1 files changed, 964 insertions, 577 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index f6e3af31b403..2f32969c09df 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -25,17 +25,35 @@
 #include <linux/ftrace.h>
 #include <linux/sysctl.h>
 #include <linux/ctype.h>
-#include <linux/hash.h>
 #include <linux/list.h>
 
 #include <asm/ftrace.h>
 
 #include "trace.h"
 
+#define FTRACE_WARN_ON(cond)                    \
+        do {                                    \
+                if (WARN_ON(cond))              \
+                        ftrace_kill();          \
+        } while (0)
+
+#define FTRACE_WARN_ON_ONCE(cond)               \
+        do {                                    \
+                if (WARN_ON_ONCE(cond))         \
+                        ftrace_kill();          \
+        } while (0)
+
 /* ftrace_enabled is a method to turn ftrace on or off */
 int ftrace_enabled __read_mostly;
 static int last_ftrace_enabled;
 
+/* set when tracing only a pid */
+struct pid *ftrace_pid_trace;
+static struct pid * const ftrace_swapper_pid = &init_struct_pid;
+
+/* Quick disabling of function tracer. */
+int function_trace_stop;
+
 /*
  * ftrace_disabled is set when an anomaly is discovered.
  * ftrace_disabled is much stronger than ftrace_enabled.
@@ -44,6 +62,7 @@ static int ftrace_disabled __read_mostly;
 
 static DEFINE_SPINLOCK(ftrace_lock);
 static DEFINE_MUTEX(ftrace_sysctl_lock);
+static DEFINE_MUTEX(ftrace_start_lock);
 
 static struct ftrace_ops ftrace_list_end __read_mostly =
 {
@@ -52,6 +71,8 @@ static struct ftrace_ops ftrace_list_end __read_mostly =
 
 static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end;
 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
+ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
+ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
 
 static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
 {
@@ -68,6 +89,21 @@ static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
         };
 }
 
+static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
+{
+        if (!test_tsk_trace_trace(current))
+                return;
+
+        ftrace_pid_function(ip, parent_ip);
+}
+
+static void set_ftrace_pid_function(ftrace_func_t func)
+{
+        /* do not set ftrace_pid_function to itself! */
+        if (func != ftrace_pid_func)
+                ftrace_pid_function = func;
+}
+
 /**
  * clear_ftrace_function - reset the ftrace function
  *
@@ -77,11 +113,27 @@ static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
 void clear_ftrace_function(void)
 {
         ftrace_trace_function = ftrace_stub;
+        __ftrace_trace_function = ftrace_stub;
+        ftrace_pid_function = ftrace_stub;
+}
+
+#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+/*
+ * For those archs that do not test ftrace_trace_stop in their
+ * mcount call site, we need to do it from C.
+ */
+static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
+{
+        if (function_trace_stop)
+                return;
+
+        __ftrace_trace_function(ip, parent_ip);
 }
+#endif
 
 static int __register_ftrace_function(struct ftrace_ops *ops)
 {
-        /* Should never be called by interrupts */
+        /* should not be called from interrupt context */
         spin_lock(&ftrace_lock);
 
         ops->next = ftrace_list;
@@ -95,14 +147,28 @@ static int __register_ftrace_function(struct ftrace_ops *ops)
         ftrace_list = ops;
 
         if (ftrace_enabled) {
+                ftrace_func_t func;
+
+                if (ops->next == &ftrace_list_end)
+                        func = ops->func;
+                else
+                        func = ftrace_list_func;
+
+                if (ftrace_pid_trace) {
+                        set_ftrace_pid_function(func);
+                        func = ftrace_pid_func;
+                }
+
                 /*
                  * For one func, simply call it directly.
                  * For more than one func, call the chain.
                  */
-                if (ops->next == &ftrace_list_end)
-                        ftrace_trace_function = ops->func;
-                else
-                        ftrace_trace_function = ftrace_list_func;
+#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+                ftrace_trace_function = func;
+#else
+                __ftrace_trace_function = func;
+                ftrace_trace_function = ftrace_test_stop_func;
+#endif
         }
 
         spin_unlock(&ftrace_lock);
@@ -115,6 +181,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
         struct ftrace_ops **p;
         int ret = 0;
 
+        /* should not be called from interrupt context */
         spin_lock(&ftrace_lock);
 
         /*
@@ -140,9 +207,19 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
 
         if (ftrace_enabled) {
                 /* If we only have one func left, then call that directly */
-                if (ftrace_list == &ftrace_list_end ||
-                    ftrace_list->next == &ftrace_list_end)
-                        ftrace_trace_function = ftrace_list->func;
+                if (ftrace_list->next == &ftrace_list_end) {
+                        ftrace_func_t func = ftrace_list->func;
+
+                        if (ftrace_pid_trace) {
+                                set_ftrace_pid_function(func);
+                                func = ftrace_pid_func;
+                        }
+#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+                        ftrace_trace_function = func;
+#else
+                        __ftrace_trace_function = func;
+#endif
+                }
         }
 
  out:
@@ -151,9 +228,48 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
         return ret;
 }
 
+static void ftrace_update_pid_func(void)
+{
+        ftrace_func_t func;
+
+        /* should not be called from interrupt context */
+        spin_lock(&ftrace_lock);
+
+        if (ftrace_trace_function == ftrace_stub)
+                goto out;
+
+        func = ftrace_trace_function;
+
+        if (ftrace_pid_trace) {
+                set_ftrace_pid_function(func);
+                func = ftrace_pid_func;
+        } else {
+                if (func == ftrace_pid_func)
+                        func = ftrace_pid_function;
+        }
+
+#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+        ftrace_trace_function = func;
+#else
+        __ftrace_trace_function = func;
+#endif
+
+ out:
+        spin_unlock(&ftrace_lock);
+}
+
 #ifdef CONFIG_DYNAMIC_FTRACE
+#ifndef CONFIG_FTRACE_MCOUNT_RECORD
+# error Dynamic ftrace depends on MCOUNT_RECORD
+#endif
 
-static struct task_struct *ftraced_task;
+/*
+ * Since MCOUNT_ADDR may point to mcount itself, we do not want
+ * to get it confused by reading a reference in the code as we
+ * are parsing on objcopy output of text. Use a variable for
+ * it instead.
+ */
+static unsigned long mcount_addr = MCOUNT_ADDR;
 
 enum {
         FTRACE_ENABLE_CALLS             = (1 << 0),
@@ -161,18 +277,14 @@ enum {
         FTRACE_UPDATE_TRACE_FUNC        = (1 << 2),
         FTRACE_ENABLE_MCOUNT            = (1 << 3),
         FTRACE_DISABLE_MCOUNT           = (1 << 4),
+        FTRACE_START_FUNC_RET           = (1 << 5),
+        FTRACE_STOP_FUNC_RET            = (1 << 6),
 };
 
 static int ftrace_filtered;
-static int tracing_on;
-static int frozen_record_count;
-
-static struct hlist_head ftrace_hash[FTRACE_HASHSIZE];
 
-static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu);
+static LIST_HEAD(ftrace_new_addrs);
 
-static DEFINE_SPINLOCK(ftrace_shutdown_lock);
-static DEFINE_MUTEX(ftraced_lock);
 static DEFINE_MUTEX(ftrace_regex_lock);
 
 struct ftrace_page {
@@ -190,16 +302,13 @@ struct ftrace_page {
 static struct ftrace_page       *ftrace_pages_start;
 static struct ftrace_page       *ftrace_pages;
 
-static int ftraced_trigger;
-static int ftraced_suspend;
-static int ftraced_stop;
-
-static int ftrace_record_suspend;
-
 static struct dyn_ftrace *ftrace_free_records;
 
 
 #ifdef CONFIG_KPROBES
+
+static int frozen_record_count;
+
 static inline void freeze_record(struct dyn_ftrace *rec)
 {
         if (!(rec->flags & FTRACE_FL_FROZEN)) {
@@ -226,79 +335,36 @@ static inline int record_frozen(struct dyn_ftrace *rec)
 # define record_frozen(rec)                     ({ 0; })
 #endif /* CONFIG_KPROBES */
 
-int skip_trace(unsigned long ip)
+static void ftrace_free_rec(struct dyn_ftrace *rec)
 {
-        unsigned long fl;
-        struct dyn_ftrace *rec;
-        struct hlist_node *t;
-        struct hlist_head *head;
-
-        if (frozen_record_count == 0)
-                return 0;
-
-        head = &ftrace_hash[hash_long(ip, FTRACE_HASHBITS)];
-        hlist_for_each_entry_rcu(rec, t, head, node) {
-                if (rec->ip == ip) {
-                        if (record_frozen(rec)) {
-                                if (rec->flags & FTRACE_FL_FAILED)
-                                        return 1;
-
-                                if (!(rec->flags & FTRACE_FL_CONVERTED))
-                                        return 1;
-
-                                if (!tracing_on || !ftrace_enabled)
-                                        return 1;
-
-                                if (ftrace_filtered) {
-                                        fl = rec->flags & (FTRACE_FL_FILTER |
-                                                           FTRACE_FL_NOTRACE);
-                                        if (!fl || (fl & FTRACE_FL_NOTRACE))
-                                                return 1;
-                                }
-                        }
-                        break;
-                }
-        }
-
-        return 0;
+        rec->ip = (unsigned long)ftrace_free_records;
+        ftrace_free_records = rec;
+        rec->flags |= FTRACE_FL_FREE;
 }
 
-static inline int
-ftrace_ip_in_hash(unsigned long ip, unsigned long key)
+void ftrace_release(void *start, unsigned long size)
 {
-        struct dyn_ftrace *p;
-        struct hlist_node *t;
-        int found = 0;
-
-        hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) {
-                if (p->ip == ip) {
-                        found = 1;
-                        break;
-                }
-        }
-
-        return found;
-}
+        struct dyn_ftrace *rec;
+        struct ftrace_page *pg;
+        unsigned long s = (unsigned long)start;
+        unsigned long e = s + size;
+        int i;
 
-static inline void
-ftrace_add_hash(struct dyn_ftrace *node, unsigned long key)
-{
-        hlist_add_head_rcu(&node->node, &ftrace_hash[key]);
-}
+        if (ftrace_disabled || !start)
+                return;
 
-/* called from kstop_machine */
-static inline void ftrace_del_hash(struct dyn_ftrace *node)
-{
-        hlist_del(&node->node);
-}
+        /* should not be called from interrupt context */
+        spin_lock(&ftrace_lock);
 
-static void ftrace_free_rec(struct dyn_ftrace *rec)
-{
-        /* no locking, only called from kstop_machine */
+        for (pg = ftrace_pages_start; pg; pg = pg->next) {
+                for (i = 0; i < pg->index; i++) {
+                        rec = &pg->records[i];
 
-        rec->ip = (unsigned long)ftrace_free_records;
-        ftrace_free_records = rec;
-        rec->flags |= FTRACE_FL_FREE;
+                        if ((rec->ip >= s) && (rec->ip < e))
+                                ftrace_free_rec(rec);
+                }
+        }
+        spin_unlock(&ftrace_lock);
 }
 
 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
@@ -310,10 +376,8 @@ static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
                 rec = ftrace_free_records;
 
                 if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
-                        WARN_ON_ONCE(1);
+                        FTRACE_WARN_ON_ONCE(1);
                         ftrace_free_records = NULL;
-                        ftrace_disabled = 1;
-                        ftrace_enabled = 0;
                         return NULL;
                 }
 
@@ -323,182 +387,163 @@ static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
         }
 
         if (ftrace_pages->index == ENTRIES_PER_PAGE) {
-                if (!ftrace_pages->next)
-                        return NULL;
+                if (!ftrace_pages->next) {
+                        /* allocate another page */
+                        ftrace_pages->next =
+                                (void *)get_zeroed_page(GFP_KERNEL);
+                        if (!ftrace_pages->next)
+                                return NULL;
+                }
                 ftrace_pages = ftrace_pages->next;
         }
 
         return &ftrace_pages->records[ftrace_pages->index++];
 }
 
-static void
+static struct dyn_ftrace *
 ftrace_record_ip(unsigned long ip)
 {
-        struct dyn_ftrace *node;
-        unsigned long flags;
-        unsigned long key;
-        int resched;
-        int atomic;
-        int cpu;
-
-        if (!ftrace_enabled || ftrace_disabled)
-                return;
-
-        resched = need_resched();
-        preempt_disable_notrace();
-
-        /*
-         * We simply need to protect against recursion.
-         * Use the the raw version of smp_processor_id and not
-         * __get_cpu_var which can call debug hooks that can
-         * cause a recursive crash here.
-         */
-        cpu = raw_smp_processor_id();
-        per_cpu(ftrace_shutdown_disable_cpu, cpu)++;
-        if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1)
-                goto out;
-
-        if (unlikely(ftrace_record_suspend))
-                goto out;
-
-        key = hash_long(ip, FTRACE_HASHBITS);
-
-        WARN_ON_ONCE(key >= FTRACE_HASHSIZE);
-
-        if (ftrace_ip_in_hash(ip, key))
-                goto out;
-
-        atomic = irqs_disabled();
-
-        spin_lock_irqsave(&ftrace_shutdown_lock, flags);
+        struct dyn_ftrace *rec;
 
-        /* This ip may have hit the hash before the lock */
-        if (ftrace_ip_in_hash(ip, key))
-                goto out_unlock;
+        if (ftrace_disabled)
+                return NULL;
 
-        node = ftrace_alloc_dyn_node(ip);
-        if (!node)
-                goto out_unlock;
+        rec = ftrace_alloc_dyn_node(ip);
+        if (!rec)
+                return NULL;
 
-        node->ip = ip;
+        rec->ip = ip;
 
-        ftrace_add_hash(node, key);
+        list_add(&rec->list, &ftrace_new_addrs);
 
-        ftraced_trigger = 1;
+        return rec;
+}
 
- out_unlock:
-        spin_unlock_irqrestore(&ftrace_shutdown_lock, flags);
- out:
-        per_cpu(ftrace_shutdown_disable_cpu, cpu)--;
+static void print_ip_ins(const char *fmt, unsigned char *p)
+{
+        int i;
 
-        /* prevent recursion with scheduler */
-        if (resched)
-                preempt_enable_no_resched_notrace();
-        else
-                preempt_enable_notrace();
+        printk(KERN_CONT "%s", fmt);
+
+        for (i = 0; i < MCOUNT_INSN_SIZE; i++)
+                printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
+}
+
+static void ftrace_bug(int failed, unsigned long ip)
+{
+        switch (failed) {
+        case -EFAULT:
+                FTRACE_WARN_ON_ONCE(1);
+                pr_info("ftrace faulted on modifying ");
+                print_ip_sym(ip);
+                break;
+        case -EINVAL:
+                FTRACE_WARN_ON_ONCE(1);
+                pr_info("ftrace failed to modify ");
+                print_ip_sym(ip);
+                print_ip_ins(" actual: ", (unsigned char *)ip);
+                printk(KERN_CONT "\n");
+                break;
+        case -EPERM:
+                FTRACE_WARN_ON_ONCE(1);
+                pr_info("ftrace faulted on writing ");
+                print_ip_sym(ip);
+                break;
+        default:
+                FTRACE_WARN_ON_ONCE(1);
+                pr_info("ftrace faulted on unknown error ");
+                print_ip_sym(ip);
+        }
 }
 
-#define FTRACE_ADDR ((long)(ftrace_caller))
 
 static int
-__ftrace_replace_code(struct dyn_ftrace *rec,
-                      unsigned char *old, unsigned char *new, int enable)
+__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
 {
         unsigned long ip, fl;
+        unsigned long ftrace_addr;
+
+        ftrace_addr = (unsigned long)ftrace_caller;
 
         ip = rec->ip;
 
-        if (ftrace_filtered && enable) {
+        /*
+         * If this record is not to be traced and
+         * it is not enabled then do nothing.
+         *
+         * If this record is not to be traced and
+         * it is enabled then disabled it.
+         *
+         */
+        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) {
                 /*
-                 * If filtering is on:
-                 *
-                 * If this record is set to be filtered and
-                 * is enabled then do nothing.
-                 *
-                 * If this record is set to be filtered and
-                 * it is not enabled, enable it.
-                 *
-                 * If this record is not set to be filtered
-                 * and it is not enabled do nothing.
-                 *
-                 * If this record is set not to trace then
-                 * do nothing.
-                 *
-                 * If this record is set not to trace and
-                 * it is enabled then disable it.
-                 *
-                 * If this record is not set to be filtered and
-                 * it is enabled, disable it.
+                 * Filtering is on:
                  */
 
-                fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE |
-                                   FTRACE_FL_ENABLED);
+                fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
 
-                if ((fl ==  (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) ||
-                    (fl ==  (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) ||
-                    !fl || (fl == FTRACE_FL_NOTRACE))
+                /* Record is filtered and enabled, do nothing */
+                if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
                         return 0;
 
-                /*
-                 * If it is enabled disable it,
-                 * otherwise enable it!
-                 */
-                if (fl & FTRACE_FL_ENABLED) {
-                        /* swap new and old */
-                        new = old;
-                        old = ftrace_call_replace(ip, FTRACE_ADDR);
+                /* Record is not filtered and is not 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 {
-                        new = ftrace_call_replace(ip, FTRACE_ADDR);
+                else
+                /* Otherwise record is filtered but not enabled, enable it */
                         rec->flags |= FTRACE_FL_ENABLED;
-                }
         } else {
+                /* Disable or not filtered */
 
                 if (enable) {
-                        /*
-                         * If this record is set not to trace and is
-                         * not enabled, do nothing.
-                         */
-                        fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED);
-                        if (fl == FTRACE_FL_NOTRACE)
-                                return 0;
-
-                        new = ftrace_call_replace(ip, FTRACE_ADDR);
-                } else
-                        old = ftrace_call_replace(ip, FTRACE_ADDR);
-
-                if (enable) {
+                        /* if record is enabled, do nothing */
                         if (rec->flags & FTRACE_FL_ENABLED)
                                 return 0;
+
                         rec->flags |= FTRACE_FL_ENABLED;
+
                 } else {
+
+                        /* if record is not enabled do nothing */
                         if (!(rec->flags & FTRACE_FL_ENABLED))
                                 return 0;
+
                         rec->flags &= ~FTRACE_FL_ENABLED;
                 }
         }
 
-        return ftrace_modify_code(ip, old, new);
+        if (rec->flags & FTRACE_FL_ENABLED)
+                return ftrace_make_call(rec, ftrace_addr);
+        else
+                return ftrace_make_nop(NULL, rec, ftrace_addr);
 }
 
 static void ftrace_replace_code(int enable)
 {
         int i, failed;
-        unsigned char *new = NULL, *old = NULL;
         struct dyn_ftrace *rec;
         struct ftrace_page *pg;
 
-        if (enable)
-                old = ftrace_nop_replace();
-        else
-                new = ftrace_nop_replace();
-
         for (pg = ftrace_pages_start; pg; pg = pg->next) {
                 for (i = 0; i < pg->index; i++) {
                         rec = &pg->records[i];
 
-                        /* don't modify code that has already faulted */
-                        if (rec->flags & FTRACE_FL_FAILED)
+                        /*
+                         * Skip over free records and records that have
+                         * failed.
+                         */
+                        if (rec->flags & FTRACE_FL_FREE ||
+                            rec->flags & FTRACE_FL_FAILED)
                                 continue;
 
                         /* ignore updates to this record's mcount site */
@@ -509,78 +554,52 @@ static void ftrace_replace_code(int enable)
                                 unfreeze_record(rec);
                         }
 
-                        failed = __ftrace_replace_code(rec, old, new, enable);
+                        failed = __ftrace_replace_code(rec, enable);
                         if (failed && (rec->flags & FTRACE_FL_CONVERTED)) {
                                 rec->flags |= FTRACE_FL_FAILED;
                                 if ((system_state == SYSTEM_BOOTING) ||
                                     !core_kernel_text(rec->ip)) {
-                                        ftrace_del_hash(rec);
                                         ftrace_free_rec(rec);
-                                }
+                                } else
+                                        ftrace_bug(failed, rec->ip);
                         }
                 }
         }
 }
 
-static void ftrace_shutdown_replenish(void)
-{
-        if (ftrace_pages->next)
-                return;
-
-        /* allocate another page */
-        ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL);
-}
-
 static int
-ftrace_code_disable(struct dyn_ftrace *rec)
+ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
 {
         unsigned long ip;
-        unsigned char *nop, *call;
-        int failed;
+        int ret;
 
         ip = rec->ip;
 
-        nop = ftrace_nop_replace();
-        call = ftrace_call_replace(ip, MCOUNT_ADDR);
-
-        failed = ftrace_modify_code(ip, call, nop);
-        if (failed) {
+        ret = ftrace_make_nop(mod, rec, mcount_addr);
+        if (ret) {
+                ftrace_bug(ret, ip);
                 rec->flags |= FTRACE_FL_FAILED;
                 return 0;
         }
         return 1;
 }
 
-static int __ftrace_update_code(void *ignore);
-
 static int __ftrace_modify_code(void *data)
 {
-        unsigned long addr;
         int *command = data;
 
-        if (*command & FTRACE_ENABLE_CALLS) {
-                /*
-                 * Update any recorded ips now that we have the
-                 * machine stopped
-                 */
-                __ftrace_update_code(NULL);
+        if (*command & FTRACE_ENABLE_CALLS)
                 ftrace_replace_code(1);
-                tracing_on = 1;
-        } else if (*command & FTRACE_DISABLE_CALLS) {
+        else if (*command & FTRACE_DISABLE_CALLS)
                 ftrace_replace_code(0);
-                tracing_on = 0;
-        }
 
         if (*command & FTRACE_UPDATE_TRACE_FUNC)
                 ftrace_update_ftrace_func(ftrace_trace_function);
 
-        if (*command & FTRACE_ENABLE_MCOUNT) {
-                addr = (unsigned long)ftrace_record_ip;
-                ftrace_mcount_set(&addr);
-        } else if (*command & FTRACE_DISABLE_MCOUNT) {
-                addr = (unsigned long)ftrace_stub;
-                ftrace_mcount_set(&addr);
-        }
+        if (*command & FTRACE_START_FUNC_RET)
+                ftrace_enable_ftrace_graph_caller();
+        else if (*command & FTRACE_STOP_FUNC_RET)
+                ftrace_disable_ftrace_graph_caller();
 
         return 0;
 }
@@ -590,62 +609,44 @@ static void ftrace_run_update_code(int command)
         stop_machine(__ftrace_modify_code, &command, NULL);
 }
 
-void ftrace_disable_daemon(void)
-{
-        /* Stop the daemon from calling kstop_machine */
-        mutex_lock(&ftraced_lock);
-        ftraced_stop = 1;
-        mutex_unlock(&ftraced_lock);
-
-        ftrace_force_update();
-}
-
-void ftrace_enable_daemon(void)
-{
-        mutex_lock(&ftraced_lock);
-        ftraced_stop = 0;
-        mutex_unlock(&ftraced_lock);
-
-        ftrace_force_update();
-}
-
 static ftrace_func_t saved_ftrace_func;
+static int ftrace_start_up;
 
-static void ftrace_startup(void)
+static void ftrace_startup_enable(int command)
 {
-        int command = 0;
-
-        if (unlikely(ftrace_disabled))
-                return;
-
-        mutex_lock(&ftraced_lock);
-        ftraced_suspend++;
-        if (ftraced_suspend == 1)
-                command |= FTRACE_ENABLE_CALLS;
-
         if (saved_ftrace_func != ftrace_trace_function) {
                 saved_ftrace_func = ftrace_trace_function;
                 command |= FTRACE_UPDATE_TRACE_FUNC;
         }
 
         if (!command || !ftrace_enabled)
-                goto out;
+                return;
 
         ftrace_run_update_code(command);
- out:
-        mutex_unlock(&ftraced_lock);
 }
 
-static void ftrace_shutdown(void)
+static void ftrace_startup(int command)
 {
-        int command = 0;
+        if (unlikely(ftrace_disabled))
+                return;
+
+        mutex_lock(&ftrace_start_lock);
+        ftrace_start_up++;
+        command |= FTRACE_ENABLE_CALLS;
 
+        ftrace_startup_enable(command);
+
+        mutex_unlock(&ftrace_start_lock);
+}
+
+static void ftrace_shutdown(int command)
+{
         if (unlikely(ftrace_disabled))
                 return;
 
-        mutex_lock(&ftraced_lock);
-        ftraced_suspend--;
-        if (!ftraced_suspend)
+        mutex_lock(&ftrace_start_lock);
+        ftrace_start_up--;
+        if (!ftrace_start_up)
                 command |= FTRACE_DISABLE_CALLS;
 
         if (saved_ftrace_func != ftrace_trace_function) {
@@ -658,7 +659,7 @@ static void ftrace_shutdown(void)
 
         ftrace_run_update_code(command);
  out:
-        mutex_unlock(&ftraced_lock);
+        mutex_unlock(&ftrace_start_lock);
 }
 
 static void ftrace_startup_sysctl(void)
@@ -668,15 +669,15 @@ static void ftrace_startup_sysctl(void)
         if (unlikely(ftrace_disabled))
                 return;
 
-        mutex_lock(&ftraced_lock);
+        mutex_lock(&ftrace_start_lock);
         /* Force update next time */
         saved_ftrace_func = NULL;
-        /* ftraced_suspend is true if we want ftrace running */
-        if (ftraced_suspend)
+        /* ftrace_start_up is true if we want ftrace running */
+        if (ftrace_start_up)
                 command |= FTRACE_ENABLE_CALLS;
 
         ftrace_run_update_code(command);
-        mutex_unlock(&ftraced_lock);
+        mutex_unlock(&ftrace_start_lock);
 }
 
 static void ftrace_shutdown_sysctl(void)
@@ -686,153 +687,51 @@ static void ftrace_shutdown_sysctl(void)
         if (unlikely(ftrace_disabled))
                 return;
 
-        mutex_lock(&ftraced_lock);
-        /* ftraced_suspend is true if ftrace is running */
-        if (ftraced_suspend)
+        mutex_lock(&ftrace_start_lock);
+        /* ftrace_start_up is true if ftrace is running */
+        if (ftrace_start_up)
                 command |= FTRACE_DISABLE_CALLS;
 
         ftrace_run_update_code(command);
-        mutex_unlock(&ftraced_lock);
+        mutex_unlock(&ftrace_start_lock);
 }
 
 static cycle_t          ftrace_update_time;
 static unsigned long    ftrace_update_cnt;
 unsigned long           ftrace_update_tot_cnt;
 
-static int __ftrace_update_code(void *ignore)
+static int ftrace_update_code(struct module *mod)
 {
-        int i, save_ftrace_enabled;
+        struct dyn_ftrace *p, *t;
         cycle_t start, stop;
-        struct dyn_ftrace *p;
-        struct hlist_node *t, *n;
-        struct hlist_head *head, temp_list;
-
-        /* Don't be recording funcs now */
-        ftrace_record_suspend++;
-        save_ftrace_enabled = ftrace_enabled;
-        ftrace_enabled = 0;
 
         start = ftrace_now(raw_smp_processor_id());
         ftrace_update_cnt = 0;
 
-        /* No locks needed, the machine is stopped! */
-        for (i = 0; i < FTRACE_HASHSIZE; i++) {
-                INIT_HLIST_HEAD(&temp_list);
-                head = &ftrace_hash[i];
+        list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) {
 
-                /* all CPUS are stopped, we are safe to modify code */
-                hlist_for_each_entry_safe(p, t, n, head, node) {
-                        /* Skip over failed records which have not been
-                         * freed. */
-                        if (p->flags & FTRACE_FL_FAILED)
-                                continue;
-
-                        /* Unconverted records are always at the head of the
-                         * hash bucket. Once we encounter a converted record,
-                         * simply skip over to the next bucket. Saves ftraced
-                         * some processor cycles (ftrace does its bid for
-                         * global warming :-p ). */
-                        if (p->flags & (FTRACE_FL_CONVERTED))
-                                break;
-
-                        /* Ignore updates to this record's mcount site.
-                         * Reintroduce this record at the head of this
-                         * bucket to attempt to "convert" it again if
-                         * the kprobe on it is unregistered before the
-                         * next run. */
-                        if (get_kprobe((void *)p->ip)) {
-                                ftrace_del_hash(p);
-                                INIT_HLIST_NODE(&p->node);
-                                hlist_add_head(&p->node, &temp_list);
-                                freeze_record(p);
-                                continue;
-                        } else {
-                                unfreeze_record(p);
-                        }
+                /* If something went wrong, bail without enabling anything */
+                if (unlikely(ftrace_disabled))
+                        return -1;
 
-                        /* convert record (i.e, patch mcount-call with NOP) */
-                        if (ftrace_code_disable(p)) {
-                                p->flags |= FTRACE_FL_CONVERTED;
-                                ftrace_update_cnt++;
-                        } else {
-                                if ((system_state == SYSTEM_BOOTING) ||
-                                    !core_kernel_text(p->ip)) {
-                                        ftrace_del_hash(p);
-                                        ftrace_free_rec(p);
-                                }
-                        }
-                }
+                list_del_init(&p->list);
 
-                hlist_for_each_entry_safe(p, t, n, &temp_list, node) {
-                        hlist_del(&p->node);
-                        INIT_HLIST_NODE(&p->node);
-                        hlist_add_head(&p->node, head);
-                }
+                /* convert record (i.e, patch mcount-call with NOP) */
+                if (ftrace_code_disable(mod, p)) {
+                        p->flags |= FTRACE_FL_CONVERTED;
+                        ftrace_update_cnt++;
+                } else
+                        ftrace_free_rec(p);
         }
 
         stop = ftrace_now(raw_smp_processor_id());
         ftrace_update_time = stop - start;
         ftrace_update_tot_cnt += ftrace_update_cnt;
-        ftraced_trigger = 0;
-
-        ftrace_enabled = save_ftrace_enabled;
-        ftrace_record_suspend--;
 
         return 0;
 }
 
-static int ftrace_update_code(void)
-{
-        if (unlikely(ftrace_disabled) ||
-            !ftrace_enabled || !ftraced_trigger)
-                return 0;
-
-        stop_machine(__ftrace_update_code, NULL, NULL);
-
-        return 1;
-}
-
-static int ftraced(void *ignore)
-{
-        unsigned long usecs;
-
-        while (!kthread_should_stop()) {
-
-                set_current_state(TASK_INTERRUPTIBLE);
-
-                /* check once a second */
-                schedule_timeout(HZ);
-
-                if (unlikely(ftrace_disabled))
-                        continue;
-
-                mutex_lock(&ftrace_sysctl_lock);
-                mutex_lock(&ftraced_lock);
-                if (!ftraced_suspend && !ftraced_stop &&
-                    ftrace_update_code()) {
-                        usecs = nsecs_to_usecs(ftrace_update_time);
-                        if (ftrace_update_tot_cnt > 100000) {
-                                ftrace_update_tot_cnt = 0;
-                                pr_info("hm, dftrace overflow: %lu change%s"
-                                        " (%lu total) in %lu usec%s\n",
-                                        ftrace_update_cnt,
-                                        ftrace_update_cnt != 1 ? "s" : "",
-                                        ftrace_update_tot_cnt,
-                                        usecs, usecs != 1 ? "s" : "");
-                                ftrace_disabled = 1;
-                                WARN_ON_ONCE(1);
-                        }
-                }
-                mutex_unlock(&ftraced_lock);
-                mutex_unlock(&ftrace_sysctl_lock);
-
-                ftrace_shutdown_replenish();
-        }
-        __set_current_state(TASK_RUNNING);
-        return 0;
-}
-
-static int __init ftrace_dyn_table_alloc(void)
+static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
 {
         struct ftrace_page *pg;
         int cnt;
@@ -859,7 +758,9 @@ static int __init ftrace_dyn_table_alloc(void)
 
         pg = ftrace_pages = ftrace_pages_start;
 
-        cnt = NR_TO_INIT / ENTRIES_PER_PAGE;
+        cnt = num_to_init / ENTRIES_PER_PAGE;
+        pr_info("ftrace: allocating %ld entries in %d pages\n",
+                num_to_init, cnt + 1);
 
         for (i = 0; i < cnt; i++) {
                 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
@@ -884,7 +785,6 @@ enum {
 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
 
 struct ftrace_iterator {
-        loff_t                  pos;
         struct ftrace_page      *pg;
         unsigned                idx;
         unsigned                flags;
@@ -901,21 +801,26 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
 
         (*pos)++;
 
+        /* should not be called from interrupt context */
+        spin_lock(&ftrace_lock);
  retry:
         if (iter->idx >= iter->pg->index) {
                 if (iter->pg->next) {
                         iter->pg = iter->pg->next;
                         iter->idx = 0;
                         goto retry;
+                } else {
+                        iter->idx = -1;
                 }
         } else {
                 rec = &iter->pg->records[iter->idx++];
-                if ((!(iter->flags & FTRACE_ITER_FAILURES) &&
+                if ((rec->flags & FTRACE_FL_FREE) ||
+
+                    (!(iter->flags & FTRACE_ITER_FAILURES) &&
                      (rec->flags & FTRACE_FL_FAILED)) ||
 
                     ((iter->flags & FTRACE_ITER_FAILURES) &&
-                     (!(rec->flags & FTRACE_FL_FAILED) ||
-                      (rec->flags & FTRACE_FL_FREE))) ||
+                     !(rec->flags & FTRACE_FL_FAILED)) ||
 
                     ((iter->flags & FTRACE_ITER_FILTER) &&
                      !(rec->flags & FTRACE_FL_FILTER)) ||
@@ -926,8 +831,7 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
                         goto retry;
                 }
         }
-
-        iter->pos = *pos;
+        spin_unlock(&ftrace_lock);
 
         return rec;
 }
@@ -936,16 +840,16 @@ static void *t_start(struct seq_file *m, loff_t *pos)
 {
         struct ftrace_iterator *iter = m->private;
         void *p = NULL;
-        loff_t l = -1;
 
-        if (*pos != iter->pos) {
-                for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l))
-                        ;
-        } else {
-                l = *pos;
-                p = t_next(m, p, &l);
+        if (*pos > 0) {
+                if (iter->idx < 0)
+                        return p;
+                (*pos)--;
+                iter->idx--;
         }
 
+        p = t_next(m, p, pos);
+
         return p;
 }
 
@@ -989,7 +893,6 @@ ftrace_avail_open(struct inode *inode, struct file *file)
                 return -ENOMEM;
 
         iter->pg = ftrace_pages_start;
-        iter->pos = -1;
 
         ret = seq_open(file, &show_ftrace_seq_ops);
         if (!ret) {
@@ -1039,8 +942,8 @@ static void ftrace_filter_reset(int enable)
         unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
         unsigned i;
 
-        /* keep kstop machine from running */
-        preempt_disable();
+        /* should not be called from interrupt context */
+        spin_lock(&ftrace_lock);
         if (enable)
                 ftrace_filtered = 0;
         pg = ftrace_pages_start;
@@ -1053,7 +956,7 @@ static void ftrace_filter_reset(int enable)
                 }
                 pg = pg->next;
         }
-        preempt_enable();
+        spin_unlock(&ftrace_lock);
 }
 
 static int
@@ -1076,7 +979,6 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable)
 
         if (file->f_mode & FMODE_READ) {
                 iter->pg = ftrace_pages_start;
-                iter->pos = -1;
                 iter->flags = enable ? FTRACE_ITER_FILTER :
                         FTRACE_ITER_NOTRACE;
 
@@ -1145,6 +1047,13 @@ ftrace_match(unsigned char *buff, int len, int enable)
         int type = MATCH_FULL;
         unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
         unsigned i, match = 0, search_len = 0;
+        int not = 0;
+
+        if (buff[0] == '!') {
+                not = 1;
+                buff++;
+                len--;
+        }
 
         for (i = 0; i < len; i++) {
                 if (buff[i] == '*') {
@@ -1165,8 +1074,8 @@ ftrace_match(unsigned char *buff, int len, int enable)
                 }
         }
 
-        /* keep kstop machine from running */
-        preempt_disable();
+        /* should not be called from interrupt context */
+        spin_lock(&ftrace_lock);
         if (enable)
                 ftrace_filtered = 1;
         pg = ftrace_pages_start;
@@ -1198,12 +1107,16 @@ ftrace_match(unsigned char *buff, int len, int enable)
                                         matched = 1;
                                 break;
                         }
-                        if (matched)
-                                rec->flags |= flag;
+                        if (matched) {
+                                if (not)
+                                        rec->flags &= ~flag;
+                                else
+                                        rec->flags |= flag;
+                        }
                 }
                 pg = pg->next;
         }
-        preempt_enable();
+        spin_unlock(&ftrace_lock);
 }
 
 static ssize_t
@@ -1366,10 +1279,10 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
         }
 
         mutex_lock(&ftrace_sysctl_lock);
-        mutex_lock(&ftraced_lock);
-        if (iter->filtered && ftraced_suspend && ftrace_enabled)
+        mutex_lock(&ftrace_start_lock);
+        if (ftrace_start_up && ftrace_enabled)
                 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
-        mutex_unlock(&ftraced_lock);
+        mutex_unlock(&ftrace_start_lock);
         mutex_unlock(&ftrace_sysctl_lock);
 
         kfree(iter);
@@ -1389,55 +1302,6 @@ ftrace_notrace_release(struct inode *inode, struct file *file)
         return ftrace_regex_release(inode, file, 0);
 }
 
-static ssize_t
-ftraced_read(struct file *filp, char __user *ubuf,
-                     size_t cnt, loff_t *ppos)
-{
-        /* don't worry about races */
-        char *buf = ftraced_stop ? "disabled\n" : "enabled\n";
-        int r = strlen(buf);
-
-        return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
-}
-
-static ssize_t
-ftraced_write(struct file *filp, const char __user *ubuf,
-                      size_t cnt, loff_t *ppos)
-{
-        char buf[64];
-        long val;
-        int ret;
-
-        if (cnt >= sizeof(buf))
-                return -EINVAL;
-
-        if (copy_from_user(&buf, ubuf, cnt))
-                return -EFAULT;
-
-        if (strncmp(buf, "enable", 6) == 0)
-                val = 1;
-        else if (strncmp(buf, "disable", 7) == 0)
-                val = 0;
-        else {
-                buf[cnt] = 0;
-
-                ret = strict_strtoul(buf, 10, &val);
-                if (ret < 0)
-                        return ret;
-
-                val = !!val;
-        }
-
-        if (val)
-                ftrace_enable_daemon();
-        else
-                ftrace_disable_daemon();
-
-        filp->f_pos += cnt;
-
-        return cnt;
-}
-
 static struct file_operations ftrace_avail_fops = {
         .open = ftrace_avail_open,
         .read = seq_read,
@@ -1468,60 +1332,233 @@ static struct file_operations ftrace_notrace_fops = {
         .release = ftrace_notrace_release,
 };
 
-static struct file_operations ftraced_fops = {
-        .open = tracing_open_generic,
-        .read = ftraced_read,
-        .write = ftraced_write,
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+static DEFINE_MUTEX(graph_lock);
+
+int ftrace_graph_count;
+unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
+
+static void *
+g_next(struct seq_file *m, void *v, loff_t *pos)
+{
+        unsigned long *array = m->private;
+        int index = *pos;
+
+        (*pos)++;
+
+        if (index >= ftrace_graph_count)
+                return NULL;
+
+        return &array[index];
+}
+
+static void *g_start(struct seq_file *m, loff_t *pos)
+{
+        void *p = NULL;
+
+        mutex_lock(&graph_lock);
+
+        p = g_next(m, p, pos);
+
+        return p;
+}
+
+static void g_stop(struct seq_file *m, void *p)
+{
+        mutex_unlock(&graph_lock);
+}
+
+static int g_show(struct seq_file *m, void *v)
+{
+        unsigned long *ptr = v;
+        char str[KSYM_SYMBOL_LEN];
+
+        if (!ptr)
+                return 0;
+
+        kallsyms_lookup(*ptr, NULL, NULL, NULL, str);
+
+        seq_printf(m, "%s\n", str);
+
+        return 0;
+}
+
+static struct seq_operations ftrace_graph_seq_ops = {
+        .start = g_start,
+        .next = g_next,
+        .stop = g_stop,
+        .show = g_show,
 };
 
-/**
- * ftrace_force_update - force an update to all recording ftrace functions
- */
-int ftrace_force_update(void)
+static int
+ftrace_graph_open(struct inode *inode, struct file *file)
 {
         int ret = 0;
 
         if (unlikely(ftrace_disabled))
                 return -ENODEV;
 
-        mutex_lock(&ftrace_sysctl_lock);
-        mutex_lock(&ftraced_lock);
-
-        /*
-         * If ftraced_trigger is not set, then there is nothing
-         * to update.
-         */
-        if (ftraced_trigger && !ftrace_update_code())
-                ret = -EBUSY;
+        mutex_lock(&graph_lock);
+        if ((file->f_mode & FMODE_WRITE) &&
+            !(file->f_flags & O_APPEND)) {
+                ftrace_graph_count = 0;
+                memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
+        }
 
-        mutex_unlock(&ftraced_lock);
-        mutex_unlock(&ftrace_sysctl_lock);
+        if (file->f_mode & FMODE_READ) {
+                ret = seq_open(file, &ftrace_graph_seq_ops);
+                if (!ret) {
+                        struct seq_file *m = file->private_data;
+                        m->private = ftrace_graph_funcs;
+                }
+        } else
+                file->private_data = ftrace_graph_funcs;
+        mutex_unlock(&graph_lock);
 
         return ret;
 }
 
-static void ftrace_force_shutdown(void)
+static ssize_t
+ftrace_graph_read(struct file *file, char __user *ubuf,
+                       size_t cnt, loff_t *ppos)
 {
-        struct task_struct *task;
-        int command = FTRACE_DISABLE_CALLS | FTRACE_UPDATE_TRACE_FUNC;
+        if (file->f_mode & FMODE_READ)
+                return seq_read(file, ubuf, cnt, ppos);
+        else
+                return -EPERM;
+}
 
-        mutex_lock(&ftraced_lock);
-        task = ftraced_task;
-        ftraced_task = NULL;
-        ftraced_suspend = -1;
-        ftrace_run_update_code(command);
-        mutex_unlock(&ftraced_lock);
+static int
+ftrace_set_func(unsigned long *array, int idx, char *buffer)
+{
+        char str[KSYM_SYMBOL_LEN];
+        struct dyn_ftrace *rec;
+        struct ftrace_page *pg;
+        int found = 0;
+        int i, j;
+
+        if (ftrace_disabled)
+                return -ENODEV;
+
+        /* should not be called from interrupt context */
+        spin_lock(&ftrace_lock);
+
+        for (pg = ftrace_pages_start; pg; pg = pg->next) {
+                for (i = 0; i < pg->index; i++) {
+                        rec = &pg->records[i];
+
+                        if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))
+                                continue;
+
+                        kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
+                        if (strcmp(str, buffer) == 0) {
+                                found = 1;
+                                for (j = 0; j < idx; j++)
+                                        if (array[j] == rec->ip) {
+                                                found = 0;
+                                                break;
+                                        }
+                                if (found)
+                                        array[idx] = rec->ip;
+                                break;
+                        }
+                }
+        }
+        spin_unlock(&ftrace_lock);
 
-        if (task)
-                kthread_stop(task);
+        return found ? 0 : -EINVAL;
 }
 
-static __init int ftrace_init_debugfs(void)
+static ssize_t
+ftrace_graph_write(struct file *file, const char __user *ubuf,
+                   size_t cnt, loff_t *ppos)
 {
-        struct dentry *d_tracer;
-        struct dentry *entry;
+        unsigned char buffer[FTRACE_BUFF_MAX+1];
+        unsigned long *array;
+        size_t read = 0;
+        ssize_t ret;
+        int index = 0;
+        char ch;
 
-        d_tracer = tracing_init_dentry();
+        if (!cnt || cnt < 0)
+                return 0;
+
+        mutex_lock(&graph_lock);
+
+        if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) {
+                ret = -EBUSY;
+                goto out;
+        }
+
+        if (file->f_mode & FMODE_READ) {
+                struct seq_file *m = file->private_data;
+                array = m->private;
+        } else
+                array = file->private_data;
+
+        ret = get_user(ch, ubuf++);
+        if (ret)
+                goto out;
+        read++;
+        cnt--;
+
+        /* skip white space */
+        while (cnt && isspace(ch)) {
+                ret = get_user(ch, ubuf++);
+                if (ret)
+                        goto out;
+                read++;
+                cnt--;
+        }
+
+        if (isspace(ch)) {
+                *ppos += read;
+                ret = read;
+                goto out;
+        }
+
+        while (cnt && !isspace(ch)) {
+                if (index < FTRACE_BUFF_MAX)
+                        buffer[index++] = ch;
+                else {
+                        ret = -EINVAL;
+                        goto out;
+                }
+                ret = get_user(ch, ubuf++);
+                if (ret)
+                        goto out;
+                read++;
+                cnt--;
+        }
+        buffer[index] = 0;
+
+        /* we allow only one at a time */
+        ret = ftrace_set_func(array, ftrace_graph_count, buffer);
+        if (ret)
+                goto out;
+
+        ftrace_graph_count++;
+
+        file->f_pos += read;
+
+        ret = read;
+ out:
+        mutex_unlock(&graph_lock);
+
+        return ret;
+}
+
+static const struct file_operations ftrace_graph_fops = {
+        .open = ftrace_graph_open,
+        .read = ftrace_graph_read,
+        .write = ftrace_graph_write,
+};
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
+{
+        struct dentry *entry;
 
         entry = debugfs_create_file("available_filter_functions", 0444,
                                     d_tracer, NULL, &ftrace_avail_fops);
@@ -1546,97 +1583,295 @@ static __init int ftrace_init_debugfs(void)
                 pr_warning("Could not create debugfs "
                            "'set_ftrace_notrace' entry\n");
 
-        entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer,
-                                    NULL, &ftraced_fops);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+        entry = debugfs_create_file("set_graph_function", 0444, d_tracer,
+                                    NULL,
+                                    &ftrace_graph_fops);
         if (!entry)
                 pr_warning("Could not create debugfs "
-                           "'ftraced_enabled' entry\n");
+                           "'set_graph_function' entry\n");
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
         return 0;
 }
 
-fs_initcall(ftrace_init_debugfs);
-
-static int __init ftrace_dynamic_init(void)
+static int ftrace_convert_nops(struct module *mod,
+                               unsigned long *start,
+                               unsigned long *end)
 {
-        struct task_struct *p;
+        unsigned long *p;
         unsigned long addr;
+        unsigned long flags;
+
+        mutex_lock(&ftrace_start_lock);
+        p = start;
+        while (p < end) {
+                addr = ftrace_call_adjust(*p++);
+                /*
+                 * Some architecture linkers will pad between
+                 * the different mcount_loc sections of different
+                 * object files to satisfy alignments.
+                 * Skip any NULL pointers.
+                 */
+                if (!addr)
+                        continue;
+                ftrace_record_ip(addr);
+        }
+
+        /* disable interrupts to prevent kstop machine */
+        local_irq_save(flags);
+        ftrace_update_code(mod);
+        local_irq_restore(flags);
+        mutex_unlock(&ftrace_start_lock);
+
+        return 0;
+}
+
+void ftrace_init_module(struct module *mod,
+                        unsigned long *start, unsigned long *end)
+{
+        if (ftrace_disabled || start == end)
+                return;
+        ftrace_convert_nops(mod, start, end);
+}
+
+extern unsigned long __start_mcount_loc[];
+extern unsigned long __stop_mcount_loc[];
+
+void __init ftrace_init(void)
+{
+        unsigned long count, addr, flags;
         int ret;
 
-        addr = (unsigned long)ftrace_record_ip;
+        /* Keep the ftrace pointer to the stub */
+        addr = (unsigned long)ftrace_stub;
 
-        stop_machine(ftrace_dyn_arch_init, &addr, NULL);
+        local_irq_save(flags);
+        ftrace_dyn_arch_init(&addr);
+        local_irq_restore(flags);
 
         /* ftrace_dyn_arch_init places the return code in addr */
-        if (addr) {
-                ret = (int)addr;
+        if (addr)
                 goto failed;
-        }
 
-        ret = ftrace_dyn_table_alloc();
-        if (ret)
-                goto failed;
+        count = __stop_mcount_loc - __start_mcount_loc;
 
-        p = kthread_run(ftraced, NULL, "ftraced");
-        if (IS_ERR(p)) {
-                ret = -1;
+        ret = ftrace_dyn_table_alloc(count);
+        if (ret)
                 goto failed;
-        }
 
         last_ftrace_enabled = ftrace_enabled = 1;
-        ftraced_task = p;
 
-        return 0;
+        ret = ftrace_convert_nops(NULL,
+                                  __start_mcount_loc,
+                                  __stop_mcount_loc);
 
+        return;
  failed:
         ftrace_disabled = 1;
-        return ret;
 }
 
-core_initcall(ftrace_dynamic_init);
 #else
-# define ftrace_startup()               do { } while (0)
-# define ftrace_shutdown()              do { } while (0)
+
+static int __init ftrace_nodyn_init(void)
+{
+        ftrace_enabled = 1;
+        return 0;
+}
+device_initcall(ftrace_nodyn_init);
+
+static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
+static inline void ftrace_startup_enable(int command) { }
+/* Keep as macros so we do not need to define the commands */
+# define ftrace_startup(command)        do { } while (0)
+# define ftrace_shutdown(command)       do { } while (0)
 # define ftrace_startup_sysctl()        do { } while (0)
 # define ftrace_shutdown_sysctl()       do { } while (0)
-# define ftrace_force_shutdown()        do { } while (0)
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
-/**
- * ftrace_kill_atomic - kill ftrace from critical sections
- *
- * This function should be used by panic code. It stops ftrace
- * but in a not so nice way. If you need to simply kill ftrace
- * from a non-atomic section, use ftrace_kill.
- */
-void ftrace_kill_atomic(void)
+static ssize_t
+ftrace_pid_read(struct file *file, char __user *ubuf,
+                       size_t cnt, loff_t *ppos)
 {
-        ftrace_disabled = 1;
-        ftrace_enabled = 0;
-#ifdef CONFIG_DYNAMIC_FTRACE
-        ftraced_suspend = -1;
-#endif
-        clear_ftrace_function();
+        char buf[64];
+        int r;
+
+        if (ftrace_pid_trace == ftrace_swapper_pid)
+                r = sprintf(buf, "swapper tasks\n");
+        else if (ftrace_pid_trace)
+                r = sprintf(buf, "%u\n", pid_nr(ftrace_pid_trace));
+        else
+                r = sprintf(buf, "no pid\n");
+
+        return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static void clear_ftrace_swapper(void)
+{
+        struct task_struct *p;
+        int cpu;
+
+        get_online_cpus();
+        for_each_online_cpu(cpu) {
+                p = idle_task(cpu);
+                clear_tsk_trace_trace(p);
+        }
+        put_online_cpus();
+}
+
+static void set_ftrace_swapper(void)
+{
+        struct task_struct *p;
+        int cpu;
+
+        get_online_cpus();
+        for_each_online_cpu(cpu) {
+                p = idle_task(cpu);
+                set_tsk_trace_trace(p);
+        }
+        put_online_cpus();
+}
+
+static void clear_ftrace_pid(struct pid *pid)
+{
+        struct task_struct *p;
+
+        do_each_pid_task(pid, PIDTYPE_PID, p) {
+                clear_tsk_trace_trace(p);
+        } while_each_pid_task(pid, PIDTYPE_PID, p);
+        put_pid(pid);
+}
+
+static void set_ftrace_pid(struct pid *pid)
+{
+        struct task_struct *p;
+
+        do_each_pid_task(pid, PIDTYPE_PID, p) {
+                set_tsk_trace_trace(p);
+        } while_each_pid_task(pid, PIDTYPE_PID, p);
+}
+
+static void clear_ftrace_pid_task(struct pid **pid)
+{
+        if (*pid == ftrace_swapper_pid)
+                clear_ftrace_swapper();
+        else
+                clear_ftrace_pid(*pid);
+
+        *pid = NULL;
+}
+
+static void set_ftrace_pid_task(struct pid *pid)
+{
+        if (pid == ftrace_swapper_pid)
+                set_ftrace_swapper();
+        else
+                set_ftrace_pid(pid);
+}
+
+static ssize_t
+ftrace_pid_write(struct file *filp, const char __user *ubuf,
+                   size_t cnt, loff_t *ppos)
+{
+        struct pid *pid;
+        char buf[64];
+        long val;
+        int ret;
+
+        if (cnt >= sizeof(buf))
+                return -EINVAL;
+
+        if (copy_from_user(&buf, ubuf, cnt))
+                return -EFAULT;
+
+        buf[cnt] = 0;
+
+        ret = strict_strtol(buf, 10, &val);
+        if (ret < 0)
+                return ret;
+
+        mutex_lock(&ftrace_start_lock);
+        if (val < 0) {
+                /* disable pid tracing */
+                if (!ftrace_pid_trace)
+                        goto out;
+
+                clear_ftrace_pid_task(&ftrace_pid_trace);
+
+        } else {
+                /* swapper task is special */
+                if (!val) {
+                        pid = ftrace_swapper_pid;
+                        if (pid == ftrace_pid_trace)
+                                goto out;
+                } else {
+                        pid = find_get_pid(val);
+
+                        if (pid == ftrace_pid_trace) {
+                                put_pid(pid);
+                                goto out;
+                        }
+                }
+
+                if (ftrace_pid_trace)
+                        clear_ftrace_pid_task(&ftrace_pid_trace);
+
+                if (!pid)
+                        goto out;
+
+                ftrace_pid_trace = pid;
+
+                set_ftrace_pid_task(ftrace_pid_trace);
+        }
+
+        /* update the function call */
+        ftrace_update_pid_func();
+        ftrace_startup_enable(0);
+
+ out:
+        mutex_unlock(&ftrace_start_lock);
+
+        return cnt;
 }
 
+static struct file_operations ftrace_pid_fops = {
+        .read = ftrace_pid_read,
+        .write = ftrace_pid_write,
+};
+
+static __init int ftrace_init_debugfs(void)
+{
+        struct dentry *d_tracer;
+        struct dentry *entry;
+
+        d_tracer = tracing_init_dentry();
+        if (!d_tracer)
+                return 0;
+
+        ftrace_init_dyn_debugfs(d_tracer);
+
+        entry = debugfs_create_file("set_ftrace_pid", 0644, d_tracer,
+                                    NULL, &ftrace_pid_fops);
+        if (!entry)
+                pr_warning("Could not create debugfs "
+                           "'set_ftrace_pid' entry\n");
+        return 0;
+}
+
+fs_initcall(ftrace_init_debugfs);
+
 /**
- * ftrace_kill - totally shutdown ftrace
+ * ftrace_kill - kill ftrace
  *
- * This is a safety measure. If something was detected that seems
- * wrong, calling this function will keep ftrace from doing
- * any more modifications, and updates.
- * used when something went wrong.
+ * This function should be used by panic code. It stops ftrace
+ * but in a not so nice way. If you need to simply kill ftrace
+ * from a non-atomic section, use ftrace_kill.
  */
 void ftrace_kill(void)
 {
-        mutex_lock(&ftrace_sysctl_lock);
         ftrace_disabled = 1;
         ftrace_enabled = 0;
-
         clear_ftrace_function();
-        mutex_unlock(&ftrace_sysctl_lock);
-
-        /* Try to totally disable ftrace */
-        ftrace_force_shutdown();
 }
 
 /**
@@ -1658,10 +1893,11 @@ int register_ftrace_function(struct ftrace_ops *ops)
                 return -1;
 
         mutex_lock(&ftrace_sysctl_lock);
+
         ret = __register_ftrace_function(ops);
-        ftrace_startup();
-        mutex_unlock(&ftrace_sysctl_lock);
+        ftrace_startup(0);
 
+        mutex_unlock(&ftrace_sysctl_lock);
         return ret;
 }
 
@@ -1677,7 +1913,7 @@ int unregister_ftrace_function(struct ftrace_ops *ops)
 
         mutex_lock(&ftrace_sysctl_lock);
         ret = __unregister_ftrace_function(ops);
-        ftrace_shutdown();
+        ftrace_shutdown(0);
         mutex_unlock(&ftrace_sysctl_lock);
 
         return ret;
@@ -1725,3 +1961,154 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
         mutex_unlock(&ftrace_sysctl_lock);
         return ret;
 }
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+static atomic_t ftrace_graph_active;
+
+int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
+{
+        return 0;
+}
+
+/* The callbacks that hook a function */
+trace_func_graph_ret_t ftrace_graph_return =
+                        (trace_func_graph_ret_t)ftrace_stub;
+trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
+
+/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
+static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
+{
+        int i;
+        int ret = 0;
+        unsigned long flags;
+        int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
+        struct task_struct *g, *t;
+
+        for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
+                ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
+                                        * sizeof(struct ftrace_ret_stack),
+                                        GFP_KERNEL);
+                if (!ret_stack_list[i]) {
+                        start = 0;
+                        end = i;
+                        ret = -ENOMEM;
+                        goto free;
+                }
+        }
+
+        read_lock_irqsave(&tasklist_lock, flags);
+        do_each_thread(g, t) {
+                if (start == end) {
+                        ret = -EAGAIN;
+                        goto unlock;
+                }
+
+                if (t->ret_stack == NULL) {
+                        t->curr_ret_stack = -1;
+                        /* Make sure IRQs see the -1 first: */
+                        barrier();
+                        t->ret_stack = ret_stack_list[start++];
+                        atomic_set(&t->tracing_graph_pause, 0);
+                        atomic_set(&t->trace_overrun, 0);
+                }
+        } while_each_thread(g, t);
+
+unlock:
+        read_unlock_irqrestore(&tasklist_lock, flags);
+free:
+        for (i = start; i < end; i++)
+                kfree(ret_stack_list[i]);
+        return ret;
+}
+
+/* Allocate a return stack for each task */
+static int start_graph_tracing(void)
+{
+        struct ftrace_ret_stack **ret_stack_list;
+        int ret;
+
+        ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
+                                sizeof(struct ftrace_ret_stack *),
+                                GFP_KERNEL);
+
+        if (!ret_stack_list)
+                return -ENOMEM;
+
+        do {
+                ret = alloc_retstack_tasklist(ret_stack_list);
+        } while (ret == -EAGAIN);
+
+        kfree(ret_stack_list);
+        return ret;
+}
+
+int register_ftrace_graph(trace_func_graph_ret_t retfunc,
+                        trace_func_graph_ent_t entryfunc)
+{
+        int ret = 0;
+
+        mutex_lock(&ftrace_sysctl_lock);
+
+        atomic_inc(&ftrace_graph_active);
+        ret = start_graph_tracing();
+        if (ret) {
+                atomic_dec(&ftrace_graph_active);
+                goto out;
+        }
+
+        ftrace_graph_return = retfunc;
+        ftrace_graph_entry = entryfunc;
+
+        ftrace_startup(FTRACE_START_FUNC_RET);
+
+out:
+        mutex_unlock(&ftrace_sysctl_lock);
+        return ret;
+}
+
+void unregister_ftrace_graph(void)
+{
+        mutex_lock(&ftrace_sysctl_lock);
+
+        atomic_dec(&ftrace_graph_active);
+        ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
+        ftrace_graph_entry = ftrace_graph_entry_stub;
+        ftrace_shutdown(FTRACE_STOP_FUNC_RET);
+
+        mutex_unlock(&ftrace_sysctl_lock);
+}
+
+/* Allocate a return stack for newly created task */
+void ftrace_graph_init_task(struct task_struct *t)
+{
+        if (atomic_read(&ftrace_graph_active)) {
+                t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
+                                * sizeof(struct ftrace_ret_stack),
+                                GFP_KERNEL);
+                if (!t->ret_stack)
+                        return;
+                t->curr_ret_stack = -1;
+                atomic_set(&t->tracing_graph_pause, 0);
+                atomic_set(&t->trace_overrun, 0);
+        } else
+                t->ret_stack = NULL;
+}
+
+void ftrace_graph_exit_task(struct task_struct *t)
+{
+        struct ftrace_ret_stack *ret_stack = t->ret_stack;
+
+        t->ret_stack = NULL;
+        /* NULL must become visible to IRQs before we free it: */
+        barrier();
+
+        kfree(ret_stack);
+}
+
+void ftrace_graph_stop(void)
+{
+        ftrace_stop();
+}
+#endif
+