ -3633,9 +3459,6 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
 	cnt = ring_buffer_commit_overrun_cpu(tr->buffer, cpu);
 	trace_seq_printf(s, "commit overrun: %ld\n", cnt);
 
-	cnt = ring_buffer_nmi_dropped_cpu(tr->buffer, cpu);
-	trace_seq_printf(s, "nmi dropped: %ld\n", cnt);
-
 	count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len);
 
 	kfree(s);
@@ -4273,7 +4096,6 @@ void ftrace_dump(void)
 
 __init static int tracer_alloc_buffers(void)
 {
-	struct trace_array_cpu *data;
 	int ring_buf_size;
 	int i;
 	int ret = -ENOMEM;
@@ -4323,7 +4145,7 @@ __init static int tracer_alloc_buffers(void)
 
 	/* Allocate the first page for all buffers */
 	for_each_tracing_cpu(i) {
-		data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
+		global_trace.data[i] = &per_cpu(global_trace_cpu, i);
 		max_tr.data[i] = &per_cpu(max_data, i);
 	}
 
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 8b9f4f6e9559..300ef788c976 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -34,8 +34,6 @@ enum trace_type {
 	TRACE_GRAPH_ENT,
 	TRACE_USER_STACK,
 	TRACE_HW_BRANCHES,
-	TRACE_SYSCALL_ENTER,
-	TRACE_SYSCALL_EXIT,
 	TRACE_KMEM_ALLOC,
 	TRACE_KMEM_FREE,
 	TRACE_POWER,
@@ -319,10 +317,6 @@ extern void __ftrace_bad_type(void);
 			  TRACE_KMEM_ALLOC);	\
 		IF_ASSIGN(var, ent, struct kmemtrace_free_entry,	\
 			  TRACE_KMEM_FREE);	\
-		IF_ASSIGN(var, ent, struct syscall_trace_enter,		\
-			  TRACE_SYSCALL_ENTER);				\
-		IF_ASSIGN(var, ent, struct syscall_trace_exit,		\
-			  TRACE_SYSCALL_EXIT);				\
 		__ftrace_bad_type();					\
 	} while (0)
 
@@ -467,6 +461,7 @@ void trace_function(struct trace_array *tr,
 
 void trace_graph_return(struct ftrace_graph_ret *trace);
 int trace_graph_entry(struct ftrace_graph_ent *trace);
+void set_graph_array(struct trace_array *tr);
 
 void tracing_start_cmdline_record(void);
 void tracing_stop_cmdline_record(void);
@@ -485,9 +480,31 @@ void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 void update_max_tr_single(struct trace_array *tr,
 			  struct task_struct *tsk, int cpu);
 
-void __trace_stack(struct trace_array *tr,
-		   unsigned long flags,
-		   int skip, int pc);
+#ifdef CONFIG_STACKTRACE
+void ftrace_trace_stack(struct trace_array *tr, unsigned long flags,
+			int skip, int pc);
+
+void ftrace_trace_userstack(struct trace_array *tr, unsigned long flags,
+			    int pc);
+
+void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
+		   int pc);
+#else
+static inline void ftrace_trace_stack(struct trace_array *tr,
+				      unsigned long flags, int skip, int pc)
+{
+}
+
+static inline void ftrace_trace_userstack(struct trace_array *tr,
+					  unsigned long flags, int pc)
+{
+}
+
+static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
+				 int skip, int pc)
+{
+}
+#endif /* CONFIG_STACKTRACE */
 
 extern cycle_t ftrace_now(int cpu);
 
@@ -513,6 +530,10 @@ extern unsigned long ftrace_update_tot_cnt;
 extern int DYN_FTRACE_TEST_NAME(void);
 #endif
 
+extern int ring_buffer_expanded;
+extern bool tracing_selftest_disabled;
+DECLARE_PER_CPU(local_t, ftrace_cpu_disabled);
+
 #ifdef CONFIG_FTRACE_STARTUP_TEST
 extern int trace_selftest_startup_function(struct tracer *trace,
 					   struct trace_array *tr);
@@ -743,13 +764,15 @@ struct event_filter {
 	int			n_preds;
 	struct filter_pred	**preds;
 	char			*filter_string;
+	bool			no_reset;
 };
 
 struct event_subsystem {
 	struct list_head	list;
 	const char		*name;
 	struct dentry		*entry;
-	void			*filter;
+	struct event_filter	*filter;
+	int			nr_events;
 };
 
 struct filter_pred;
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index e75276a49cf5..b568ade8f453 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -17,6 +17,8 @@
 #include <linux/ctype.h>
 #include <linux/delay.h>
 
+#include <asm/setup.h>
+
 #include "trace_output.h"
 
 #define TRACE_SYSTEM "TRACE_SYSTEM"
@@ -84,14 +86,14 @@ static void ftrace_event_enable_disable(struct ftrace_event_call *call,
 		if (call->enabled) {
 			call->enabled = 0;
 			tracing_stop_cmdline_record();
-			call->unregfunc();
+			call->unregfunc(call->data);
 		}
 		break;
 	case 1:
 		if (!call->enabled) {
 			call->enabled = 1;
 			tracing_start_cmdline_record();
-			call->regfunc();
+			call->regfunc(call->data);
 		}
 		break;
 	}
@@ -574,7 +576,7 @@ event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
 	trace_seq_printf(s, "format:\n");
 	trace_write_header(s);
 
-	r = call->show_format(s);
+	r = call->show_format(call, s);
 	if (!r) {
 		/*
 		 * ug!  The format output is bigger than a PAGE!!
@@ -849,8 +851,10 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
 
 	/* First see if we did not already create this dir */
 	list_for_each_entry(system, &event_subsystems, list) {
-		if (strcmp(system->name, name) == 0)
+		if (strcmp(system->name, name) == 0) {
+			system->nr_events++;
 			return system->entry;
+		}
 	}
 
 	/* need to create new entry */
@@ -869,6 +873,7 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
 		return d_events;
 	}
 
+	system->nr_events = 1;
 	system->name = kstrdup(name, GFP_KERNEL);
 	if (!system->name) {
 		debugfs_remove(system->entry);
@@ -920,15 +925,6 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
 	if (strcmp(call->system, TRACE_SYSTEM) != 0)
 		d_events = event_subsystem_dir(call->system, d_events);
 
-	if (call->raw_init) {
-		ret = call->raw_init();
-		if (ret < 0) {
-			pr_warning("Could not initialize trace point"
-				   " events/%s\n", call->name);
-			return ret;
-		}
-	}
-
 	call->dir = debugfs_create_dir(call->name, d_events);
 	if (!call->dir) {
 		pr_warning("Could not create debugfs "
@@ -987,6 +983,32 @@ struct ftrace_module_file_ops {
 	struct file_operations		filter;
 };
 
+static void remove_subsystem_dir(const char *name)
+{
+	struct event_subsystem *system;
+
+	if (strcmp(name, TRACE_SYSTEM) == 0)
+		return;
+
+	list_for_each_entry(system, &event_subsystems, list) {
+		if (strcmp(system->name, name) == 0) {
+			if (!--system->nr_events) {
+				struct event_filter *filter = system->filter;
+
+				debugfs_remove_recursive(system->entry);
+				list_del(&system->list);
+				if (filter) {
+					kfree(filter->filter_string);
+					kfree(filter);
+				}
+				kfree(system->name);
+				kfree(system);
+			}
+			break;
+		}
+	}
+}
+
 static struct ftrace_module_file_ops *
 trace_create_file_ops(struct module *mod)
 {
@@ -1027,6 +1049,7 @@ static void trace_module_add_events(struct module *mod)
 	struct ftrace_module_file_ops *file_ops = NULL;
 	struct ftrace_event_call *call, *start, *end;
 	struct dentry *d_events;
+	int ret;
 
 	start = mod->trace_events;
 	end = mod->trace_events + mod->num_trace_events;
@@ -1042,7 +1065,15 @@ static void trace_module_add_events(struct module *mod)
 		/* The linker may leave blanks */
 		if (!call->name)
 			continue;
-
+		if (call->raw_init) {
+			ret = call->raw_init();
+			if (ret < 0) {
+				if (ret != -ENOSYS)
+					pr_warning("Could not initialize trace "
+					"point events/%s\n", call->name);
+				continue;
+			}
+		}
 		/*
 		 * This module has events, create file ops for this module
 		 * if not already done.
@@ -1077,6 +1108,7 @@ static void trace_module_remove_events(struct module *mod)
 			list_del(&call->list);
 			trace_destroy_fields(call);
 			destroy_preds(call);
+			remove_subsystem_dir(call->system);
 		}
 	}
 
@@ -1133,6 +1165,18 @@ struct notifier_block trace_module_nb = {
 extern struct ftrace_event_call __start_ftrace_events[];
 extern struct ftrace_event_call __stop_ftrace_events[];
 
+static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
+
+static __init int setup_trace_event(char *str)
+{
+	strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
+	ring_buffer_expanded = 1;
+	tracing_selftest_disabled = 1;
+
+	return 1;
+}
+__setup("trace_event=", setup_trace_event);
+
 static __init int event_trace_init(void)
 {
 	struct ftrace_event_call *call;
@@ -1140,6 +1184,8 @@ static __init int event_trace_init(void)
 	struct dentry *entry;
 	struct dentry *d_events;
 	int ret;
+	char *buf = bootup_event_buf;
+	char *token;
 
 	d_tracer = tracing_init_dentry();
 	if (!d_tracer)
@@ -1179,12 +1225,34 @@ static __init int event_trace_init(void)
 		/* The linker may leave blanks */
 		if (!call->name)
 			continue;
+		if (call->raw_init) {
+			ret = call->raw_init();
+			if (ret < 0) {
+				if (ret != -ENOSYS)
+					pr_warning("Could not initialize trace "
+					"point events/%s\n", call->name);
+				continue;
+			}
+		}
 		list_add(&call->list, &ftrace_events);
 		event_create_dir(call, d_events, &ftrace_event_id_fops,
 				 &ftrace_enable_fops, &ftrace_event_filter_fops,
 				 &ftrace_event_format_fops);
 	}
 
+	while (true) {
+		token = strsep(&buf, ",");
+
+		if (!token)
+			break;
+		if (!*token)
+			continue;
+
+		ret = ftrace_set_clr_event(token, 1);
+		if (ret)
+			pr_warning("Failed to enable trace event: %s\n", token);
+	}
+
 	ret = register_module_notifier(&trace_module_nb);
 	if (ret)
 		pr_warning("Failed to register trace events module notifier\n");
@@ -1392,10 +1460,10 @@ static __init void event_trace_self_test_with_function(void)
 
 static __init int event_trace_self_tests_init(void)
 {
-
-	event_trace_self_tests();
-
-	event_trace_self_test_with_function();
+	if (!tracing_selftest_disabled) {
+		event_trace_self_tests();
+		event_trace_self_test_with_function();
+	}
 
 	return 0;
 }
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index f32dc9d1ea7b..490337abed75 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -176,11 +176,13 @@ static int filter_pred_string(struct filter_pred *pred, void *event,
 static int filter_pred_strloc(struct filter_pred *pred, void *event,
 			      int val1, int val2)
 {
-	unsigned short str_loc = *(unsigned short *)(event + pred->offset);
+	u32 str_item = *(u32 *)(event + pred->offset);
+	int str_loc = str_item & 0xffff;
+	int str_len = str_item >> 16;
 	char *addr = (char *)(event + str_loc);
 	int cmp, match;
 
-	cmp = strncmp(addr, pred->str_val, pred->str_len);
+	cmp = strncmp(addr, pred->str_val, str_len);
 
 	match = (!cmp) ^ pred->not;
 
@@ -418,24 +420,29 @@ oom:
 }
 EXPORT_SYMBOL_GPL(init_preds);
 
-static void filter_free_subsystem_preds(struct event_subsystem *system)
+enum {
+	FILTER_DISABLE_ALL,
+	FILTER_INIT_NO_RESET,
+	FILTER_SKIP_NO_RESET,
+};
+
+static void filter_free_subsystem_preds(struct event_subsystem *system,
+					int flag)
 {
-	struct event_filter *filter = system->filter;
 	struct ftrace_event_call *call;
-	int i;
-
-	if (filter->n_preds) {
-		for (i = 0; i < filter->n_preds; i++)
-			filter_free_pred(filter->preds[i]);
-		kfree(filter->preds);
-		filter->preds = NULL;
-		filter->n_preds = 0;
-	}
 
 	list_for_each_entry(call, &ftrace_events, list) {
 		if (!call->define_fields)
 			continue;
 
+		if (flag == FILTER_INIT_NO_RESET) {
+			call->filter->no_reset = false;
+			continue;
+		}
+
+		if (flag == FILTER_SKIP_NO_RESET && call->filter->no_reset)
+			continue;
+
 		if (!strcmp(call->system, system->name)) {
 			filter_disable_preds(call);
 			remove_filter_string(call->filter);
@@ -537,7 +544,8 @@ static filter_pred_fn_t select_comparison_fn(int op, int field_size,
 
 static int filter_add_pred(struct filter_parse_state *ps,
 			   struct ftrace_event_call *call,
-			   struct filter_pred *pred)
+			   struct filter_pred *pred,
+			   bool dry_run)
 {
 	struct ftrace_event_field *field;
 	filter_pred_fn_t fn;
@@ -549,10 +557,12 @@ static int filter_add_pred(struct filter_parse_state *ps,
 
 	if (pred->op == OP_AND) {
 		pred->pop_n = 2;
-		return filter_add_pred_fn(ps, call, pred, filter_pred_and);
+		fn = filter_pred_and;
+		goto add_pred_fn;
 	} else if (pred->op == OP_OR) {
 		pred->pop_n = 2;
-		return filter_add_pred_fn(ps, call, pred, filter_pred_or);
+		fn = filter_pred_or;
+		goto add_pred_fn;
 	}
 
 	field = find_event_field(call, pred->field_name);
@@ -575,9 +585,6 @@ static int filter_add_pred(struct filter_parse_state *ps,
 		else
 			fn = filter_pred_strloc;
 		pred->str_len = field->size;
-		if (pred->op == OP_NE)
-			pred->not = 1;
-		return filter_add_pred_fn(ps, call, pred, fn);
 	} else {
 		if (field->is_signed)
 			ret = strict_strtoll(pred->str_val, 0, &val);
@@ -588,41 +595,33 @@ static int filter_add_pred(struct filter_parse_state *ps,
 			return -EINVAL;
 		}
 		pred->val = val;
-	}
 
-	fn = select_comparison_fn(pred->op, field->size, field->is_signed);
-	if (!fn) {
-		parse_error(ps, FILT_ERR_INVALID_OP, 0);
-		return -EINVAL;
+		fn = select_comparison_fn(pred->op, field->size,
+					  field->is_signed);
+		if (!fn) {
+			parse_error(ps, FILT_ERR_INVALID_OP, 0);
+			return -EINVAL;
+		}
 	}
 
 	if (pred->op == OP_NE)
 		pred->not = 1;
 
-	return filter_add_pred_fn(ps, call, pred, fn);
+add_pred_fn:
+	if (!dry_run)
+		return filter_add_pred_fn(ps, call, pred, fn);
+	return 0;
 }
 
 static int filter_add_subsystem_pred(struct filter_parse_state *ps,
 				     struct event_subsystem *system,
 				     struct filter_pred *pred,
-				     char *filter_string)
+				     char *filter_string,
+				     bool dry_run)
 {
-	struct event_filter *filter = system->filter;
 	struct ftrace_event_call *call;
 	int err = 0;
-
-	if (!filter->preds) {
-		filter->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred),
-					GFP_KERNEL);
-
-		if (!filter->preds)
-			return -ENOMEM;
-	}
-
-	if (filter->n_preds == MAX_FILTER_PRED) {
-		parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
-		return -ENOSPC;
-	}
+	bool fail = true;
 
 	list_for_each_entry(call, &ftrace_events, list) {
 
@@ -632,19 +631,24 @@ static int filter_add_subsystem_pred(struct filter_parse_state *ps,
 		if (strcmp(call->system, system->name))
 			continue;
 
-		err = filter_add_pred(ps, call, pred);
-		if (err) {
-			filter_free_subsystem_preds(system);
-			parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
-			goto out;
-		}
-		replace_filter_string(call->filter, filter_string);
+		if (call->filter->no_reset)
+			continue;
+
+		err = filter_add_pred(ps, call, pred, dry_run);
+		if (err)
+			call->filter->no_reset = true;
+		else
+			fail = false;
+
+		if (!dry_run)
+			replace_filter_string(call->filter, filter_string);
 	}
 
-	filter->preds[filter->n_preds] = pred;
-	filter->n_preds++;
-out:
-	return err;
+	if (fail) {
+		parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
+		return err;
+	}
+	return 0;
 }
 
 static void parse_init(struct filter_parse_state *ps,
@@ -1003,12 +1007,14 @@ static int check_preds(struct filter_parse_state *ps)
 static int replace_preds(struct event_subsystem *system,
 			 struct ftrace_event_call *call,
 			 struct filter_parse_state *ps,
-			 char *filter_string)
+			 char *filter_string,
+			 bool dry_run)
 {
 	char *operand1 = NULL, *operand2 = NULL;
 	struct filter_pred *pred;
 	struct postfix_elt *elt;
 	int err;
+	int n_preds = 0;
 
 	err = check_preds(ps);
 	if (err)
@@ -1027,24 +1033,14 @@ static int replace_preds(struct event_subsystem *system,
 			continue;
 		}
 
+		if (n_preds++ == MAX_FILTER_PRED) {
+			parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
+			return -ENOSPC;
+		}
+
 		if (elt->op == OP_AND || elt->op == OP_OR) {
 			pred = create_logical_pred(elt->op);
-			if (!pred)
-				return -ENOMEM;
-			if (call) {
-				err = filter_add_pred(ps, call, pred);
-				filter_free_pred(pred);
-			} else {
-				err = filter_add_subsystem_pred(ps, system,
-							pred, filter_string);
-				if (err)
-					filter_free_pred(pred);
-			}
-			if (err)
-				return err;
-
-			operand1 = operand2 = NULL;
-			continue;
+			goto add_pred;
 		}
 
 		if (!operand1 || !operand2) {
@@ -1053,17 +1049,15 @@ static int replace_preds(struct event_subsystem *system,
 		}
 
 		pred = create_pred(elt->op, operand1, operand2);
+add_pred:
 		if (!pred)
 			return -ENOMEM;
-		if (call) {
-			err = filter_add_pred(ps, call, pred);
-			filter_free_pred(pred);
-		} else {
+		if (call)
+			err = filter_add_pred(ps, call, pred, false);
+		else
 			err = filter_add_subsystem_pred(ps, system, pred,
-							filter_string);
-			if (err)
-				filter_free_pred(pred);
-		}
+						filter_string, dry_run);
+		filter_free_pred(pred);
 		if (err)
 			return err;
 
@@ -1103,7 +1097,7 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
 		goto out;
 	}
 
-	err = replace_preds(NULL, call, ps, filter_string);
+	err = replace_preds(NULL, call, ps, filter_string, false);
 	if (err)
 		append_filter_err(ps, call->filter);
 
@@ -1127,7 +1121,7 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
 	mutex_lock(&event_mutex);
 
 	if (!strcmp(strstrip(filter_string), "0")) {
-		filter_free_subsystem_preds(system);
+		filter_free_subsystem_preds(system, FILTER_DISABLE_ALL);
 		remove_filter_string(system->filter);
 		mutex_unlock(&event_mutex);
 		return 0;
@@ -1138,7 +1132,6 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
 	if (!ps)
 		goto out_unlock;
 
-	filter_free_subsystem_preds(system);
 	replace_filter_string(system->filter, filter_string);
 
 	parse_init(ps, filter_ops, filter_string);
@@ -1148,9 +1141,23 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
 		goto out;
 	}
 
-	err = replace_preds(system, NULL, ps, filter_string);
-	if (err)
+	filter_free_subsystem_preds(system, FILTER_INIT_NO_RESET);
+
+	/* try to see the filter can be applied to which events */
+	err = replace_preds(system, NULL, ps, filter_string, true);
+	if (err) {
 		append_filter_err(ps, system->filter);
+		goto out;
+	}
+
+	filter_free_subsystem_preds(system, FILTER_SKIP_NO_RESET);
+
+	/* really apply the filter to the events */
+	err = replace_preds(system, NULL, ps, filter_string, false);
+	if (err) {
+		append_filter_err(ps, system->filter);
+		filter_free_subsystem_preds(system, 2);
+	}
 
 out:
 	filter_opstack_clear(ps);
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index d06cf898dc86..956d4bc675e5 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -60,7 +60,8 @@ extern void __bad_type_size(void);
 #undef TRACE_EVENT_FORMAT
 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)	\
 static int								\
-ftrace_format_##call(struct trace_seq *s)				\
+ftrace_format_##call(struct ftrace_event_call *unused,			\
+		      struct trace_seq *s)				\
 {									\
 	struct args field;						\
 	int ret;							\
@@ -76,7 +77,8 @@ ftrace_format_##call(struct trace_seq *s)				\
 #define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct,	\
 				    tpfmt)				\
 static int								\
-ftrace_format_##call(struct trace_seq *s)				\
+ftrace_format_##call(struct ftrace_event_call *unused,			\
+		      struct trace_seq *s)				\
 {									\
 	struct args field;						\
 	int ret;							\
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 75ef000613c3..5b01b94518fc 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -288,11 +288,9 @@ static int
 ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
 			 struct ftrace_probe_ops *ops, void *data)
 {
-	char str[KSYM_SYMBOL_LEN];
 	long count = (long)data;
 
-	kallsyms_lookup(ip, NULL, NULL, NULL, str);
-	seq_printf(m, "%s:", str);
+	seq_printf(m, "%pf:", (void *)ip);
 
 	if (ops == &traceon_probe_ops)
 		seq_printf(m, "traceon");
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 420ec3487579..3f4a251b7d16 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -52,7 +52,7 @@ static struct tracer_flags tracer_flags = {
 	.opts = trace_opts
 };
 
-/* pid on the last trace processed */
+static struct trace_array *graph_array;
 
 
 /* Add a function return address to the trace stack on thread info.*/
@@ -166,10 +166,121 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
 	return ret;
 }
 
+static int __trace_graph_entry(struct trace_array *tr,
+				struct ftrace_graph_ent *trace,
+				unsigned long flags,
+				int pc)
+{
+	struct ftrace_event_call *call = &event_funcgraph_entry;
+	struct ring_buffer_event *event;
+	struct ftrace_graph_ent_entry *entry;
+
+	if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+		return 0;
+
+	event = trace_buffer_lock_reserve(tr, TRACE_GRAPH_ENT,
+					  sizeof(*entry), flags, pc);
+	if (!event)
+		return 0;
+	entry	= ring_buffer_event_data(event);
+	entry->graph_ent			= *trace;
+	if (!filter_current_check_discard(call, entry, event))
+		ring_buffer_unlock_commit(tr->buffer, event);
+
+	return 1;
+}
+
+int trace_graph_entry(struct ftrace_graph_ent *trace)
+{
+	struct trace_array *tr = graph_array;
+	struct trace_array_cpu *data;
+	unsigned long flags;
+	long disabled;
+	int ret;
+	int cpu;
+	int pc;
+
+	if (unlikely(!tr))
+		return 0;
+
+	if (!ftrace_trace_task(current))
+		return 0;
+
+	if (!ftrace_graph_addr(trace->func))
+		return 0;
+
+	local_irq_save(flags);
+	cpu = raw_smp_processor_id();
+	data = tr->data[cpu];
+	disabled = atomic_inc_return(&data->disabled);
+	if (likely(disabled == 1)) {
+		pc = preempt_count();
+		ret = __trace_graph_entry(tr, trace, flags, pc);
+	} else {
+		ret = 0;
+	}
+	/* Only do the atomic if it is not already set */
+	if (!test_tsk_trace_graph(current))
+		set_tsk_trace_graph(current);
+
+	atomic_dec(&data->disabled);
+	local_irq_restore(flags);
+
+	return ret;
+}
+
+static void __trace_graph_return(struct trace_array *tr,
+				struct ftrace_graph_ret *trace,
+				unsigned long flags,
+				int pc)
+{
+	struct ftrace_event_call *call = &event_funcgraph_exit;
+	struct ring_buffer_event *event;
+	struct ftrace_graph_ret_entry *entry;
+
+	if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+		return;
+
+	event = trace_buffer_lock_reserve(tr, TRACE_GRAPH_RET,
+					  sizeof(*entry), flags, pc);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	entry->ret				= *trace;
+	if (!filter_current_check_discard(call, entry, event))
+		ring_buffer_unlock_commit(tr->buffer, event);
+}
+
+void trace_graph_return(struct ftrace_graph_ret *trace)
+{
+	struct trace_array *tr = graph_array;
+	struct trace_array_cpu *data;
+	unsigned long flags;
+	long disabled;
+	int cpu;
+	int pc;
+
+	local_irq_save(flags);
+	cpu = raw_smp_processor_id();
+	data = tr->data[cpu];
+	disabled = atomic_inc_return(&data->disabled);
+	if (likely(disabled == 1)) {
+		pc = preempt_count();
+		__trace_graph_return(tr, trace, flags, pc);
+	}
+	if (!trace->depth)
+		clear_tsk_trace_graph(current);
+	atomic_dec(&data->disabled);
+	local_irq_restore(flags);
+}
+
 static int graph_trace_init(struct trace_array *tr)
 {
-	int ret = register_ftrace_graph(&trace_graph_return,
-					&trace_graph_entry);
+	int ret;
+
+	graph_array = tr;
+	ret = register_ftrace_graph(&trace_graph_return,
+				    &trace_graph_entry);
 	if (ret)
 		return ret;
 	tracing_start_cmdline_record();
@@ -177,49 +288,30 @@ static int graph_trace_init(struct trace_array *tr)
 	return 0;
 }
 
+void set_graph_array(struct trace_array *tr)
+{
+	graph_array = tr;
+}
+
 static void graph_trace_reset(struct trace_array *tr)
 {
 	tracing_stop_cmdline_record();
 	unregister_ftrace_graph();
 }
 
-static inline int log10_cpu(int nb)
-{
-	if (nb / 100)
-		return 3;
-	if (nb / 10)
-		return 2;
-	return 1;
-}
+static int max_bytes_for_cpu;
 
 static enum print_line_t
 print_graph_cpu(struct trace_seq *s, int cpu)
 {
-	int i;
 	int ret;
-	int log10_this = log10_cpu(cpu);
-	int log10_all = log10_cpu(cpumask_weight(cpu_online_mask));
-
 
 	/*
 	 * Start with a space character - to make it stand out
 	 * to the right a bit when trace output is pasted into
 	 * email:
 	 */
-	ret = trace_seq_printf(s, " ");
-
-	/*
-	 * Tricky - we space the CPU field according to the max
-	 * number of online CPUs. On a 2-cpu system it would take
-	 * a maximum of 1 digit - on a 128 cpu system it would
-	 * take up to 3 digits:
-	 */
-	for (i = 0; i < log10_all - log10_this; i++) {
-		ret = trace_seq_printf(s, " ");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
-	ret = trace_seq_printf(s, "%d) ", cpu);
+	ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
@@ -565,11 +657,7 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
 
-	ret = seq_print_ip_sym(s, call->func, 0);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	ret = trace_seq_printf(s, "();\n");
+	ret = trace_seq_printf(s, "%pf();\n", (void *)call->func);
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
@@ -612,11 +700,7 @@ print_graph_entry_nested(struct trace_iterator *iter,
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
 
-	ret = seq_print_ip_sym(s, call->func, 0);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	ret = trace_seq_printf(s, "() {\n");
+	ret = trace_seq_printf(s, "%pf() {\n", (void *)call->func);
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
@@ -934,6 +1018,8 @@ static struct tracer graph_trace __read_mostly = {
 
 static __init int init_graph_trace(void)
 {
+	max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
+
 	return register_tracer(&graph_trace);
 }
 
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index a98106dd979c..e1285d7b5488 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -20,6 +20,34 @@ static int			sched_ref;
 static DEFINE_MUTEX(sched_register_mutex);
 static int			sched_stopped;
 
+
+void
+tracing_sched_switch_trace(struct trace_array *tr,
+			   struct task_struct *prev,
+			   struct task_struct *next,
+			   unsigned long flags, int pc)
+{
+	struct ftrace_event_call *call = &event_context_switch;
+	struct ring_buffer_event *event;
+	struct ctx_switch_entry *entry;
+
+	event = trace_buffer_lock_reserve(tr, TRACE_CTX,
+					  sizeof(*entry), flags, pc);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	entry->prev_pid			= prev->pid;
+	entry->prev_prio		= prev->prio;
+	entry->prev_state		= prev->state;
+	entry->next_pid			= next->pid;
+	entry->next_prio		= next->prio;
+	entry->next_state		= next->state;
+	entry->next_cpu	= task_cpu(next);
+
+	if (!filter_check_discard(call, entry, tr->buffer, event))
+		trace_buffer_unlock_commit(tr, event, flags, pc);
+}
+
 static void
 probe_sched_switch(struct rq *__rq, struct task_struct *prev,
 			struct task_struct *next)
@@ -49,6 +77,35 @@ probe_sched_switch(struct rq *__rq, struct task_struct *prev,
 	local_irq_restore(flags);
 }
 
+void
+tracing_sched_wakeup_trace(struct trace_array *tr,
+			   struct task_struct *wakee,
+			   struct task_struct *curr,
+			   unsigned long flags, int pc)
+{
+	struct ftrace_event_call *call = &event_wakeup;
+	struct ring_buffer_event *event;
+	struct ctx_switch_entry *entry;
+
+	event = trace_buffer_lock_reserve(tr, TRACE_WAKE,
+					  sizeof(*entry), flags, pc);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	entry->prev_pid			= curr->pid;
+	entry->prev_prio		= curr->prio;
+	entry->prev_state		= curr->state;
+	entry->next_pid			= wakee->pid;
+	entry->next_prio		= wakee->prio;
+	entry->next_state		= wakee->state;
+	entry->next_cpu			= task_cpu(wakee);
+
+	if (!filter_check_discard(call, entry, tr->buffer, event))
+		ring_buffer_unlock_commit(tr->buffer, event);
+	ftrace_trace_stack(tr, flags, 6, pc);
+	ftrace_trace_userstack(tr, flags, pc);
+}
+
 static void
 probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee, int success)
 {
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 00dd6485bdd7..d2cdbabb4ead 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -288,6 +288,7 @@ trace_selftest_startup_function_graph(struct tracer *trace,
 	 * to detect and recover from possible hangs
 	 */
 	tracing_reset_online_cpus(tr);
+	set_graph_array(tr);
 	ret = register_ftrace_graph(&trace_graph_return,
 				    &trace_graph_entry_watchdog);
 	if (ret) {
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 6a2a9d484cd6..0f6facb050a1 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -186,43 +186,33 @@ static const struct file_operations stack_max_size_fops = {
 };
 
 static void *
-t_next(struct seq_file *m, void *v, loff_t *pos)
+__next(struct seq_file *m, loff_t *pos)
 {
-	long i;
+	long n = *pos - 1;
 
-	(*pos)++;
-
-	if (v == SEQ_START_TOKEN)
-		i = 0;
-	else {
-		i = *(long *)v;
-		i++;
-	}
-
-	if (i >= max_stack_trace.nr_entries ||
-	    stack_dump_trace[i] == ULONG_MAX)
+	if (n >= max_stack_trace.nr_entries || stack_dump_trace[n] == ULONG_MAX)
 		return NULL;
 
-	m->private = (void *)i;
-
+	m->private = (void *)n;
 	return &m->private;
 }
 
-static void *t_start(struct seq_file *m, loff_t *pos)
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
 {
-	void *t = SEQ_START_TOKEN;
-	loff_t l = 0;
+	(*pos)++;
+	return __next(m, pos);
+}
 
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
 	local_irq_disable();
 	__raw_spin_lock(&max_stack_lock);
 
 	if (*pos == 0)
 		return SEQ_START_TOKEN;
 
-	for (; t && l < *pos; t = t_next(m, t, &l))
-		;
-
-	return t;
+	return __next(m, pos);
 }
 
 static void t_stop(struct seq_file *m, void *p)
@@ -234,15 +224,8 @@ static void t_stop(struct seq_file *m, void *p)
 static int trace_lookup_stack(struct seq_file *m, long i)
 {
 	unsigned long addr = stack_dump_trace[i];
-#ifdef CONFIG_KALLSYMS
-	char str[KSYM_SYMBOL_LEN];
-
-	sprint_symbol(str, addr);
 
-	return seq_printf(m, "%s\n", str);
-#else
-	return seq_printf(m, "%p\n", (void*)addr);
-#endif
+	return seq_printf(m, "%pF\n", (void *)addr);
 }
 
 static void print_disabled(struct seq_file *m)
diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c
index aea321c82fa0..a4bb239eb987 100644
--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -49,7 +49,8 @@ static struct dentry		*stat_dir;
  * but it will at least advance closer to the next one
  * to be released.
  */
-static struct rb_node *release_next(struct rb_node *node)
+static struct rb_node *release_next(struct tracer_stat *ts,
+				    struct rb_node *node)
 {
 	struct stat_node *snode;
 	struct rb_node *parent = rb_parent(node);
@@ -67,6 +68,8 @@ static struct rb_node *release_next(struct rb_node *node)
 			parent->rb_right = NULL;
 
 		snode = container_of(node, struct stat_node, node);
+		if (ts->stat_release)
+			ts->stat_release(snode->stat);
 		kfree(snode);
 
 		return parent;
@@ -78,7 +81,7 @@ static void __reset_stat_session(struct stat_session *session)
 	struct rb_node *node = session->stat_root.rb_node;
 
 	while (node)
-		node = release_next(node);
+		node = release_next(session->ts, node);
 
 	session->stat_root = RB_ROOT;
 }
@@ -200,17 +203,21 @@ static void *stat_seq_start(struct seq_file *s, loff_t *pos)
 {
 	struct stat_session *session = s->private;
 	struct rb_node *node;
+	int n = *pos;
 	int i;
 
 	/* Prevent from tracer switch or rbtree modification */
 	mutex_lock(&session->stat_mutex);
 
 	/* If we are in the beginning of the file, print the headers */
-	if (!*pos && session->ts->stat_headers)
-		return SEQ_START_TOKEN;
+	if (session->ts->stat_headers) {
+		if (n == 0)
+			return SEQ_START_TOKEN;
+		n--;
+	}
 
 	node = rb_first(&session->stat_root);
-	for (i = 0; node && i < *pos; i++)
+	for (i = 0; node && i < n; i++)
 		node = rb_next(node);
 
 	return node;
diff --git a/kernel/trace/trace_stat.h b/kernel/trace/trace_stat.h
index f3546a2cd826..8f03914b9a6a 100644
--- a/kernel/trace/trace_stat.h
+++ b/kernel/trace/trace_stat.h
@@ -18,6 +18,8 @@ struct tracer_stat {
 	int			(*stat_cmp)(void *p1, void *p2);
 	/* Print a stat entry */
 	int			(*stat_show)(struct seq_file *s, void *p);
+	/* Release an entry */
+	void			(*stat_release)(void *stat);
 	/* Print the headers of your stat entries */
 	int			(*stat_headers)(struct seq_file *s);
 };
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 5e579645ac86..f130dacfeef4 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -1,30 +1,17 @@
 #include <trace/syscall.h>
 #include <linux/kernel.h>
+#include <linux/ftrace.h>
+#include <linux/perf_counter.h>
 #include <asm/syscall.h>
 
 #include "trace_output.h"
 #include "trace.h"
 
-/* Keep a counter of the syscall tracing users */
-static int refcount;
-
-/* Prevent from races on thread flags toggling */
 static DEFINE_MUTEX(syscall_trace_lock);
-
-/* Option to display the parameters types */
-enum {
-	TRACE_SYSCALLS_OPT_TYPES = 0x1,
-};
-
-static struct tracer_opt syscalls_opts[] = {
-	{ TRACER_OPT(syscall_arg_type, TRACE_SYSCALLS_OPT_TYPES) },
-	{ }
-};
-
-static struct tracer_flags syscalls_flags = {
-	.val = 0, /* By default: no parameters types */
-	.opts = syscalls_opts
-};
+static int sys_refcount_enter;
+static int sys_refcount_exit;
+static DECLARE_BITMAP(enabled_enter_syscalls, FTRACE_SYSCALL_MAX);
+static DECLARE_BITMAP(enabled_exit_syscalls, FTRACE_SYSCALL_MAX);
 
 enum print_line_t
 print_syscall_enter(struct trace_iterator *iter, int flags)
@@ -35,21 +22,25 @@ print_syscall_enter(struct trace_iterator *iter, int flags)
 	struct syscall_metadata *entry;
 	int i, ret, syscall;
 
-	trace_assign_type(trace, ent);
-
+	trace = (typeof(trace))ent;
 	syscall = trace->nr;
-
 	entry = syscall_nr_to_meta(syscall);
+
 	if (!entry)
 		goto end;
 
+	if (entry->enter_id != ent->type) {
+		WARN_ON_ONCE(1);
+		goto end;
+	}
+
 	ret = trace_seq_printf(s, "%s(", entry->name);
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
 	for (i = 0; i < entry->nb_args; i++) {
 		/* parameter types */
-		if (syscalls_flags.val & TRACE_SYSCALLS_OPT_TYPES) {
+		if (trace_flags & TRACE_ITER_VERBOSE) {
 			ret = trace_seq_printf(s, "%s ", entry->types[i]);
 			if (!ret)
 				return TRACE_TYPE_PARTIAL_LINE;
@@ -77,16 +68,20 @@ print_syscall_exit(struct trace_iterator *iter, int flags)
 	struct syscall_metadata *entry;
 	int ret;
 
-	trace_assign_type(trace, ent);
-
+	trace = (typeof(trace))ent;
 	syscall = trace->nr;
-
 	entry = syscall_nr_to_meta(syscall);
+
 	if (!entry) {
 		trace_seq_printf(s, "\n");
 		return TRACE_TYPE_HANDLED;
 	}
 
+	if (entry->exit_id != ent->type) {
+		WARN_ON_ONCE(1);
+		return TRACE_TYPE_UNHANDLED;
+	}
+
 	ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name,
 				trace->ret);
 	if (!ret)
@@ -95,54 +90,53 @@ print_syscall_exit(struct trace_iterator *iter, int flags)
 	return TRACE_TYPE_HANDLED;
 }
 
-void start_ftrace_syscalls(void)
-{
-	unsigned long flags;
-	struct task_struct *g, *t;
-
-	mutex_lock(&syscall_trace_lock);
-
-	/* Don't enable the flag on the tasks twice */
-	if (++refcount != 1)
-		goto unlock;
-
-	arch_init_ftrace_syscalls();
-	read_lock_irqsave(&tasklist_lock, flags);
-
-	do_each_thread(g, t) {
-		set_tsk_thread_flag(t, TIF_SYSCALL_FTRACE);
-	} while_each_thread(g, t);
-
-	read_unlock_irqrestore(&tasklist_lock, flags);
-
-unlock:
-	mutex_unlock(&syscall_trace_lock);
-}
-
-void stop_ftrace_syscalls(void)
+int ftrace_format_syscall(struct ftrace_event_call *call, struct trace_seq *s)
 {
-	unsigned long flags;
-	struct task_struct *g, *t;
+	int i;
+	int nr;
+	int ret = 0;
+	struct syscall_metadata *entry;
+	int offset = sizeof(struct trace_entry);
 
-	mutex_lock(&syscall_trace_lock);
+	nr = syscall_name_to_nr((char *)call->data);
+	entry = syscall_nr_to_meta(nr);
 
-	/* There are perhaps still some users */
-	if (--refcount)
-		goto unlock;
+	if (!entry)
+		return ret;
 
-	read_lock_irqsave(&tasklist_lock, flags);
+	for (i = 0; i < entry->nb_args; i++) {
+		ret = trace_seq_printf(s, "\tfield:%s %s;", entry->types[i],
+				        entry->args[i]);
+		if (!ret)
+			return 0;
+		ret = trace_seq_printf(s, "\toffset:%d;\tsize:%lu;\n", offset,
+				       sizeof(unsigned long));
+		if (!ret)
+			return 0;
+		offset += sizeof(unsigned long);
+	}
 
-	do_each_thread(g, t) {
-		clear_tsk_thread_flag(t, TIF_SYSCALL_FTRACE);
-	} while_each_thread(g, t);
+	trace_seq_printf(s, "\nprint fmt: \"");
+	for (i = 0; i < entry->nb_args; i++) {
+		ret = trace_seq_printf(s, "%s: 0x%%0%lulx%s", entry->args[i],
+				        sizeof(unsigned long),
+					i == entry->nb_args - 1 ? "\", " : ", ");
+		if (!ret)
+			return 0;
+	}
 
-	read_unlock_irqrestore(&tasklist_lock, flags);
+	for (i = 0; i < entry->nb_args; i++) {
+		ret = trace_seq_printf(s, "((unsigned long)(REC->%s))%s",
+				        entry->args[i],
+					i == entry->nb_args - 1 ? "\n" : ", ");
+		if (!ret)
+			return 0;
+	}
 
-unlock:
-	mutex_unlock(&syscall_trace_lock);
+	return ret;
 }
 
-void ftrace_syscall_enter(struct pt_regs *regs)
+void ftrace_syscall_enter(struct pt_regs *regs, long id)
 {
 	struct syscall_trace_enter *entry;
 	struct syscall_metadata *sys_data;
@@ -151,6 +145,8 @@ void ftrace_syscall_enter(struct pt_regs *regs)
 	int syscall_nr;
 
 	syscall_nr = syscall_get_nr(current, regs);
+	if (!test_bit(syscall_nr, enabled_enter_syscalls))
+		return;
 
 	sys_data = syscall_nr_to_meta(syscall_nr);
 	if (!sys_data)
@@ -158,7 +154,7 @@ void ftrace_syscall_enter(struct pt_regs *regs)
 
 	size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
 
-	event = trace_current_buffer_lock_reserve(TRACE_SYSCALL_ENTER, size,
+	event = trace_current_buffer_lock_reserve(sys_data->enter_id, size,
 							0, 0);
 	if (!event)
 		return;
@@ -171,7 +167,7 @@ void ftrace_syscall_enter(struct pt_regs *regs)
 	trace_wake_up();
 }
 
-void ftrace_syscall_exit(struct pt_regs *regs)
+void ftrace_syscall_exit(struct pt_regs *regs, long ret)
 {
 	struct syscall_trace_exit *entry;
 	struct syscall_metadata *sys_data;
@@ -179,12 +175,14 @@ void ftrace_syscall_exit(struct pt_regs *regs)
 	int syscall_nr;
 
 	syscall_nr = syscall_get_nr(current, regs);
+	if (!test_bit(syscall_nr, enabled_exit_syscalls))
+		return;
 
 	sys_data = syscall_nr_to_meta(syscall_nr);
 	if (!sys_data)
 		return;
 
-	event = trace_current_buffer_lock_reserve(TRACE_SYSCALL_EXIT,
+	event = trace_current_buffer_lock_reserve(sys_data->exit_id,
 				sizeof(*entry), 0, 0);
 	if (!event)
 		return;
@@ -197,54 +195,247 @@ void ftrace_syscall_exit(struct pt_regs *regs)
 	trace_wake_up();
 }
 
-static int init_syscall_tracer(struct trace_array *tr)
+int reg_event_syscall_enter(void *ptr)
 {
-	start_ftrace_syscalls();
+	int ret = 0;
+	int num;
+	char *name;
+
+	name = (char *)ptr;
+	num = syscall_name_to_nr(name);
+	if (num < 0 || num >= FTRACE_SYSCALL_MAX)
+		return -ENOSYS;
+	mutex_lock(&syscall_trace_lock);
+	if (!sys_refcount_enter)
+		ret = register_trace_syscall_enter(ftrace_syscall_enter);
+	if (ret) {
+		pr_info("event trace: Could not activate"
+				"syscall entry trace point");
+	} else {
+		set_bit(num, enabled_enter_syscalls);
+		sys_refcount_enter++;
+	}
+	mutex_unlock(&syscall_trace_lock);
+	return ret;
+}
+
+void unreg_event_syscall_enter(void *ptr)
+{
+	int num;
+	char *name;
+
+	name = (char *)ptr;
+	num = syscall_name_to_nr(name);
+	if (num < 0 || num >= FTRACE_SYSCALL_MAX)
+		return;
+	mutex_lock(&syscall_trace_lock);
+	sys_refcount_enter--;
+	clear_bit(num, enabled_enter_syscalls);
+	if (!sys_refcount_enter)
+		unregister_trace_syscall_enter(ftrace_syscall_enter);
+	mutex_unlock(&syscall_trace_lock);
+}
 
-	return 0;
+int reg_event_syscall_exit(void *ptr)
+{
+	int ret = 0;
+	int num;
+	char *name;
+
+	name = (char *)ptr;
+	num = syscall_name_to_nr(name);
+	if (num < 0 || num >= FTRACE_SYSCALL_MAX)
+		return -ENOSYS;
+	mutex_lock(&syscall_trace_lock);
+	if (!sys_refcount_exit)
+		ret = register_trace_syscall_exit(ftrace_syscall_exit);
+	if (ret) {
+		pr_info("event trace: Could not activate"
+				"syscall exit trace point");
+	} else {
+		set_bit(num, enabled_exit_syscalls);
+		sys_refcount_exit++;
+	}
+	mutex_unlock(&syscall_trace_lock);
+	return ret;
 }
 
-static void reset_syscall_tracer(struct trace_array *tr)
+void unreg_event_syscall_exit(void *ptr)
 {
-	stop_ftrace_syscalls();
-	tracing_reset_online_cpus(tr);
+	int num;
+	char *name;
+
+	name = (char *)ptr;
+	num = syscall_name_to_nr(name);
+	if (num < 0 || num >= FTRACE_SYSCALL_MAX)
+		return;
+	mutex_lock(&syscall_trace_lock);
+	sys_refcount_exit--;
+	clear_bit(num, enabled_exit_syscalls);
+	if (!sys_refcount_exit)
+		unregister_trace_syscall_exit(ftrace_syscall_exit);
+	mutex_unlock(&syscall_trace_lock);
 }
 
-static struct trace_event syscall_enter_event = {
-	.type	 	= TRACE_SYSCALL_ENTER,
-	.trace		= print_syscall_enter,
+struct trace_event event_syscall_enter = {
+	.trace			= print_syscall_enter,
 };
 
-static struct trace_event syscall_exit_event = {
-	.type	 	= TRACE_SYSCALL_EXIT,
-	.trace		= print_syscall_exit,
+struct trace_event event_syscall_exit = {
+	.trace			= print_syscall_exit,
 };
 
-static struct tracer syscall_tracer __read_mostly = {
-	.name	     	= "syscall",
-	.init		= init_syscall_tracer,
-	.reset		= reset_syscall_tracer,
-	.flags		= &syscalls_flags,
+#ifdef CONFIG_EVENT_PROFILE
+
+struct syscall_enter_record {
+	struct trace_entry	entry;
+	unsigned long		args[0];
+};
+
+struct syscall_exit_record {
+	struct trace_entry	entry;
+	unsigned long		ret;
 };
 
-__init int register_ftrace_syscalls(void)
+static DECLARE_BITMAP(enabled_prof_enter_syscalls, FTRACE_SYSCALL_MAX);
+static DECLARE_BITMAP(enabled_prof_exit_syscalls, FTRACE_SYSCALL_MAX);
+static int sys_prof_refcount_enter;
+static int sys_prof_refcount_exit;
+
+static void prof_syscall_enter(struct pt_regs *regs, long id)
 {
-	int ret;
+	struct syscall_enter_record *rec;
+	struct syscall_metadata *sys_data;
+	int syscall_nr;
+	int size;
 
-	ret = register_ftrace_event(&syscall_enter_event);
-	if (!ret) {
-		printk(KERN_WARNING "event %d failed to register\n",
-		       syscall_enter_event.type);
-		WARN_ON_ONCE(1);
+	syscall_nr = syscall_get_nr(current, regs);
+	if (!test_bit(syscall_nr, enabled_prof_enter_syscalls))
+		return;
+
+	sys_data = syscall_nr_to_meta(syscall_nr);
+	if (!sys_data)
+		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);
+
+	do {
+		char raw_data[size];
+
+		/* zero the dead bytes from align to not leak stack to user */
+		*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+
+		rec = (struct syscall_enter_record *) raw_data;
+		tracing_generic_entry_update(&rec->entry, 0, 0);
+		rec->entry.type = sys_data->enter_id;
+		syscall_get_arguments(current, regs, 0, sys_data->nb_args,
+				       (unsigned long *)&rec->args);
+		perf_tpcounter_event(sys_data->enter_id, 0, 1, rec, size);
+	} while(0);
+}
+
+int reg_prof_syscall_enter(char *name)
+{
+	int ret = 0;
+	int num;
+
+	num = syscall_name_to_nr(name);
+	if (num < 0 || num >= FTRACE_SYSCALL_MAX)
+		return -ENOSYS;
+
+	mutex_lock(&syscall_trace_lock);
+	if (!sys_prof_refcount_enter)
+		ret = register_trace_syscall_enter(prof_syscall_enter);
+	if (ret) {
+		pr_info("event trace: Could not activate"
+				"syscall entry trace point");
+	} else {
+		set_bit(num, enabled_prof_enter_syscalls);
+		sys_prof_refcount_enter++;
 	}
+	mutex_unlock(&syscall_trace_lock);
+	return ret;
+}
 
-	ret = register_ftrace_event(&syscall_exit_event);
-	if (!ret) {
-		printk(KERN_WARNING "event %d failed to register\n",
-		       syscall_exit_event.type);
-		WARN_ON_ONCE(1);
+void unreg_prof_syscall_enter(char *name)
+{
+	int num;
+
+	num = syscall_name_to_nr(name);
+	if (num < 0 || num >= FTRACE_SYSCALL_MAX)
+		return;
+
+	mutex_lock(&syscall_trace_lock);
+	sys_prof_refcount_enter--;
+	clear_bit(num, enabled_prof_enter_syscalls);
+	if (!sys_prof_refcount_enter)
+		unregister_trace_syscall_enter(prof_syscall_enter);
+	mutex_unlock(&syscall_trace_lock);
+}
+
+static void prof_syscall_exit(struct pt_regs *regs, long ret)
+{
+	struct syscall_metadata *sys_data;
+	struct syscall_exit_record rec;
+	int syscall_nr;
+
+	syscall_nr = syscall_get_nr(current, regs);
+	if (!test_bit(syscall_nr, enabled_prof_exit_syscalls))
+		return;
+
+	sys_data = syscall_nr_to_meta(syscall_nr);
+	if (!sys_data)
+		return;
+
+	tracing_generic_entry_update(&rec.entry, 0, 0);
+	rec.entry.type = sys_data->exit_id;
+	rec.ret = syscall_get_return_value(current, regs);
+
+	perf_tpcounter_event(sys_data->exit_id, 0, 1, &rec, sizeof(rec));
+}
+
+int reg_prof_syscall_exit(char *name)
+{
+	int ret = 0;
+	int num;
+
+	num = syscall_name_to_nr(name);
+	if (num < 0 || num >= FTRACE_SYSCALL_MAX)
+		return -ENOSYS;
+
+	mutex_lock(&syscall_trace_lock);
+	if (!sys_prof_refcount_exit)
+		ret = register_trace_syscall_exit(prof_syscall_exit);
+	if (ret) {
+		pr_info("event trace: Could not activate"
+				"syscall entry trace point");
+	} else {
+		set_bit(num, enabled_prof_exit_syscalls);
+		sys_prof_refcount_exit++;
 	}
+	mutex_unlock(&syscall_trace_lock);
+	return ret;
+}
+
+void unreg_prof_syscall_exit(char *name)
+{
+	int num;
+
+	num = syscall_name_to_nr(name);
+	if (num < 0 || num >= FTRACE_SYSCALL_MAX)
+		return;
 
-	return register_tracer(&syscall_tracer);
+	mutex_lock(&syscall_trace_lock);
+	sys_prof_refcount_exit--;
+	clear_bit(num, enabled_prof_exit_syscalls);
+	if (!sys_prof_refcount_exit)
+		unregister_trace_syscall_exit(prof_syscall_exit);
+	mutex_unlock(&syscall_trace_lock);
 }
-device_initcall(register_ftrace_syscalls);
+
+#endif
+
+
diff --git a/kernel/trace/trace_workqueue.c b/kernel/trace/trace_workqueue.c
index 97fcea4acce1..40cafb07dffd 100644
--- a/kernel/trace/trace_workqueue.c
+++ b/kernel/trace/trace_workqueue.c
@@ -9,6 +9,7 @@
 #include <trace/events/workqueue.h>
 #include <linux/list.h>
 #include <linux/percpu.h>
+#include <linux/kref.h>
 #include "trace_stat.h"
 #include "trace.h"
 
@@ -16,6 +17,7 @@
 /* A cpu workqueue thread */
 struct cpu_workqueue_stats {
 	struct list_head            list;
+	struct kref                 kref;
 	int		            cpu;
 	pid_t			    pid;
 /* Can be inserted from interrupt or user context, need to be atomic */
@@ -39,6 +41,11 @@ struct workqueue_global_stats {
 static DEFINE_PER_CPU(struct workqueue_global_stats, all_workqueue_stat);
 #define workqueue_cpu_stat(cpu) (&per_cpu(all_workqueue_stat, cpu))
 
+static void cpu_workqueue_stat_free(struct kref *kref)
+{
+	kfree(container_of(kref, struct cpu_workqueue_stats, kref));
+}
+
 /* Insertion of a work */
 static void
 probe_workqueue_insertion(struct task_struct *wq_thread,
@@ -96,8 +103,8 @@ static void probe_workqueue_creation(struct task_struct *wq_thread, int cpu)
 		return;
 	}
 	INIT_LIST_HEAD(&cws->list);
+	kref_init(&cws->kref);
 	cws->cpu = cpu;
-
 	cws->pid = wq_thread->pid;
 
 	spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
@@ -118,7 +125,7 @@ static void probe_workqueue_destruction(struct task_struct *wq_thread)
 							list) {
 		if (node->pid == wq_thread->pid) {
 			list_del(&node->list);
-			kfree(node);
+			kref_put(&node->kref, cpu_workqueue_stat_free);
 			goto found;
 		}
 	}
@@ -137,9 +144,11 @@ static struct cpu_workqueue_stats *workqueue_stat_start_cpu(int cpu)
 
 	spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
 
-	if (!list_empty(&workqueue_cpu_stat(cpu)->list))
+	if (!list_empty(&workqueue_cpu_stat(cpu)->list)) {
 		ret = list_entry(workqueue_cpu_stat(cpu)->list.next,
 				 struct cpu_workqueue_stats, list);
+		kref_get(&ret->kref);
+	}
 
 	spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
 
@@ -162,9 +171,9 @@ static void *workqueue_stat_start(struct tracer_stat *trace)
 static void *workqueue_stat_next(void *prev, int idx)
 {
 	struct cpu_workqueue_stats *prev_cws = prev;
+	struct cpu_workqueue_stats *ret;
 	int cpu = prev_cws->cpu;
 	unsigned long flags;
-	void *ret = NULL;
 
 	spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
 	if (list_is_last(&prev_cws->list, &workqueue_cpu_stat(cpu)->list)) {
@@ -175,11 +184,14 @@ static void *workqueue_stat_next(void *prev, int idx)
 				return NULL;
 		} while (!(ret = workqueue_stat_start_cpu(cpu)));
 		return ret;
+	} else {
+		ret = list_entry(prev_cws->list.next,
+				 struct cpu_workqueue_stats, list);
+		kref_get(&ret->kref);
 	}
 	spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
 
-	return list_entry(prev_cws->list.next, struct cpu_workqueue_stats,
-			  list);
+	return ret;
 }
 
 static int workqueue_stat_show(struct seq_file *s, void *p)
@@ -203,6 +215,13 @@ static int workqueue_stat_show(struct seq_file *s, void *p)
 	return 0;
 }
 
+static void workqueue_stat_release(void *stat)
+{
+	struct cpu_workqueue_stats *node = stat;
+
+	kref_put(&node->kref, cpu_workqueue_stat_free);
+}
+
 static int workqueue_stat_headers(struct seq_file *s)
 {
 	seq_printf(s, "# CPU  INSERTED  EXECUTED   NAME\n");
@@ -215,6 +234,7 @@ struct tracer_stat workqueue_stats __read_mostly = {
 	.stat_start = workqueue_stat_start,
 	.stat_next = workqueue_stat_next,
 	.stat_show = workqueue_stat_show,
+	.stat_release = workqueue_stat_release,
 	.stat_headers = workqueue_stat_headers
 };
 
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 1ef5d3a601c7..35dd27adb82c 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -24,6 +24,7 @@
 #include <linux/tracepoint.h>
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <linux/sched.h>
 
 extern struct tracepoint __start___tracepoints[];
 extern struct tracepoint __stop___tracepoints[];
@@ -577,3 +578,43 @@ static int init_tracepoints(void)
 __initcall(init_tracepoints);
 
 #endif /* CONFIG_MODULES */
+
+#ifdef CONFIG_FTRACE_SYSCALLS
+
+static DEFINE_MUTEX(regfunc_mutex);
+static int sys_tracepoint_refcount;
+
+void syscall_regfunc(void)
+{
+	unsigned long flags;
+	struct task_struct *g, *t;
+
+	mutex_lock(&regfunc_mutex);
+	if (!sys_tracepoint_refcount) {
+		read_lock_irqsave(&tasklist_lock, flags);
+		do_each_thread(g, t) {
+			set_tsk_thread_flag(t, TIF_SYSCALL_FTRACE);
+		} while_each_thread(g, t);
+		read_unlock_irqrestore(&tasklist_lock, flags);
+	}
+	sys_tracepoint_refcount++;
+	mutex_unlock(&regfunc_mutex);
+}
+
+void syscall_unregfunc(void)
+{
+	unsigned long flags;
+	struct task_struct *g, *t;
+
+	mutex_lock(&regfunc_mutex);
+	sys_tracepoint_refcount--;
+	if (!sys_tracepoint_refcount) {
+		read_lock_irqsave(&tasklist_lock, flags);
+		do_each_thread(g, t) {
+			clear_tsk_thread_flag(t, TIF_SYSCALL_FTRACE);
+		} while_each_thread(g, t);
+		read_unlock_irqrestore(&tasklist_lock, flags);
+	}
+	mutex_unlock(&regfunc_mutex);
+}
+#endif