Merge tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "There was a lot of clean ups and minor fixes.  One of those clean ups
  was to the trace_seq code.  It also removed the return values to the
  trace_seq_*() functions and use trace_seq_has_overflowed() to see if
  the buffer filled up or not.  This is similar to work being done to
  the seq_file code as well in another tree.

  Some of the other goodies include:

   - Added some "!" (NOT) logic to the tracing filter.

   - Fixed the frame pointer logic to the x86_64 mcount trampolines

   - Added the logic for dynamic trampolines on !CONFIG_PREEMPT systems.
     That is, the ftrace trampoline can be dynamically allocated and be
     called directly by functions that only have a single hook to them"

* tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (55 commits)
  tracing: Truncated output is better than nothing
  tracing: Add additional marks to signal very large time deltas
  Documentation: describe trace_buf_size parameter more accurately
  tracing: Allow NOT to filter AND and OR clauses
  tracing: Add NOT to filtering logic
  ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter
  ftrace/x86: Get rid of ftrace_caller_setup
  ftrace/x86: Have save_mcount_regs macro also save stack frames if needed
  ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs
  ftrace/x86: Simplify save_mcount_regs on getting RIP
  ftrace/x86: Have save_mcount_regs store RIP in %rdi for first parameter
  ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments
  ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file
  ftrace/x86: Have static tracing also use ftrace_caller_setup
  ftrace/x86: Have static function tracing always test for function graph
  kprobes: Add IPMODIFY flag to kprobe_ftrace_ops
  ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict
  kprobes/ftrace: Recover original IP if pre_handler doesn't change it
  tracing/trivial: Fix typos and make an int into a bool
  tracing: Deletion of an unnecessary check before iput()
  ...

25 files changed, 1132 insertions, 1177 deletions

diff --git a/kernel/extable.c b/kernel/extable.c
index d8a6446adbcb..c98f926277a8 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -18,6 +18,7 @@
 #include <linux/ftrace.h>
 #include <linux/memory.h>
 #include <linux/module.h>
+#include <linux/ftrace.h>
 #include <linux/mutex.h>
 #include <linux/init.h>
 
@@ -102,6 +103,8 @@ int __kernel_text_address(unsigned long addr)
 		return 1;
 	if (is_module_text_address(addr))
 		return 1;
+	if (is_ftrace_trampoline(addr))
+		return 1;
 	/*
 	 * There might be init symbols in saved stacktraces.
 	 * Give those symbols a chance to be printed in
@@ -119,7 +122,9 @@ int kernel_text_address(unsigned long addr)
 {
 	if (core_kernel_text(addr))
 		return 1;
-	return is_module_text_address(addr);
+	if (is_module_text_address(addr))
+		return 1;
+	return is_ftrace_trampoline(addr);
 }
 
 /*
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 3995f546d0f3..831978cebf1d 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -915,7 +915,7 @@ static struct kprobe *alloc_aggr_kprobe(struct kprobe *p)
 #ifdef CONFIG_KPROBES_ON_FTRACE
 static struct ftrace_ops kprobe_ftrace_ops __read_mostly = {
 	.func = kprobe_ftrace_handler,
-	.flags = FTRACE_OPS_FL_SAVE_REGS,
+	.flags = FTRACE_OPS_FL_SAVE_REGS | FTRACE_OPS_FL_IPMODIFY,
 };
 static int kprobe_ftrace_enabled;
 
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index c1bd4ada2a04..11b9cb36092b 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1142,9 +1142,9 @@ static void get_pdu_remap(const struct trace_entry *ent,
 	r->sector_from = be64_to_cpu(sector_from);
 }
 
-typedef int (blk_log_action_t) (struct trace_iterator *iter, const char *act);
+typedef void (blk_log_action_t) (struct trace_iterator *iter, const char *act);
 
-static int blk_log_action_classic(struct trace_iterator *iter, const char *act)
+static void blk_log_action_classic(struct trace_iterator *iter, const char *act)
 {
 	char rwbs[RWBS_LEN];
 	unsigned long long ts  = iter->ts;
@@ -1154,33 +1154,33 @@ static int blk_log_action_classic(struct trace_iterator *iter, const char *act)
 
 	fill_rwbs(rwbs, t);
 
-	return trace_seq_printf(&iter->seq,
-				"%3d,%-3d %2d %5d.%09lu %5u %2s %3s ",
-				MAJOR(t->device), MINOR(t->device), iter->cpu,
-				secs, nsec_rem, iter->ent->pid, act, rwbs);
+	trace_seq_printf(&iter->seq,
+			 "%3d,%-3d %2d %5d.%09lu %5u %2s %3s ",
+			 MAJOR(t->device), MINOR(t->device), iter->cpu,
+			 secs, nsec_rem, iter->ent->pid, act, rwbs);
 }
 
-static int blk_log_action(struct trace_iterator *iter, const char *act)
+static void blk_log_action(struct trace_iterator *iter, const char *act)
 {
 	char rwbs[RWBS_LEN];
 	const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
 
 	fill_rwbs(rwbs, t);
-	return trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
-				MAJOR(t->device), MINOR(t->device), act, rwbs);
+	trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
+			 MAJOR(t->device), MINOR(t->device), act, rwbs);
 }
 
-static int blk_log_dump_pdu(struct trace_seq *s, const struct trace_entry *ent)
+static void blk_log_dump_pdu(struct trace_seq *s, const struct trace_entry *ent)
 {
 	const unsigned char *pdu_buf;
 	int pdu_len;
-	int i, end, ret;
+	int i, end;
 
 	pdu_buf = pdu_start(ent);
 	pdu_len = te_blk_io_trace(ent)->pdu_len;
 
 	if (!pdu_len)
-		return 1;
+		return;
 
 	/* find the last zero that needs to be printed */
 	for (end = pdu_len - 1; end >= 0; end--)
@@ -1188,119 +1188,107 @@ static int blk_log_dump_pdu(struct trace_seq *s, const struct trace_entry *ent)
 			break;
 	end++;
 
-	if (!trace_seq_putc(s, '('))
-		return 0;
+	trace_seq_putc(s, '(');
 
 	for (i = 0; i < pdu_len; i++) {
 
-		ret = trace_seq_printf(s, "%s%02x",
-				       i == 0 ? "" : " ", pdu_buf[i]);
-		if (!ret)
-			return ret;
+		trace_seq_printf(s, "%s%02x",
+				 i == 0 ? "" : " ", pdu_buf[i]);
 
 		/*
 		 * stop when the rest is just zeroes and indicate so
 		 * with a ".." appended
 		 */
-		if (i == end && end != pdu_len - 1)
-			return trace_seq_puts(s, " ..) ");
+		if (i == end && end != pdu_len - 1) {
+			trace_seq_puts(s, " ..) ");
+			return;
+		}
 	}
 
-	return trace_seq_puts(s, ") ");
+	trace_seq_puts(s, ") ");
 }
 
-static int blk_log_generic(struct trace_seq *s, const struct trace_entry *ent)
+static void blk_log_generic(struct trace_seq *s, const struct trace_entry *ent)
 {
 	char cmd[TASK_COMM_LEN];
 
 	trace_find_cmdline(ent->pid, cmd);
 
 	if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
-		int ret;
-
-		ret = trace_seq_printf(s, "%u ", t_bytes(ent));
-		if (!ret)
-			return 0;
-		ret = blk_log_dump_pdu(s, ent);
-		if (!ret)
-			return 0;
-		return trace_seq_printf(s, "[%s]\n", cmd);
+		trace_seq_printf(s, "%u ", t_bytes(ent));
+		blk_log_dump_pdu(s, ent);
+		trace_seq_printf(s, "[%s]\n", cmd);
 	} else {
 		if (t_sec(ent))
-			return trace_seq_printf(s, "%llu + %u [%s]\n",
+			trace_seq_printf(s, "%llu + %u [%s]\n",
 						t_sector(ent), t_sec(ent), cmd);
-		return trace_seq_printf(s, "[%s]\n", cmd);
+		else
+			trace_seq_printf(s, "[%s]\n", cmd);
 	}
 }
 
-static int blk_log_with_error(struct trace_seq *s,
+static void blk_log_with_error(struct trace_seq *s,
 			      const struct trace_entry *ent)
 {
 	if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
-		int ret;
-
-		ret = blk_log_dump_pdu(s, ent);
-		if (ret)
-			return trace_seq_printf(s, "[%d]\n", t_error(ent));
-		return 0;
+		blk_log_dump_pdu(s, ent);
+		trace_seq_printf(s, "[%d]\n", t_error(ent));
 	} else {
 		if (t_sec(ent))
-			return trace_seq_printf(s, "%llu + %u [%d]\n",
-						t_sector(ent),
-						t_sec(ent), t_error(ent));
-		return trace_seq_printf(s, "%llu [%d]\n",
-					t_sector(ent), t_error(ent));
+			trace_seq_printf(s, "%llu + %u [%d]\n",
+					 t_sector(ent),
+					 t_sec(ent), t_error(ent));
+		else
+			trace_seq_printf(s, "%llu [%d]\n",
+					 t_sector(ent), t_error(ent));
 	}
 }
 
-static int blk_log_remap(struct trace_seq *s, const struct trace_entry *ent)
+static void blk_log_remap(struct trace_seq *s, const struct trace_entry *ent)
 {
 	struct blk_io_trace_remap r = { .device_from = 0, };
 
 	get_pdu_remap(ent, &r);
-	return trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
-				t_sector(ent), t_sec(ent),
-				MAJOR(r.device_from), MINOR(r.device_from),
-				(unsigned long long)r.sector_from);
+	trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
+			 t_sector(ent), t_sec(ent),
+			 MAJOR(r.device_from), MINOR(r.device_from),
+			 (unsigned long long)r.sector_from);
 }
 
-static int blk_log_plug(struct trace_seq *s, const struct trace_entry *ent)
+static void blk_log_plug(struct trace_seq *s, const struct trace_entry *ent)
 {
 	char cmd[TASK_COMM_LEN];
 
 	trace_find_cmdline(ent->pid, cmd);
 
-	return trace_seq_printf(s, "[%s]\n", cmd);
+	trace_seq_printf(s, "[%s]\n", cmd);
 }
 
-static int blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent)
+static void blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent)
 {
 	char cmd[TASK_COMM_LEN];
 
 	trace_find_cmdline(ent->pid, cmd);
 
-	return trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent));
+	trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent));
 }
 
-static int blk_log_split(struct trace_seq *s, const struct trace_entry *ent)
+static void blk_log_split(struct trace_seq *s, const struct trace_entry *ent)
 {
 	char cmd[TASK_COMM_LEN];
 
 	trace_find_cmdline(ent->pid, cmd);
 
-	return trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent),
-				get_pdu_int(ent), cmd);
+	trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent),
+			 get_pdu_int(ent), cmd);
 }
 
-static int blk_log_msg(struct trace_seq *s, const struct trace_entry *ent)
+static void blk_log_msg(struct trace_seq *s, const struct trace_entry *ent)
 {
-	int ret;
 	const struct blk_io_trace *t = te_blk_io_trace(ent);
 
-	ret = trace_seq_putmem(s, t + 1, t->pdu_len);
-	if (ret)
-		return trace_seq_putc(s, '\n');
-	return ret;
+	trace_seq_putmem(s, t + 1, t->pdu_len);
+	trace_seq_putc(s, '\n');
 }
 
 /*
@@ -1339,7 +1327,7 @@ static void blk_tracer_reset(struct trace_array *tr)
 
 static const struct {
 	const char *act[2];
-	int	   (*print)(struct trace_seq *s, const struct trace_entry *ent);
+	void	   (*print)(struct trace_seq *s, const struct trace_entry *ent);
 } what2act[] = {
 	[__BLK_TA_QUEUE]	= {{  "Q", "queue" },	   blk_log_generic },
 	[__BLK_TA_BACKMERGE]	= {{  "M", "backmerge" },  blk_log_generic },
@@ -1364,7 +1352,6 @@ static enum print_line_t print_one_line(struct trace_iterator *iter,
 	struct trace_seq *s = &iter->seq;
 	const struct blk_io_trace *t;
 	u16 what;
-	int ret;
 	bool long_act;
 	blk_log_action_t *log_action;
 
@@ -1374,21 +1361,18 @@ static enum print_line_t print_one_line(struct trace_iterator *iter,
 	log_action = classic ? &blk_log_action_classic : &blk_log_action;
 
 	if (t->action == BLK_TN_MESSAGE) {
-		ret = log_action(iter, long_act ? "message" : "m");
-		if (ret)
-			ret = blk_log_msg(s, iter->ent);
-		goto out;
+		log_action(iter, long_act ? "message" : "m");
+		blk_log_msg(s, iter->ent);
 	}
 
 	if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
-		ret = trace_seq_printf(s, "Unknown action %x\n", what);
+		trace_seq_printf(s, "Unknown action %x\n", what);
 	else {
-		ret = log_action(iter, what2act[what].act[long_act]);
-		if (ret)
-			ret = what2act[what].print(s, iter->ent);
+		log_action(iter, what2act[what].act[long_act]);
+		what2act[what].print(s, iter->ent);
 	}
-out:
-	return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
+
+	return trace_handle_return(s);
 }
 
 static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
@@ -1397,7 +1381,7 @@ static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
 	return print_one_line(iter, false);
 }
 
-static int blk_trace_synthesize_old_trace(struct trace_iterator *iter)
+static void blk_trace_synthesize_old_trace(struct trace_iterator *iter)
 {
 	struct trace_seq *s = &iter->seq;
 	struct blk_io_trace *t = (struct blk_io_trace *)iter->ent;
@@ -1407,18 +1391,18 @@ static int blk_trace_synthesize_old_trace(struct trace_iterator *iter)
 		.time     = iter->ts,
 	};
 
-	if (!trace_seq_putmem(s, &old, offset))
-		return 0;
-	return trace_seq_putmem(s, &t->sector,
-				sizeof(old) - offset + t->pdu_len);
+	trace_seq_putmem(s, &old, offset);
+	trace_seq_putmem(s, &t->sector,
+			 sizeof(old) - offset + t->pdu_len);
 }
 
 static enum print_line_t
 blk_trace_event_print_binary(struct trace_iterator *iter, int flags,
 			     struct trace_event *event)
 {
-	return blk_trace_synthesize_old_trace(iter) ?
-			TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
+	blk_trace_synthesize_old_trace(iter);
+
+	return trace_handle_return(&iter->seq);
 }
 
 static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 31c90fec4158..929a733d302e 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -387,6 +387,8 @@ static int remove_ftrace_list_ops(struct ftrace_ops **list,
 	return ret;
 }
 
+static void ftrace_update_trampoline(struct ftrace_ops *ops);
+
 static int __register_ftrace_function(struct ftrace_ops *ops)
 {
 	if (ops->flags & FTRACE_OPS_FL_DELETED)
@@ -416,9 +418,13 @@ static int __register_ftrace_function(struct ftrace_ops *ops)
 		if (control_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);
 
+	ftrace_update_trampoline(ops);
+
 	if (ftrace_enabled)
 		update_ftrace_function();
 
@@ -565,13 +571,13 @@ static int function_stat_cmp(void *p1, void *p2)
 static int function_stat_headers(struct seq_file *m)
 {
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-	seq_printf(m, "  Function                               "
-		   "Hit    Time            Avg             s^2\n"
-		      "  --------                               "
-		   "---    ----            ---             ---\n");
+	seq_puts(m, "  Function                               "
+		 "Hit    Time            Avg             s^2\n"
+		    "  --------                               "
+		 "---    ----            ---             ---\n");
 #else
-	seq_printf(m, "  Function                               Hit\n"
-		      "  --------                               ---\n");
+	seq_puts(m, "  Function                               Hit\n"
+		    "  --------                               ---\n");
 #endif
 	return 0;
 }
@@ -598,7 +604,7 @@ static int function_stat_show(struct seq_file *m, void *v)
 	seq_printf(m, "  %-30.30s  %10lu", str, rec->counter);
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-	seq_printf(m, "    ");
+	seq_puts(m, "    ");
 	avg = rec->time;
 	do_div(avg, rec->counter);
 
@@ -1111,6 +1117,43 @@ static struct ftrace_ops global_ops = {
 					  FTRACE_OPS_FL_INITIALIZED,
 };
 
+/*
+ * This is used by __kernel_text_address() to return true if the
+ * address is on a dynamically allocated trampoline that would
+ * not return true for either core_kernel_text() or
+ * is_module_text_address().
+ */
+bool is_ftrace_trampoline(unsigned long addr)
+{
+	struct ftrace_ops *op;
+	bool ret = false;
+
+	/*
+	 * Some of the ops may be dynamically allocated,
+	 * they are freed after a synchronize_sched().
+	 */
+	preempt_disable_notrace();
+
+	do_for_each_ftrace_op(op, ftrace_ops_list) {
+		/*
+		 * This is to check for dynamically allocated trampolines.
+		 * Trampolines that are in kernel text will have
+		 * core_kernel_text() return true.
+		 */
+		if (op->trampoline && op->trampoline_size)
+			if (addr >= op->trampoline &&
+			    addr < op->trampoline + op->trampoline_size) {
+				ret = true;
+				goto out;
+			}
+	} while_for_each_ftrace_op(op);
+
+ out:
+	preempt_enable_notrace();
+
+	return ret;
+}
+
 struct ftrace_page {
 	struct ftrace_page	*next;
 	struct dyn_ftrace	*records;
@@ -1315,6 +1358,9 @@ ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
 static void
 ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
 
+static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
+				       struct ftrace_hash *new_hash);
+
 static int
 ftrace_hash_move(struct ftrace_ops *ops, int enable,
 		 struct ftrace_hash **dst, struct ftrace_hash *src)
@@ -1325,8 +1371,13 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable,
 	struct ftrace_hash *new_hash;
 	int size = src->count;
 	int bits = 0;
+	int ret;
 	int i;
 
+	/* Reject setting notrace hash on IPMODIFY ftrace_ops */
+	if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
+		return -EINVAL;
+
 	/*
 	 * If the new source is empty, just free dst and assign it
 	 * the empty_hash.
@@ -1360,6 +1411,16 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable,
 	}
 
 update:
+	/* Make sure this can be applied if it is IPMODIFY ftrace_ops */
+	if (enable) {
+		/* IPMODIFY should be updated only when filter_hash updating */
+		ret = ftrace_hash_ipmodify_update(ops, new_hash);
+		if (ret < 0) {
+			free_ftrace_hash(new_hash);
+			return ret;
+		}
+	}
+
 	/*
 	 * Remove the current set, update the hash and add
 	 * them back.
@@ -1724,6 +1785,114 @@ static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
 	ftrace_hash_rec_update_modify(ops, filter_hash, 1);
 }
 
+/*
+ * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
+ * or no-needed to update, -EBUSY if it detects a conflict of the flag
+ * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
+ * Note that old_hash and new_hash has below meanings
+ *  - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
+ *  - If the hash is EMPTY_HASH, it hits nothing
+ *  - Anything else hits the recs which match the hash entries.
+ */
+static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
+					 struct ftrace_hash *old_hash,
+					 struct ftrace_hash *new_hash)
+{
+	struct ftrace_page *pg;
+	struct dyn_ftrace *rec, *end = NULL;
+	int in_old, in_new;
+
+	/* Only update if the ops has been registered */
+	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+		return 0;
+
+	if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
+		return 0;
+
+	/*
+	 * Since the IPMODIFY is a very address sensitive action, we do not
+	 * allow ftrace_ops to set all functions to new hash.
+	 */
+	if (!new_hash || !old_hash)
+		return -EINVAL;
+
+	/* Update rec->flags */
+	do_for_each_ftrace_rec(pg, rec) {
+		/* We need to update only differences of filter_hash */
+		in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
+		in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
+		if (in_old == in_new)
+			continue;
+
+		if (in_new) {
+			/* New entries must ensure no others are using it */
+			if (rec->flags & FTRACE_FL_IPMODIFY)
+				goto rollback;
+			rec->flags |= FTRACE_FL_IPMODIFY;
+		} else /* Removed entry */
+			rec->flags &= ~FTRACE_FL_IPMODIFY;
+	} while_for_each_ftrace_rec();
+
+	return 0;
+
+rollback:
+	end = rec;
+
+	/* Roll back what we did above */
+	do_for_each_ftrace_rec(pg, rec) {
+		if (rec == end)
+			goto err_out;
+
+		in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
+		in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
+		if (in_old == in_new)
+			continue;
+
+		if (in_new)
+			rec->flags &= ~FTRACE_FL_IPMODIFY;
+		else
+			rec->flags |= FTRACE_FL_IPMODIFY;
+	} while_for_each_ftrace_rec();
+
+err_out:
+	return -EBUSY;
+}
+
+static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
+{
+	struct ftrace_hash *hash = ops->func_hash->filter_hash;
+
+	if (ftrace_hash_empty(hash))
+		hash = NULL;
+
+	return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
+}
+
+/* Disabling always succeeds */
+static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
+{
+	struct ftrace_hash *hash = ops->func_hash->filter_hash;
+
+	if (ftrace_hash_empty(hash))
+		hash = NULL;
+
+	__ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
+}
+
+static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
+				       struct ftrace_hash *new_hash)
+{
+	struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
+
+	if (ftrace_hash_empty(old_hash))
+		old_hash = NULL;
+
+	if (ftrace_hash_empty(new_hash))
+		new_hash = NULL;
+
+	return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
+}
+
 static void print_ip_ins(const char *fmt, unsigned char *p)
 {
 	int i;
@@ -1734,10 +1903,13 @@ static void print_ip_ins(const char *fmt, unsigned char *p)
 		printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
 }
 
+static struct ftrace_ops *
+ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
+
 /**
  * ftrace_bug - report and shutdown function tracer
  * @failed: The failed type (EFAULT, EINVAL, EPERM)
- * @ip: The address that failed
+ * @rec: The record that failed
  *
  * The arch code that enables or disables the function tracing
  * can call ftrace_bug() when it has detected a problem in
@@ -1746,8 +1918,10 @@ static void print_ip_ins(const char *fmt, unsigned char *p)
  * EINVAL - if what is read at @ip is not what was expected
  * EPERM - if the problem happens on writting to the @ip address
  */
-void ftrace_bug(int failed, unsigned long ip)
+void ftrace_bug(int failed, struct dyn_ftrace *rec)
 {
+	unsigned long ip = rec ? rec->ip : 0;
+
 	switch (failed) {
 	case -EFAULT:
 		FTRACE_WARN_ON_ONCE(1);
@@ -1759,7 +1933,7 @@ void ftrace_bug(int failed, unsigned long ip)
 		pr_info("ftrace failed to modify ");
 		print_ip_sym(ip);
 		print_ip_ins(" actual: ", (unsigned char *)ip);
-		printk(KERN_CONT "\n");
+		pr_cont("\n");
 		break;
 	case -EPERM:
 		FTRACE_WARN_ON_ONCE(1);
@@ -1771,6 +1945,24 @@ void ftrace_bug(int failed, unsigned long ip)
 		pr_info("ftrace faulted on unknown error ");
 		print_ip_sym(ip);
 	}
+	if (rec) {
+		struct ftrace_ops *ops = NULL;
+
+		pr_info("ftrace record flags: %lx\n", rec->flags);
+		pr_cont(" (%ld)%s", ftrace_rec_count(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
+				pr_cont("\ttramp: ERROR!");
+
+		}
+		ip = ftrace_get_addr_curr(rec);
+		pr_cont(" expected tramp: %lx\n", ip);
+	}
 }
 
 static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
@@ -2093,7 +2285,7 @@ void __weak ftrace_replace_code(int enable)
 	do_for_each_ftrace_rec(pg, rec) {
 		failed = __ftrace_replace_code(rec, enable);
 		if (failed) {
-			ftrace_bug(failed, rec->ip);
+			ftrace_bug(failed, rec);
 			/* Stop processing */
 			return;
 		}
@@ -2175,17 +2367,14 @@ struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
 static int
 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
 {
-	unsigned long ip;
 	int ret;
 
-	ip = rec->ip;
-
 	if (unlikely(ftrace_disabled))
 		return 0;
 
 	ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
 	if (ret) {
-		ftrace_bug(ret, ip);
+		ftrace_bug(ret, rec);
 		return 0;
 	}
 	return 1;
@@ -2320,6 +2509,10 @@ static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
 static ftrace_func_t saved_ftrace_func;
 static int ftrace_start_up;
 
+void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
+{
+}
+
 static void control_ops_free(struct ftrace_ops *ops)
 {
 	free_percpu(ops->disabled);
@@ -2369,6 +2562,15 @@ static int ftrace_startup(struct ftrace_ops *ops, int command)
 	 */
 	ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
 
+	ret = ftrace_hash_ipmodify_enable(ops);
+	if (ret < 0) {
+		/* Rollback registration process */
+		__unregister_ftrace_function(ops);
+		ftrace_start_up--;
+		ops->flags &= ~FTRACE_OPS_FL_ENABLED;
+		return ret;
+	}
+
 	ftrace_hash_rec_enable(ops, 1);
 
 	ftrace_startup_enable(command);
@@ -2397,6 +2599,8 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command)
 	 */
 	WARN_ON_ONCE(ftrace_start_up < 0);
 
+	/* Disabling ipmodify never fails */
+	ftrace_hash_ipmodify_disable(ops);
 	ftrace_hash_rec_disable(ops, 1);
 
 	ops->flags &= ~FTRACE_OPS_FL_ENABLED;
@@ -2471,6 +2675,8 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command)
 	if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) {
 		schedule_on_each_cpu(ftrace_sync);
 
+		arch_ftrace_trampoline_free(ops);
+
 		if (ops->flags & FTRACE_OPS_FL_CONTROL)
 			control_ops_free(ops);
 	}
@@ -2623,7 +2829,7 @@ static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
 			if (ftrace_start_up && cnt) {
 				int failed = __ftrace_replace_code(p, 1);
 				if (failed)
-					ftrace_bug(failed, p->ip);
+					ftrace_bug(failed, p);
 			}
 		}
 	}
@@ -2948,6 +3154,22 @@ static void t_stop(struct seq_file *m, void *p)
 	mutex_unlock(&ftrace_lock);
 }
 
+void * __weak
+arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
+{
+	return NULL;
+}
+
+static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
+				struct dyn_ftrace *rec)
+{
+	void *ptr;
+
+	ptr = arch_ftrace_trampoline_func(ops, rec);
+	if (ptr)
+		seq_printf(m, " ->%pS", ptr);
+}
+
 static int t_show(struct seq_file *m, void *v)
 {
 	struct ftrace_iterator *iter = m->private;
@@ -2958,9 +3180,9 @@ static int t_show(struct seq_file *m, void *v)
 
 	if (iter->flags & FTRACE_ITER_PRINTALL) {
 		if (iter->flags & FTRACE_ITER_NOTRACE)
-			seq_printf(m, "#### no functions disabled ####\n");
+			seq_puts(m, "#### no functions disabled ####\n");
 		else
-			seq_printf(m, "#### all functions enabled ####\n");
+			seq_puts(m, "#### all functions enabled ####\n");
 		return 0;
 	}
 
@@ -2971,22 +3193,25 @@ 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)%s",
+		struct ftrace_ops *ops = NULL;
+
+		seq_printf(m, " (%ld)%s%s",
 			   ftrace_rec_count(rec),
-			   rec->flags & FTRACE_FL_REGS ? " R" : "  ");
+			   rec->flags & FTRACE_FL_REGS ? " R" : "  ",
+			   rec->flags & FTRACE_FL_IPMODIFY ? " I" : "  ");
 		if (rec->flags & FTRACE_FL_TRAMP_EN) {
-			struct ftrace_ops *ops;
-
 			ops = ftrace_find_tramp_ops_any(rec);
 			if (ops)
 				seq_printf(m, "\ttramp: %pS",
 					   (void *)ops->trampoline);
 			else
-				seq_printf(m, "\ttramp: ERROR!");
+				seq_puts(m, "\ttramp: ERROR!");
+
 		}
+		add_trampoline_func(m, ops, rec);
 	}	
 
-	seq_printf(m, "\n");
+	seq_putc(m, '\n');
 
 	return 0;
 }
@@ -3020,9 +3245,6 @@ ftrace_enabled_open(struct inode *inode, struct file *file)
 {
 	struct ftrace_iterator *iter;
 
-	if (unlikely(ftrace_disabled))
-		return -ENODEV;
-
 	iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
 	if (iter) {
 		iter->pg = ftrace_pages_start;
@@ -3975,6 +4197,9 @@ static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
 static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
 static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer);
 
+static unsigned long save_global_trampoline;
+static unsigned long save_global_flags;
+
 static int __init set_graph_function(char *str)
 {
 	strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
@@ -4183,9 +4408,9 @@ static int g_show(struct seq_file *m, void *v)
 		struct ftrace_graph_data *fgd = m->private;
 
 		if (fgd->table == ftrace_graph_funcs)
-			seq_printf(m, "#### all functions enabled ####\n");
+			seq_puts(m, "#### all functions enabled ####\n");
 		else
-			seq_printf(m, "#### no functions disabled ####\n");
+			seq_puts(m, "#### no functions disabled ####\n");
 		return 0;
 	}
 
@@ -4696,6 +4921,32 @@ void __init ftrace_init(void)
 	ftrace_disabled = 1;
 }
 
+/* Do nothing if arch does not support this */
+void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
+{
+}
+
+static void ftrace_update_trampoline(struct ftrace_ops *ops)
+{
+
+/*
+ * Currently there's no safe way to free a trampoline when the kernel
+ * is configured with PREEMPT. That is because a task could be preempted
+ * when it jumped to the trampoline, it may be preempted for a long time
+ * depending on the system load, and currently there's no way to know
+ * when it will be off the trampoline. If the trampoline is freed
+ * too early, when the task runs again, it will be executing on freed
+ * memory and crash.
+ */
+#ifdef CONFIG_PREEMPT
+	/* Currently, only non dynamic ops can have a trampoline */
+	if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
+		return;
+#endif
+
+	arch_ftrace_update_trampoline(ops);
+}
+
 #else
 
 static struct ftrace_ops global_ops = {
@@ -4738,6 +4989,10 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
 	return 1;
 }