Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace

5 files changed, 946 insertions, 197 deletions

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 106b7909d500..b331e216d8a1 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -95,10 +95,41 @@ stack_trace_sysctl(struct ctl_table *table, int write,
                    loff_t *ppos);
 #endif
 
+struct ftrace_func_command {
+        struct list_head        list;
+        char                    *name;
+        int                     (*func)(char *func, char *cmd,
+                                        char *params, int enable);
+};
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 /* asm/ftrace.h must be defined for archs supporting dynamic ftrace */
 #include <asm/ftrace.h>
 
+struct seq_file;
+
+struct ftrace_hook_ops {
+        void                    (*func)(unsigned long ip,
+                                        unsigned long parent_ip,
+                                        void **data);
+        int                     (*callback)(unsigned long ip, void **data);
+        void                    (*free)(void **data);
+        int                     (*print)(struct seq_file *m,
+                                         unsigned long ip,
+                                         struct ftrace_hook_ops *ops,
+                                         void *data);
+};
+
+extern int
+register_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
+                              void *data);
+extern void
+unregister_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
+                                void *data);
+extern void
+unregister_ftrace_function_hook_func(char *glob, struct ftrace_hook_ops *ops);
+extern void unregister_ftrace_function_hook_all(char *glob);
+
 enum {
         FTRACE_FL_FREE          = (1 << 0),
         FTRACE_FL_FAILED        = (1 << 1),
@@ -119,6 +150,9 @@ struct dyn_ftrace {
 int ftrace_force_update(void);
 void ftrace_set_filter(unsigned char *buf, int len, int reset);
 
+int register_ftrace_command(struct ftrace_func_command *cmd);
+int unregister_ftrace_command(struct ftrace_func_command *cmd);
+
 /* defined in arch */
 extern int ftrace_ip_converted(unsigned long ip);
 extern int ftrace_dyn_arch_init(void *data);
@@ -202,6 +236,12 @@ extern void ftrace_enable_daemon(void);
 # define ftrace_disable_daemon()                do { } while (0)
 # define ftrace_enable_daemon()                 do { } while (0)
 static inline void ftrace_release(void *start, unsigned long size) { }
+static inline int register_ftrace_command(struct ftrace_func_command *cmd)
+{
+}
+static inline int unregister_ftrace_command(char *cmd_name)
+{
+}
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
 /* totally disable ftrace - can not re-enable after this */
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index 8e6646a54acf..f5e793d69bd3 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -128,10 +128,12 @@ void ring_buffer_normalize_time_stamp(int cpu, u64 *ts);
 void tracing_on(void);
 void tracing_off(void);
 void tracing_off_permanent(void);
+int tracing_is_on(void);
 #else
 static inline void tracing_on(void) { }
 static inline void tracing_off(void) { }
 static inline void tracing_off_permanent(void) { }
+static inline int tracing_is_on(void) { return 0; }
 #endif
 
 void *ring_buffer_alloc_read_page(struct ring_buffer *buffer);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1796e018fbff..6533c1d20155 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -27,6 +27,7 @@
 #include <linux/sysctl.h>
 #include <linux/ctype.h>
 #include <linux/list.h>
+#include <linux/hash.h>
 
 #include <asm/ftrace.h>
 
@@ -44,14 +45,14 @@
                         ftrace_kill();          \
         } while (0)
 
+/* hash bits for specific function selection */
+#define FTRACE_HASH_BITS 7
+#define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
+
 /* 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;
 
@@ -61,9 +62,7 @@ int function_trace_stop;
  */
 static int ftrace_disabled __read_mostly;
 
-static DEFINE_SPINLOCK(ftrace_lock);
-static DEFINE_MUTEX(ftrace_sysctl_lock);
-static DEFINE_MUTEX(ftrace_start_lock);
+static DEFINE_MUTEX(ftrace_lock);
 
 static struct ftrace_ops ftrace_list_end __read_mostly =
 {
@@ -134,9 +133,6 @@ static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
 
 static int __register_ftrace_function(struct ftrace_ops *ops)
 {
-        /* should not be called from interrupt context */
-        spin_lock(&ftrace_lock);
-
         ops->next = ftrace_list;
         /*
          * We are entering ops into the ftrace_list but another
@@ -172,18 +168,12 @@ static int __register_ftrace_function(struct ftrace_ops *ops)
 #endif
         }
 
-        spin_unlock(&ftrace_lock);
-
         return 0;
 }
 
 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);
 
         /*
          * If we are removing the last function, then simply point
@@ -192,17 +182,15 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
         if (ftrace_list == ops && ops->next == &ftrace_list_end) {
                 ftrace_trace_function = ftrace_stub;
                 ftrace_list = &ftrace_list_end;
-                goto out;
+                return 0;
         }
 
         for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next)
                 if (*p == ops)
                         break;
 
-        if (*p != ops) {
-                ret = -1;
-                goto out;
-        }
+        if (*p != ops)
+                return -1;
 
         *p = (*p)->next;
 
@@ -223,18 +211,14 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
                 }
         }
 
- out:
-        spin_unlock(&ftrace_lock);
-
-        return ret;
+        return 0;
 }
 
 static void ftrace_update_pid_func(void)
 {
         ftrace_func_t func;
 
-        /* should not be called from interrupt context */
-        spin_lock(&ftrace_lock);
+        mutex_lock(&ftrace_lock);
 
         if (ftrace_trace_function == ftrace_stub)
                 goto out;
@@ -256,7 +240,7 @@ static void ftrace_update_pid_func(void)
 #endif
 
  out:
-        spin_unlock(&ftrace_lock);
+        mutex_unlock(&ftrace_lock);
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE
@@ -264,6 +248,21 @@ static void ftrace_update_pid_func(void)
 # error Dynamic ftrace depends on MCOUNT_RECORD
 #endif
 
+/* set when tracing only a pid */
+struct pid *ftrace_pid_trace;
+static struct pid * const ftrace_swapper_pid = &init_struct_pid;
+static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
+
+struct ftrace_func_hook {
+        struct hlist_node       node;
+        struct ftrace_hook_ops  *ops;
+        unsigned long           flags;
+        unsigned long           ip;
+        void                    *data;
+        struct rcu_head         rcu;
+};
+
+
 enum {
         FTRACE_ENABLE_CALLS             = (1 << 0),
         FTRACE_DISABLE_CALLS            = (1 << 1),
@@ -297,6 +296,19 @@ static struct ftrace_page	*ftrace_pages;
 
 static struct dyn_ftrace *ftrace_free_records;
 
+/*
+ * This is a double for. Do not use 'break' to break out of the loop,
+ * you must use a goto.
+ */
+#define do_for_each_ftrace_rec(pg, rec)                                 \
+        for (pg = ftrace_pages_start; pg; pg = pg->next) {              \
+                int _____i;                                             \
+                for (_____i = 0; _____i < pg->index; _____i++) {        \
+                        rec = &pg->records[_____i];
+
+#define while_for_each_ftrace_rec()             \
+                }                               \
+        }
 
 #ifdef CONFIG_KPROBES
 
@@ -341,23 +353,16 @@ void ftrace_release(void *start, unsigned long size)
         struct ftrace_page *pg;
         unsigned long s = (unsigned long)start;
         unsigned long e = s + size;
-        int i;
 
         if (ftrace_disabled || !start)
                 return;
 
-        /* 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->ip >= s) && (rec->ip < e))
-                                ftrace_free_rec(rec);
-                }
-        }
-        spin_unlock(&ftrace_lock);
+        mutex_lock(&ftrace_lock);
+        do_for_each_ftrace_rec(pg, rec) {
+                if ((rec->ip >= s) && (rec->ip < e))
+                        ftrace_free_rec(rec);
+        } while_for_each_ftrace_rec();
+        mutex_unlock(&ftrace_lock);
 }
 
 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
@@ -523,41 +528,37 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
 
 static void ftrace_replace_code(int enable)
 {
-        int i, failed;
+        int failed;
         struct dyn_ftrace *rec;
         struct ftrace_page *pg;
 
-        for (pg = ftrace_pages_start; pg; pg = pg->next) {
-                for (i = 0; i < pg->index; i++) {
-                        rec = &pg->records[i];
-
-                        /*
-                         * Skip over free records and records that have
-                         * failed.
-                         */
-                        if (rec->flags & FTRACE_FL_FREE ||
-                            rec->flags & FTRACE_FL_FAILED)
-                                continue;
+        do_for_each_ftrace_rec(pg, rec) {
+                /*
+                 * 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 */
-                        if (get_kprobe((void *)rec->ip)) {
-                                freeze_record(rec);
-                                continue;
-                        } else {
-                                unfreeze_record(rec);
-                        }
+                /* ignore updates to this record's mcount site */
+                if (get_kprobe((void *)rec->ip)) {
+                        freeze_record(rec);
+                        continue;
+                } else {
+                        unfreeze_record(rec);
+                }
 
-                        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_free_rec(rec);
-                                } else
-                                        ftrace_bug(failed, rec->ip);
-                        }
+                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_free_rec(rec);
+                        } else
+                                ftrace_bug(failed, rec->ip);
                 }
-        }
+        } while_for_each_ftrace_rec();
 }
 
 static int
@@ -623,13 +624,10 @@ static void ftrace_startup(int command)
         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)
@@ -637,7 +635,6 @@ static void ftrace_shutdown(int command)
         if (unlikely(ftrace_disabled))
                 return;
 
-        mutex_lock(&ftrace_start_lock);
         ftrace_start_up--;
         if (!ftrace_start_up)
                 command |= FTRACE_DISABLE_CALLS;
@@ -648,11 +645,9 @@ static void ftrace_shutdown(int command)
         }
 
         if (!command || !ftrace_enabled)
-                goto out;
+                return;
 
         ftrace_run_update_code(command);
- out:
-        mutex_unlock(&ftrace_start_lock);
 }
 
 static void ftrace_startup_sysctl(void)
@@ -662,7 +657,6 @@ static void ftrace_startup_sysctl(void)
         if (unlikely(ftrace_disabled))
                 return;
 
-        mutex_lock(&ftrace_start_lock);
         /* Force update next time */
         saved_ftrace_func = NULL;
         /* ftrace_start_up is true if we want ftrace running */
@@ -670,7 +664,6 @@ static void ftrace_startup_sysctl(void)
                 command |= FTRACE_ENABLE_CALLS;
 
         ftrace_run_update_code(command);
-        mutex_unlock(&ftrace_start_lock);
 }
 
 static void ftrace_shutdown_sysctl(void)
@@ -680,13 +673,11 @@ static void ftrace_shutdown_sysctl(void)
         if (unlikely(ftrace_disabled))
                 return;
 
-        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(&ftrace_start_lock);
 }
 
 static cycle_t          ftrace_update_time;
@@ -773,12 +764,15 @@ enum {
         FTRACE_ITER_CONT        = (1 << 1),
         FTRACE_ITER_NOTRACE     = (1 << 2),
         FTRACE_ITER_FAILURES    = (1 << 3),
+        FTRACE_ITER_PRINTALL    = (1 << 4),
+        FTRACE_ITER_HASH        = (1 << 5),
 };
 
 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
 
 struct ftrace_iterator {
         struct ftrace_page      *pg;
+        int                     hidx;
         int                     idx;
         unsigned                flags;
         unsigned char           buffer[FTRACE_BUFF_MAX+1];
@@ -787,15 +781,89 @@ struct ftrace_iterator {
 };
 
 static void *
+t_hash_next(struct seq_file *m, void *v, loff_t *pos)
+{
+        struct ftrace_iterator *iter = m->private;
+        struct hlist_node *hnd = v;
+        struct hlist_head *hhd;
+
+        WARN_ON(!(iter->flags & FTRACE_ITER_HASH));
+
+        (*pos)++;
+
+ retry:
+        if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
+                return NULL;
+
+        hhd = &ftrace_func_hash[iter->hidx];
+
+        if (hlist_empty(hhd)) {
+                iter->hidx++;
+                hnd = NULL;
+                goto retry;
+        }
+
+        if (!hnd)
+                hnd = hhd->first;
+        else {
+                hnd = hnd->next;
+                if (!hnd) {
+                        iter->hidx++;
+                        goto retry;
+                }
+        }
+
+        return hnd;
+}
+
+static void *t_hash_start(struct seq_file *m, loff_t *pos)
+{
+        struct ftrace_iterator *iter = m->private;
+        void *p = NULL;
+
+        iter->flags |= FTRACE_ITER_HASH;
+
+        return t_hash_next(m, p, pos);
+}
+
+static int t_hash_show(struct seq_file *m, void *v)
+{
+        struct ftrace_func_hook *rec;
+        struct hlist_node *hnd = v;
+        char str[KSYM_SYMBOL_LEN];
+
+        rec = hlist_entry(hnd, struct ftrace_func_hook, 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);
+
+        if (rec->data)
+                seq_printf(m, ":%p", rec->data);
+        seq_putc(m, '\n');
+
+        return 0;
+}
+
+static void *
 t_next(struct seq_file *m, void *v, loff_t *pos)
 {
         struct ftrace_iterator *iter = m->private;
         struct dyn_ftrace *rec = NULL;
 
+        if (iter->flags & FTRACE_ITER_HASH)
+                return t_hash_next(m, v, pos);
+
         (*pos)++;
 
-        /* should not be called from interrupt context */
-        spin_lock(&ftrace_lock);
+        if (iter->flags & FTRACE_ITER_PRINTALL)
+                return NULL;
+
  retry:
         if (iter->idx >= iter->pg->index) {
                 if (iter->pg->next) {
@@ -824,7 +892,6 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
                         goto retry;
                 }
         }
-        spin_unlock(&ftrace_lock);
 
         return rec;
 }
@@ -834,6 +901,23 @@ static void *t_start(struct seq_file *m, loff_t *pos)
         struct ftrace_iterator *iter = m->private;
         void *p = NULL;
 
+        mutex_lock(&ftrace_lock);
+        /*
+         * For set_ftrace_filter reading, if we have the filter
+         * off, we can short cut and just print out that all
+         * functions are enabled.
+         */
+        if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) {
+                if (*pos > 0)
+                        return t_hash_start(m, pos);
+                iter->flags |= FTRACE_ITER_PRINTALL;
+                (*pos)++;
+                return iter;
+        }
+
+        if (iter->flags & FTRACE_ITER_HASH)
+                return t_hash_start(m, pos);
+
         if (*pos > 0) {
                 if (iter->idx < 0)
                         return p;
@@ -843,18 +927,31 @@ static void *t_start(struct seq_file *m, loff_t *pos)
 
         p = t_next(m, p, pos);
 
+        if (!p)
+                return t_hash_start(m, pos);
+
         return p;
 }
 
 static void t_stop(struct seq_file *m, void *p)
 {
+        mutex_unlock(&ftrace_lock);
 }
 
 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);
+
+        if (iter->flags & FTRACE_ITER_PRINTALL) {
+                seq_printf(m, "#### all functions enabled ####\n");
+                return 0;
+        }
+
         if (!rec)
                 return 0;
 
@@ -933,23 +1030,16 @@ static void ftrace_filter_reset(int enable)
         struct ftrace_page *pg;
         struct dyn_ftrace *rec;
         unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
-        unsigned i;
 
-        /* should not be called from interrupt context */
-        spin_lock(&ftrace_lock);
+        mutex_lock(&ftrace_lock);
         if (enable)
                 ftrace_filtered = 0;
-        pg = ftrace_pages_start;
-        while (pg) {
-                for (i = 0; i < pg->index; i++) {
-                        rec = &pg->records[i];
-                        if (rec->flags & FTRACE_FL_FAILED)
-                                continue;
-                        rec->flags &= ~type;
-                }
-                pg = pg->next;
-        }
-        spin_unlock(&ftrace_lock);
+        do_for_each_ftrace_rec(pg, rec) {
+                if (rec->flags & FTRACE_FL_FAILED)
+                        continue;
+                rec->flags &= ~type;
+        } while_for_each_ftrace_rec();
+        mutex_unlock(&ftrace_lock);
 }
 
 static int
@@ -1030,86 +1120,533 @@ enum {
         MATCH_END_ONLY,
 };
 
-static void
-ftrace_match(unsigned char *buff, int len, int enable)
+/*
+ * (static function - no need for kernel doc)
+ *
+ * Pass in a buffer containing a glob and this function will
+ * set search to point to the search part of the buffer and
+ * return the type of search it is (see enum above).
+ * This does modify buff.
+ *
+ * Returns enum type.
+ *  search returns the pointer to use for comparison.
+ *  not returns 1 if buff started with a '!'
+ *     0 otherwise.
+ */
+static int
+ftrace_setup_glob(char *buff, int len, char **search, int *not)
 {
-        char str[KSYM_SYMBOL_LEN];
-        char *search = NULL;
-        struct ftrace_page *pg;
-        struct dyn_ftrace *rec;
         int type = MATCH_FULL;
-        unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
-        unsigned i, match = 0, search_len = 0;
-        int not = 0;
+        int i;
 
         if (buff[0] == '!') {
-                not = 1;
+                *not = 1;
                 buff++;
                 len--;
-        }
+        } else
+                *not = 0;
+
+        *search = buff;
 
         for (i = 0; i < len; i++) {
                 if (buff[i] == '*') {
                         if (!i) {
-                                search = buff + i + 1;
+                                *search = buff + 1;
                                 type = MATCH_END_ONLY;
-                                search_len = len - (i + 1);
                         } else {
-                                if (type == MATCH_END_ONLY) {
+                                if (type == MATCH_END_ONLY)
                                         type = MATCH_MIDDLE_ONLY;
-                                } else {
-                                        match = i;
+                                else
                                         type = MATCH_FRONT_ONLY;
-                                }
                                 buff[i] = 0;
                                 break;
                         }
                 }
         }
 
-        /* should not be called from interrupt context */
-        spin_lock(&ftrace_lock);
-        if (enable)
-                ftrace_filtered = 1;
-        pg = ftrace_pages_start;
-        while (pg) {
-                for (i = 0; i < pg->index; i++) {
-                        int matched = 0;
-                        char *ptr;
-
-                        rec = &pg->records[i];
-                        if (rec->flags & FTRACE_FL_FAILED)
+        return type;
+}
+
+static int ftrace_match(char *str, char *regex, int len, int type)
+{
+        int matched = 0;
+        char *ptr;
+
+        switch (type) {
+        case MATCH_FULL:
+                if (strcmp(str, regex) == 0)
+                        matched = 1;
+                break;
+        case MATCH_FRONT_ONLY:
+                if (strncmp(str, regex, len) == 0)
+                        matched = 1;
+                break;
+        case MATCH_MIDDLE_ONLY:
+                if (strstr(str, regex))
+                        matched = 1;
+                break;
+        case MATCH_END_ONLY:
+                ptr = strstr(str, regex);
+                if (ptr && (ptr[len] == 0))
+                        matched = 1;
+                break;
+        }
+
+        return matched;
+}
+
+static int
+ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type)
+{
+        char str[KSYM_SYMBOL_LEN];
+
+        kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
+        return ftrace_match(str, regex, len, type);
+}
+
+static void ftrace_match_records(char *buff, int len, int enable)
+{
+        char *search;
+        struct ftrace_page *pg;
+        struct dyn_ftrace *rec;
+        int type;
+        unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
+        unsigned search_len;
+        int not;
+
+        type = ftrace_setup_glob(buff, len, &search, &not);
+
+        search_len = strlen(search);
+
+        mutex_lock(&ftrace_lock);
+        do_for_each_ftrace_rec(pg, rec) {
+
+                if (rec->flags & FTRACE_FL_FAILED)
+                        continue;
+
+                if (ftrace_match_record(rec, search, search_len, type)) {
+                        if (not)
+                                rec->flags &= ~flag;
+                        else
+                                rec->flags |= flag;
+                }
+                /*
+                 * Only enable filtering if we have a function that
+                 * is filtered on.
+                 */
+                if (enable && (rec->flags & FTRACE_FL_FILTER))
+                        ftrace_filtered = 1;
+        } while_for_each_ftrace_rec();
+        mutex_unlock(&ftrace_lock);
+}
+
+static int
+ftrace_match_module_record(struct dyn_ftrace *rec, char *mod,
+                           char *regex, int len, int type)
+{
+        char str[KSYM_SYMBOL_LEN];
+        char *modname;
+
+        kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
+
+        if (!modname || strcmp(modname, mod))
+                return 0;
+
+        /* blank search means to match all funcs in the mod */
+        if (len)
+                return ftrace_match(str, regex, len, type);
+        else
+                return 1;
+}
+
+static void ftrace_match_module_records(char *buff, char *mod, int enable)
+{
+        char *search = buff;
+        struct ftrace_page *pg;
+        struct dyn_ftrace *rec;
+        int type = MATCH_FULL;
+        unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
+        unsigned search_len = 0;
+        int not = 0;
+
+        /* blank or '*' mean the same */
+        if (strcmp(buff, "*") == 0)
+                buff[0] = 0;
+
+        /* handle the case of 'dont filter this module' */
+        if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
+                buff[0] = 0;
+                not = 1;
+        }
+
+        if (strlen(buff)) {
+                type = ftrace_setup_glob(buff, strlen(buff), &search, &not);
+                search_len = strlen(search);
+        }
+
+        mutex_lock(&ftrace_lock);
+        do_for_each_ftrace_rec(pg, rec) {
+
+                if (rec->flags & FTRACE_FL_FAILED)
+                        continue;
+
+                if (ftrace_match_module_record(rec, mod,
+                                               search, search_len, type)) {
+                        if (not)
+                                rec->flags &= ~flag;
+                        else
+                                rec->flags |= flag;
+                }
+                if (enable && (rec->flags & FTRACE_FL_FILTER))
+                        ftrace_filtered = 1;
+
+        } while_for_each_ftrace_rec();
+        mutex_unlock(&ftrace_lock);
+}
+
+/*
+ * We register the module command as a template to show others how
+ * to register the a command as well.
+ */
+
+static int
+ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
+{
+        char *mod;
+
+        /*
+         * cmd == 'mod' because we only registered this func
+         * for the 'mod' ftrace_func_command.
+         * But if you register one func with multiple commands,
+         * you can tell which command was used by the cmd
+         * parameter.
+         */
+
+        /* we must have a module name */
+        if (!param)
+                return -EINVAL;
+
+        mod = strsep(&param, ":");
+        if (!strlen(mod))
+                return -EINVAL;
+
+        ftrace_match_module_records(func, mod, enable);
+        return 0;
+}
+
+static struct ftrace_func_command ftrace_mod_cmd = {
+        .name                   = "mod",
+        .func                   = ftrace_mod_callback,
+};
+
+static int __init ftrace_mod_cmd_init(void)
+{
+        return register_ftrace_command(&ftrace_mod_cmd);
+}
+device_initcall(ftrace_mod_cmd_init);
+
+static void
+function_trace_hook_call(unsigned long ip, unsigned long parent_ip)
+{
+        struct ftrace_func_hook *entry;
+        struct hlist_head *hhd;
+        struct hlist_node *n;
+        unsigned long key;
+        int resched;
+
+        key = hash_long(ip, FTRACE_HASH_BITS);
+
+        hhd = &ftrace_func_hash[key];
+
+        if (hlist_empty(hhd))
+                return;
+
+        /*
+         * Disable preemption for these calls to prevent a RCU grace
+         * period. This syncs the hash iteration and freeing of items
+         * on the hash. rcu_read_lock is too dangerous here.
+         */
+        resched = ftrace_preempt_disable();
+        hlist_for_each_entry_rcu(entry, n, hhd, node) {
+                if (entry->ip == ip)
+                        entry->ops->func(ip, parent_ip, &entry->data);
+        }
+        ftrace_preempt_enable(resched);
+}
+
+static struct ftrace_ops trace_hook_ops __read_mostly =
+{
+        .func = function_trace_hook_call,
+};
+
+static int ftrace_hook_registered;
+
+static void __enable_ftrace_function_hook(void)
+{
+        int i;
+
+        if (ftrace_hook_registered)
+                return;
+
+        for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
+                struct hlist_head *hhd = &ftrace_func_hash[i];
+                if (hhd->first)
+                        break;
+        }
+        /* Nothing registered? */
+        if (i == FTRACE_FUNC_HASHSIZE)
+                return;
+
+        __register_ftrace_function(&trace_hook_ops);
+        ftrace_startup(0);
+        ftrace_hook_registered = 1;
+}
+
+static void __disable_ftrace_function_hook(void)
+{
+        int i;
+
+        if (!ftrace_hook_registered)
+                return;
+
+        for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
+                struct hlist_head *hhd = &ftrace_func_hash[i];
+                if (hhd->first)
+                        return;
+        }
+
+        /* no more funcs left */
+        __unregister_ftrace_function(&trace_hook_ops);
+        ftrace_shutdown(0);
+        ftrace_hook_registered = 0;
+}
+
+
+static void ftrace_free_entry_rcu(struct rcu_head *rhp)
+{
+        struct ftrace_func_hook *entry =
+                container_of(rhp, struct ftrace_func_hook, rcu);
+
+        if (entry->ops->free)
+                entry->ops->free(&entry->data);
+        kfree(entry);
+}
+
+
+int
+register_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
+                              void *data)
+{
+        struct ftrace_func_hook *entry;
+        struct ftrace_page *pg;
+        struct dyn_ftrace *rec;
+        unsigned long key;
+        int type, len, not;
+        int count = 0;
+        char *search;
+
+        type = ftrace_setup_glob(glob, strlen(glob), &search, &not);
+        len = strlen(search);
+
+        /* we do not support '!' for function hooks */
+        if (WARN_ON(not))
+                return -EINVAL;
+
+        mutex_lock(&ftrace_lock);
+        do_for_each_ftrace_rec(pg, rec) {
+
+                if (rec->flags & FTRACE_FL_FAILED)
+                        continue;
+
+                if (!ftrace_match_record(rec, search, len, type))
+                        continue;
+
+                entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+                if (!entry) {
+                        /* If we did not hook to any, then return error */
+                        if (!count)
+                                count = -ENOMEM;
+                        goto out_unlock;
+                }
+
+                count++;
+
+                entry->data = data;
+
+                /*
+                 * The caller might want to do something special
+                 * for each function we find. We call the callback
+                 * to give the caller an opportunity to do so.
+                 */
+                if (ops->callback) {
+                        if (ops->callback(rec->ip, &entry->data) < 0) {
+                                /* caller does not like this func */
+                                kfree(entry);
                                 continue;
-                        kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
-                        switch (type) {
-                        case MATCH_FULL:
-                                if (strcmp(str, buff) == 0)
-                                        matched = 1;
-                                break;
-                        case MATCH_FRONT_ONLY:
-                                if (memcmp(str, buff, match) == 0)
-                                        matched = 1;
-                                break;
-                        case MATCH_MIDDLE_ONLY:
-                                if (strstr(str, search))
-                                        matched = 1;
-                                break;
-                        case MATCH_END_ONLY:
-                                ptr = strstr(str, search);
-                                if (ptr && (ptr[search_len] == 0))
-                                        matched = 1;
-                                break;
                         }
-                        if (matched) {
-                                if (not)
-                                        rec->flags &= ~flag;
-                                else
-                                        rec->flags |= flag;
+                }
+
+                entry->ops = ops;
+                entry->ip = rec->ip;
+
+                key = hash_long(entry->ip, FTRACE_HASH_BITS);
+                hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
+
+        } while_for_each_ftrace_rec();
+        __enable_ftrace_function_hook();
+
+ out_unlock:
+        mutex_unlock(&ftrace_lock);
+
+        return count;
+}
+
+enum {
+        HOOK_TEST_FUNC          = 1,
+        HOOK_TEST_DATA          = 2
+};
+
+static void
+__unregister_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
+                                  void *data, int flags)
+{
+        struct ftrace_func_hook *entry;
+        struct hlist_node *n, *tmp;
+        char str[KSYM_SYMBOL_LEN];
+        int type = MATCH_FULL;
+        int i, len = 0;
+        char *search;
+
+        if (glob && (strcmp(glob, "*") || !strlen(glob)))
+                glob = NULL;
+        else {
+                int not;
+
+                type = ftrace_setup_glob(glob, strlen(glob), &search, &not);
+                len = strlen(search);
+
+                /* we do not support '!' for function hooks */
+                if (WARN_ON(not))
+                        return;
+        }
+
+        mutex_lock(&ftrace_lock);
+        for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
+                struct hlist_head *hhd = &ftrace_func_hash[i];
+
+                hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
+
+                        /* break up if statements for readability */
+                        if ((flags & HOOK_TEST_FUNC) && entry->ops != ops)
+                                continue;
+
+                        if ((flags & HOOK_TEST_DATA) && entry->data != data)
+                                continue;
+
+                        /* do this last, since it is the most expensive */
+                        if (glob) {
+                                kallsyms_lookup(entry->ip, NULL, NULL,
+                                                NULL, str);
+                                if (!ftrace_match(str, glob, len, type))
+                                        continue;
                         }
+
+                        hlist_del(&entry->node);
+                        call_rcu(&entry->rcu, ftrace_free_entry_rcu);
                 }
-                pg = pg->next;
         }
-        spin_unlock(&ftrace_lock);
+        __disable_ftrace_function_hook();
+        mutex_unlock(&ftrace_lock);
+}
+
+void
+unregister_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
+                                void *data)
+{
+        __unregister_ftrace_function_hook(glob, ops, data,
+                                          HOOK_TEST_FUNC | HOOK_TEST_DATA);
+}
+
+void
+unregister_ftrace_function_hook_func(char *glob, struct ftrace_hook_ops *ops)
+{
+        __unregister_ftrace_function_hook(glob, ops, NULL, HOOK_TEST_FUNC);
+}
+
+void unregister_ftrace_function_hook_all(char *glob)
+{
+        __unregister_ftrace_function_hook(glob, NULL, NULL, 0);
+}
+
+static LIST_HEAD(ftrace_commands);
+static DEFINE_MUTEX(ftrace_cmd_mutex);
+
+int register_ftrace_command(struct ftrace_func_command *cmd)
+{
+        struct ftrace_func_command *p;
+        int ret = 0;
+
+        mutex_lock(&ftrace_cmd_mutex);
+        list_for_each_entry(p, &ftrace_commands, list) {
+                if (strcmp(cmd->name, p->name) == 0) {
+                        ret = -EBUSY;
+                        goto out_unlock;
+                }
+        }
+        list_add(&cmd->list, &ftrace_commands);
+ out_unlock:
+        mutex_unlock(&ftrace_cmd_mutex);
+
+        return ret;
+}
+
+int unregister_ftrace_command(struct ftrace_func_command *cmd)
+{
+        struct ftrace_func_command *p, *n;
+        int ret = -ENODEV;
+
+        mutex_lock(&ftrace_cmd_mutex);
+        list_for_each_entry_safe(p, n, &ftrace_commands, list) {
+                if (strcmp(cmd->name, p->name) == 0) {
+                        ret = 0;
+                        list_del_init(&p->list);
+                        goto out_unlock;
+                }
+        }
+ out_unlock:
+        mutex_unlock(&ftrace_cmd_mutex);
+
+        return ret;
+}
+
+static int ftrace_process_regex(char *buff, int len, int enable)
+{
+        struct ftrace_func_command *p;
+        char *func, *command, *next = buff;
+        int ret = -EINVAL;
+
+        func = strsep(&next, ":");
+
+        if (!next) {
+                ftrace_match_records(func, len, enable);
+                return 0;
+        }
+
+        /* command found */
+
+        command = strsep(&next, ":");
+
+        mutex_lock(&ftrace_cmd_mutex);
+        list_for_each_entry(p, &ftrace_commands, list) {
+                if (strcmp(p->name, command) == 0) {
+                        ret = p->func(func, command, next, enable);
+                        goto out_unlock;
+                }
+        }
+ out_unlock:
+        mutex_unlock(&ftrace_cmd_mutex);
+
+        return ret;
 }
 
 static ssize_t
@@ -1179,7 +1716,10 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
         if (isspace(ch)) {
                 iter->filtered++;
                 iter->buffer[iter->buffer_idx] = 0;
-                ftrace_match(iter->buffer, iter->buffer_idx, enable);
+                ret = ftrace_process_regex(iter->buffer,
+                                           iter->buffer_idx, enable);
+                if (ret)
+                        goto out;
                 iter->buffer_idx = 0;
         } else
                 iter->flags |= FTRACE_ITER_CONT;
@@ -1218,7 +1758,7 @@ ftrace_set_regex(unsigned char *buf, int len, int reset, int enable)
         if (reset)
                 ftrace_filter_reset(enable);
         if (buf)
-                ftrace_match(buf, len, enable);
+                ftrace_match_records(buf, len, enable);
         mutex_unlock(&ftrace_regex_lock);
 }
 
@@ -1268,15 +1808,13 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
         if (iter->buffer_idx) {
                 iter->filtered++;
                 iter->buffer[iter->buffer_idx] = 0;
-                ftrace_match(iter->buffer, iter->buffer_idx, enable);
+                ftrace_match_records(iter->buffer, iter->buffer_idx, enable);
         }
 
-        mutex_lock(&ftrace_sysctl_lock);
-        mutex_lock(&ftrace_start_lock);
+        mutex_lock(&ftrace_lock);
         if (ftrace_start_up && ftrace_enabled)
                 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
-        mutex_unlock(&ftrace_start_lock);
-        mutex_unlock(&ftrace_sysctl_lock);
+        mutex_unlock(&ftrace_lock);
 
         kfree(iter);
         mutex_unlock(&ftrace_regex_lock);
@@ -1429,36 +1967,33 @@ ftrace_set_func(unsigned long *array, int idx, char *buffer)
         struct dyn_ftrace *rec;
         struct ftrace_page *pg;
         int found = 0;
-        int i, j;
+        int 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];
+        mutex_lock(&ftrace_lock);
+        do_for_each_ftrace_rec(pg, rec) {
 
-                        if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))
-                                continue;
+                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;
-                        }
+                kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
+                if (strcmp(str, buffer) == 0) {
+                        /* Return 1 if we add it to the array */
+                        found = 1;
+                        for (j = 0; j < idx; j++)
+                                if (array[j] == rec->ip) {
+                                        found = 0;
+                                        break;
+                                }
+                        if (found)
+                                array[idx] = rec->ip;
+                        goto out;
                 }
-        }
-        spin_unlock(&ftrace_lock);
+        } while_for_each_ftrace_rec();
+ out:
+        mutex_unlock(&ftrace_lock);
 
         return found ? 0 : -EINVAL;
 }
@@ -1596,7 +2131,7 @@ static int ftrace_convert_nops(struct module *mod,
         unsigned long addr;
         unsigned long flags;
 
-        mutex_lock(&ftrace_start_lock);
+        mutex_lock(&ftrace_lock);
         p = start;
         while (p < end) {
                 addr = ftrace_call_adjust(*p++);
@@ -1615,7 +2150,7 @@ static int ftrace_convert_nops(struct module *mod,
         local_irq_save(flags);
         ftrace_update_code(mod);
         local_irq_restore(flags);
-        mutex_unlock(&ftrace_start_lock);
+        mutex_unlock(&ftrace_lock);
 
         return 0;
 }
@@ -1788,7 +2323,7 @@ ftrace_pid_write(struct file *filp, const char __user *ubuf,
         if (ret < 0)
                 return ret;
 
-        mutex_lock(&ftrace_start_lock);
+        mutex_lock(&ftrace_lock);
         if (val < 0) {
                 /* disable pid tracing */
                 if (!ftrace_pid_trace)
@@ -1827,7 +2362,7 @@ ftrace_pid_write(struct file *filp, const char __user *ubuf,
         ftrace_startup_enable(0);
 
  out:
-        mutex_unlock(&ftrace_start_lock);
+        mutex_unlock(&ftrace_lock);
 
         return cnt;
 }
@@ -1890,12 +2425,12 @@ int register_ftrace_function(struct ftrace_ops *ops)
         if (unlikely(ftrace_disabled))
                 return -1;
 
-        mutex_lock(&ftrace_sysctl_lock);
+        mutex_lock(&ftrace_lock);
 
         ret = __register_ftrace_function(ops);
         ftrace_startup(0);
 
-        mutex_unlock(&ftrace_sysctl_lock);
+        mutex_unlock(&ftrace_lock);
         return ret;
 }
 
@@ -1909,10 +2444,10 @@ int unregister_ftrace_function(struct ftrace_ops *ops)
 {
         int ret;
 
-        mutex_lock(&ftrace_sysctl_lock);
+        mutex_lock(&ftrace_lock);
         ret = __unregister_ftrace_function(ops);
         ftrace_shutdown(0);
-        mutex_unlock(&ftrace_sysctl_lock);
+        mutex_unlock(&ftrace_lock);
 
         return ret;
 }
@@ -1927,7 +2462,7 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
         if (unlikely(ftrace_disabled))
                 return -ENODEV;
 
-        mutex_lock(&ftrace_sysctl_lock);
+        mutex_lock(&ftrace_lock);
 
         ret  = proc_dointvec(table, write, file, buffer, lenp, ppos);
 
@@ -1956,7 +2491,7 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
         }
 
  out:
-        mutex_unlock(&ftrace_sysctl_lock);
+        mutex_unlock(&ftrace_lock);
         return ret;
 }
 
@@ -2068,7 +2603,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 {
         int ret = 0;
 
-        mutex_lock(&ftrace_sysctl_lock);
+        mutex_lock(&ftrace_lock);
 
         ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
         register_pm_notifier(&ftrace_suspend_notifier);
@@ -2086,13 +2621,13 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
         ftrace_startup(FTRACE_START_FUNC_RET);
 
 out:
-        mutex_unlock(&ftrace_sysctl_lock);
+        mutex_unlock(&ftrace_lock);
         return ret;
 }
 
 void unregister_ftrace_graph(void)
 {
-        mutex_lock(&ftrace_sysctl_lock);
+        mutex_lock(&ftrace_lock);
 
         atomic_dec(&ftrace_graph_active);
         ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
@@ -2100,7 +2635,7 @@ void unregister_ftrace_graph(void)
         ftrace_shutdown(FTRACE_STOP_FUNC_RET);
         unregister_pm_notifier(&ftrace_suspend_notifier);
 
-        mutex_unlock(&ftrace_sysctl_lock);
+        mutex_unlock(&ftrace_lock);
 }
 
 /* Allocate a return stack for newly created task */
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 2b4626ce95d6..8f19f1aa42b0 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -98,6 +98,15 @@ void tracing_off_permanent(void)
         set_bit(RB_BUFFERS_DISABLED_BIT, &ring_buffer_flags);
 }
 
+/**
+ * tracing_is_on - show state of ring buffers enabled
+ */
+int tracing_is_on(void)
+{
+        return ring_buffer_flags == RB_BUFFERS_ON;
+}
+EXPORT_SYMBOL_GPL(tracing_is_on);
+
 #include "trace.h"
 
 /* Up this if you want to test the TIME_EXTENTS and normalization */
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 36bf9568ccd9..f520aa419dff 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -9,6 +9,7 @@
  *  Copyright (C) 2004-2006 Ingo Molnar
  *  Copyright (C) 2004 William Lee Irwin III
  */
+#include <linux/ring_buffer.h>
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
 #include <linux/ftrace.h>
@@ -231,9 +232,171 @@ static struct tracer function_trace __read_mostly =
 #endif
 };
 
+#ifdef CONFIG_DYNAMIC_FTRACE
+static void
+ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data)
+{
+        long *count = (long *)data;
+
+        if (tracing_is_on())
+                return;
+
+        if (!*count)
+                return;
+
+        if (*count != -1)
+                (*count)--;
+
+        tracing_on();
+}
+
+static void
+ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data)
+{
+        long *count = (long *)data;
+
+        if (!tracing_is_on())
+                return;
+
+        if (!*count)
+                return;
+
+        if (*count != -1)
+                (*count)--;
+
+        tracing_off();
+}
+
+static int
+ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
+                         struct ftrace_hook_ops *ops, void *data);
+
+static struct ftrace_hook_ops traceon_hook_ops = {
+        .func                   = ftrace_traceon,
+        .print                  = ftrace_trace_onoff_print,
+};
+
+static struct ftrace_hook_ops traceoff_hook_ops = {
+        .func                   = ftrace_traceoff,
+        .print                  = ftrace_trace_onoff_print,
+};
+
+static int
+ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
+                         struct ftrace_hook_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);
+
+        if (ops == &traceon_hook_ops)
+                seq_printf(m, "traceon");
+        else
+                seq_printf(m, "traceoff");
+
+        if (count != -1)
+                seq_printf(m, ":count=%ld", count);
+        seq_putc(m, '\n');
+
+        return 0;
+}
+
+static int
+ftrace_trace_onoff_unreg(char *glob, char *cmd, char *param)
+{
+        struct ftrace_hook_ops *ops;
+
+        /* we register both traceon and traceoff to this callback */
+        if (strcmp(cmd, "traceon") == 0)
+                ops = &traceon_hook_ops;
+        else
+                ops = &traceoff_hook_ops;
+
+        unregister_ftrace_function_hook_func(glob, ops);
+
+        return 0;
+}
+
+static int
+ftrace_trace_onoff_callback(char *glob, char *cmd, char *param, int enable)
+{
+        struct ftrace_hook_ops *ops;
+        void *count = (void *)-1;
+        char *number;
+        int ret;
+
+        /* hash funcs only work with set_ftrace_filter */
+        if (!enable)
+                return -EINVAL;
+
+        if (glob[0] == '!')
+                return ftrace_trace_onoff_unreg(glob+1, cmd, param);
+
+        /* we register both traceon and traceoff to this callback */
+        if (strcmp(cmd, "traceon") == 0)
+                ops = &traceon_hook_ops;
+        else
+                ops = &traceoff_hook_ops;
+
+        if (!param)
+                goto out_reg;
+
+        number = strsep(&param, ":");
+
+        if (!strlen(number))
+                goto out_reg;
+
+        /*
+         * We use the callback data field (which is a pointer)
+         * as our counter.
+         */
+        ret = strict_strtoul(number, 0, (unsigned long *)&count);
+        if (ret)
+                return ret;
+
+ out_reg:
+        ret = register_ftrace_function_hook(glob, ops, count);
+
+        return ret;
+}
+
+static struct ftrace_func_command ftrace_traceon_cmd = {
+        .name                   = "traceon",
+        .func                   = ftrace_trace_onoff_callback,
+};
+
+static struct ftrace_func_command ftrace_traceoff_cmd = {
+        .name                   = "traceoff",
+        .func                   = ftrace_trace_onoff_callback,
+};
+
+static int __init init_func_cmd_traceon(void)
+{
+        int ret;
+
+        ret = register_ftrace_command(&ftrace_traceoff_cmd);
+        if (ret)
+                return ret;
+
+        ret = register_ftrace_command(&ftrace_traceon_cmd);
+        if (ret)
+                unregister_ftrace_command(&ftrace_traceoff_cmd);
+        return ret;
+}
+#else
+static inline int init_func_cmd_traceon(void)
+{
+        return 0;
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
 static __init int init_function_trace(void)
 {
+        init_func_cmd_traceon();
         return register_tracer(&function_trace);
 }
 
 device_initcall(init_function_trace);
+