16 files changed, 659 insertions, 165 deletions

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 8c4c07071cc5..4cea4f41c1d9 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -49,6 +49,11 @@ config HAVE_SYSCALL_TRACEPOINTS
         help
           See Documentation/trace/ftrace-design.txt
 
+config HAVE_FENTRY
+        bool
+        help
+          Arch supports the gcc options -pg with -mfentry
+
 config HAVE_C_RECORDMCOUNT
         bool
         help
@@ -57,8 +62,12 @@ config HAVE_C_RECORDMCOUNT
 config TRACER_MAX_TRACE
         bool
 
+config TRACE_CLOCK
+        bool
+
 config RING_BUFFER
         bool
+        select TRACE_CLOCK
 
 config FTRACE_NMI_ENTER
        bool
@@ -109,6 +118,7 @@ config TRACING
         select NOP_TRACER
         select BINARY_PRINTF
         select EVENT_TRACING
+        select TRACE_CLOCK
 
 config GENERIC_TRACER
         bool
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index b831087c8200..d7e2068e4b71 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -5,10 +5,12 @@ ifdef CONFIG_FUNCTION_TRACER
 ORIG_CFLAGS := $(KBUILD_CFLAGS)
 KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS))
 
+ifdef CONFIG_FTRACE_SELFTEST
 # selftest needs instrumentation
 CFLAGS_trace_selftest_dynamic.o = -pg
 obj-y += trace_selftest_dynamic.o
 endif
+endif
 
 # If unlikely tracing is enabled, do not trace these files
 ifdef CONFIG_TRACING_BRANCHES
@@ -17,11 +19,7 @@ endif
 
 CFLAGS_trace_events_filter.o := -I$(src)
 
-#
-# Make the trace clocks available generally: it's infrastructure
-# relied on by ptrace for example:
-#
-obj-y += trace_clock.o
+obj-$(CONFIG_TRACE_CLOCK) += trace_clock.o
 
 obj-$(CONFIG_FUNCTION_TRACER) += libftrace.o
 obj-$(CONFIG_RING_BUFFER) += ring_buffer.o
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index b4f20fba09fc..9dcf15d38380 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -64,12 +64,20 @@
 
 #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL)
 
+static struct ftrace_ops ftrace_list_end __read_mostly = {
+        .func           = ftrace_stub,
+        .flags          = FTRACE_OPS_FL_RECURSION_SAFE,
+};
+
 /* ftrace_enabled is a method to turn ftrace on or off */
 int ftrace_enabled __read_mostly;
 static int last_ftrace_enabled;
 
 /* Quick disabling of function tracer. */
-int function_trace_stop;
+int function_trace_stop __read_mostly;
+
+/* Current function tracing op */
+struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
 
 /* List for set_ftrace_pid's pids. */
 LIST_HEAD(ftrace_pids);
@@ -86,22 +94,43 @@ static int ftrace_disabled __read_mostly;
 
 static DEFINE_MUTEX(ftrace_lock);
 
-static struct ftrace_ops ftrace_list_end __read_mostly = {
-        .func           = ftrace_stub,
-};
-
 static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
 static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
 static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
-static ftrace_func_t __ftrace_trace_function_delay __read_mostly = ftrace_stub;
-ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
 ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
 static struct ftrace_ops global_ops;
 static struct ftrace_ops control_ops;
 
-static void
-ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
+#if ARCH_SUPPORTS_FTRACE_OPS
+static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
+                                 struct ftrace_ops *op, struct pt_regs *regs);
+#else
+/* See comment below, where ftrace_ops_list_func is defined */
+static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
+#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
+#endif
+
+/**
+ * ftrace_nr_registered_ops - return number of ops registered
+ *
+ * Returns the number of ftrace_ops registered and tracing functions
+ */
+int ftrace_nr_registered_ops(void)
+{
+        struct ftrace_ops *ops;
+        int cnt = 0;
+
+        mutex_lock(&ftrace_lock);
+
+        for (ops = ftrace_ops_list;
+             ops != &ftrace_list_end; ops = ops->next)
+                cnt++;
+
+        mutex_unlock(&ftrace_lock);
+
+        return cnt;
+}
 
 /*
  * Traverse the ftrace_global_list, invoking all entries.  The reason that we
@@ -112,29 +141,29 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
  *
  * Silly Alpha and silly pointer-speculation compiler optimizations!
  */
-static void ftrace_global_list_func(unsigned long ip,
-                                    unsigned long parent_ip)
+static void
+ftrace_global_list_func(unsigned long ip, unsigned long parent_ip,
+                        struct ftrace_ops *op, struct pt_regs *regs)
 {
-        struct ftrace_ops *op;
-
         if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))
                 return;
 
         trace_recursion_set(TRACE_GLOBAL_BIT);
         op = rcu_dereference_raw(ftrace_global_list); /*see above*/
         while (op != &ftrace_list_end) {
-                op->func(ip, parent_ip);
+                op->func(ip, parent_ip, op, regs);
                 op = rcu_dereference_raw(op->next); /*see above*/
         };
         trace_recursion_clear(TRACE_GLOBAL_BIT);
 }
 
-static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
+static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
+                            struct ftrace_ops *op, struct pt_regs *regs)
 {
         if (!test_tsk_trace_trace(current))
                 return;
 
-        ftrace_pid_function(ip, parent_ip);
+        ftrace_pid_function(ip, parent_ip, op, regs);
 }
 
 static void set_ftrace_pid_function(ftrace_func_t func)
@@ -153,25 +182,9 @@ static void set_ftrace_pid_function(ftrace_func_t func)
 void clear_ftrace_function(void)
 {
         ftrace_trace_function = ftrace_stub;
-        __ftrace_trace_function = ftrace_stub;
-        __ftrace_trace_function_delay = ftrace_stub;
         ftrace_pid_function = ftrace_stub;
 }
 
-#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
-/*
- * For those archs that do not test ftrace_trace_stop in their
- * mcount call site, we need to do it from C.
- */
-static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
-{
-        if (function_trace_stop)
-                return;
-
-        __ftrace_trace_function(ip, parent_ip);
-}
-#endif
-
 static void control_ops_disable_all(struct ftrace_ops *ops)
 {
         int cpu;
@@ -230,28 +243,27 @@ static void update_ftrace_function(void)
 
         /*
          * If we are at the end of the list and this ops is
-         * not dynamic, then have the mcount trampoline call
-         * the function directly
+         * recursion safe and not dynamic and the arch supports passing ops,
+         * then have the mcount trampoline call the function directly.
          */
         if (ftrace_ops_list == &ftrace_list_end ||
             (ftrace_ops_list->next == &ftrace_list_end &&
-             !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC)))
+             !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) &&
+             (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) &&
+             !FTRACE_FORCE_LIST_FUNC)) {
+                /* Set the ftrace_ops that the arch callback uses */
+                if (ftrace_ops_list == &global_ops)
+                        function_trace_op = ftrace_global_list;
+                else
+                        function_trace_op = ftrace_ops_list;
                 func = ftrace_ops_list->func;
-        else
+        } else {
+                /* Just use the default ftrace_ops */
+                function_trace_op = &ftrace_list_end;
                 func = ftrace_ops_list_func;
+        }
 
-#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
         ftrace_trace_function = func;
-#else
-#ifdef CONFIG_DYNAMIC_FTRACE
-        /* do not update till all functions have been modified */
-        __ftrace_trace_function_delay = func;
-#else
-        __ftrace_trace_function = func;
-#endif
-        ftrace_trace_function =
-                (func == ftrace_stub) ? func : ftrace_test_stop_func;
-#endif
 }
 
 static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
@@ -325,6 +337,20 @@ static int __register_ftrace_function(struct ftrace_ops *ops)
         if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK)
                 return -EINVAL;
 
+#ifndef ARCH_SUPPORTS_FTRACE_SAVE_REGS
+        /*
+         * If the ftrace_ops specifies SAVE_REGS, then it only can be used
+         * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
+         * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
+         */
+        if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
+            !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
+                return -EINVAL;
+
+        if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
+                ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
+#endif
+
         if (!core_kernel_data((unsigned long)ops))
                 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
 
@@ -773,7 +799,8 @@ ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
 }
 
 static void
-function_profile_call(unsigned long ip, unsigned long parent_ip)
+function_profile_call(unsigned long ip, unsigned long parent_ip,
+                      struct ftrace_ops *ops, struct pt_regs *regs)
 {
         struct ftrace_profile_stat *stat;
         struct ftrace_profile *rec;
@@ -803,7 +830,7 @@ function_profile_call(unsigned long ip, unsigned long parent_ip)
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 static int profile_graph_entry(struct ftrace_graph_ent *trace)
 {
-        function_profile_call(trace->func, 0);
+        function_profile_call(trace->func, 0, NULL, NULL);
         return 1;
 }
 
@@ -863,6 +890,7 @@ static void unregister_ftrace_profiler(void)
 #else
 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
         .func           = function_profile_call,
+        .flags          = FTRACE_OPS_FL_RECURSION_SAFE,
 };
 
 static int register_ftrace_profiler(void)
@@ -1045,6 +1073,7 @@ static struct ftrace_ops global_ops = {
         .func                   = ftrace_stub,
         .notrace_hash           = EMPTY_HASH,
         .filter_hash            = EMPTY_HASH,
+        .flags                  = FTRACE_OPS_FL_RECURSION_SAFE,
 };
 
 static DEFINE_MUTEX(ftrace_regex_lock);
@@ -1525,6 +1554,12 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
                         rec->flags++;
                         if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX))
                                 return;
+                        /*
+                         * If any ops wants regs saved for this function
+                         * then all ops will get saved regs.
+                         */
+                        if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
+                                rec->flags |= FTRACE_FL_REGS;
                 } else {
                         if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0))
                                 return;
@@ -1616,18 +1651,59 @@ static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
         if (enable && (rec->flags & ~FTRACE_FL_MASK))
                 flag = FTRACE_FL_ENABLED;
 
+        /*
+         * If enabling and the REGS flag does not match the REGS_EN, then
+         * do not ignore this record. Set flags to fail the compare against
+         * ENABLED.
+         */
+        if (flag &&
+            (!(rec->flags & FTRACE_FL_REGS) != !(rec->flags & FTRACE_FL_REGS_EN)))
+                flag |= FTRACE_FL_REGS;
+
         /* If the state of this record hasn't changed, then do nothing */
         if ((rec->flags & FTRACE_FL_ENABLED) == flag)
                 return FTRACE_UPDATE_IGNORE;
 
         if (flag) {
-                if (update)
+                /* Save off if rec is being enabled (for return value) */
+                flag ^= rec->flags & FTRACE_FL_ENABLED;
+
+                if (update) {
                         rec->flags |= FTRACE_FL_ENABLED;
-                return FTRACE_UPDATE_MAKE_CALL;
+                        if (flag & FTRACE_FL_REGS) {
+                                if (rec->flags & FTRACE_FL_REGS)
+                                        rec->flags |= FTRACE_FL_REGS_EN;
+                                else
+                                        rec->flags &= ~FTRACE_FL_REGS_EN;
+                        }
+                }
+
+                /*
+                 * If this record is being updated from a nop, then
+                 *   return UPDATE_MAKE_CALL.
+                 * Otherwise, if the EN flag is set, then return
+                 *   UPDATE_MODIFY_CALL_REGS to tell the caller to convert
+                 *   from the non-save regs, to a save regs function.
+                 * Otherwise,
+                 *   return UPDATE_MODIFY_CALL to tell the caller to convert
+                 *   from the save regs, to a non-save regs function.
+                 */
+                if (flag & FTRACE_FL_ENABLED)
+                        return FTRACE_UPDATE_MAKE_CALL;
+                else if (rec->flags & FTRACE_FL_REGS_EN)
+                        return FTRACE_UPDATE_MODIFY_CALL_REGS;
+                else
+                        return FTRACE_UPDATE_MODIFY_CALL;
         }
 
-        if (update)
-                rec->flags &= ~FTRACE_FL_ENABLED;
+        if (update) {
+                /* If there's no more users, clear all flags */
+                if (!(rec->flags & ~FTRACE_FL_MASK))
+                        rec->flags = 0;
+                else
+                        /* Just disable the record (keep REGS state) */
+                        rec->flags &= ~FTRACE_FL_ENABLED;
+        }
 
         return FTRACE_UPDATE_MAKE_NOP;
 }
@@ -1662,13 +1738,17 @@ int ftrace_test_record(struct dyn_ftrace *rec, int enable)
 static int
 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
 {
+        unsigned long ftrace_old_addr;
         unsigned long ftrace_addr;
         int ret;
 
-        ftrace_addr = (unsigned long)FTRACE_ADDR;
-
         ret = ftrace_update_record(rec, enable);
 
+        if (rec->flags & FTRACE_FL_REGS)
+                ftrace_addr = (unsigned long)FTRACE_REGS_ADDR;
+        else
+                ftrace_addr = (unsigned long)FTRACE_ADDR;
+
         switch (ret) {
         case FTRACE_UPDATE_IGNORE:
                 return 0;
@@ -1678,6 +1758,15 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
 
         case FTRACE_UPDATE_MAKE_NOP:
                 return ftrace_make_nop(NULL, rec, ftrace_addr);
+
+        case FTRACE_UPDATE_MODIFY_CALL_REGS:
+        case FTRACE_UPDATE_MODIFY_CALL:
+                if (rec->flags & FTRACE_FL_REGS)
+                        ftrace_old_addr = (unsigned long)FTRACE_ADDR;
+                else
+                        ftrace_old_addr = (unsigned long)FTRACE_REGS_ADDR;
+
+                return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
         }
 
         return -1; /* unknow ftrace bug */
@@ -1882,16 +1971,6 @@ static void ftrace_run_update_code(int command)
          */
         arch_ftrace_update_code(command);
 
-#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
-        /*
-         * For archs that call ftrace_test_stop_func(), we must
-         * wait till after we update all the function callers
-         * before we update the callback. This keeps different
-         * ops that record different functions from corrupting
-         * each other.
-         */
-        __ftrace_trace_function = __ftrace_trace_function_delay;
-#endif
         function_trace_stop--;
 
         ret = ftrace_arch_code_modify_post_process();
@@ -2441,8 +2520,9 @@ static int t_show(struct seq_file *m, void *v)
 
         seq_printf(m, "%ps", (void *)rec->ip);
         if (iter->flags & FTRACE_ITER_ENABLED)
-                seq_printf(m, " (%ld)",
-                           rec->flags & ~FTRACE_FL_MASK);
+                seq_printf(m, " (%ld)%s",
+                           rec->flags & ~FTRACE_FL_MASK,
+                           rec->flags & FTRACE_FL_REGS ? " R" : "");
         seq_printf(m, "\n");
 
         return 0;
@@ -2790,8 +2870,8 @@ static int __init ftrace_mod_cmd_init(void)
 }
 device_initcall(ftrace_mod_cmd_init);
 
-static void
-function_trace_probe_call(unsigned long ip, unsigned long parent_ip)
+static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
+                                      struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
         struct ftrace_func_probe *entry;
         struct hlist_head *hhd;
@@ -3162,8 +3242,27 @@ ftrace_notrace_write(struct file *file, const char __user *ubuf,
 }
 
 static int
-ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
-                 int reset, int enable)
+ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
+{
+        struct ftrace_func_entry *entry;
+
+        if (!ftrace_location(ip))
+                return -EINVAL;
+
+        if (remove) {
+                entry = ftrace_lookup_ip(hash, ip);
+                if (!entry)
+                        return -ENOENT;
+                free_hash_entry(hash, entry);
+                return 0;
+        }
+
+        return add_hash_entry(hash, ip);
+}
+
+static int
+ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
+                unsigned long ip, int remove, int reset, int enable)
 {
         struct ftrace_hash **orig_hash;
         struct ftrace_hash *hash;
@@ -3192,6 +3291,11 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
                 ret = -EINVAL;
                 goto out_regex_unlock;
         }
+        if (ip) {
+                ret = ftrace_match_addr(hash, ip, remove);
+                if (ret < 0)
+                        goto out_regex_unlock;
+        }
 
         mutex_lock(&ftrace_lock);
         ret = ftrace_hash_move(ops, enable, orig_hash, hash);
@@ -3208,6 +3312,37 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
         return ret;
 }
 
+static int
+ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
+                int reset, int enable)
+{
+        return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
+}
+
+/**
+ * ftrace_set_filter_ip - set a function to filter on in ftrace by address
+ * @ops - the ops to set the filter with
+ * @ip - the address to add to or remove from the filter.
+ * @remove - non zero to remove the ip from the filter
+ * @reset - non zero to reset all filters before applying this filter.
+ *
+ * Filters denote which functions should be enabled when tracing is enabled
+ * If @ip is NULL, it failes to update filter.
+ */
+int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
+                         int remove, int reset)
+{
+        return ftrace_set_addr(ops, ip, remove, reset, 1);
+}
+EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
+
+static int
+ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
+                 int reset, int enable)
+{
+        return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
+}
+
 /**
  * ftrace_set_filter - set a function to filter on in ftrace
  * @ops - the ops to set the filter with
@@ -3912,6 +4047,7 @@ void __init ftrace_init(void)
 
 static struct ftrace_ops global_ops = {
         .func                   = ftrace_stub,
+        .flags                  = FTRACE_OPS_FL_RECURSION_SAFE,
 };
 
 static int __init ftrace_nodyn_init(void)
@@ -3942,10 +4078,9 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
 static void
-ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip)
+ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
+                        struct ftrace_ops *op, struct pt_regs *regs)
 {
-        struct ftrace_ops *op;
-
         if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
                 return;
 
@@ -3959,7 +4094,7 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip)
         while (op != &ftrace_list_end) {
                 if (!ftrace_function_local_disabled(op) &&
                     ftrace_ops_test(op, ip))
-                        op->func(ip, parent_ip);
+                        op->func(ip, parent_ip, op, regs);
 
                 op = rcu_dereference_raw(op->next);
         };
@@ -3969,13 +4104,18 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip)
 
 static struct ftrace_ops control_ops = {
         .func = ftrace_ops_control_func,
+        .flags = FTRACE_OPS_FL_RECURSION_SAFE,
 };
 
-static void
-ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
+static inline void
+__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
+                       struct ftrace_ops *ignored, struct pt_regs *regs)
 {
         struct ftrace_ops *op;
 
+        if (function_trace_stop)
+                return;
+
         if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT)))
                 return;
 
@@ -3988,13 +4128,39 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
         op = rcu_dereference_raw(ftrace_ops_list);
         while (op != &ftrace_list_end) {
                 if (ftrace_ops_test(op, ip))
-                        op->func(ip, parent_ip);
+                        op->func(ip, parent_ip, op, regs);
                 op = rcu_dereference_raw(op->next);
         };
         preempt_enable_notrace();
         trace_recursion_clear(TRACE_INTERNAL_BIT);
 }
 
+/*
+ * Some archs only support passing ip and parent_ip. Even though
+ * the list function ignores the op parameter, we do not want any
+ * C side effects, where a function is called without the caller
+ * sending a third parameter.
+ * Archs are to support both the regs and ftrace_ops at the same time.
+ * If they support ftrace_ops, it is assumed they support regs.
+ * If call backs want to use regs, they must either check for regs
+ * being NULL, or ARCH_SUPPORTS_FTRACE_SAVE_REGS.
+ * Note, ARCH_SUPPORT_SAVE_REGS expects a full regs to be saved.
+ * An architecture can pass partial regs with ftrace_ops and still
+ * set the ARCH_SUPPORT_FTARCE_OPS.
+ */
+#if ARCH_SUPPORTS_FTRACE_OPS
+static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
+                                 struct ftrace_ops *op, struct pt_regs *regs)
+{
+        __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
+}
+#else
+static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
+{
+        __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
+}
+#endif
+
 static void clear_ftrace_swapper(void)
 {
         struct task_struct *p;
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 49491fa7daa2..b32ed0e385a5 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2816,7 +2816,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_enable);
  * to the buffer after this will fail and return NULL.
  *
  * This is different than ring_buffer_record_disable() as
- * it works like an on/off switch, where as the disable() verison
+ * it works like an on/off switch, where as the disable() version
  * must be paired with a enable().
  */
 void ring_buffer_record_off(struct ring_buffer *buffer)
@@ -2839,7 +2839,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_off);
  * ring_buffer_record_off().
  *
  * This is different than ring_buffer_record_enable() as
- * it works like an on/off switch, where as the enable() verison
+ * it works like an on/off switch, where as the enable() version
  * must be paired with a disable().
  */
 void ring_buffer_record_on(struct ring_buffer *buffer)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5c38c81496ce..cdcb59450b49 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -328,7 +328,7 @@ static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
 unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
         TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME |
         TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE |
-        TRACE_ITER_IRQ_INFO;
+        TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS;
 
 static int trace_stop_count;
 static DEFINE_RAW_SPINLOCK(tracing_start_lock);
@@ -426,15 +426,15 @@ __setup("trace_buf_size=", set_buf_size);
 
 static int __init set_tracing_thresh(char *str)
 {
-        unsigned long threshhold;
+        unsigned long threshold;
         int ret;
 
         if (!str)
                 return 0;
-        ret = strict_strtoul(str, 0, &threshhold);
+        ret = strict_strtoul(str, 0, &threshold);
         if (ret < 0)
                 return 0;
-        tracing_thresh = threshhold * 1000;
+        tracing_thresh = threshold * 1000;
         return 1;
 }
 __setup("tracing_thresh=", set_tracing_thresh);
@@ -470,6 +470,7 @@ static const char *trace_options[] = {
         "overwrite",
         "disable_on_free",
         "irq-info",
+        "markers",
         NULL
 };
 
@@ -2060,7 +2061,8 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
         seq_puts(m, "#    -----------------\n");
         seq_printf(m, "#    | task: %.16s-%d "
                    "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
-                   data->comm, data->pid, data->uid, data->nice,
+                   data->comm, data->pid,
+                   from_kuid_munged(seq_user_ns(m), data->uid), data->nice,
                    data->policy, data->rt_priority);
         seq_puts(m, "#    -----------------\n");
 
@@ -3886,6 +3888,9 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
         if (tracing_disabled)
                 return -EINVAL;
 
+        if (!(trace_flags & TRACE_ITER_MARKERS))
+                return -EINVAL;
+
         if (cnt > TRACE_BUF_SIZE)
                 cnt = TRACE_BUF_SIZE;
 
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 55e1f7f0db12..c15f528c1af4 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -147,7 +147,7 @@ struct trace_array_cpu {
         unsigned long           skipped_entries;
         cycle_t                 preempt_timestamp;
         pid_t                   pid;
-        uid_t                   uid;
+        kuid_t                  uid;
         char                    comm[TASK_COMM_LEN];
 };
 
@@ -472,11 +472,11 @@ extern void trace_find_cmdline(int pid, char comm[]);
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 extern unsigned long ftrace_update_tot_cnt;
+#endif
 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 extern int DYN_FTRACE_TEST_NAME(void);
 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
 extern int DYN_FTRACE_TEST_NAME2(void);
-#endif
 
 extern int ring_buffer_expanded;
 extern bool tracing_selftest_disabled;
@@ -680,6 +680,7 @@ enum trace_iterator_flags {
         TRACE_ITER_OVERWRITE            = 0x200000,
         TRACE_ITER_STOP_ON_FREE         = 0x400000,
         TRACE_ITER_IRQ_INFO             = 0x800000,
+        TRACE_ITER_MARKERS              = 0x1000000,
 };
 
 /*
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 8a6d2ee2086c..84b1e045faba 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -258,7 +258,8 @@ EXPORT_SYMBOL_GPL(perf_trace_buf_prepare);
 
 #ifdef CONFIG_FUNCTION_TRACER
 static void
-perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip)
+perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip,
+                          struct ftrace_ops *ops, struct pt_regs *pt_regs)
 {
         struct ftrace_entry *entry;
         struct hlist_head *head;
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 29111da1d100..d608d09d08c0 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1199,6 +1199,31 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
         return 0;
 }
 
+static void event_remove(struct ftrace_event_call *call)
+{
+        ftrace_event_enable_disable(call, 0);
+        if (call->event.funcs)
+                __unregister_ftrace_event(&call->event);
+        list_del(&call->list);
+}
+
+static int event_init(struct ftrace_event_call *call)
+{
+        int ret = 0;
+
+        if (WARN_ON(!call->name))
+                return -EINVAL;
+
+        if (call->class->raw_init) {
+                ret = call->class->raw_init(call);
+                if (ret < 0 && ret != -ENOSYS)
+                        pr_warn("Could not initialize trace events/%s\n",
+                                call->name);
+        }
+
+        return ret;
+}
+
 static int
 __trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
                        const struct file_operations *id,
@@ -1209,19 +1234,9 @@ __trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
         struct dentry *d_events;
         int ret;
 
-        /* The linker may leave blanks */
-        if (!call->name)
-                return -EINVAL;
-
-        if (call->class->raw_init) {
-                ret = call->class->raw_init(call);
-                if (ret < 0) {
-                        if (ret != -ENOSYS)
-                                pr_warning("Could not initialize trace events/%s\n",
-                                           call->name);
-                        return ret;
-                }
-        }
+        ret = event_init(call);
+        if (ret < 0)
+                return ret;
 
         d_events = event_trace_events_dir();
         if (!d_events)
@@ -1272,13 +1287,10 @@ static void remove_subsystem_dir(const char *name)
  */
 static void __trace_remove_event_call(struct ftrace_event_call *call)
 {
-        ftrace_event_enable_disable(call, 0);
-        if (call->event.funcs)
-                __unregister_ftrace_event(&call->event);
-        debugfs_remove_recursive(call->dir);
-        list_del(&call->list);
+        event_remove(call);
         trace_destroy_fields(call);
         destroy_preds(call);
+        debugfs_remove_recursive(call->dir);
         remove_subsystem_dir(call->class->system);
 }
 
@@ -1450,15 +1462,43 @@ static __init int setup_trace_event(char *str)
 }
 __setup("trace_event=", setup_trace_event);
 
+static __init int event_trace_enable(void)
+{
+        struct ftrace_event_call **iter, *call;
+        char *buf = bootup_event_buf;
+        char *token;
+        int ret;
+
+        for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
+
+                call = *iter;
+                ret = event_init(call);
+                if (!ret)
+                        list_add(&call->list, &ftrace_events);
+        }
+
+        while (true) {
+                token = strsep(&buf, ",");
+
+                if (!token)
+                        break;
+                if (!*token)
+                        continue;
+
+                ret = ftrace_set_clr_event(token, 1);
+                if (ret)
+                        pr_warn("Failed to enable trace event: %s\n", token);
+        }
+        return 0;
+}
+
 static __init int event_trace_init(void)
 {
-        struct ftrace_event_call **call;
+        struct ftrace_event_call *call;
         struct dentry *d_tracer;
         struct dentry *entry;
         struct dentry *d_events;
         int ret;
-        char *buf = bootup_event_buf;
-        char *token;
 
         d_tracer = tracing_init_dentry();
         if (!d_tracer)
@@ -1497,24 +1537,19 @@ static __init int event_trace_init(void)
         if (trace_define_common_fields())
                 pr_warning("tracing: Failed to allocate common fields");
 
-        for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
-                __trace_add_event_call(*call, NULL, &ftrace_event_id_fops,
+        /*
+         * Early initialization already enabled ftrace event.
+         * Now it's only necessary to create the event directory.
+         */
+        list_for_each_entry(call, &ftrace_events, list) {
+
+                ret = event_create_dir(call, d_events,
+                                       &ftrace_event_id_fops,
                                        &ftrace_enable_fops,
                                        &ftrace_event_filter_fops,
                                        &ftrace_event_format_fops);
-        }
-
-        while (true) {
-                token = strsep(&buf, ",");
-
-                if (!token)
-                        break;
-                if (!*token)
-                        continue;
-
-                ret = ftrace_set_clr_event(token, 1);
-                if (ret)
-                        pr_warning("Failed to enable trace event: %s\n", token);
+                if (ret < 0)
+                        event_remove(call);
         }
 
         ret = register_module_notifier(&trace_module_nb);
@@ -1523,6 +1558,7 @@ static __init int event_trace_init(void)
 
         return 0;
 }
+core_initcall(event_trace_enable);
 fs_initcall(event_trace_init);
 
 #ifdef CONFIG_FTRACE_STARTUP_TEST
@@ -1646,9 +1682,11 @@ static __init void event_trace_self_tests(void)
                 event_test_stuff();
 
                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
-                if (WARN_ON_ONCE(ret))
+                if (WARN_ON_ONCE(ret)) {
                         pr_warning("error disabling system %s\n",
                                    system->name);
+                        continue;
+                }
 
                 pr_cont("OK\n");
         }
@@ -1681,7 +1719,8 @@ static __init void event_trace_self_tests(void)
 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
 
 static void
-function_test_events_call(unsigned long ip, unsigned long parent_ip)
+function_test_events_call(unsigned long ip, unsigned long parent_ip,
+                          struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
         struct ring_buffer_event *event;
         struct ring_buffer *buffer;
@@ -1720,6 +1759,7 @@ function_test_events_call(unsigned long ip, unsigned long parent_ip)
 static struct ftrace_ops trace_ops __initdata  =
 {
         .func = function_test_events_call,
+        .flags = FTRACE_OPS_FL_RECURSION_SAFE,
 };
 
 static __init void event_trace_self_test_with_function(void)
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 431dba8b7542..c154797a7ff7 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -2002,7 +2002,7 @@ static int ftrace_function_set_regexp(struct ftrace_ops *ops, int filter,
 static int __ftrace_function_set_filter(int filter, char *buf, int len,
                                         struct function_filter_data *data)
 {
-        int i, re_cnt, ret;
+        int i, re_cnt, ret = -EINVAL;
         int *reset;
         char **re;
 
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index a426f410c060..483162a9f908 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -49,7 +49,8 @@ static void function_trace_start(struct trace_array *tr)
 }
 
 static void
-function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip)
+function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip,
+                                 struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
         struct trace_array *tr = func_trace;
         struct trace_array_cpu *data;
@@ -84,7 +85,9 @@ enum {
 static struct tracer_flags func_flags;
 
 static void
-function_trace_call(unsigned long ip, unsigned long parent_ip)
+function_trace_call(unsigned long ip, unsigned long parent_ip,
+                    struct ftrace_ops *op, struct pt_regs *pt_regs)
+
 {
         struct trace_array *tr = func_trace;
         struct trace_array_cpu *data;
@@ -121,7 +124,8 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
 }
 
 static void
-function_stack_trace_call(unsigned long ip, unsigned long parent_ip)
+function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
+                          struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
         struct trace_array *tr = func_trace;
         struct trace_array_cpu *data;
@@ -164,13 +168,13 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip)
 static struct ftrace_ops trace_ops __read_mostly =
 {
         .func = function_trace_call,
-        .flags = FTRACE_OPS_FL_GLOBAL,
+        .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE,
 };
 
 static struct ftrace_ops trace_stack_ops __read_mostly =
 {
         .func = function_stack_trace_call,
-        .flags = FTRACE_OPS_FL_GLOBAL,
+        .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE,
 };
 
 static struct tracer_opt func_opts[] = {
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index ce27c8ba8d31..99b4378393d5 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -143,7 +143,7 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
                 return;
         }
 
-#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST
+#if defined(CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST) && !defined(CC_USING_FENTRY)
         /*
          * The arch may choose to record the frame pointer used
          * and check it here to make sure that it is what we expect it
@@ -154,6 +154,9 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
          *
          * Currently, x86_32 with optimize for size (-Os) makes the latest
          * gcc do the above.
+         *
+         * Note, -mfentry does not use frame pointers, and this test
+         *  is not needed if CC_USING_FENTRY is set.
          */
         if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
                 ftrace_graph_stop();
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 99d20e920368..d98ee8283b29 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -136,7 +136,8 @@ static int func_prolog_dec(struct trace_array *tr,
  * irqsoff uses its own tracer function to keep the overhead down:
  */
 static void
-irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip)
+irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip,
+                    struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
         struct trace_array *tr = irqsoff_trace;
         struct trace_array_cpu *data;
@@ -153,7 +154,7 @@ irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip)
 static struct ftrace_ops trace_ops __read_mostly =
 {
         .func = irqsoff_tracer_call,
-        .flags = FTRACE_OPS_FL_GLOBAL,
+        .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE,
 };
 #endif /* CONFIG_FUNCTION_TRACER */
 
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index ff791ea48b57..02170c00c413 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -108,7 +108,8 @@ out_enable:
  * wakeup uses its own tracer function to keep the overhead down:
  */
 static void
-wakeup_tracer_call(unsigned long ip, unsigned long parent_ip)
+wakeup_tracer_call(unsigned long ip, unsigned long parent_ip,
+                   struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
         struct trace_array *tr = wakeup_trace;
         struct trace_array_cpu *data;
@@ -129,7 +130,7 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip)
 static struct ftrace_ops trace_ops __read_mostly =
 {
         .func = wakeup_tracer_call,
-        .flags = FTRACE_OPS_FL_GLOBAL,
+        .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE,
 };
 #endif /* CONFIG_FUNCTION_TRACER */
 
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 288541f977fb..2c00a691a540 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -103,54 +103,67 @@ static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret)
 
 static int trace_selftest_test_probe1_cnt;
 static void trace_selftest_test_probe1_func(unsigned long ip,
-                                            unsigned long pip)
+                                            unsigned long pip,
+                                            struct ftrace_ops *op,
+                                            struct pt_regs *pt_regs)
 {
         trace_selftest_test_probe1_cnt++;
 }
 
 static int trace_selftest_test_probe2_cnt;
 static void trace_selftest_test_probe2_func(unsigned long ip,
-                                            unsigned long pip)
+                                            unsigned long pip,
+                                            struct ftrace_ops *op,
+                                            struct pt_regs *pt_regs)
 {
         trace_selftest_test_probe2_cnt++;
 }
 
 static int trace_selftest_test_probe3_cnt;
 static void trace_selftest_test_probe3_func(unsigned long ip,
-                                            unsigned long pip)
+                                            unsigned long pip,
+                                            struct ftrace_ops *op,
+                                            struct pt_regs *pt_regs)
 {
         trace_selftest_test_probe3_cnt++;
 }
 
 static int trace_selftest_test_global_cnt;
 static void trace_selftest_test_global_func(unsigned long ip,
-                                            unsigned long pip)
+                                            unsigned long pip,
+                                            struct ftrace_ops *op,
+                                            struct pt_regs *pt_regs)
 {
         trace_selftest_test_global_cnt++;
 }
 
 static int trace_selftest_test_dyn_cnt;
 static void trace_selftest_test_dyn_func(unsigned long ip,
-                                         unsigned long pip)
+                                         unsigned long pip,
+                                         struct ftrace_ops *op,
+                                         struct pt_regs *pt_regs)
 {
         trace_selftest_test_dyn_cnt++;
 }
 
 static struct ftrace_ops test_probe1 = {
         .func                   = trace_selftest_test_probe1_func,
+        .flags                  = FTRACE_OPS_FL_RECURSION_SAFE,
 };
 
 static struct ftrace_ops test_probe2 = {
         .func                   = trace_selftest_test_probe2_func,
+        .flags                  = FTRACE_OPS_FL_RECURSION_SAFE,
 };
 
 static struct ftrace_ops test_probe3 = {
         .func                   = trace_selftest_test_probe3_func,
+        .flags                  = FTRACE_OPS_FL_RECURSION_SAFE,
 };
 
 static struct ftrace_ops test_global = {
-        .func                   = trace_selftest_test_global_func,
-        .flags                  = FTRACE_OPS_FL_GLOBAL,
+        .func           = trace_selftest_test_global_func,
+        .flags          = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE,
 };
 
 static void print_counts(void)
@@ -393,10 +406,253 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 
         return ret;
 }
+
+static int trace_selftest_recursion_cnt;
+static void trace_selftest_test_recursion_func(unsigned long ip,
+                                               unsigned long pip,
+                                               struct ftrace_ops *op,
+                                               struct pt_regs *pt_regs)
+{
+        /*
+         * This function is registered without the recursion safe flag.
+         * The ftrace infrastructure should provide the recursion
+         * protection. If not, this will crash the kernel!
+         */
+        trace_selftest_recursion_cnt++;
+        DYN_FTRACE_TEST_NAME();
+}
+
+static void trace_selftest_test_recursion_safe_func(unsigned long ip,
+                                                    unsigned long pip,
+                                                    struct ftrace_ops *op,
+                                                    struct pt_regs *pt_regs)
+{
+        /*
+         * We said we would provide our own recursion. By calling
+         * this function again, we should recurse back into this function
+         * and count again. But this only happens if the arch supports
+         * all of ftrace features and nothing else is using the function
+         * tracing utility.
+         */
+        if (trace_selftest_recursion_cnt++)
+                return;
+        DYN_FTRACE_TEST_NAME();
+}
+
+static struct ftrace_ops test_rec_probe = {
+        .func                   = trace_selftest_test_recursion_func,
+};
+
+static struct ftrace_ops test_recsafe_probe = {
+        .func                   = trace_selftest_test_recursion_safe_func,
+        .flags                  = FTRACE_OPS_FL_RECURSION_SAFE,
+};
+
+static int
+trace_selftest_function_recursion(void)
+{
+        int save_ftrace_enabled = ftrace_enabled;
+        int save_tracer_enabled = tracer_enabled;
+        char *func_name;
+        int len;
+        int ret;
+        int cnt;
+
+        /* The previous test PASSED */
+        pr_cont("PASSED\n");
+        pr_info("Testing ftrace recursion: ");
+
+
+        /* enable tracing, and record the filter function */
+        ftrace_enabled = 1;
+        tracer_enabled = 1;
+
+        /* Handle PPC64 '.' name */
+        func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
+        len = strlen(func_name);
+
+        ret = ftrace_set_filter(&test_rec_probe, func_name, len, 1);
+        if (ret) {
+                pr_cont("*Could not set filter* ");
+                goto out;
+        }
+
+        ret = register_ftrace_function(&test_rec_probe);
+        if (ret) {
+                pr_cont("*could not register callback* ");
+                goto out;
+        }
+
+        DYN_FTRACE_TEST_NAME();
+
+        unregister_ftrace_function(&test_rec_probe);
+
+        ret = -1;
+        if (trace_selftest_recursion_cnt != 1) {
+                pr_cont("*callback not called once (%d)* ",
+                        trace_selftest_recursion_cnt);
+                goto out;
+        }
+
+        trace_selftest_recursion_cnt = 1;
+
+        pr_cont("PASSED\n");
+        pr_info("Testing ftrace recursion safe: ");
+
+        ret = ftrace_set_filter(&test_recsafe_probe, func_name, len, 1);
+        if (ret) {
+                pr_cont("*Could not set filter* ");
+                goto out;
+        }
+
+        ret = register_ftrace_function(&test_recsafe_probe);
+        if (ret) {
+                pr_cont("*could not register callback* ");
+                goto out;
+        }
+
+        DYN_FTRACE_TEST_NAME();
+
+        unregister_ftrace_function(&test_recsafe_probe);
+
+        /*
+         * If arch supports all ftrace features, and no other task
+         * was on the list, we should be fine.
+         */
+        if (!ftrace_nr_registered_ops() && !FTRACE_FORCE_LIST_FUNC)
+                cnt = 2; /* Should have recursed */
+        else
+                cnt = 1;
+
+        ret = -1;
+        if (trace_selftest_recursion_cnt != cnt) {
+                pr_cont("*callback not called expected %d times (%d)* ",
+                        cnt, trace_selftest_recursion_cnt);
+                goto out;
+        }
+
+        ret = 0;
+out:
+        ftrace_enabled = save_ftrace_enabled;
+        tracer_enabled = save_tracer_enabled;
+
+        return ret;
+}
 #else
 # define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; })
+# define trace_selftest_function_recursion() ({ 0; })
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
+static enum {
+        TRACE_SELFTEST_REGS_START,
+        TRACE_SELFTEST_REGS_FOUND,
+        TRACE_SELFTEST_REGS_NOT_FOUND,
+} trace_selftest_regs_stat;
+
+static void trace_selftest_test_regs_func(unsigned long ip,
+                                          unsigned long pip,
+                                          struct ftrace_ops *op,
+                                          struct pt_regs *pt_regs)
+{
+        if (pt_regs)
+                trace_selftest_regs_stat = TRACE_SELFTEST_REGS_FOUND;
+        else
+                trace_selftest_regs_stat = TRACE_SELFTEST_REGS_NOT_FOUND;
+}
+
+static struct ftrace_ops test_regs_probe = {
+        .func           = trace_selftest_test_regs_func,
+        .flags          = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_SAVE_REGS,
+};
+
+static int
+trace_selftest_function_regs(void)
+{
+        int save_ftrace_enabled = ftrace_enabled;
+        int save_tracer_enabled = tracer_enabled;
+        char *func_name;
+        int len;
+        int ret;
+        int supported = 0;
+
+#ifdef ARCH_SUPPORTS_FTRACE_SAVE_REGS
+        supported = 1;
+#endif
+
+        /* The previous test PASSED */
+        pr_cont("PASSED\n");
+        pr_info("Testing ftrace regs%s: ",
+                !supported ? "(no arch support)" : "");
+
+        /* enable tracing, and record the filter function */
+        ftrace_enabled = 1;
+        tracer_enabled = 1;
+
+        /* Handle PPC64 '.' name */
+        func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
+        len = strlen(func_name);
+
+        ret = ftrace_set_filter(&test_regs_probe, func_name, len, 1);
+        /*
+         * If DYNAMIC_FTRACE is not set, then we just trace all functions.
+         * This test really doesn't care.
+         */
+        if (ret && ret != -ENODEV) {
+                pr_cont("*Could not set filter* ");
+                goto out;
+        }
+
+        ret = register_ftrace_function(&test_regs_probe);
+        /*
+         * Now if the arch does not support passing regs, then this should
+         * have failed.
+         */
+        if (!supported) {
+                if (!ret) {
+                        pr_cont("*registered save-regs without arch support* ");
+                        goto out;
+                }
+                test_regs_probe.flags |= FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED;
+                ret = register_ftrace_function(&test_regs_probe);
+        }
+        if (ret) {
+                pr_cont("*could not register callback* ");
+                goto out;
+        }
+
+
+        DYN_FTRACE_TEST_NAME();
+
+        unregister_ftrace_function(&test_regs_probe);
+
+        ret = -1;
+
+        switch (trace_selftest_regs_stat) {
+        case TRACE_SELFTEST_REGS_START:
+                pr_cont("*callback never called* ");
+                goto out;
+
+        case TRACE_SELFTEST_REGS_FOUND:
+                if (supported)
+                        break;
+                pr_cont("*callback received regs without arch support* ");
+                goto out;
+
+        case TRACE_SELFTEST_REGS_NOT_FOUND:
+                if (!supported)
+                        break;
+                pr_cont("*callback received NULL regs* ");
+                goto out;
+        }
+
+        ret = 0;
+out:
+        ftrace_enabled = save_ftrace_enabled;
+        tracer_enabled = save_tracer_enabled;
+
+        return ret;
+}
+
 /*
  * Simple verification test of ftrace function tracer.
  * Enable ftrace, sleep 1/10 second, and then read the trace
@@ -442,7 +698,14 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
 
         ret = trace_selftest_startup_dynamic_tracing(trace, tr,
                                                      DYN_FTRACE_TEST_NAME);
+        if (ret)
+                goto out;
 
+        ret = trace_selftest_function_recursion();
+        if (ret)
+                goto out;
+
+        ret = trace_selftest_function_regs();
  out:
         ftrace_enabled = save_ftrace_enabled;
         tracer_enabled = save_tracer_enabled;
@@ -778,6 +1041,8 @@ static int trace_wakeup_test_thread(void *data)
         set_current_state(TASK_INTERRUPTIBLE);
         schedule();
 
+        complete(x);
+
         /* we are awake, now wait to disappear */
         while (!kthread_should_stop()) {
                 /*
@@ -821,24 +1086,21 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
         /* reset the max latency */
         tracing_max_latency = 0;
 
-        /* sleep to let the RT thread sleep too */
-        msleep(100);
+        while (p->on_rq) {
+                /*
+                 * Sleep to make sure the RT thread is asleep too.
+                 * On virtual machines we can't rely on timings,
+                 * but we want to make sure this test still works.
+                 */
+                msleep(100);
+        }
 
-        /*
-         * Yes this is slightly racy. It is possible that for some
-         * strange reason that the RT thread we created, did not
-         * call schedule for 100ms after doing the completion,
-         * and we do a wakeup on a task that already is awake.
-         * But that is extremely unlikely, and the worst thing that
-         * happens in such a case, is that we disable tracing.
-         * Honestly, if this race does happen something is horrible
-         * wrong with the system.
-         */
+        init_completion(&isrt);
 
         wake_up_process(p);
 
-        /* give a little time to let the thread wake up */
-        msleep(100);
+        /* Wait for the task to wake up */
+        wait_for_completion(&isrt);
 
         /* stop the tracing. */
         tracing_stop();
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index d4545f49242e..0c1b165778e5 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -111,7 +111,8 @@ static inline void check_stack(void)
 }
 
 static void
-stack_trace_call(unsigned long ip, unsigned long parent_ip)
+stack_trace_call(unsigned long ip, unsigned long parent_ip,
+                 struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
         int cpu;
 
@@ -136,6 +137,7 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip)
 static struct ftrace_ops trace_ops __read_mostly =
 {
         .func = stack_trace_call,
+        .flags = FTRACE_OPS_FL_RECURSION_SAFE,
 };
 
 static ssize_t
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 6b245f64c8dd..2485a7d09b11 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -487,7 +487,7 @@ int __init init_ftrace_syscalls(void)
 
         return 0;
 }
-core_initcall(init_ftrace_syscalls);
+early_initcall(init_ftrace_syscalls);
 
 #ifdef CONFIG_PERF_EVENTS