GFS2: Clear dirty bit at end of inode glock sync
[safe/jmp/linux-2.6] / kernel / trace / ftrace.c
index d2b1565..f1ed080 100644 (file)
@@ -17,6 +17,7 @@
 #include <linux/clocksource.h>
 #include <linux/kallsyms.h>
 #include <linux/seq_file.h>
+#include <linux/suspend.h>
 #include <linux/debugfs.h>
 #include <linux/hardirq.h>
 #include <linux/kthread.h>
@@ -26,6 +27,9 @@
 #include <linux/sysctl.h>
 #include <linux/ctype.h>
 #include <linux/list.h>
+#include <linux/hash.h>
+
+#include <trace/sched.h>
 
 #include <asm/ftrace.h>
 
                        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 = (struct pid *)1;
-
 /* Quick disabling of function tracer. */
 int function_trace_stop;
 
@@ -60,9 +64,7 @@ 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 =
 {
@@ -133,9 +135,6 @@ 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
@@ -171,18 +170,12 @@ 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
@@ -191,17 +184,15 @@ 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;
 
@@ -222,21 +213,15 @@ 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);
-
        if (ftrace_trace_function == ftrace_stub)
-               goto out;
+               return;
 
        func = ftrace_trace_function;
 
@@ -253,23 +238,29 @@ static void ftrace_update_pid_func(void)
 #else
        __ftrace_trace_function = func;
 #endif
-
- out:
-       spin_unlock(&ftrace_lock);
 }
 
+/* set when tracing only a pid */
+struct pid *ftrace_pid_trace;
+static struct pid * const ftrace_swapper_pid = &init_struct_pid;
+
 #ifdef CONFIG_DYNAMIC_FTRACE
+
 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
 # error Dynamic ftrace depends on MCOUNT_RECORD
 #endif
 
-/*
- * 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;
+static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
+
+struct ftrace_func_probe {
+       struct hlist_node       node;
+       struct ftrace_probe_ops *ops;
+       unsigned long           flags;
+       unsigned long           ip;
+       void                    *data;
+       struct rcu_head         rcu;
+};
+
 
 enum {
        FTRACE_ENABLE_CALLS             = (1 << 0),
@@ -283,13 +274,13 @@ enum {
 
 static int ftrace_filtered;
 
-static LIST_HEAD(ftrace_new_addrs);
+static struct dyn_ftrace *ftrace_new_addrs;
 
 static DEFINE_MUTEX(ftrace_regex_lock);
 
 struct ftrace_page {
        struct ftrace_page      *next;
-       unsigned long           index;
+       int                     index;
        struct dyn_ftrace       records[];
 };
 
@@ -304,6 +295,19 @@ 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
 
@@ -337,7 +341,7 @@ static inline int record_frozen(struct dyn_ftrace *rec)
 
 static void ftrace_free_rec(struct dyn_ftrace *rec)
 {
-       rec->ip = (unsigned long)ftrace_free_records;
+       rec->freelist = ftrace_free_records;
        ftrace_free_records = rec;
        rec->flags |= FTRACE_FL_FREE;
 }
@@ -348,23 +352,22 @@ 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);
+       mutex_lock(&ftrace_lock);
+       do_for_each_ftrace_rec(pg, rec) {
+               if ((rec->ip >= s) && (rec->ip < e)) {
+                       /*
+                        * rec->ip is changed in ftrace_free_rec()
+                        * It should not between s and e if record was freed.
+                        */
+                       FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE);
+                       ftrace_free_rec(rec);
                }
-       }
-       spin_unlock(&ftrace_lock);
+       } while_for_each_ftrace_rec();
+       mutex_unlock(&ftrace_lock);
 }
 
 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
@@ -381,7 +384,7 @@ static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
                        return NULL;
                }
 
-               ftrace_free_records = (void *)rec->ip;
+               ftrace_free_records = rec->freelist;
                memset(rec, 0, sizeof(*rec));
                return rec;
        }
@@ -413,8 +416,8 @@ ftrace_record_ip(unsigned long ip)
                return NULL;
 
        rec->ip = ip;
-
-       list_add(&rec->list, &ftrace_new_addrs);
+       rec->newlist = ftrace_new_addrs;
+       ftrace_new_addrs = rec;
 
        return rec;
 }
@@ -460,10 +463,10 @@ static void ftrace_bug(int failed, unsigned long ip)
 static int
 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
 {
-       unsigned long ip, fl;
        unsigned long ftrace_addr;
+       unsigned long ip, fl;
 
-       ftrace_addr = (unsigned long)ftrace_caller;
+       ftrace_addr = (unsigned long)FTRACE_ADDR;
 
        ip = rec->ip;
 
@@ -472,7 +475,7 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
         * it is not enabled then do nothing.
         *
         * If this record is not to be traced and
-        * it is enabled then disabled it.
+        * it is enabled then disable it.
         *
         */
        if (rec->flags & FTRACE_FL_NOTRACE) {
@@ -492,7 +495,7 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
                if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
                        return 0;
 
-               /* Record is not filtered and is not enabled do nothing */
+               /* Record is not filtered or enabled, do nothing */
                if (!fl)
                        return 0;
 
@@ -514,7 +517,7 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
 
                } else {
 
-                       /* if record is not enabled do nothing */
+                       /* if record is not enabled, do nothing */
                        if (!(rec->flags & FTRACE_FL_ENABLED))
                                return 0;
 
@@ -530,41 +533,41 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
 
 static void ftrace_replace_code(int enable)
 {
-       int i, failed;
        struct dyn_ftrace *rec;
        struct ftrace_page *pg;
+       int failed;
 
-       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, records that have
+                * failed and not converted.
+                */
+               if (rec->flags & FTRACE_FL_FREE ||
+                   rec->flags & FTRACE_FL_FAILED ||
+                   !(rec->flags & FTRACE_FL_CONVERTED))
+                       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_FAILED;
+                       if ((system_state == SYSTEM_BOOTING) ||
+                           !core_kernel_text(rec->ip)) {
+                               ftrace_free_rec(rec);
+                               } else {
+                               ftrace_bug(failed, rec->ip);
+                                       /* Stop processing */
+                                       return;
+                               }
                }
-       }
+       } while_for_each_ftrace_rec();
 }
 
 static int
@@ -575,7 +578,7 @@ ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
 
        ip = rec->ip;
 
-       ret = ftrace_make_nop(mod, rec, mcount_addr);
+       ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
        if (ret) {
                ftrace_bug(ret, ip);
                rec->flags |= FTRACE_FL_FAILED;
@@ -584,6 +587,24 @@ ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
        return 1;
 }
 
+/*
+ * archs can override this function if they must do something
+ * before the modifying code is performed.
+ */
+int __weak ftrace_arch_code_modify_prepare(void)
+{
+       return 0;
+}
+
+/*
+ * archs can override this function if they must do something
+ * after the modifying code is performed.
+ */
+int __weak ftrace_arch_code_modify_post_process(void)
+{
+       return 0;
+}
+
 static int __ftrace_modify_code(void *data)
 {
        int *command = data;
@@ -606,7 +627,17 @@ static int __ftrace_modify_code(void *data)
 
 static void ftrace_run_update_code(int command)
 {
+       int ret;
+
+       ret = ftrace_arch_code_modify_prepare();
+       FTRACE_WARN_ON(ret);
+       if (ret)
+               return;
+
        stop_machine(__ftrace_modify_code, &command, NULL);
+
+       ret = ftrace_arch_code_modify_post_process();
+       FTRACE_WARN_ON(ret);
 }
 
 static ftrace_func_t saved_ftrace_func;
@@ -630,13 +661,10 @@ 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)
@@ -644,7 +672,6 @@ 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;
@@ -655,11 +682,9 @@ 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)
@@ -669,7 +694,6 @@ 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 */
@@ -677,7 +701,6 @@ 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)
@@ -687,13 +710,11 @@ 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;
@@ -702,19 +723,21 @@ unsigned long             ftrace_update_tot_cnt;
 
 static int ftrace_update_code(struct module *mod)
 {
-       struct dyn_ftrace *p, *t;
+       struct dyn_ftrace *p;
        cycle_t start, stop;
 
        start = ftrace_now(raw_smp_processor_id());
        ftrace_update_cnt = 0;
 
-       list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) {
+       while (ftrace_new_addrs) {
 
                /* If something went wrong, bail without enabling anything */
                if (unlikely(ftrace_disabled))
                        return -1;
 
-               list_del_init(&p->list);
+               p = ftrace_new_addrs;
+               ftrace_new_addrs = p->newlist;
+               p->flags = 0L;
 
                /* convert record (i.e, patch mcount-call with NOP) */
                if (ftrace_code_disable(mod, p)) {
@@ -780,13 +803,16 @@ 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;
-       unsigned                idx;
+       int                     hidx;
+       int                     idx;
        unsigned                flags;
        unsigned char           buffer[FTRACE_BUFF_MAX+1];
        unsigned                buffer_idx;
@@ -794,15 +820,89 @@ 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_probe *rec;
+       struct hlist_node *hnd = v;
+       char str[KSYM_SYMBOL_LEN];
+
+       rec = hlist_entry(hnd, struct ftrace_func_probe, node);
+
+       if (rec->ops->print)
+               return rec->ops->print(m, rec->ip, rec->ops, rec->data);
+
+       kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
+       seq_printf(m, "%s:", str);
+
+       kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str);
+       seq_printf(m, "%s", str);
+
+       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) {
@@ -831,7 +931,6 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
                        goto retry;
                }
        }
-       spin_unlock(&ftrace_lock);
 
        return rec;
 }
@@ -841,6 +940,23 @@ 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;
@@ -850,18 +966,31 @@ 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;
 
@@ -940,23 +1069,16 @@ 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
@@ -1007,16 +1129,6 @@ ftrace_notrace_open(struct inode *inode, struct file *file)
        return ftrace_regex_open(inode, file, 0);
 }
 
-static ssize_t
-ftrace_regex_read(struct file *file, char __user *ubuf,
-                      size_t cnt, loff_t *ppos)
-{
-       if (file->f_mode & FMODE_READ)
-               return seq_read(file, ubuf, cnt, ppos);
-       else
-               return -EPERM;
-}
-
 static loff_t
 ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
 {
@@ -1037,75 +1149,536 @@ 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 i;
+
+       if (buff[0] == '!') {
+               *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)
+{
+       unsigned int search_len;
+       struct ftrace_page *pg;
+       struct dyn_ftrace *rec;
+       unsigned long flag;
+       char *search;
+       int type;
+       int not;
+
+       flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
+       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)
+{
+       unsigned search_len = 0;
+       struct ftrace_page *pg;
+       struct dyn_ftrace *rec;
+       int type = MATCH_FULL;
+       char *search = buff;
+       unsigned long flag;
+       int not = 0;
+
+       flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
+
+       /* 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_probe_call(unsigned long ip, unsigned long parent_ip)
+{
+       struct ftrace_func_probe *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_probe_ops __read_mostly =
+{
+       .func = function_trace_probe_call,
+};
+
+static int ftrace_probe_registered;
+
+static void __enable_ftrace_function_probe(void)
+{
+       int i;
+
+       if (ftrace_probe_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_probe_ops);
+       ftrace_startup(0);
+       ftrace_probe_registered = 1;
+}
+
+static void __disable_ftrace_function_probe(void)
+{
+       int i;
+
+       if (!ftrace_probe_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_probe_ops);
+       ftrace_shutdown(0);
+       ftrace_probe_registered = 0;
+}
+
+
+static void ftrace_free_entry_rcu(struct rcu_head *rhp)
+{
+       struct ftrace_func_probe *entry =
+               container_of(rhp, struct ftrace_func_probe, rcu);
+
+       if (entry->ops->free)
+               entry->ops->free(&entry->data);
+       kfree(entry);
+}
+
+
+int
+register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
+                             void *data)
+{
+       struct ftrace_func_probe *entry;
+       struct ftrace_page *pg;
+       struct dyn_ftrace *rec;
+       int type, len, not;
+       unsigned long key;
+       int count = 0;
+       char *search;
+
+       type = ftrace_setup_glob(glob, strlen(glob), &search, &not);
+       len = strlen(search);
+
+       /* we do not support '!' for function probes */
+       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 process 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)
-                               rec->flags |= flag;
                }
-               pg = pg->next;
+
+               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_probe();
+
+ out_unlock:
+       mutex_unlock(&ftrace_lock);
+
+       return count;
+}
+
+enum {
+       PROBE_TEST_FUNC         = 1,
+       PROBE_TEST_DATA         = 2
+};
+
+static void
+__unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
+                                 void *data, int flags)
+{
+       struct ftrace_func_probe *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 probes */
+               if (WARN_ON(not))
+                       return;
        }
-       spin_unlock(&ftrace_lock);
+
+       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 & PROBE_TEST_FUNC) && entry->ops != ops)
+                               continue;
+
+                       if ((flags & PROBE_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);
+               }
+       }
+       __disable_ftrace_function_probe();
+       mutex_unlock(&ftrace_lock);
+}
+
+void
+unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
+                               void *data)
+{
+       __unregister_ftrace_function_probe(glob, ops, data,
+                                         PROBE_TEST_FUNC | PROBE_TEST_DATA);
+}
+
+void
+unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
+{
+       __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
+}
+
+void unregister_ftrace_function_probe_all(char *glob)
+{
+       __unregister_ftrace_function_probe(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)
+{
+       char *func, *command, *next = buff;
+       struct ftrace_func_command *p;
+       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
@@ -1175,7 +1748,10 @@ 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;
@@ -1214,7 +1790,7 @@ 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);
 }
 
@@ -1264,15 +1840,13 @@ 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);
@@ -1291,31 +1865,31 @@ ftrace_notrace_release(struct inode *inode, struct file *file)
        return ftrace_regex_release(inode, file, 0);
 }
 
-static struct file_operations ftrace_avail_fops = {
+static const struct file_operations ftrace_avail_fops = {
        .open = ftrace_avail_open,
        .read = seq_read,
        .llseek = seq_lseek,
        .release = ftrace_avail_release,
 };
 
-static struct file_operations ftrace_failures_fops = {
+static const struct file_operations ftrace_failures_fops = {
        .open = ftrace_failures_open,
        .read = seq_read,
        .llseek = seq_lseek,
        .release = ftrace_avail_release,
 };
 
-static struct file_operations ftrace_filter_fops = {
+static const struct file_operations ftrace_filter_fops = {
        .open = ftrace_filter_open,
-       .read = ftrace_regex_read,
+       .read = seq_read,
        .write = ftrace_filter_write,
        .llseek = ftrace_regex_lseek,
        .release = ftrace_filter_release,
 };
 
-static struct file_operations ftrace_notrace_fops = {
+static const struct file_operations ftrace_notrace_fops = {
        .open = ftrace_notrace_open,
-       .read = ftrace_regex_read,
+       .read = seq_read,
        .write = ftrace_notrace_write,
        .llseek = ftrace_regex_lseek,
        .release = ftrace_notrace_release,
@@ -1348,6 +1922,10 @@ static void *g_start(struct seq_file *m, loff_t *pos)
 
        mutex_lock(&graph_lock);
 
+       /* Nothing, tell g_show to print all functions are enabled */
+       if (!ftrace_graph_count && !*pos)
+               return (void *)1;
+
        p = g_next(m, p, pos);
 
        return p;
@@ -1366,6 +1944,11 @@ static int g_show(struct seq_file *m, void *v)
        if (!ptr)
                return 0;
 
+       if (ptr == (unsigned long *)1) {
+               seq_printf(m, "#### all functions enabled ####\n");
+               return 0;
+       }
+
        kallsyms_lookup(*ptr, NULL, NULL, NULL, str);
 
        seq_printf(m, "%s\n", str);
@@ -1408,53 +1991,53 @@ ftrace_graph_open(struct inode *inode, struct file *file)
        return ret;
 }
 
-static ssize_t
-ftrace_graph_read(struct file *file, char __user *ubuf,
-                      size_t cnt, loff_t *ppos)
-{
-       if (file->f_mode & FMODE_READ)
-               return seq_read(file, ubuf, cnt, ppos);
-       else
-               return -EPERM;
-}
-
 static int
-ftrace_set_func(unsigned long *array, int idx, char *buffer)
+ftrace_set_func(unsigned long *array, int *idx, char *buffer)
 {
-       char str[KSYM_SYMBOL_LEN];
        struct dyn_ftrace *rec;
        struct ftrace_page *pg;
+       int search_len;
        int found = 0;
-       int i, j;
+       int type, not;
+       char *search;
+       bool exists;
+       int i;
 
        if (ftrace_disabled)
                return -ENODEV;
 
-       /* should not be called from interrupt context */
-       spin_lock(&ftrace_lock);
+       /* decode regex */
+       type = ftrace_setup_glob(buffer, strlen(buffer), &search, &not);
+       if (not)
+               return -EINVAL;
 
-       for (pg = ftrace_pages_start; pg; pg = pg->next) {
-               for (i = 0; i < pg->index; i++) {
-                       rec = &pg->records[i];
+       search_len = strlen(search);
 
-                       if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))
-                               continue;
+       mutex_lock(&ftrace_lock);
+       do_for_each_ftrace_rec(pg, rec) {
+
+               if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
+                       break;
+
+               if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))
+                       continue;
 
-                       kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
-                       if (strcmp(str, buffer) == 0) {
+               if (ftrace_match_record(rec, search, search_len, type)) {
+                       /* ensure it is not already in the array */
+                       exists = false;
+                       for (i = 0; i < *idx; i++)
+                               if (array[i] == rec->ip) {
+                                       exists = true;
+                                       break;
+                               }
+                       if (!exists) {
+                               array[(*idx)++] = rec->ip;
                                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);
+       } while_for_each_ftrace_rec();
+
+       mutex_unlock(&ftrace_lock);
 
        return found ? 0 : -EINVAL;
 }
@@ -1522,13 +2105,11 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
        }
        buffer[index] = 0;
 
-       /* we allow only one at a time */
-       ret = ftrace_set_func(array, ftrace_graph_count, buffer);
+       /* we allow only one expression 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;
@@ -1540,7 +2121,7 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
 
 static const struct file_operations ftrace_graph_fops = {
        .open = ftrace_graph_open,
-       .read = ftrace_graph_read,
+       .read = seq_read,
        .write = ftrace_graph_write,
 };
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
@@ -1592,7 +2173,7 @@ 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++);
@@ -1611,7 +2192,7 @@ 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;
 }
@@ -1688,7 +2269,7 @@ ftrace_pid_read(struct file *file, char __user *ubuf,
        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));
+               r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace));
        else
                r = sprintf(buf, "no pid\n");
 
@@ -1725,9 +2306,12 @@ static void clear_ftrace_pid(struct pid *pid)
 {
        struct task_struct *p;
 
+       rcu_read_lock();
        do_each_pid_task(pid, PIDTYPE_PID, p) {
                clear_tsk_trace_trace(p);
        } while_each_pid_task(pid, PIDTYPE_PID, p);
+       rcu_read_unlock();
+
        put_pid(pid);
 }
 
@@ -1735,9 +2319,11 @@ static void set_ftrace_pid(struct pid *pid)
 {
        struct task_struct *p;
 
+       rcu_read_lock();
        do_each_pid_task(pid, PIDTYPE_PID, p) {
                set_tsk_trace_trace(p);
        } while_each_pid_task(pid, PIDTYPE_PID, p);
+       rcu_read_unlock();
 }
 
 static void clear_ftrace_pid_task(struct pid **pid)
@@ -1779,7 +2365,7 @@ 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)
@@ -1818,12 +2404,12 @@ 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;
 }
 
-static struct file_operations ftrace_pid_fops = {
+static const struct file_operations ftrace_pid_fops = {
        .read = ftrace_pid_read,
        .write = ftrace_pid_write,
 };
@@ -1846,7 +2432,6 @@ static __init int ftrace_init_debugfs(void)
                           "'set_ftrace_pid' entry\n");
        return 0;
 }
-
 fs_initcall(ftrace_init_debugfs);
 
 /**
@@ -1881,17 +2466,17 @@ 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;
 }
 
 /**
- * unregister_ftrace_function - unresgister a function for profiling.
+ * unregister_ftrace_function - unregister a function for profiling.
  * @ops - ops structure that holds the function to unregister
  *
  * Unregister a function that was added to be called by ftrace profiling.
@@ -1900,10 +2485,10 @@ 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;
 }
@@ -1918,7 +2503,7 @@ 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);
 
@@ -1947,13 +2532,14 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
        }
 
  out:
-       mutex_unlock(&ftrace_sysctl_lock);
+       mutex_unlock(&ftrace_lock);
        return ret;
 }
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
 static atomic_t ftrace_graph_active;
+static struct notifier_block ftrace_suspend_notifier;
 
 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
 {
@@ -1998,6 +2584,7 @@ static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
                        /* 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);
@@ -2010,11 +2597,43 @@ free:
        return ret;
 }
 
+static void
+ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev,
+                               struct task_struct *next)
+{
+       unsigned long long timestamp;
+       int index;
+
+       /*
+        * Does the user want to count the time a function was asleep.
+        * If so, do not update the time stamps.
+        */
+       if (trace_flags & TRACE_ITER_SLEEP_TIME)
+               return;
+
+       timestamp = trace_clock_local();
+
+       prev->ftrace_timestamp = timestamp;
+
+       /* only process tasks that we timestamped */
+       if (!next->ftrace_timestamp)
+               return;
+
+       /*
+        * Update all the counters in next to make up for the
+        * time next was sleeping.
+        */
+       timestamp -= next->ftrace_timestamp;
+
+       for (index = next->curr_ret_stack; index >= 0; index--)
+               next->ret_stack[index].calltime += timestamp;
+}
+
 /* Allocate a return stack for each task */
 static int start_graph_tracing(void)
 {
        struct ftrace_ret_stack **ret_stack_list;
-       int ret;
+       int ret, cpu;
 
        ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
                                sizeof(struct ftrace_ret_stack *),
@@ -2023,20 +2642,61 @@ static int start_graph_tracing(void)
        if (!ret_stack_list)
                return -ENOMEM;
 
+       /* The cpu_boot init_task->ret_stack will never be freed */
+       for_each_online_cpu(cpu)
+               ftrace_graph_init_task(idle_task(cpu));
+
        do {
                ret = alloc_retstack_tasklist(ret_stack_list);
        } while (ret == -EAGAIN);
 
+       if (!ret) {
+               ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch);
+               if (ret)
+                       pr_info("ftrace_graph: Couldn't activate tracepoint"
+                               " probe to kernel_sched_switch\n");
+       }
+
        kfree(ret_stack_list);
        return ret;
 }
 
+/*
+ * Hibernation protection.
+ * The state of the current task is too much unstable during
+ * suspend/restore to disk. We want to protect against that.
+ */
+static int
+ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
+                                                       void *unused)
+{
+       switch (state) {
+       case PM_HIBERNATION_PREPARE:
+               pause_graph_tracing();
+               break;
+
+       case PM_POST_HIBERNATION:
+               unpause_graph_tracing();
+               break;
+       }
+       return NOTIFY_DONE;
+}
+
 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
                        trace_func_graph_ent_t entryfunc)
 {
        int ret = 0;
 
-       mutex_lock(&ftrace_sysctl_lock);
+       mutex_lock(&ftrace_lock);
+
+       /* we currently allow only one tracer registered at a time */
+       if (atomic_read(&ftrace_graph_active)) {
+               ret = -EBUSY;
+               goto out;
+       }
+
+       ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
+       register_pm_notifier(&ftrace_suspend_notifier);
 
        atomic_inc(&ftrace_graph_active);
        ret = start_graph_tracing();
@@ -2051,20 +2711,26 @@ 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);
+
+       if (!unlikely(atomic_read(&ftrace_graph_active)))
+               goto out;
 
        atomic_dec(&ftrace_graph_active);
+       unregister_trace_sched_switch(ftrace_graph_probe_sched_switch);
        ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
        ftrace_graph_entry = ftrace_graph_entry_stub;
        ftrace_shutdown(FTRACE_STOP_FUNC_RET);
+       unregister_pm_notifier(&ftrace_suspend_notifier);
 
-       mutex_unlock(&ftrace_sysctl_lock);
+ out:
+       mutex_unlock(&ftrace_lock);
 }
 
 /* Allocate a return stack for newly created task */
@@ -2077,7 +2743,9 @@ void ftrace_graph_init_task(struct task_struct *t)
                if (!t->ret_stack)
                        return;
                t->curr_ret_stack = -1;
+               atomic_set(&t->tracing_graph_pause, 0);
                atomic_set(&t->trace_overrun, 0);
+               t->ftrace_timestamp = 0;
        } else
                t->ret_stack = NULL;
 }