1 files changed, 96 insertions, 512 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 4dda4f60a2a9..4a39d24568c8 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -25,13 +25,24 @@
 #include <linux/ftrace.h>
 #include <linux/sysctl.h>
 #include <linux/ctype.h>
-#include <linux/hash.h>
 #include <linux/list.h>
 
 #include <asm/ftrace.h>
 
 #include "trace.h"
 
+#define FTRACE_WARN_ON(cond)                    \
+        do {                                    \
+                if (WARN_ON(cond))              \
+                        ftrace_kill();          \
+        } while (0)
+
+#define FTRACE_WARN_ON_ONCE(cond)               \
+        do {                                    \
+                if (WARN_ON_ONCE(cond))         \
+                        ftrace_kill();          \
+        } while (0)
+
 /* ftrace_enabled is a method to turn ftrace on or off */
 int ftrace_enabled __read_mostly;
 static int last_ftrace_enabled;
@@ -153,21 +164,8 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-
 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
-/*
- * The hash lock is only needed when the recording of the mcount
- * callers are dynamic. That is, by the caller themselves and
- * not recorded via the compilation.
- */
-static DEFINE_SPINLOCK(ftrace_hash_lock);
-#define ftrace_hash_lock(flags)   spin_lock_irqsave(&ftrace_hash_lock, flags)
-#define ftrace_hash_unlock(flags) \
-                        spin_unlock_irqrestore(&ftrace_hash_lock, flags)
-#else
-/* This is protected via the ftrace_lock with MCOUNT_RECORD. */
-#define ftrace_hash_lock(flags)   do { (void)(flags); } while (0)
-#define ftrace_hash_unlock(flags) do { } while(0)
+# error Dynamic ftrace depends on MCOUNT_RECORD
 #endif
 
 /*
@@ -178,8 +176,6 @@ static DEFINE_SPINLOCK(ftrace_hash_lock);
  */
 static unsigned long mcount_addr = MCOUNT_ADDR;
 
-static struct task_struct *ftraced_task;
-
 enum {
         FTRACE_ENABLE_CALLS             = (1 << 0),
         FTRACE_DISABLE_CALLS            = (1 << 1),
@@ -190,13 +186,9 @@ enum {
 
 static int ftrace_filtered;
 static int tracing_on;
-static int frozen_record_count;
-
-static struct hlist_head ftrace_hash[FTRACE_HASHSIZE];
 
-static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu);
+static LIST_HEAD(ftrace_new_addrs);
 
-static DEFINE_MUTEX(ftraced_lock);
 static DEFINE_MUTEX(ftrace_regex_lock);
 
 struct ftrace_page {
@@ -214,16 +206,13 @@ struct ftrace_page {
 static struct ftrace_page       *ftrace_pages_start;
 static struct ftrace_page       *ftrace_pages;
 
-static int ftraced_trigger;
-static int ftraced_suspend;
-static int ftraced_stop;
-
-static int ftrace_record_suspend;
-
 static struct dyn_ftrace *ftrace_free_records;
 
 
 #ifdef CONFIG_KPROBES
+
+static int frozen_record_count;
+
 static inline void freeze_record(struct dyn_ftrace *rec)
 {
         if (!(rec->flags & FTRACE_FL_FROZEN)) {
@@ -250,72 +239,6 @@ static inline int record_frozen(struct dyn_ftrace *rec)
 # define record_frozen(rec)                     ({ 0; })
 #endif /* CONFIG_KPROBES */
 
-int skip_trace(unsigned long ip)
-{
-        unsigned long fl;
-        struct dyn_ftrace *rec;
-        struct hlist_node *t;
-        struct hlist_head *head;
-
-        if (frozen_record_count == 0)
-                return 0;
-
-        head = &ftrace_hash[hash_long(ip, FTRACE_HASHBITS)];
-        hlist_for_each_entry_rcu(rec, t, head, node) {
-                if (rec->ip == ip) {
-                        if (record_frozen(rec)) {
-                                if (rec->flags & FTRACE_FL_FAILED)
-                                        return 1;
-
-                                if (!(rec->flags & FTRACE_FL_CONVERTED))
-                                        return 1;
-
-                                if (!tracing_on || !ftrace_enabled)
-                                        return 1;
-
-                                if (ftrace_filtered) {
-                                        fl = rec->flags & (FTRACE_FL_FILTER |
-                                                           FTRACE_FL_NOTRACE);
-                                        if (!fl || (fl & FTRACE_FL_NOTRACE))
-                                                return 1;
-                                }
-                        }
-                        break;
-                }
-        }
-
-        return 0;
-}
-
-static inline int
-ftrace_ip_in_hash(unsigned long ip, unsigned long key)
-{
-        struct dyn_ftrace *p;
-        struct hlist_node *t;
-        int found = 0;
-
-        hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) {
-                if (p->ip == ip) {
-                        found = 1;
-                        break;
-                }
-        }
-
-        return found;
-}
-
-static inline void
-ftrace_add_hash(struct dyn_ftrace *node, unsigned long key)
-{
-        hlist_add_head_rcu(&node->node, &ftrace_hash[key]);
-}
-
-/* called from kstop_machine */
-static inline void ftrace_del_hash(struct dyn_ftrace *node)
-{
-        hlist_del(&node->node);
-}
-
 static void ftrace_free_rec(struct dyn_ftrace *rec)
 {
         rec->ip = (unsigned long)ftrace_free_records;
@@ -346,7 +269,6 @@ void ftrace_release(void *start, unsigned long size)
                 }
         }
         spin_unlock(&ftrace_lock);
-
 }
 
 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
@@ -358,10 +280,8 @@ static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
                 rec = ftrace_free_records;
 
                 if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
-                        WARN_ON_ONCE(1);
+                        FTRACE_WARN_ON_ONCE(1);
                         ftrace_free_records = NULL;
-                        ftrace_disabled = 1;
-                        ftrace_enabled = 0;
                         return NULL;
                 }
 
@@ -371,76 +291,36 @@ static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
         }
 
         if (ftrace_pages->index == ENTRIES_PER_PAGE) {
-                if (!ftrace_pages->next)
-                        return NULL;
+                if (!ftrace_pages->next) {
+                        /* allocate another page */
+                        ftrace_pages->next =
+                                (void *)get_zeroed_page(GFP_KERNEL);
+                        if (!ftrace_pages->next)
+                                return NULL;
+                }
                 ftrace_pages = ftrace_pages->next;
         }
 
         return &ftrace_pages->records[ftrace_pages->index++];
 }
 
-static void
+static struct dyn_ftrace *
 ftrace_record_ip(unsigned long ip)
 {
-        struct dyn_ftrace *node;
-        unsigned long flags;
-        unsigned long key;
-        int resched;
-        int cpu;
+        struct dyn_ftrace *rec;
 
         if (!ftrace_enabled || ftrace_disabled)
-                return;
-
-        resched = need_resched();
-        preempt_disable_notrace();
+                return NULL;
 
-        /*
-         * We simply need to protect against recursion.
-         * Use the the raw version of smp_processor_id and not
-         * __get_cpu_var which can call debug hooks that can
-         * cause a recursive crash here.
-         */
-        cpu = raw_smp_processor_id();
-        per_cpu(ftrace_shutdown_disable_cpu, cpu)++;
-        if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1)
-                goto out;
-
-        if (unlikely(ftrace_record_suspend))
-                goto out;
-
-        key = hash_long(ip, FTRACE_HASHBITS);
-
-        WARN_ON_ONCE(key >= FTRACE_HASHSIZE);
-
-        if (ftrace_ip_in_hash(ip, key))
-                goto out;
-
-        ftrace_hash_lock(flags);
-
-        /* This ip may have hit the hash before the lock */
-        if (ftrace_ip_in_hash(ip, key))
-                goto out_unlock;
-
-        node = ftrace_alloc_dyn_node(ip);
-        if (!node)
-                goto out_unlock;
-
-        node->ip = ip;
-
-        ftrace_add_hash(node, key);
+        rec = ftrace_alloc_dyn_node(ip);
+        if (!rec)
+                return NULL;
 
-        ftraced_trigger = 1;
+        rec->ip = ip;
 
- out_unlock:
-        ftrace_hash_unlock(flags);
- out:
-        per_cpu(ftrace_shutdown_disable_cpu, cpu)--;
+        list_add(&rec->list, &ftrace_new_addrs);
 
-        /* prevent recursion with scheduler */
-        if (resched)
-                preempt_enable_no_resched_notrace();
-        else
-                preempt_enable_notrace();
+        return rec;
 }
 
 #define FTRACE_ADDR ((long)(ftrace_caller))
@@ -559,7 +439,6 @@ static void ftrace_replace_code(int enable)
                                 rec->flags |= FTRACE_FL_FAILED;
                                 if ((system_state == SYSTEM_BOOTING) ||
                                     !core_kernel_text(rec->ip)) {
-                                        ftrace_del_hash(rec);
                                         ftrace_free_rec(rec);
                                 }
                         }
@@ -567,15 +446,6 @@ static void ftrace_replace_code(int enable)
         }
 }
 
-static void ftrace_shutdown_replenish(void)
-{
-        if (ftrace_pages->next)
-                return;
-
-        /* allocate another page */
-        ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL);
-}
-
 static void print_ip_ins(const char *fmt, unsigned char *p)
 {
         int i;
@@ -591,23 +461,23 @@ ftrace_code_disable(struct dyn_ftrace *rec)
 {
         unsigned long ip;
         unsigned char *nop, *call;
-        int failed;
+        int ret;
 
         ip = rec->ip;
 
         nop = ftrace_nop_replace();
         call = ftrace_call_replace(ip, mcount_addr);
 
-        failed = ftrace_modify_code(ip, call, nop);
-        if (failed) {
-                switch (failed) {
-                case 1:
-                        WARN_ON_ONCE(1);
+        ret = ftrace_modify_code(ip, call, nop);
+        if (ret) {
+                switch (ret) {
+                case -EFAULT:
+                        FTRACE_WARN_ON_ONCE(1);
                         pr_info("ftrace faulted on modifying ");
                         print_ip_sym(ip);
                         break;
-                case 2:
-                        WARN_ON_ONCE(1);
+                case -EINVAL:
+                        FTRACE_WARN_ON_ONCE(1);
                         pr_info("ftrace failed to modify ");
                         print_ip_sym(ip);
                         print_ip_ins(" expected: ", call);
@@ -615,6 +485,15 @@ ftrace_code_disable(struct dyn_ftrace *rec)
                         print_ip_ins(" replace: ", nop);
                         printk(KERN_CONT "\n");
                         break;
+                case -EPERM:
+                        FTRACE_WARN_ON_ONCE(1);
+                        pr_info("ftrace faulted on writing ");
+                        print_ip_sym(ip);
+                        break;
+                default:
+                        FTRACE_WARN_ON_ONCE(1);
+                        pr_info("ftrace faulted on unknown error ");
+                        print_ip_sym(ip);
                 }
 
                 rec->flags |= FTRACE_FL_FAILED;
@@ -623,19 +502,11 @@ ftrace_code_disable(struct dyn_ftrace *rec)
         return 1;
 }
 
-static int __ftrace_update_code(void *ignore);
-
 static int __ftrace_modify_code(void *data)
 {
-        unsigned long addr;
         int *command = data;
 
         if (*command & FTRACE_ENABLE_CALLS) {
-                /*
-                 * Update any recorded ips now that we have the
-                 * machine stopped
-                 */
-                __ftrace_update_code(NULL);
                 ftrace_replace_code(1);
                 tracing_on = 1;
         } else if (*command & FTRACE_DISABLE_CALLS) {
@@ -646,14 +517,6 @@ static int __ftrace_modify_code(void *data)
         if (*command & FTRACE_UPDATE_TRACE_FUNC)
                 ftrace_update_ftrace_func(ftrace_trace_function);
 
-        if (*command & FTRACE_ENABLE_MCOUNT) {
-                addr = (unsigned long)ftrace_record_ip;
-                ftrace_mcount_set(&addr);
-        } else if (*command & FTRACE_DISABLE_MCOUNT) {
-                addr = (unsigned long)ftrace_stub;
-                ftrace_mcount_set(&addr);
-        }
-
         return 0;
 }
 
@@ -662,26 +525,9 @@ static void ftrace_run_update_code(int command)
         stop_machine(__ftrace_modify_code, &command, NULL);
 }
 
-void ftrace_disable_daemon(void)
-{
-        /* Stop the daemon from calling kstop_machine */
-        mutex_lock(&ftraced_lock);
-        ftraced_stop = 1;
-        mutex_unlock(&ftraced_lock);
-
-        ftrace_force_update();
-}
-
-void ftrace_enable_daemon(void)
-{
-        mutex_lock(&ftraced_lock);
-        ftraced_stop = 0;
-        mutex_unlock(&ftraced_lock);
-
-        ftrace_force_update();
-}
-
 static ftrace_func_t saved_ftrace_func;
+static int ftrace_start;
+static DEFINE_MUTEX(ftrace_start_lock);
 
 static void ftrace_startup(void)
 {
@@ -690,9 +536,9 @@ static void ftrace_startup(void)
         if (unlikely(ftrace_disabled))
                 return;
 
-        mutex_lock(&ftraced_lock);
-        ftraced_suspend++;
-        if (ftraced_suspend == 1)
+        mutex_lock(&ftrace_start_lock);
+        ftrace_start++;
+        if (ftrace_start == 1)
                 command |= FTRACE_ENABLE_CALLS;
 
         if (saved_ftrace_func != ftrace_trace_function) {
@@ -705,7 +551,7 @@ static void ftrace_startup(void)
 
         ftrace_run_update_code(command);
  out:
-        mutex_unlock(&ftraced_lock);
+        mutex_unlock(&ftrace_start_lock);
 }
 
 static void ftrace_shutdown(void)
@@ -715,9 +561,9 @@ static void ftrace_shutdown(void)
         if (unlikely(ftrace_disabled))
                 return;
 
-        mutex_lock(&ftraced_lock);
-        ftraced_suspend--;
-        if (!ftraced_suspend)
+        mutex_lock(&ftrace_start_lock);
+        ftrace_start--;
+        if (!ftrace_start)
                 command |= FTRACE_DISABLE_CALLS;
 
         if (saved_ftrace_func != ftrace_trace_function) {
@@ -730,7 +576,7 @@ static void ftrace_shutdown(void)
 
         ftrace_run_update_code(command);
  out:
-        mutex_unlock(&ftraced_lock);
+        mutex_unlock(&ftrace_start_lock);
 }
 
 static void ftrace_startup_sysctl(void)
@@ -740,15 +586,15 @@ static void ftrace_startup_sysctl(void)
         if (unlikely(ftrace_disabled))
                 return;
 
-        mutex_lock(&ftraced_lock);
+        mutex_lock(&ftrace_start_lock);
         /* Force update next time */
         saved_ftrace_func = NULL;
-        /* ftraced_suspend is true if we want ftrace running */
-        if (ftraced_suspend)
+        /* ftrace_start is true if we want ftrace running */
+        if (ftrace_start)
                 command |= FTRACE_ENABLE_CALLS;
 
         ftrace_run_update_code(command);
-        mutex_unlock(&ftraced_lock);
+        mutex_unlock(&ftrace_start_lock);
 }
 
 static void ftrace_shutdown_sysctl(void)
@@ -758,112 +604,50 @@ static void ftrace_shutdown_sysctl(void)
         if (unlikely(ftrace_disabled))
                 return;
 
-        mutex_lock(&ftraced_lock);
-        /* ftraced_suspend is true if ftrace is running */
-        if (ftraced_suspend)
+        mutex_lock(&ftrace_start_lock);
+        /* ftrace_start is true if ftrace is running */
+        if (ftrace_start)
                 command |= FTRACE_DISABLE_CALLS;
 
         ftrace_run_update_code(command);
-        mutex_unlock(&ftraced_lock);
+        mutex_unlock(&ftrace_start_lock);
 }
 
 static cycle_t          ftrace_update_time;
 static unsigned long    ftrace_update_cnt;
 unsigned long           ftrace_update_tot_cnt;
 
-static int __ftrace_update_code(void *ignore)
+static int ftrace_update_code(void)
 {
-        int i, save_ftrace_enabled;
+        struct dyn_ftrace *p, *t;
         cycle_t start, stop;
-        struct dyn_ftrace *p;
-        struct hlist_node *t, *n;
-        struct hlist_head *head, temp_list;
-
-        /* Don't be recording funcs now */
-        ftrace_record_suspend++;
-        save_ftrace_enabled = ftrace_enabled;
-        ftrace_enabled = 0;
 
         start = ftrace_now(raw_smp_processor_id());
         ftrace_update_cnt = 0;
 
-        /* No locks needed, the machine is stopped! */
-        for (i = 0; i < FTRACE_HASHSIZE; i++) {
-                INIT_HLIST_HEAD(&temp_list);
-                head = &ftrace_hash[i];
+        list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) {
 
-                /* all CPUS are stopped, we are safe to modify code */
-                hlist_for_each_entry_safe(p, t, n, head, node) {
-                        /* Skip over failed records which have not been
-                         * freed. */
-                        if (p->flags & FTRACE_FL_FAILED)
-                                continue;
+                /* If something went wrong, bail without enabling anything */
+                if (unlikely(ftrace_disabled))
+                        return -1;
 
-                        /* Unconverted records are always at the head of the
-                         * hash bucket. Once we encounter a converted record,
-                         * simply skip over to the next bucket. Saves ftraced
-                         * some processor cycles (ftrace does its bid for
-                         * global warming :-p ). */
-                        if (p->flags & (FTRACE_FL_CONVERTED))
-                                break;
+                list_del_init(&p->list);
 
-                        /* Ignore updates to this record's mcount site.
-                         * Reintroduce this record at the head of this
-                         * bucket to attempt to "convert" it again if
-                         * the kprobe on it is unregistered before the
-                         * next run. */
-                        if (get_kprobe((void *)p->ip)) {
-                                ftrace_del_hash(p);
-                                INIT_HLIST_NODE(&p->node);
-                                hlist_add_head(&p->node, &temp_list);
-                                freeze_record(p);
-                                continue;
-                        } else {
-                                unfreeze_record(p);
-                        }
-
-                        /* convert record (i.e, patch mcount-call with NOP) */
-                        if (ftrace_code_disable(p)) {
-                                p->flags |= FTRACE_FL_CONVERTED;
-                                ftrace_update_cnt++;
-                        } else {
-                                if ((system_state == SYSTEM_BOOTING) ||
-                                    !core_kernel_text(p->ip)) {
-                                        ftrace_del_hash(p);
-                                        ftrace_free_rec(p);
-                                }
-                        }
-                }
-
-                hlist_for_each_entry_safe(p, t, n, &temp_list, node) {
-                        hlist_del(&p->node);
-                        INIT_HLIST_NODE(&p->node);
-                        hlist_add_head(&p->node, head);
-                }
+                /* convert record (i.e, patch mcount-call with NOP) */
+                if (ftrace_code_disable(p)) {
+                        p->flags |= FTRACE_FL_CONVERTED;
+                        ftrace_update_cnt++;
+                } else
+                        ftrace_free_rec(p);
         }
 
         stop = ftrace_now(raw_smp_processor_id());
         ftrace_update_time = stop - start;
         ftrace_update_tot_cnt += ftrace_update_cnt;
-        ftraced_trigger = 0;
-
-        ftrace_enabled = save_ftrace_enabled;
-        ftrace_record_suspend--;
 
         return 0;
 }
 
-static int ftrace_update_code(void)
-{
-        if (unlikely(ftrace_disabled) ||
-            !ftrace_enabled || !ftraced_trigger)
-                return 0;
-
-        stop_machine(__ftrace_update_code, NULL, NULL);
-
-        return 1;
-}
-
 static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
 {
         struct ftrace_page *pg;
@@ -892,7 +676,7 @@ static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
         pg = ftrace_pages = ftrace_pages_start;
 
         cnt = num_to_init / ENTRIES_PER_PAGE;
-        pr_info("ftrace: allocating %ld hash entries in %d pages\n",
+        pr_info("ftrace: allocating %ld entries in %d pages\n",
                 num_to_init, cnt);
 
         for (i = 0; i < cnt; i++) {
@@ -1401,10 +1185,10 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
         }
 
         mutex_lock(&ftrace_sysctl_lock);
-        mutex_lock(&ftraced_lock);
-        if (iter->filtered && ftraced_suspend && ftrace_enabled)
+        mutex_lock(&ftrace_start_lock);
+        if (iter->filtered && ftrace_start && ftrace_enabled)
                 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
-        mutex_unlock(&ftraced_lock);
+        mutex_unlock(&ftrace_start_lock);
         mutex_unlock(&ftrace_sysctl_lock);
 
         kfree(iter);
@@ -1424,55 +1208,6 @@ ftrace_notrace_release(struct inode *inode, struct file *file)
         return ftrace_regex_release(inode, file, 0);
 }
 
-static ssize_t
-ftraced_read(struct file *filp, char __user *ubuf,
-                     size_t cnt, loff_t *ppos)
-{
-        /* don't worry about races */
-        char *buf = ftraced_stop ? "disabled\n" : "enabled\n";
-        int r = strlen(buf);
-
-        return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
-}
-
-static ssize_t
-ftraced_write(struct file *filp, const char __user *ubuf,
-                      size_t cnt, loff_t *ppos)
-{
-        char buf[64];
-        long val;
-        int ret;
-
-        if (cnt >= sizeof(buf))
-                return -EINVAL;
-
-        if (copy_from_user(&buf, ubuf, cnt))
-                return -EFAULT;
-
-        if (strncmp(buf, "enable", 6) == 0)
-                val = 1;
-        else if (strncmp(buf, "disable", 7) == 0)
-                val = 0;
-        else {
-                buf[cnt] = 0;
-
-                ret = strict_strtoul(buf, 10, &val);
-                if (ret < 0)
-                        return ret;
-
-                val = !!val;
-        }
-
-        if (val)
-                ftrace_enable_daemon();
-        else
-                ftrace_disable_daemon();
-
-        filp->f_pos += cnt;
-
-        return cnt;
-}
-
 static struct file_operations ftrace_avail_fops = {
         .open = ftrace_avail_open,
         .read = seq_read,
@@ -1503,54 +1238,6 @@ static struct file_operations ftrace_notrace_fops = {
         .release = ftrace_notrace_release,
 };
 
-static struct file_operations ftraced_fops = {
-        .open = tracing_open_generic,
-        .read = ftraced_read,
-        .write = ftraced_write,
-};
-
-/**
- * ftrace_force_update - force an update to all recording ftrace functions
- */
-int ftrace_force_update(void)
-{
-        int ret = 0;
-
-        if (unlikely(ftrace_disabled))
-                return -ENODEV;
-
-        mutex_lock(&ftrace_sysctl_lock);
-        mutex_lock(&ftraced_lock);
-
-        /*
-         * If ftraced_trigger is not set, then there is nothing
-         * to update.
-         */
-        if (ftraced_trigger && !ftrace_update_code())
-                ret = -EBUSY;
-
-        mutex_unlock(&ftraced_lock);
-        mutex_unlock(&ftrace_sysctl_lock);
-
-        return ret;
-}
-
-static void ftrace_force_shutdown(void)
-{
-        struct task_struct *task;
-        int command = FTRACE_DISABLE_CALLS | FTRACE_UPDATE_TRACE_FUNC;
-
-        mutex_lock(&ftraced_lock);
-        task = ftraced_task;
-        ftraced_task = NULL;
-        ftraced_suspend = -1;
-        ftrace_run_update_code(command);
-        mutex_unlock(&ftraced_lock);
-
-        if (task)
-                kthread_stop(task);
-}
-
 static __init int ftrace_init_debugfs(void)
 {
         struct dentry *d_tracer;
@@ -1581,17 +1268,11 @@ static __init int ftrace_init_debugfs(void)
                 pr_warning("Could not create debugfs "
                            "'set_ftrace_notrace' entry\n");
 
-        entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer,
-                                    NULL, &ftraced_fops);
-        if (!entry)
-                pr_warning("Could not create debugfs "
-                           "'ftraced_enabled' entry\n");
         return 0;
 }
 
 fs_initcall(ftrace_init_debugfs);
 
-#ifdef CONFIG_FTRACE_MCOUNT_RECORD
 static int ftrace_convert_nops(unsigned long *start,
                                unsigned long *end)
 {
@@ -1599,20 +1280,18 @@ static int ftrace_convert_nops(unsigned long *start,
         unsigned long addr;
         unsigned long flags;
 
+        mutex_lock(&ftrace_start_lock);
         p = start;
         while (p < end) {
                 addr = ftrace_call_adjust(*p++);
-                /* should not be called from interrupt context */
-                spin_lock(&ftrace_lock);
                 ftrace_record_ip(addr);
-                spin_unlock(&ftrace_lock);
-                ftrace_shutdown_replenish();
         }
 
-        /* p is ignored */
+        /* disable interrupts to prevent kstop machine */
         local_irq_save(flags);
-        __ftrace_update_code(p);
+        ftrace_update_code();
         local_irq_restore(flags);
+        mutex_unlock(&ftrace_start_lock);
 
         return 0;
 }
@@ -1658,130 +1337,34 @@ void __init ftrace_init(void)
  failed:
         ftrace_disabled = 1;
 }
-#else /* CONFIG_FTRACE_MCOUNT_RECORD */
-static int ftraced(void *ignore)
-{
-        unsigned long usecs;
-
-        while (!kthread_should_stop()) {
-
-                set_current_state(TASK_INTERRUPTIBLE);
-
-                /* check once a second */
-                schedule_timeout(HZ);
 
-                if (unlikely(ftrace_disabled))
-                        continue;
-
-                mutex_lock(&ftrace_sysctl_lock);
-                mutex_lock(&ftraced_lock);
-                if (!ftraced_suspend && !ftraced_stop &&
-                    ftrace_update_code()) {
-                        usecs = nsecs_to_usecs(ftrace_update_time);
-                        if (ftrace_update_tot_cnt > 100000) {
-                                ftrace_update_tot_cnt = 0;
-                                pr_info("hm, dftrace overflow: %lu change%s"
-                                        " (%lu total) in %lu usec%s\n",
-                                        ftrace_update_cnt,
-                                        ftrace_update_cnt != 1 ? "s" : "",
-                                        ftrace_update_tot_cnt,
-                                        usecs, usecs != 1 ? "s" : "");
-                                ftrace_disabled = 1;
-                                WARN_ON_ONCE(1);
-                        }
-                }
-                mutex_unlock(&ftraced_lock);
-                mutex_unlock(&ftrace_sysctl_lock);
-
-                ftrace_shutdown_replenish();
-        }
-        __set_current_state(TASK_RUNNING);
-        return 0;
-}
+#else
 
-static int __init ftrace_dynamic_init(void)
+static int __init ftrace_nodyn_init(void)
 {
-        struct task_struct *p;
-        unsigned long addr;
-        int ret;
-
-        addr = (unsigned long)ftrace_record_ip;
-
-        stop_machine(ftrace_dyn_arch_init, &addr, NULL);
-
-        /* ftrace_dyn_arch_init places the return code in addr */
-        if (addr) {
-                ret = (int)addr;
-                goto failed;
-        }
-
-        ret = ftrace_dyn_table_alloc(NR_TO_INIT);
-        if (ret)
-                goto failed;
-
-        p = kthread_run(ftraced, NULL, "ftraced");
-        if (IS_ERR(p)) {
-                ret = -1;
-                goto failed;
-        }
-
-        last_ftrace_enabled = ftrace_enabled = 1;
-        ftraced_task = p;
-
+        ftrace_enabled = 1;
         return 0;
-
- failed:
-        ftrace_disabled = 1;
-        return ret;
 }
+device_initcall(ftrace_nodyn_init);
 
-core_initcall(ftrace_dynamic_init);
-#endif /* CONFIG_FTRACE_MCOUNT_RECORD */
-
-#else
 # define ftrace_startup()               do { } while (0)
 # define ftrace_shutdown()              do { } while (0)
 # define ftrace_startup_sysctl()        do { } while (0)
 # define ftrace_shutdown_sysctl()       do { } while (0)
-# define ftrace_force_shutdown()        do { } while (0)
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
 /**
- * ftrace_kill_atomic - kill ftrace from critical sections
+ * ftrace_kill - kill ftrace
  *
  * This function should be used by panic code. It stops ftrace
  * but in a not so nice way. If you need to simply kill ftrace
  * from a non-atomic section, use ftrace_kill.
  */
-void ftrace_kill_atomic(void)
-{
-        ftrace_disabled = 1;
-        ftrace_enabled = 0;
-#ifdef CONFIG_DYNAMIC_FTRACE
-        ftraced_suspend = -1;
-#endif
-        clear_ftrace_function();
-}
-
-/**
- * ftrace_kill - totally shutdown ftrace
- *
- * This is a safety measure. If something was detected that seems
- * wrong, calling this function will keep ftrace from doing
- * any more modifications, and updates.
- * used when something went wrong.
- */
 void ftrace_kill(void)
 {
-        mutex_lock(&ftrace_sysctl_lock);
         ftrace_disabled = 1;
         ftrace_enabled = 0;
-
         clear_ftrace_function();
-        mutex_unlock(&ftrace_sysctl_lock);
-
-        /* Try to totally disable ftrace */
-        ftrace_force_shutdown();
 }
 
 /**
@@ -1870,3 +1453,4 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
         mutex_unlock(&ftrace_sysctl_lock);
         return ret;
 }
+