Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf updates from Ingo Molnar:
 "Kernel side changes:

   - Ftrace is one of the last W^X violators (after this only KLP is
     left). These patches move it over to the generic text_poke()
     interface and thereby get rid of this oddity. This requires a
     surprising amount of surgery, by Peter Zijlstra.

   - x86/AMD PMUs: add support for 'Large Increment per Cycle Events' to
     count certain types of events that have a special, quirky hw ABI
     (by Kim Phillips)

   - kprobes fixes by Masami Hiramatsu

  Lots of tooling updates as well, the following subcommands were
  updated: annotate/report/top, c2c, clang, record, report/top TUI,
  sched timehist, tests; plus updates were done to the gtk ui, libperf,
  headers and the parser"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
  perf/x86/amd: Add support for Large Increment per Cycle Events
  perf/x86/amd: Constrain Large Increment per Cycle events
  perf/x86/intel/rapl: Add Comet Lake support
  tracing: Initialize ret in syscall_enter_define_fields()
  perf header: Use last modification time for timestamp
  perf c2c: Fix return type for histogram sorting comparision functions
  perf beauty sockaddr: Fix augmented syscall format warning
  perf/ui/gtk: Fix gtk2 build
  perf ui gtk: Add missing zalloc object
  perf tools: Use %define api.pure full instead of %pure-parser
  libperf: Setup initial evlist::all_cpus value
  perf report: Fix no libunwind compiled warning break s390 issue
  perf tools: Support --prefix/--prefix-strip
  perf report: Clarify in help that --children is default
  tools build: Fix test-clang.cpp with Clang 8+
  perf clang: Fix build with Clang 9
  kprobes: Fix optimize_kprobe()/unoptimize_kprobe() cancellation logic
  tools lib: Fix builds when glibc contains strlcpy()
  perf report/top: Make 'e' visible in the help and make it toggle showing callchains
  perf report/top: Do not offer annotation for symbols without samples
  ...

6 files changed, 358 insertions, 740 deletions

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 9ec463fe96f2..34360ca301a2 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -936,44 +936,81 @@ static void do_sync_core(void *info)
 	sync_core();
 }
 
-static struct bp_patching_desc {
+void text_poke_sync(void)
+{
+	on_each_cpu(do_sync_core, NULL, 1);
+}
+
+struct text_poke_loc {
+	s32 rel_addr; /* addr := _stext + rel_addr */
+	s32 rel32;
+	u8 opcode;
+	const u8 text[POKE_MAX_OPCODE_SIZE];
+};
+
+struct bp_patching_desc {
 	struct text_poke_loc *vec;
 	int nr_entries;
-} bp_patching;
+	atomic_t refs;
+};
+
+static struct bp_patching_desc *bp_desc;
+
+static inline struct bp_patching_desc *try_get_desc(struct bp_patching_desc **descp)
+{
+	struct bp_patching_desc *desc = READ_ONCE(*descp); /* rcu_dereference */
+
+	if (!desc || !atomic_inc_not_zero(&desc->refs))
+		return NULL;
+
+	return desc;
+}
+
+static inline void put_desc(struct bp_patching_desc *desc)
+{
+	smp_mb__before_atomic();
+	atomic_dec(&desc->refs);
+}
 
-static int patch_cmp(const void *key, const void *elt)
+static inline void *text_poke_addr(struct text_poke_loc *tp)
+{
+	return _stext + tp->rel_addr;
+}
+
+static int notrace patch_cmp(const void *key, const void *elt)
 {
 	struct text_poke_loc *tp = (struct text_poke_loc *) elt;
 
-	if (key < tp->addr)
+	if (key < text_poke_addr(tp))
 		return -1;
-	if (key > tp->addr)
+	if (key > text_poke_addr(tp))
 		return 1;
 	return 0;
 }
 NOKPROBE_SYMBOL(patch_cmp);
 
-int poke_int3_handler(struct pt_regs *regs)
+int notrace poke_int3_handler(struct pt_regs *regs)
 {
+	struct bp_patching_desc *desc;
 	struct text_poke_loc *tp;
+	int len, ret = 0;
 	void *ip;
 
+	if (user_mode(regs))
+		return 0;
+
 	/*
 	 * Having observed our INT3 instruction, we now must observe
-	 * bp_patching.nr_entries.
+	 * bp_desc:
 	 *
-	 *	nr_entries != 0			INT3
+	 *	bp_desc = desc			INT3
 	 *	WMB				RMB
-	 *	write INT3			if (nr_entries)
-	 *
-	 * Idem for other elements in bp_patching.
+	 *	write INT3			if (desc)
 	 */
 	smp_rmb();
 
-	if (likely(!bp_patching.nr_entries))
-		return 0;
-
-	if (user_mode(regs))
+	desc = try_get_desc(&bp_desc);
+	if (!desc)
 		return 0;
 
 	/*
@@ -984,19 +1021,20 @@ int poke_int3_handler(struct pt_regs *regs)
 	/*
 	 * Skip the binary search if there is a single member in the vector.
 	 */
-	if (unlikely(bp_patching.nr_entries > 1)) {
-		tp = bsearch(ip, bp_patching.vec, bp_patching.nr_entries,
+	if (unlikely(desc->nr_entries > 1)) {
+		tp = bsearch(ip, desc->vec, desc->nr_entries,
 			     sizeof(struct text_poke_loc),
 			     patch_cmp);
 		if (!tp)
-			return 0;
+			goto out_put;
 	} else {
-		tp = bp_patching.vec;
-		if (tp->addr != ip)
-			return 0;
+		tp = desc->vec;
+		if (text_poke_addr(tp) != ip)
+			goto out_put;
 	}
 
-	ip += tp->len;
+	len = text_opcode_size(tp->opcode);
+	ip += len;
 
 	switch (tp->opcode) {
 	case INT3_INSN_OPCODE:
@@ -1004,7 +1042,7 @@ int poke_int3_handler(struct pt_regs *regs)
 		 * Someone poked an explicit INT3, they'll want to handle it,
 		 * do not consume.
 		 */
-		return 0;
+		goto out_put;
 
 	case CALL_INSN_OPCODE:
 		int3_emulate_call(regs, (long)ip + tp->rel32);
@@ -1019,10 +1057,18 @@ int poke_int3_handler(struct pt_regs *regs)
 		BUG();
 	}
 
-	return 1;
+	ret = 1;
+
+out_put:
+	put_desc(desc);
+	return ret;
 }
 NOKPROBE_SYMBOL(poke_int3_handler);
 
+#define TP_VEC_MAX (PAGE_SIZE / sizeof(struct text_poke_loc))
+static struct text_poke_loc tp_vec[TP_VEC_MAX];
+static int tp_vec_nr;
+
 /**
  * text_poke_bp_batch() -- update instructions on live kernel on SMP
  * @tp:			vector of instructions to patch
@@ -1044,16 +1090,20 @@ NOKPROBE_SYMBOL(poke_int3_handler);
  *		  replacing opcode
  *	- sync cores
  */
-void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries)
+static void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries)
 {
+	struct bp_patching_desc desc = {
+		.vec = tp,
+		.nr_entries = nr_entries,
+		.refs = ATOMIC_INIT(1),
+	};
 	unsigned char int3 = INT3_INSN_OPCODE;
 	unsigned int i;
 	int do_sync;
 
 	lockdep_assert_held(&text_mutex);
 
-	bp_patching.vec = tp;
-	bp_patching.nr_entries = nr_entries;
+	smp_store_release(&bp_desc, &desc); /* rcu_assign_pointer */
 
 	/*
 	 * Corresponding read barrier in int3 notifier for making sure the
@@ -1065,18 +1115,20 @@ void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries)
 	 * First step: add a int3 trap to the address that will be patched.
 	 */
 	for (i = 0; i < nr_entries; i++)
-		text_poke(tp[i].addr, &int3, sizeof(int3));
+		text_poke(text_poke_addr(&tp[i]), &int3, INT3_INSN_SIZE);
 
-	on_each_cpu(do_sync_core, NULL, 1);
+	text_poke_sync();
 
 	/*
 	 * Second step: update all but the first byte of the patched range.
 	 */
 	for (do_sync = 0, i = 0; i < nr_entries; i++) {
-		if (tp[i].len - sizeof(int3) > 0) {
-			text_poke((char *)tp[i].addr + sizeof(int3),
-				  (const char *)tp[i].text + sizeof(int3),
-				  tp[i].len - sizeof(int3));
+		int len = text_opcode_size(tp[i].opcode);
+
+		if (len - INT3_INSN_SIZE > 0) {
+			text_poke(text_poke_addr(&tp[i]) + INT3_INSN_SIZE,
+				  (const char *)tp[i].text + INT3_INSN_SIZE,
+				  len - INT3_INSN_SIZE);
 			do_sync++;
 		}
 	}
@@ -1087,7 +1139,7 @@ void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries)
 		 * not necessary and we'd be safe even without it. But
 		 * better safe than sorry (plus there's not only Intel).
 		 */
-		on_each_cpu(do_sync_core, NULL, 1);
+		text_poke_sync();
 	}
 
 	/*
@@ -1098,19 +1150,20 @@ void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries)
 		if (tp[i].text[0] == INT3_INSN_OPCODE)
 			continue;
 
-		text_poke(tp[i].addr, tp[i].text, sizeof(int3));
+		text_poke(text_poke_addr(&tp[i]), tp[i].text, INT3_INSN_SIZE);
 		do_sync++;
 	}
 
 	if (do_sync)
-		on_each_cpu(do_sync_core, NULL, 1);
+		text_poke_sync();
 
 	/*
-	 * sync_core() implies an smp_mb() and orders this store against
-	 * the writing of the new instruction.
+	 * Remove and synchronize_rcu(), except we have a very primitive
+	 * refcount based completion.
 	 */
-	bp_patching.vec = NULL;
-	bp_patching.nr_entries = 0;
+	WRITE_ONCE(bp_desc, NULL); /* RCU_INIT_POINTER */
+	if (!atomic_dec_and_test(&desc.refs))
+		atomic_cond_read_acquire(&desc.refs, !VAL);
 }
 
 void text_poke_loc_init(struct text_poke_loc *tp, void *addr,
@@ -1118,11 +1171,7 @@ void text_poke_loc_init(struct text_poke_loc *tp, void *addr,
 {
 	struct insn insn;
 
-	if (!opcode)
-		opcode = (void *)tp->text;
-	else
-		memcpy((void *)tp->text, opcode, len);
-
+	memcpy((void *)tp->text, opcode, len);
 	if (!emulate)
 		emulate = opcode;
 
@@ -1132,8 +1181,7 @@ void text_poke_loc_init(struct text_poke_loc *tp, void *addr,
 	BUG_ON(!insn_complete(&insn));
 	BUG_ON(len != insn.length);
 
-	tp->addr = addr;
-	tp->len = len;
+	tp->rel_addr = addr - (void *)_stext;
 	tp->opcode = insn.opcode.bytes[0];
 
 	switch (tp->opcode) {
@@ -1167,6 +1215,55 @@ void text_poke_loc_init(struct text_poke_loc *tp, void *addr,
 	}
 }
 
+/*
+ * We hard rely on the tp_vec being ordered; ensure this is so by flushing
+ * early if needed.
+ */
+static bool tp_order_fail(void *addr)
+{
+	struct text_poke_loc *tp;
+
+	if (!tp_vec_nr)
+		return false;
+
+	if (!addr) /* force */
+		return true;
+
+	tp = &tp_vec[tp_vec_nr - 1];
+	if ((unsigned long)text_poke_addr(tp) > (unsigned long)addr)
+		return true;
+
+	return false;
+}
+
+static void text_poke_flush(void *addr)
+{
+	if (tp_vec_nr == TP_VEC_MAX || tp_order_fail(addr)) {
+		text_poke_bp_batch(tp_vec, tp_vec_nr);
+		tp_vec_nr = 0;
+	}
+}
+
+void text_poke_finish(void)
+{
+	text_poke_flush(NULL);
+}
+
+void __ref text_poke_queue(void *addr, const void *opcode, size_t len, const void *emulate)
+{
+	struct text_poke_loc *tp;
+
+	if (unlikely(system_state == SYSTEM_BOOTING)) {
+		text_poke_early(addr, opcode, len);
+		return;
+	}
+
+	text_poke_flush(addr);
+
+	tp = &tp_vec[tp_vec_nr++];
+	text_poke_loc_init(tp, addr, opcode, len, emulate);
+}
+
 /**
  * text_poke_bp() -- update instructions on live kernel on SMP
  * @addr:	address to patch
@@ -1178,10 +1275,15 @@ void text_poke_loc_init(struct text_poke_loc *tp, void *addr,
  * dynamically allocated memory. This function should be used when it is
  * not possible to allocate memory.
  */
-void text_poke_bp(void *addr, const void *opcode, size_t len, const void *emulate)
+void __ref text_poke_bp(void *addr, const void *opcode, size_t len, const void *emulate)
 {
 	struct text_poke_loc tp;
 
+	if (unlikely(system_state == SYSTEM_BOOTING)) {
+		text_poke_early(addr, opcode, len);
+		return;
+	}
+
 	text_poke_loc_init(&tp, addr, opcode, len, emulate);
 	text_poke_bp_batch(&tp, 1);
 }
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 2009047bb015..37a0aeaf89e7 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -35,6 +35,8 @@
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 
+static int ftrace_poke_late = 0;
+
 int ftrace_arch_code_modify_prepare(void)
     __acquires(&text_mutex)
 {
@@ -44,84 +46,37 @@ int ftrace_arch_code_modify_prepare(void)
 	 * ftrace has it set to "read/write".
 	 */
 	mutex_lock(&text_mutex);
-	set_kernel_text_rw();
-	set_all_modules_text_rw();
+	ftrace_poke_late = 1;
 	return 0;
 }
 
 int ftrace_arch_code_modify_post_process(void)
     __releases(&text_mutex)
 {
-	set_all_modules_text_ro();
-	set_kernel_text_ro();
+	/*
+	 * ftrace_make_{call,nop}() may be called during
+	 * module load, and we need to finish the text_poke_queue()
+	 * that they do, here.
+	 */
+	text_poke_finish();
+	ftrace_poke_late = 0;
 	mutex_unlock(&text_mutex);
 	return 0;
 }
 
-union ftrace_code_union {
-	char code[MCOUNT_INSN_SIZE];
-	struct {
-		unsigned char op;
-		int offset;
-	} __attribute__((packed));
-};
-
-static int ftrace_calc_offset(long ip, long addr)
-{
-	return (int)(addr - ip);
-}
-
-static unsigned char *
-ftrace_text_replace(unsigned char op, unsigned long ip, unsigned long addr)
+static const char *ftrace_nop_replace(void)
 {
-	static union ftrace_code_union calc;
-
-	calc.op		= op;
-	calc.offset	= ftrace_calc_offset(ip + MCOUNT_INSN_SIZE, addr);
-
-	return calc.code;
-}
-
-static unsigned char *
-ftrace_call_replace(unsigned long ip, unsigned long addr)
-{
-	return ftrace_text_replace(0xe8, ip, addr);
-}
-
-static inline int
-within(unsigned long addr, unsigned long start, unsigned long end)
-{
-	return addr >= start && addr < end;
+	return ideal_nops[NOP_ATOMIC5];
 }
 
-static unsigned long text_ip_addr(unsigned long ip)
+static const char *ftrace_call_replace(unsigned long ip, unsigned long addr)
 {
-	/*
-	 * On x86_64, kernel text mappings are mapped read-only, so we use
-	 * the kernel identity mapping instead of the kernel text mapping
-	 * to modify the kernel text.
-	 *
-	 * For 32bit kernels, these mappings are same and we can use
-	 * kernel identity mapping to modify code.
-	 */
-	if (within(ip, (unsigned long)_text, (unsigned long)_etext))
-		ip = (unsigned long)__va(__pa_symbol(ip));
-
-	return ip;
+	return text_gen_insn(CALL_INSN_OPCODE, (void *)ip, (void *)addr);
 }
 
-static const unsigned char *ftrace_nop_replace(void)
+static int ftrace_verify_code(unsigned long ip, const char *old_code)
 {
-	return ideal_nops[NOP_ATOMIC5];
-}
-
-static int
-ftrace_modify_code_direct(unsigned long ip, unsigned const char *old_code,
-		   unsigned const char *new_code)
-{
-	unsigned char replaced[MCOUNT_INSN_SIZE];
-
-	ftrace_expected = old_code;
+	char cur_code[MCOUNT_INSN_SIZE];
 
 	/*
 	 * Note:
@@ -130,31 +85,46 @@ ftrace_modify_code_direct(unsigned long ip, unsigned const char *old_code,
 	 * 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 */
-	if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
+	if (probe_kernel_read(cur_code, (void *)ip, MCOUNT_INSN_SIZE)) {
+		WARN_ON(1);
 		return -EFAULT;
+	}
 
 	/* Make sure it is what we expect it to be */
-	if (memcmp(replaced, old_code, MCOUNT_INSN_SIZE) != 0)
+	if (memcmp(cur_code, old_code, MCOUNT_INSN_SIZE) != 0) {
+		WARN_ON(1);
 		return -EINVAL;
+	}
 
-	ip = text_ip_addr(ip);
-
-	/* replace the text with the new text */
-	if (probe_kernel_write((void *)ip, new_code, MCOUNT_INSN_SIZE))
-		return -EPERM;
+	return 0;
+}
 
-	sync_core();
+/*
+ * Marked __ref because it calls text_poke_early() which is .init.text. That is
+ * ok because that call will happen early, during boot, when .init sections are
+ * still present.
+ */
+static int __ref
+ftrace_modify_code_direct(unsigned long ip, const char *old_code,
+			  const char *new_code)
+{
+	int ret = ftrace_verify_code(ip, old_code);
+	if (ret)
+		return ret;
 
+	/* replace the text with the new text */
+	if (ftrace_poke_late)
+		text_poke_queue((void *)ip, new_code, MCOUNT_INSN_SIZE, NULL);
+	else
+		text_poke_early((void *)ip, new_code, MCOUNT_INSN_SIZE);
 	return 0;
 }
 
-int ftrace_make_nop(struct module *mod,
-		    struct dyn_ftrace *rec, unsigned long addr)
+int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
 {
-	unsigned const char *new, *old;
 	unsigned long ip = rec->ip;
+	const char *new, *old;
 
 	old = ftrace_call_replace(ip, addr);
 	new = ftrace_nop_replace();
@@ -168,19 +138,20 @@ int ftrace_make_nop(struct module *mod,
 	 * just modify the code directly.
 	 */
 	if (addr == MCOUNT_ADDR)
-		return ftrace_modify_code_direct(rec->ip, old, new);
+		return ftrace_modify_code_direct(ip, old, new);
 
-	ftrace_expected = NULL;
-
-	/* Normal cases use add_brk_on_nop */
+	/*
+	 * x86 overrides ftrace_replace_code -- this function will never be used
+	 * in this case.
+	 */
 	WARN_ONCE(1, "invalid use of ftrace_make_nop");
 	return -EINVAL;
 }
 
 int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 {
-	unsigned const char *new, *old;
 	unsigned long ip = rec->ip;
+	const char *new, *old;
 
 	old = ftrace_nop_replace();
 	new = ftrace_call_replace(ip, addr);
@@ -190,43 +161,6 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 }
 
 /*
- * The modifying_ftrace_code is used to tell the breakpoint
- * handler to call ftrace_int3_handler(). If it fails to
- * call this handler for a breakpoint added by ftrace, then
- * the kernel may crash.
- *
- * As atomic_writes on x86 do not need a barrier, we do not
- * need to add smp_mb()s for this to work. It is also considered
- * that we can not read the modifying_ftrace_code before
- * executing the breakpoint. That would be quite remarkable if
- * it could do that. Here's the flow that is required:
- *
- *   CPU-0                          CPU-1
- *
- * atomic_inc(mfc);
- * write int3s
- *				<trap-int3> // implicit (r)mb
- *				if (atomic_read(mfc))
- *					call ftrace_int3_handler()
- *
- * Then when we are finished:
- *
- * atomic_dec(mfc);
- *
- * If we hit a breakpoint that was not set by ftrace, it does not
- * matter if ftrace_int3_handler() is called or not. It will
- * simply be ignored. But it is crucial that a ftrace nop/caller
- * breakpoint is handled. No other user should ever place a
- * breakpoint on an ftrace nop/caller location. It must only
- * be done by this code.
- */
-atomic_t modifying_ftrace_code __read_mostly;
-
-static int
-ftrace_modify_code(unsigned long ip, unsigned const char *old_code,
-		   unsigned const char *new_code);
-
-/*
  * Should never be called:
  *  As it is only called by __ftrace_replace_code() which is called by
  *  ftrace_replace_code() that x86 overrides, and by ftrace_update_code()
@@ -238,452 +172,84 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 				 unsigned long addr)
 {
 	WARN_ON(1);
-	ftrace_expected = NULL;
 	return -EINVAL;
 }
 
-static unsigned long ftrace_update_func;
-static unsigned long ftrace_update_func_call;
-
-static int update_ftrace_func(unsigned long ip, void *new)
-{
-	unsigned char old[MCOUNT_INSN_SIZE];
-	int ret;
-
-	memcpy(old, (void *)ip, MCOUNT_INSN_SIZE);
-
-	ftrace_update_func = ip;
-	/* Make sure the breakpoints see the ftrace_update_func update */
-	smp_wmb();
-
-	/* See comment above by declaration of modifying_ftrace_code */
-	atomic_inc(&modifying_ftrace_code);
-
-	ret = ftrace_modify_code(ip, old, new);
-
-	atomic_dec(&modifying_ftrace_code);
-
-	return ret;
-}
-
 int ftrace_update_ftrace_func(ftrace_func_t func)
 {
-	unsigned long ip = (unsigned long)(&ftrace_call);
-	unsigned char *new;
-	int ret;
-
-	ftrace_update_func_call = (unsigned long)func;
-
-	new = ftrace_call_replace(ip, (unsigned long)func);
-	ret = update_ftrace_func(ip, new);
-
-	/* Also update the regs callback function */
-	if (!ret) {
-		ip = (unsigned long)(&ftrace_regs_call);
-		new = ftrace_call_replace(ip, (unsigned long)func);
-		ret = update_ftrace_func(ip, new);
-	}
-
-	return ret;
-}
-
-static nokprobe_inline int is_ftrace_caller(unsigned long ip)
-{
-	if (ip == ftrace_update_func)
-		return 1;
-
-	return 0;
-}
-
-/*
- * A breakpoint was added to the code address we are about to
- * modify, and this is the handle that will just skip over it.
- * We are either changing a nop into a trace call, or a trace
- * call to a nop. While the change is taking place, we treat
- * it just like it was a nop.
- */
-int ftrace_int3_handler(struct pt_regs *regs)
-{
 	unsigned long ip;
+	const char *new;
 
-	if (WARN_ON_ONCE(!regs))
-		return 0;
-
-	ip = regs->ip - INT3_INSN_SIZE;
-
-	if (ftrace_location(ip)) {
-		int3_emulate_call(regs, (unsigned long)ftrace_regs_caller);
-		return 1;
-	} else if (is_ftrace_caller(ip)) {
-		if (!ftrace_update_func_call) {
-			int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
-			return 1;
-		}
-		int3_emulate_call(regs, ftrace_update_func_call);
-		return 1;
-	}
-
-	return 0;
-}
-NOKPROBE_SYMBOL(ftrace_int3_handler);
-
-static int ftrace_write(unsigned long ip, const char *val, int size)
-{
-	ip = text_ip_addr(ip);
-
-	if (probe_kernel_write((void *)ip, val, size))
-		return -EPERM;
-
-	return 0;
-}
-
-static int add_break(unsigned long ip, const char *old)
-{
-	unsigned char replaced[MCOUNT_INSN_SIZE];
-	unsigned char brk = BREAKPOINT_INSTRUCTION;
-
-	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;
-
-	return ftrace_write(ip, &brk, 1);
-}
-
-static int add_brk_on_call(struct dyn_ftrace *rec, unsigned long addr)
-{
-	unsigned const char *old;
-	unsigned long ip = rec->ip;
-
-	old = ftrace_call_replace(ip, addr);
-
-	return add_break(rec->ip, old);
-}
-
-
-static int add_brk_on_nop(struct dyn_ftrace *rec)
-{
-	unsigned const char *old;
-
-	old = ftrace_nop_replace();
-
-	return add_break(rec->ip, old);
-}
-
-static int add_breakpoints(struct dyn_ftrace *rec, bool enable)
-{
-	unsigned long ftrace_addr;
-	int ret;
-
-	ftrace_addr = ftrace_get_addr_curr(rec);
-
-	ret = ftrace_test_record(rec, enable);
-
-	switch (ret) {
-	case FTRACE_UPDATE_IGNORE:
-		return 0;
-
-	case FTRACE_UPDATE_MAKE_CALL:
-		/* converting nop to call */
-		return add_brk_on_nop(rec);
-
-	case FTRACE_UPDATE_MODIFY_CALL:
-	case FTRACE_UPDATE_MAKE_NOP:
-		/* converting a call to a nop */
-		return add_brk_on_call(rec, ftrace_addr);
-	}
-	return 0;
-}
-
-/*
- * On error, we need to remove breakpoints. This needs to
- * be done caefully. If the address does not currently have a
- * breakpoint, we know we are done. Otherwise, we look at the
- * remaining 4 bytes of the instruction. If it matches a nop
- * we replace the breakpoint with the nop. Otherwise we replace
- * it with the call instruction.
- */
-static int remove_breakpoint(struct dyn_ftrace *rec)
-{
-	unsigned char ins[MCOUNT_INSN_SIZE];
-	unsigned char brk = BREAKPOINT_INSTRUCTION;
-	const unsigned char *nop;
-	unsigned long ftrace_addr;
-	unsigned long ip = rec->ip;
-
-	/* If we fail the read, just give up */
-	if (probe_kernel_read(ins, (void *)ip, MCOUNT_INSN_SIZE))
-		return -EFAULT;
-
-	/* If this does not have a breakpoint, we are done */
-	if (ins[0] != brk)
-		return 0;
-
-	nop = ftrace_nop_replace();
-
-	/*
-	 * If the last 4 bytes of the instruction do not match
-	 * a nop, then we assume that this is a call to ftrace_addr.
-	 */
-	if (memcmp(&ins[1], &nop[1], MCOUNT_INSN_SIZE - 1) != 0) {
-		/*
-		 * For extra paranoidism, we check if the breakpoint is on
-		 * a call that would actually jump to the ftrace_addr.
-		 * If not, don't touch the breakpoint, we make just create
-		 * a disaster.
-		 */
-		ftrace_addr = ftrace_get_addr_new(rec);
-		nop = ftrace_call_replace(ip, ftrace_addr);
-
-		if (memcmp(&ins[1], &nop[1], MCOUNT_INSN_SIZE - 1) == 0)
-			goto update;
-
-		/* Check both ftrace_addr and ftrace_old_addr */
-		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;
-	}
-
- update:
-	return ftrace_write(ip, nop, 1);
-}
-
-static int add_update_code(unsigned long ip, unsigned const char *new)
-{
-	/* skip breakpoint */
-	ip++;
-	new++;
-	return ftrace_write(ip, new, MCOUNT_INSN_SIZE - 1);
-}
-
-static int add_update_call(struct dyn_ftrace *rec, unsigned long addr)
-{
-	unsigned long ip = rec->ip;
-	unsigned const char *new;
-
-	new = ftrace_call_replace(ip, addr);
-	return add_update_code(ip, new);
-}
-
-static int add_update_nop(struct dyn_ftrace *rec)
-{
-	unsigned long ip = rec->ip;
-	unsigned const char *new;
-
-	new = ftrace_nop_replace();
-	return add_update_code(ip, new);
-}
-
-static int add_update(struct dyn_ftrace *rec, bool enable)
-{
-	unsigned long ftrace_addr;
-	int ret;
-
-	ret = ftrace_test_record(rec, enable);
-
-	ftrace_addr  = ftrace_get_addr_new(rec);
-
-	switch (ret) {
-	case FTRACE_UPDATE_IGNORE:
-		return 0;
-
-	case FTRACE_UPDATE_MODIFY_CALL:
-	case FTRACE_UPDATE_MAKE_CALL:
-		/* converting nop to call */
-		return add_update_call(rec, ftrace_addr);
-
-	case FTRACE_UPDATE_MAKE_NOP:
-		/* converting a call to a nop */
-		return add_update_nop(rec);
-	}
-
-	return 0;
-}
-
-static int finish_update_call(struct dyn_ftrace *rec, unsigned long addr)
-{
-	unsigned long ip = rec->ip;
-	unsigned const char *new;
-
-	new = ftrace_call_replace(ip, addr);
-
-	return ftrace_write(ip, new, 1);
-}
-
-static int finish_update_nop(struct dyn_ftrace *rec)
-{
-	unsigned long ip = rec->ip;
-	unsigned const char *new;
-
-	new = ftrace_nop_replace();
-
-	return ftrace_write(ip, new, 1);
-}
-
-static int finish_update(struct dyn_ftrace *rec, bool enable)
-{
-	unsigned long ftrace_addr;
-	int ret;
-
-	ret = ftrace_update_record(rec, enable);
-
-	ftrace_addr = ftrace_get_addr_new(rec);
-
-	switch (ret) {
-	case FTRACE_UPDATE_IGNORE:
-		return 0;
-
-	case FTRACE_UPDATE_MODIFY_CALL:
-	case FTRACE_UPDATE_MAKE_CALL:
-		/* converting nop to call */
-		return finish_update_call(rec, ftrace_addr);
+	ip = (unsigned long)(&ftrace_call);
+	new = ftrace_call_replace(ip, (unsigned long)func);
+	text_poke_bp((void *)ip, new, MCOUNT_INSN_SIZE, NULL);
 
-	case FTRACE_UPDATE_MAKE_NOP:
-		/* converting a call to a nop */
-		return finish_update_nop(rec);
-	}
+	ip = (unsigned long)(&ftrace_regs_call);
+	new = ftrace_call_replace(ip, (unsigned long)func);
+	text_poke_bp((void *)ip, new, MCOUNT_INSN_SIZE, NULL);
 
 	return 0;
 }
 
-static void do_sync_core(void *data)
-{
-	sync_core();
-}
-
-static void run_sync(void)
-{
-	int enable_irqs;
-
-	/* No need to sync if there's only one CPU */
-	if (num_online_cpus() == 1)
-		return;
-
-	enable_irqs = irqs_disabled();
-
-	/* We may be called with interrupts disabled (on bootup). */
-	if (enable_irqs)
-		local_irq_enable();
-	on_each_cpu(do_sync_core, NULL, 1);
-	if (enable_irqs)
-		local_irq_disable();
-}
-
 void ftrace_replace_code(int enable)
 {
 	struct ftrace_rec_iter *iter;
 	struct dyn_ftrace *rec;
-	const char *report = "adding breakpoints";
-	int count = 0;
+	const char *new, *old;
 	int ret;
 
 	for_ftrace_rec_iter(iter) {
 		rec = ftrace_rec_iter_record(iter);
 
-		ret = add_breakpoints(rec, enable);
-		if (ret)
-			goto remove_breakpoints;
-		count++;
-	}
-
-	run_sync();
+		switch (ftrace_test_record(rec, enable)) {
+		case FTRACE_UPDATE_IGNORE:
+		default:
+			continue;
 
-	report = "updating code";
-	count = 0;
+		case FTRACE_UPDATE_MAKE_CALL:
+			old = ftrace_nop_replace();
+			break;
 
-	for_ftrace_rec_iter(iter) {
-		rec = ftrace_rec_iter_record(iter);
+		case FTRACE_UPDATE_MODIFY_CALL:
+		case FTRACE_UPDATE_MAKE_NOP:
+			old = ftrace_call_replace(rec->ip, ftrace_get_addr_curr(rec));
+			break;
+		}
 
-		ret = add_update(rec, enable);
-		if (ret)
-			goto remove_breakpoints;
-		count++;
+		ret = ftrace_verify_code(rec->ip, old);
+		if (ret) {
+			ftrace_bug(ret, rec);
+			return;
+		}
 	}
 
-	run_sync();
-
-	report = "removing breakpoints";
-	count = 0;
-
 	for_ftrace_rec_iter(iter) {
 		rec = ftrace_rec_iter_record(iter);
 
-		ret = finish_update(rec, enable);
-		if (ret)
-			goto remove_breakpoints;
-		count++;
-	}
+		switch (ftrace_test_record(rec, enable)) {
+		case FTRACE_UPDATE_IGNORE:
+		default:
+			continue;
 
-	run_sync();
+		case FTRACE_UPDATE_MAKE_CALL:
+		case FTRACE_UPDATE_MODIFY_CALL:
+			new = ftrace_call_replace(rec->ip, ftrace_get_addr_new(rec));
+			break;
 
-	return;
+		case FTRACE_UPDATE_MAKE_NOP:
+			new = ftrace_nop_replace();
+			break;
+		}
 
- remove_breakpoints:
-	pr_warn("Failed on %s (%d):\n", report, count);
-	ftrace_bug(ret, rec);
-	for_ftrace_rec_iter(iter) {
-		rec = ftrace_rec_iter_record(iter);
-		/*
-		 * Breakpoints are handled only when this function is in
-		 * progress. The system could not work with them.
-		 */
-		if (remove_breakpoint(rec))
-			BUG();
+		text_poke_queue((void *)rec->ip, new, MCOUNT_INSN_SIZE, NULL);
+		ftrace_update_record(rec, enable);
 	}
-	run_sync();
-}
-
-static int
-ftrace_modify_code(unsigned long ip, unsigned const char *old_code,
-		   unsigned const char *new_code)
-{
-	int ret;
-
-	ret = add_break(ip, old_code);
-	if (ret)
-		goto out;
-
-	run_sync();
-
-	ret = add_update_code(ip, new_code);
-	if (ret)
-		goto fail_update;
-
-	run_sync();
-
-	ret = ftrace_write(ip, new_code, 1);
-	/*
-	 * The breakpoint is handled only when this function is in progress.
-	 * The system could not work if we could not remove it.
-	 */
-	BUG_ON(ret);
- out:
-	run_sync();
-	return ret;
-
- fail_update:
-	/* Also here the system could not work with the breakpoint */
-	if (ftrace_write(ip, old_code, 1))
-		BUG();
-	goto out;
+	text_poke_finish();
 }
 
 void arch_ftrace_update_code(int command)
 {
-	/* See comment above by declaration of modifying_ftrace_code */
-	atomic_inc(&modifying_ftrace_code);
-
 	ftrace_modify_all_code(command);
-
-	atomic_dec(&modifying_ftrace_code);
 }
 
 int __init ftrace_dyn_arch_init(void)
@@ -748,6 +314,7 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
 	unsigned long start_offset;
 	unsigned long end_offset;
 	unsigned long op_offset;
+	unsigned long call_offset;
 	unsigned long offset;
 	unsigned long npages;
 	unsigned long size;
@@ -764,10 +331,12 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
 		start_offset = (unsigned long)ftrace_regs_caller;
 		end_offset = (unsigned long)ftrace_regs_caller_end;
 		op_offset = (unsigned long)ftrace_regs_caller_op_ptr;
+		call_offset = (unsigned long)ftrace_regs_call;
 	} else {
 		start_offset = (unsigned long)ftrace_caller;
 		end_offset = (unsigned long)ftrace_epilogue;
 		op_offset = (unsigned long)ftrace_caller_op_ptr;
+		call_offset = (unsigned long)ftrace_call;
 	}
 
 	size = end_offset - start_offset;
@@ -824,16 +393,21 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
 	/* put in the new offset to the ftrace_ops */
 	memcpy(trampoline + op_offset, &op_ptr, OP_REF_SIZE);
 
+	/* put in the call to the function */
+	mutex_lock(&text_mutex);
+	call_offset -= start_offset;
+	memcpy(trampoline + call_offset,
+	       text_gen_insn(CALL_INSN_OPCODE,
+			     trampoline + call_offset,
+			     ftrace_ops_get_func(ops)), CALL_INSN_SIZE);
+	mutex_unlock(&text_mutex);
+
 	/* ALLOC_TRAMP flags lets us know we created it */
 	ops->flags |= FTRACE_OPS_FL_ALLOC_TRAMP;
 
 	set_vm_flush_reset_perms(trampoline);
 
-	/*
-	 * Module allocation needs to be completed by making the page
-	 * executable. The page is still writable, which is a security hazard,
-	 * but anyhow ftrace breaks W^X completely.
-	 */
+	set_memory_ro((unsigned long)trampoline, npages);
 	set_memory_x((unsigned long)trampoline, npages);
 	return (unsigned long)trampoline;
 fail:
@@ -860,62 +434,54 @@ static unsigned long calc_trampoline_call_offset(bool save_regs)
 void arch_ftrace_update_trampoline(struct ftrace_ops *ops)
 {
 	ftrace_func_t func;
-	unsigned char *new;
 	unsigned long offset;
 	unsigned long ip;
 	unsigned int size;
-	int ret, npages;
+	const char *new;
 
-	if (ops->trampoline) {
-		/*
-		 *