Merge tag 'trace-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "Not much new with tracing for this release.  Mostly just clean ups and
  minor fixes.

  Here's what else is new:

   - A new TRACE_EVENT_FN_COND macro, combining both _FN and _COND for
     those that want both.

   - New selftest to test the instance create and delete

   - Better debug output when ftrace fails"

* tag 'trace-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (24 commits)
  ftrace: Fix the race between ftrace and insmod
  ftrace: Add infrastructure for delayed enabling of module functions
  x86: ftrace: Fix the comments for ftrace_modify_code_direct()
  tracing: Fix comment to use tracing_on over tracing_enable
  metag: ftrace: Fix the comments for ftrace_modify_code
  sh: ftrace: Fix the comments for ftrace_modify_code()
  ia64: ftrace: Fix the comments for ftrace_modify_code()
  ftrace: Clean up ftrace_module_init() code
  ftrace: Join functions ftrace_module_init() and ftrace_init_module()
  tracing: Introduce TRACE_EVENT_FN_COND macro
  tracing: Use seq_buf_used() in seq_buf_to_user() instead of len
  bpf: Constify bpf_verifier_ops structure
  ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too
  ftrace: Remove use of control list and ops
  ftrace: Fix output of enabled_functions for showing tramp
  ftrace: Fix a typo in comment
  ftrace: Show all tramps registered to a record on ftrace_bug()
  ftrace: Add variable ftrace_expected for archs to show expected code
  ftrace: Add new type to distinguish what kind of ftrace_bug()
  tracing: Update cond flag when enabling or disabling a trigger
  ...

16 files changed, 476 insertions, 276 deletions

diff --git a/arch/ia64/kernel/ftrace.c b/arch/ia64/kernel/ftrace.c
index 3b0c2aa07857..cee411e647ca 100644
--- a/arch/ia64/kernel/ftrace.c
+++ b/arch/ia64/kernel/ftrace.c
@@ -97,13 +97,11 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
 	unsigned char replaced[MCOUNT_INSN_SIZE];
 
 	/*
-	 * Note: Due to modules and __init, code can
-	 *  disappear and change, we need to protect against faulting
-	 *  as well as code changing. We do this by using the
-	 *  probe_kernel_* functions.
-	 *
-	 * No real locking needed, this code is run through
-	 * kstop_machine, or before SMP starts.
+	 * Note:
+	 * We are paranoid about modifying text, as if a bug was to happen, it
+	 * could cause us to read or write to someplace that could cause harm.
+	 * Carefully read and modify the code with probe_kernel_*(), and make
+	 * sure what we read is what we expected it to be before modifying it.
 	 */
 
 	if (!do_check)
diff --git a/arch/metag/kernel/ftrace.c b/arch/metag/kernel/ftrace.c
index ed1d685157c2..ac8c039b0318 100644
--- a/arch/metag/kernel/ftrace.c
+++ b/arch/metag/kernel/ftrace.c
@@ -54,12 +54,11 @@ static int ftrace_modify_code(unsigned long pc, unsigned char *old_code,
 	unsigned char replaced[MCOUNT_INSN_SIZE];
 
 	/*
-	 * Note: Due to modules and __init, code can
-	 *  disappear and change, we need to protect against faulting
-	 *  as well as code changing.
-	 *
-	 * No real locking needed, this code is run through
-	 * kstop_machine.
+	 * Note:
+	 * We are paranoid about modifying text, as if a bug was to happen, it
+	 * could cause us to read or write to someplace that could cause harm.
+	 * Carefully read and modify the code with probe_kernel_*(), and make
+	 * sure what we read is what we expected it to be before modifying it.
 	 */
 
 	/* read the text we want to modify */
diff --git a/arch/sh/kernel/ftrace.c b/arch/sh/kernel/ftrace.c
index 079d70e6d74b..38993e09ef03 100644
--- a/arch/sh/kernel/ftrace.c
+++ b/arch/sh/kernel/ftrace.c
@@ -212,13 +212,11 @@ static int ftrace_modify_code(unsigned long ip, unsigned char *old_code,
 	unsigned char replaced[MCOUNT_INSN_SIZE];
 
 	/*
-	 * Note: Due to modules and __init, code can
-	 *  disappear and change, we need to protect against faulting
-	 *  as well as code changing. We do this by using the
-	 *  probe_kernel_* functions.
-	 *
-	 * No real locking needed, this code is run through
-	 * kstop_machine, or before SMP starts.
+	 * Note:
+	 * We are paranoid about modifying text, as if a bug was to happen, it
+	 * could cause us to read or write to someplace that could cause harm.
+	 * Carefully read and modify the code with probe_kernel_*(), and make
+	 * sure what we read is what we expected it to be before modifying it.
 	 */
 
 	/* read the text we want to modify */
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 311bcf338f07..29408d6d6626 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -105,14 +105,14 @@ ftrace_modify_code_direct(unsigned long ip, unsigned const char *old_code,
 {
 	unsigned char replaced[MCOUNT_INSN_SIZE];
 
+	ftrace_expected = old_code;
+
 	/*
-	 * Note: Due to modules and __init, code can
-	 *  disappear and change, we need to protect against faulting
-	 *  as well as code changing. We do this by using the
-	 *  probe_kernel_* functions.
-	 *
-	 * No real locking needed, this code is run through
-	 * kstop_machine, or before SMP starts.
+	 * Note:
+	 * We are paranoid about modifying text, as if a bug was to happen, it
+	 * could cause us to read or write to someplace that could cause harm.
+	 * Carefully read and modify the code with probe_kernel_*(), and make
+	 * sure what we read is what we expected it to be before modifying it.
 	 */
 
 	/* read the text we want to modify */
@@ -154,6 +154,8 @@ int ftrace_make_nop(struct module *mod,
 	if (addr == MCOUNT_ADDR)
 		return ftrace_modify_code_direct(rec->ip, old, new);
 
+	ftrace_expected = NULL;
+
 	/* Normal cases use add_brk_on_nop */
 	WARN_ONCE(1, "invalid use of ftrace_make_nop");
 	return -EINVAL;
@@ -220,6 +222,7 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 				 unsigned long addr)
 {
 	WARN_ON(1);
+	ftrace_expected = NULL;
 	return -EINVAL;
 }
 
@@ -314,6 +317,8 @@ static int add_break(unsigned long ip, const char *old)
 	if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
 		return -EFAULT;
 
+	ftrace_expected = old;
+
 	/* Make sure it is what we expect it to be */
 	if (memcmp(replaced, old, MCOUNT_INSN_SIZE) != 0)
 		return -EINVAL;
@@ -413,6 +418,8 @@ static int remove_breakpoint(struct dyn_ftrace *rec)
 		ftrace_addr = ftrace_get_addr_curr(rec);
 		nop = ftrace_call_replace(ip, ftrace_addr);
 
+		ftrace_expected = nop;
+
 		if (memcmp(&ins[1], &nop[1], MCOUNT_INSN_SIZE - 1) != 0)
 			return -EINVAL;
 	}
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 60048c50404e..0639dcc98195 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -76,8 +76,8 @@ ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
  * ENABLED - set/unset when ftrace_ops is registered/unregistered
  * DYNAMIC - set when ftrace_ops is registered to denote dynamically
  *           allocated ftrace_ops which need special care
- * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops
- *           could be controled by following calls:
+ * PER_CPU - set manualy by ftrace_ops user to denote the ftrace_ops
+ *           could be controlled by following calls:
  *             ftrace_function_local_enable
  *             ftrace_function_local_disable
  * SAVE_REGS - The ftrace_ops wants regs saved at each function called
@@ -121,7 +121,7 @@ ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
 enum {
 	FTRACE_OPS_FL_ENABLED			= 1 << 0,
 	FTRACE_OPS_FL_DYNAMIC			= 1 << 1,
-	FTRACE_OPS_FL_CONTROL			= 1 << 2,
+	FTRACE_OPS_FL_PER_CPU			= 1 << 2,
 	FTRACE_OPS_FL_SAVE_REGS			= 1 << 3,
 	FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED	= 1 << 4,
 	FTRACE_OPS_FL_RECURSION_SAFE		= 1 << 5,
@@ -134,6 +134,7 @@ enum {
 	FTRACE_OPS_FL_ALLOC_TRAMP		= 1 << 12,
 	FTRACE_OPS_FL_IPMODIFY			= 1 << 13,
 	FTRACE_OPS_FL_PID			= 1 << 14,
+	FTRACE_OPS_FL_RCU			= 1 << 15,
 };
 
 #ifdef CONFIG_DYNAMIC_FTRACE
@@ -146,11 +147,11 @@ struct ftrace_ops_hash {
 #endif
 
 /*
- * Note, ftrace_ops can be referenced outside of RCU protection.
- * (Although, for perf, the control ops prevent that). If ftrace_ops is
- * allocated and not part of kernel core data, the unregistering of it will
- * perform a scheduling on all CPUs to make sure that there are no more users.
- * Depending on the load of the system that may take a bit of time.
+ * Note, ftrace_ops can be referenced outside of RCU protection, unless
+ * the RCU flag is set. If ftrace_ops is allocated and not part of kernel
+ * core data, the unregistering of it will perform a scheduling on all CPUs
+ * to make sure that there are no more users. Depending on the load of the
+ * system that may take a bit of time.
  *
  * Any private data added must also take care not to be freed and if private
  * data is added to a ftrace_ops that is in core code, the user of the
@@ -196,34 +197,34 @@ int unregister_ftrace_function(struct ftrace_ops *ops);
 void clear_ftrace_function(void);
 
 /**
- * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu
+ * ftrace_function_local_enable - enable ftrace_ops on current cpu
  *
  * This function enables tracing on current cpu by decreasing
  * the per cpu control variable.
  * It must be called with preemption disabled and only on ftrace_ops
- * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
+ * registered with FTRACE_OPS_FL_PER_CPU. If called without preemption
  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
  */
 static inline void ftrace_function_local_enable(struct ftrace_ops *ops)
 {
-	if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
+	if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU)))
 		return;
 
 	(*this_cpu_ptr(ops->disabled))--;
 }
 
 /**
- * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu
+ * ftrace_function_local_disable - disable ftrace_ops on current cpu
  *
- * This function enables tracing on current cpu by decreasing
+ * This function disables tracing on current cpu by increasing
  * the per cpu control variable.
  * It must be called with preemption disabled and only on ftrace_ops
- * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
+ * registered with FTRACE_OPS_FL_PER_CPU. If called without preemption
  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
  */
 static inline void ftrace_function_local_disable(struct ftrace_ops *ops)
 {
-	if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
+	if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU)))
 		return;
 
 	(*this_cpu_ptr(ops->disabled))++;
@@ -235,12 +236,12 @@ static inline void ftrace_function_local_disable(struct ftrace_ops *ops)
  *
  * This function returns value of ftrace_ops::disabled on current cpu.
  * It must be called with preemption disabled and only on ftrace_ops
- * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
+ * registered with FTRACE_OPS_FL_PER_CPU. If called without preemption
  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
  */
 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops)
 {
-	WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL));
+	WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU));
 	return *this_cpu_ptr(ops->disabled);
 }
 
@@ -296,6 +297,21 @@ int ftrace_arch_code_modify_post_process(void);
 
 struct dyn_ftrace;
 
+enum ftrace_bug_type {
+	FTRACE_BUG_UNKNOWN,
+	FTRACE_BUG_INIT,
+	FTRACE_BUG_NOP,
+	FTRACE_BUG_CALL,
+	FTRACE_BUG_UPDATE,
+};
+extern enum ftrace_bug_type ftrace_bug_type;
+
+/*
+ * Archs can set this to point to a variable that holds the value that was
+ * expected at the call site before calling ftrace_bug().
+ */
+extern const void *ftrace_expected;
+
 void ftrace_bug(int err, struct dyn_ftrace *rec);
 
 struct seq_file;
@@ -341,6 +357,7 @@ bool is_ftrace_trampoline(unsigned long addr);
  *  REGS    - the record wants the function to save regs
  *  REGS_EN - the function is set up to save regs.
  *  IPMODIFY - the record allows for the IP address to be changed.
+ *  DISABLED - the record is not ready to be touched yet
  *
  * When a new ftrace_ops is registered and wants a function to save
  * pt_regs, the rec->flag REGS is set. When the function has been
@@ -355,10 +372,11 @@ enum {
 	FTRACE_FL_TRAMP		= (1UL << 28),
 	FTRACE_FL_TRAMP_EN	= (1UL << 27),
 	FTRACE_FL_IPMODIFY	= (1UL << 26),
+	FTRACE_FL_DISABLED	= (1UL << 25),
 };
 
-#define FTRACE_REF_MAX_SHIFT	26
-#define FTRACE_FL_BITS		6
+#define FTRACE_REF_MAX_SHIFT	25
+#define FTRACE_FL_BITS		7
 #define FTRACE_FL_MASKED_BITS	((1UL << FTRACE_FL_BITS) - 1)
 #define FTRACE_FL_MASK		(FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT)
 #define FTRACE_REF_MAX		((1UL << FTRACE_REF_MAX_SHIFT) - 1)
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 78e8397a1800..acd522a91539 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -479,6 +479,10 @@ extern void syscall_unregfunc(void);
 #define TRACE_EVENT_FN(name, proto, args, struct,		\
 		assign, print, reg, unreg)			\
 	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define TRACE_EVENT_FN_COND(name, proto, args, cond, struct,		\
+		assign, print, reg, unreg)			\
+	DECLARE_TRACE_CONDITION(name, PARAMS(proto),	\
+			PARAMS(args), PARAMS(cond))
 #define TRACE_EVENT_CONDITION(name, proto, args, cond,		\
 			      struct, assign, print)		\
 	DECLARE_TRACE_CONDITION(name, PARAMS(proto),		\
diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h
index 2d8639ea64d5..6e3945f64102 100644
--- a/include/trace/define_trace.h
+++ b/include/trace/define_trace.h
@@ -40,6 +40,11 @@
 		assign, print, reg, unreg)			\
 	DEFINE_TRACE_FN(name, reg, unreg)
 
+#undef TRACE_EVENT_FN_COND
+#define TRACE_EVENT_FN_COND(name, proto, args, cond, tstruct,		\
+		assign, print, reg, unreg)			\
+	DEFINE_TRACE_FN(name, reg, unreg)
+
 #undef DEFINE_EVENT
 #define DEFINE_EVENT(template, name, proto, args) \
 	DEFINE_TRACE(name)
@@ -93,6 +98,7 @@
 
 #undef TRACE_EVENT
 #undef TRACE_EVENT_FN
+#undef TRACE_EVENT_FN_COND
 #undef TRACE_EVENT_CONDITION
 #undef DECLARE_EVENT_CLASS
 #undef DEFINE_EVENT
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index de996cf61053..170c93bbdbb7 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -123,6 +123,12 @@ TRACE_MAKE_SYSTEM_STR();
 	TRACE_EVENT(name, PARAMS(proto), PARAMS(args),			\
 		PARAMS(tstruct), PARAMS(assign), PARAMS(print))		\
 
+#undef TRACE_EVENT_FN_COND
+#define TRACE_EVENT_FN_COND(name, proto, args, cond, tstruct,	\
+		assign, print, reg, unreg)				\
+	TRACE_EVENT_CONDITION(name, PARAMS(proto), PARAMS(args), PARAMS(cond),		\
+		PARAMS(tstruct), PARAMS(assign), PARAMS(print))		\
+
 #undef TRACE_EVENT_FLAGS
 #define TRACE_EVENT_FLAGS(name, value)					\
 	__TRACE_EVENT_FLAGS(name, value)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 4228fd3682c3..45dd798bcd37 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -316,7 +316,7 @@ static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type
 	return true;
 }
 
-static struct bpf_verifier_ops kprobe_prog_ops = {
+static const struct bpf_verifier_ops kprobe_prog_ops = {
 	.get_func_proto  = kprobe_prog_func_proto,
 	.is_valid_access = kprobe_prog_is_valid_access,
 };
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 3f743b147247..eca592f977b2 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -62,8 +62,6 @@
 #define FTRACE_HASH_DEFAULT_BITS 10
 #define FTRACE_HASH_MAX_BITS 12
 
-#define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_CONTROL)
-
 #ifdef CONFIG_DYNAMIC_FTRACE
 #define INIT_OPS_HASH(opsname)	\
 	.func_hash		= &opsname.local_hash,			\
@@ -113,14 +111,9 @@ static int ftrace_disabled __read_mostly;
 
 static DEFINE_MUTEX(ftrace_lock);
 
-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 struct ftrace_ops global_ops;
-static struct ftrace_ops control_ops;
-
-static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip,
-				   struct ftrace_ops *op, struct pt_regs *regs);
 
 #if ARCH_SUPPORTS_FTRACE_OPS
 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
@@ -203,7 +196,7 @@ void clear_ftrace_function(void)
 	ftrace_trace_function = ftrace_stub;
 }
 
-static void control_ops_disable_all(struct ftrace_ops *ops)
+static void per_cpu_ops_disable_all(struct ftrace_ops *ops)
 {
 	int cpu;
 
@@ -211,16 +204,19 @@ static void control_ops_disable_all(struct ftrace_ops *ops)
 		*per_cpu_ptr(ops->disabled, cpu) = 1;
 }
 
-static int control_ops_alloc(struct ftrace_ops *ops)
+static int per_cpu_ops_alloc(struct ftrace_ops *ops)
 {
 	int __percpu *disabled;
 
+	if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU)))
+		return -EINVAL;
+
 	disabled = alloc_percpu(int);
 	if (!disabled)
 		return -ENOMEM;
 
 	ops->disabled = disabled;
-	control_ops_disable_all(ops);
+	per_cpu_ops_disable_all(ops);
 	return 0;
 }
 
@@ -256,10 +252,11 @@ static inline void update_function_graph_func(void) { }
 static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
 {
 	/*
-	 * If this is a dynamic ops or we force list func,
+	 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
 	 * then it needs to call the list anyway.
 	 */
-	if (ops->flags & FTRACE_OPS_FL_DYNAMIC || FTRACE_FORCE_LIST_FUNC)
+	if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_PER_CPU |
+			  FTRACE_OPS_FL_RCU) || FTRACE_FORCE_LIST_FUNC)
 		return ftrace_ops_list_func;
 
 	return ftrace_ops_get_func(ops);
@@ -383,26 +380,6 @@ static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
 	return 0;
 }
 
-static void add_ftrace_list_ops(struct ftrace_ops **list,
-				struct ftrace_ops *main_ops,
-				struct ftrace_ops *ops)
-{
-	int first = *list == &ftrace_list_end;
-	add_ftrace_ops(list, ops);
-	if (first)
-		add_ftrace_ops(&ftrace_ops_list, main_ops);
-}
-
-static int remove_ftrace_list_ops(struct ftrace_ops **list,
-				  struct ftrace_ops *main_ops,
-				  struct ftrace_ops *ops)
-{
-	int ret = remove_ftrace_ops(list, ops);
-	if (!ret && *list == &ftrace_list_end)
-		ret = remove_ftrace_ops(&ftrace_ops_list, main_ops);
-	return ret;
-}
-
 static void ftrace_update_trampoline(struct ftrace_ops *ops);
 
 static int __register_ftrace_function(struct ftrace_ops *ops)
@@ -430,14 +407,12 @@ static int __register_ftrace_function(struct ftrace_ops *ops)
 	if (!core_kernel_data((unsigned long)ops))
 		ops->flags |= FTRACE_OPS_FL_DYNAMIC;
 
-	if (ops->flags & FTRACE_OPS_FL_CONTROL) {
-		if (control_ops_alloc(ops))
+	if (ops->flags & FTRACE_OPS_FL_PER_CPU) {
+		if (per_cpu_ops_alloc(ops))
 			return -ENOMEM;
-		add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops);
-		/* The control_ops needs the trampoline update */
-		ops = &control_ops;
-	} else
-		add_ftrace_ops(&ftrace_ops_list, ops);
+	}
+
+	add_ftrace_ops(&ftrace_ops_list, ops);
 
 	/* Always save the function, and reset at unregistering */
 	ops->saved_func = ops->func;
@@ -460,11 +435,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
 	if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
 		return -EBUSY;
 
-	if (ops->flags & FTRACE_OPS_FL_CONTROL) {
-		ret = remove_ftrace_list_ops(&ftrace_control_list,
-					     &control_ops, ops);
-	} else
-		ret = remove_ftrace_ops(&ftrace_ops_list, ops);
+	ret = remove_ftrace_ops(&ftrace_ops_list, ops);
 
 	if (ret < 0)
 		return ret;
@@ -1687,6 +1658,9 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
 		int in_hash = 0;
 		int match = 0;
 
+		if (rec->flags & FTRACE_FL_DISABLED)
+			continue;
+
 		if (all) {
 			/*
 			 * Only the filter_hash affects all records.
@@ -1940,7 +1914,7 @@ static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
 	return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
 }
 
-static void print_ip_ins(const char *fmt, unsigned char *p)
+static void print_ip_ins(const char *fmt, const unsigned char *p)
 {
 	int i;
 
@@ -1952,6 +1926,31 @@ static void print_ip_ins(const char *fmt, unsigned char *p)
 
 static struct ftrace_ops *
 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
+static struct ftrace_ops *
+ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
+
+enum ftrace_bug_type ftrace_bug_type;
+const void *ftrace_expected;
+
+static void print_bug_type(void)
+{
+	switch (ftrace_bug_type) {
+	case FTRACE_BUG_UNKNOWN:
+		break;
+	case FTRACE_BUG_INIT:
+		pr_info("Initializing ftrace call sites\n");
+		break;
+	case FTRACE_BUG_NOP:
+		pr_info("Setting ftrace call site to NOP\n");
+		break;
+	case FTRACE_BUG_CALL:
+		pr_info("Setting ftrace call site to call ftrace function\n");
+		break;
+	case FTRACE_BUG_UPDATE:
+		pr_info("Updating ftrace call site to call a different ftrace function\n");
+		break;
+	}
+}
 
 /**
  * ftrace_bug - report and shutdown function tracer
@@ -1979,8 +1978,12 @@ void ftrace_bug(int failed, struct dyn_ftrace *rec)
 		FTRACE_WARN_ON_ONCE(1);
 		pr_info("ftrace failed to modify ");
 		print_ip_sym(ip);
-		print_ip_ins(" actual: ", (unsigned char *)ip);
+		print_ip_ins(" actual:   ", (unsigned char *)ip);
 		pr_cont("\n");
+		if (ftrace_expected) {
+			print_ip_ins(" expected: ", ftrace_expected);
+			pr_cont("\n");
+		}
 		break;
 	case -EPERM:
 		FTRACE_WARN_ON_ONCE(1);
@@ -1992,6 +1995,7 @@ void ftrace_bug(int failed, struct dyn_ftrace *rec)
 		pr_info("ftrace faulted on unknown error ");
 		print_ip_sym(ip);
 	}
+	print_bug_type();
 	if (rec) {
 		struct ftrace_ops *ops = NULL;
 
@@ -2000,15 +2004,19 @@ void ftrace_bug(int failed, struct dyn_ftrace *rec)
 			rec->flags & FTRACE_FL_REGS ? " R" : "  ");
 		if (rec->flags & FTRACE_FL_TRAMP_EN) {
 			ops = ftrace_find_tramp_ops_any(rec);
-			if (ops)
-				pr_cont("\ttramp: %pS",
-					(void *)ops->trampoline);
-			else
+			if (ops) {
+				do {
+					pr_cont("\ttramp: %pS (%pS)",
+						(void *)ops->trampoline,
+						(void *)ops->func);
+					ops = ftrace_find_tramp_ops_next(rec, ops);
+				} while (ops);
+			} else
 				pr_cont("\ttramp: ERROR!");
 
 		}
 		ip = ftrace_get_addr_curr(rec);
-		pr_cont(" expected tramp: %lx\n", ip);
+		pr_cont("\n expected tramp: %lx\n", ip);
 	}
 }
 
@@ -2016,6 +2024,11 @@ static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
 {
 	unsigned long flag = 0UL;
 
+	ftrace_bug_type = FTRACE_BUG_UNKNOWN;
+
+	if (rec->flags & FTRACE_FL_DISABLED)
+		return FTRACE_UPDATE_IGNORE;
+
 	/*
 	 * If we are updating calls:
 	 *
@@ -2077,9 +2090,12 @@ static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
 		 *   from the save regs, to a non-save regs function or
 		 *   vice versa, or from a trampoline call.
 		 */
-		if (flag & FTRACE_FL_ENABLED)
+		if (flag & FTRACE_FL_ENABLED) {
+			ftrace_bug_type = FTRACE_BUG_CALL;
 			return FTRACE_UPDATE_MAKE_CALL;
+		}
 
+		ftrace_bug_type = FTRACE_BUG_UPDATE;
 		return FTRACE_UPDATE_MODIFY_CALL;
 	}
 
@@ -2096,6 +2112,7 @@ static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
 					FTRACE_FL_REGS_EN);
 	}
 
+	ftrace_bug_type = FTRACE_BUG_NOP;
 	return FTRACE_UPDATE_MAKE_NOP;
 }
 
@@ -2145,6 +2162,24 @@ ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
 }
 
 static struct ftrace_ops *
+ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
+			   struct ftrace_ops *op)
+{
+	unsigned long ip = rec->ip;
+
+	while_for_each_ftrace_op(op) {
+
+		if (!op->trampoline)
+			continue;
+
+		if (hash_contains_ip(ip, op->func_hash))
+			return op;
+	} 
+
+	return NULL;
+}
+
+static struct ftrace_ops *
 ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
 {
 	struct ftrace_ops *op;
@@ -2307,17 +2342,22 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
 
 	ret = ftrace_update_record(rec, enable);
 
+	ftrace_bug_type = FTRACE_BUG_UNKNOWN;
+
 	switch (ret) {
 	case FTRACE_UPDATE_IGNORE:
 		return 0;
 
 	case FTRACE_UPDATE_MAKE_CALL:
+		ftrace_bug_type = FTRACE_BUG_CALL;
 		return ftrace_make_call(rec, ftrace_addr);
 
 	case FTRACE_UPDATE_MAKE_NOP:
+		ftrace_bug_type = FTRACE_BUG_NOP;
 		return ftrace_make_nop(NULL, rec, ftrace_old_addr);
 
 	case FTRACE_UPDATE_MODIFY_CALL:
+		ftrace_bug_type = FTRACE_BUG_UPDATE;
 		return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
 	}
 
@@ -2425,6 +2465,7 @@ ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
 
 	ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
 	if (ret) {
+		ftrace_bug_type = FTRACE_BUG_INIT;
 		ftrace_bug(ret, rec);
 		return 0;
 	}
@@ -2566,7 +2607,7 @@ void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
 {
 }
 
-static void control_ops_free(struct ftrace_ops *ops)
+static void per_cpu_ops_free(struct ftrace_ops *ops)
 {
 	free_percpu(ops->disabled);
 }
@@ -2667,13 +2708,13 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command)
 
 	if (!command || !ftrace_enabled) {
 		/*
-		 * If these are control ops, they still need their
+		 * If these are per_cpu ops, they still need their
 		 * per_cpu field freed. Since, function tracing is
 		 * not currently active, we can just free them
 		 * without synchronizing all CPUs.
 		 */
-		if (ops->flags & FTRACE_OPS_FL_CONTROL)
-			control_ops_free(ops);
+		if (ops->flags & FTRACE_OPS_FL_PER_CPU)
+			per_cpu_ops_free(ops);
 		return 0;
 	}
 
@@ -2714,7 +2755,7 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command)
 	/*
 	 * Dynamic ops may be freed, we must make sure that all
 	 * callers are done before leaving this function.
-	 * The same goes for freeing the per_cpu data of the control
+	 * The same goes for freeing the per_cpu data of the per_cpu
 	 * ops.
 	 *
 	 * Again, normal synchronize_sched() is not good enough.
@@ -2725,13 +2766,13 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command)
 	 * infrastructure to do the synchronization, thus we must do it
 	 * ourselves.
 	 */
-	if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) {
+	if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_PER_CPU)) {
 		schedule_on_each_cpu(ftrace_sync);
 
 		arch_ftrace_trampoline_free(ops);
 
-		if (ops->flags & FTRACE_OPS_FL_CONTROL)
-			control_ops_free(ops);
+		if (ops->flags & FTRACE_OPS_FL_PER_CPU)
+			per_cpu_ops_free(ops);
 	}
 
 	return 0;
@@ -2798,9 +2839,9 @@ ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
 	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
 		return 0;
 
-	/* If ops traces all mods, we already accounted for it */
+	/* If ops traces all then it includes this function */
 	if (ops_traces_mod(ops))
-		return 0;
+		return 1;
 
 	/* The function must be in the filter */
 	if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
@@ -2814,64 +2855,41 @@ ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
 	return 1;
 }
 
-static int referenced_filters(struct dyn_ftrace *rec)
-{
-	struct ftrace_ops *ops;
-	int cnt = 0;
-
-	for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
-		if (ops_references_rec(ops, rec))
-		    cnt++;
-	}
-
-	return cnt;
-}
-
 static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
 {
 	struct ftrace_page *pg;
 	struct dyn_ftrace *p;
 	cycle_t start, stop;
 	unsigned long update_cnt = 0;
-	unsigned long ref = 0;
-	bool test = false;
+	unsigned long rec_flags = 0;
 	int i;
 
+	start = ftrace_now(raw_smp_processor_id());
+
 	/*
-	 * When adding a module, we need to check if tracers are
-	 * currently enabled and if they are set to trace all functions.
-	 * If they are, we need to enable the module functions as well
-	 * as update the reference counts for those function records.
+	 * When a module is loaded, this function is called to convert
+	 * the calls to mcount in its text to nops, and also to create
+	 * an entry in the ftrace data. Now, if ftrace is activated
+	 * after this call, but before the module sets its text to
+	 * read-only, the modification of enabling ftrace can fail if
+	 * the read-only is done while ftrace is converting the calls.
+	 * To prevent this, the module's records are set as disabled
+	 * and will be enabled after the call to set the module's text
+	 * to read-only.
 	 */
-	if (mod) {
-		struct ftrace_ops *ops;
-
-		for (ops = ftrace_ops_list;
-		     ops != &ftrace_list_end; ops = ops->next) {
-			if (ops->flags & FTRACE_OPS_FL_ENABLED) {
-				if (ops_traces_mod(ops))
-					ref++;
-				else
-					test = true;
-			}
-		}
-	}
-
-	start = ftrace_now(raw_smp_processor_id());
+	if (mod)
+		rec_flags |= FTRACE_FL_DISABLED;
 
 	for (pg = new_pgs; pg; pg = pg->next) {
 
 		for (i = 0; i < pg->index; i++) {
-			int cnt = ref;
 
 			/* If something went wrong, bail without enabling anything */
 			if (unlikely(ftrace_disabled))
 				return -1;
 
 			p = &pg->records[i];
-			if (test)
-				cnt += referenced_filters(p);
-			p->flags = cnt;
+			p->flags = rec_flags;
 
 			/*
 			 * Do the initial record conversion from mcount jump
@@ -2881,21 +2899,6 @@ static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
 				break;
 
 			update_cnt++;
-
-			/*
-			 * If the tracing is enabled, go ahead and enable the record.
-			 *
-			 * The reason not to enable the record immediatelly is the
-			 * inherent check of ftrace_make_nop/ftrace_make_call for
-			 * correct previous instructions.  Making first the NOP
-			 * conversion puts the module to the correct state, thus
-			 * passing the ftrace_make_call check.
-			 */
-			if (ftrace_start_up && cnt) {
-				int failed = __ftrace_replace_code(p, 1);
-				if (failed)
-					ftrace_bug(failed, p);
-			}
 		}
 	}
 
@@ -