1 files changed, 203 insertions, 565 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ab4c1a1fbda860..233d1af39fffe2 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -13,7 +13,7 @@
  *  Copyright (C) 2004 Nadia Yvette Chambers
  */
 #include <linux/ring_buffer.h>
-#include <generated/utsrelease.h>
+#include <linux/utsname.h>
 #include <linux/stacktrace.h>
 #include <linux/writeback.h>
 #include <linux/kallsyms.h>
@@ -39,7 +39,6 @@
 #include <linux/ctype.h>
 #include <linux/init.h>
 #include <linux/panic_notifier.h>
-#include <linux/kmemleak.h>
 #include <linux/poll.h>
 #include <linux/nmi.h>
 #include <linux/fs.h>
@@ -105,7 +104,7 @@ dummy_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
  * tracing is active, only save the comm when a trace event
  * occurred.
  */
-static DEFINE_PER_CPU(bool, trace_taskinfo_save);
+DEFINE_PER_CPU(bool, trace_taskinfo_save);
 
 /*
  * Kill all tracing for good (never come back).
@@ -131,9 +130,12 @@ cpumask_var_t __read_mostly	tracing_buffer_mask;
  * /proc/sys/kernel/ftrace_dump_on_oops
  * Set 1 if you want to dump buffers of all CPUs
  * Set 2 if you want to dump the buffer of the CPU that triggered oops
+ * Set instance name if you want to dump the specific trace instance
+ * Multiple instance dump is also supported, and instances are seperated
+ * by commas.
  */
-
-enum ftrace_dump_mode ftrace_dump_on_oops;
+/* Set to string format zero to disable by default */
+char ftrace_dump_on_oops[MAX_TRACER_SIZE] = "0";
 
 /* When set, tracing will stop when a WARN*() is hit */
 int __disable_trace_on_warning;
@@ -179,7 +181,6 @@ static void ftrace_trace_userstack(struct trace_array *tr,
 				   struct trace_buffer *buffer,
 				   unsigned int trace_ctx);
 
-#define MAX_TRACER_SIZE		100
 static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
 static char *default_bootup_tracer;
 
@@ -202,19 +203,33 @@ static int __init set_cmdline_ftrace(char *str)
 }
 __setup("ftrace=", set_cmdline_ftrace);
 
+int ftrace_dump_on_oops_enabled(void)
+{
+	if (!strcmp("0", ftrace_dump_on_oops))
+		return 0;
+	else
+		return 1;
+}
+
 static int __init set_ftrace_dump_on_oops(char *str)
 {
-	if (*str++ != '=' || !*str || !strcmp("1", str)) {
-		ftrace_dump_on_oops = DUMP_ALL;
+	if (!*str) {
+		strscpy(ftrace_dump_on_oops, "1", MAX_TRACER_SIZE);
 		return 1;
 	}
 
-	if (!strcmp("orig_cpu", str) || !strcmp("2", str)) {
-		ftrace_dump_on_oops = DUMP_ORIG;
-                return 1;
-        }
+	if (*str == ',') {
+		strscpy(ftrace_dump_on_oops, "1", MAX_TRACER_SIZE);
+		strscpy(ftrace_dump_on_oops + 1, str, MAX_TRACER_SIZE - 1);
+		return 1;
+	}
+
+	if (*str++ == '=') {
+		strscpy(ftrace_dump_on_oops, str, MAX_TRACER_SIZE);
+		return 1;
+	}
 
-        return 0;
+	return 0;
 }
 __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
 
@@ -1301,6 +1316,50 @@ static void free_snapshot(struct trace_array *tr)
 	tr->allocated_snapshot = false;
 }
 
+static int tracing_arm_snapshot_locked(struct trace_array *tr)
+{
+	int ret;
+
+	lockdep_assert_held(&trace_types_lock);
+
+	spin_lock(&tr->snapshot_trigger_lock);
+	if (tr->snapshot == UINT_MAX) {
+		spin_unlock(&tr->snapshot_trigger_lock);
+		return -EBUSY;
+	}
+
+	tr->snapshot++;
+	spin_unlock(&tr->snapshot_trigger_lock);
+
+	ret = tracing_alloc_snapshot_instance(tr);
+	if (ret) {
+		spin_lock(&tr->snapshot_trigger_lock);
+		tr->snapshot--;
+		spin_unlock(&tr->snapshot_trigger_lock);
+	}
+
+	return ret;
+}
+
+int tracing_arm_snapshot(struct trace_array *tr)
+{
+	int ret;
+
+	mutex_lock(&trace_types_lock);
+	ret = tracing_arm_snapshot_locked(tr);
+	mutex_unlock(&trace_types_lock);
+
+	return ret;
+}
+
+void tracing_disarm_snapshot(struct trace_array *tr)
+{
+	spin_lock(&tr->snapshot_trigger_lock);
+	if (!WARN_ON(!tr->snapshot))
+		tr->snapshot--;
+	spin_unlock(&tr->snapshot_trigger_lock);
+}
+
 /**
  * tracing_alloc_snapshot - allocate snapshot buffer.
  *
@@ -1374,10 +1433,6 @@ int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data,
 
 	mutex_lock(&trace_types_lock);
 
-	ret = tracing_alloc_snapshot_instance(tr);
-	if (ret)
-		goto fail_unlock;
-
 	if (tr->current_trace->use_max_tr) {
 		ret = -EBUSY;
 		goto fail_unlock;
@@ -1396,6 +1451,10 @@ int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data,
 		goto fail_unlock;
 	}
 
+	ret = tracing_arm_snapshot_locked(tr);
+	if (ret)
+		goto fail_unlock;
+
 	local_irq_disable();
 	arch_spin_lock(&tr->max_lock);
 	tr->cond_snapshot = cond_snapshot;
@@ -1440,6 +1499,8 @@ int tracing_snapshot_cond_disable(struct trace_array *tr)
 	arch_spin_unlock(&tr->max_lock);
 	local_irq_enable();
 
+	tracing_disarm_snapshot(tr);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(tracing_snapshot_cond_disable);
@@ -1482,6 +1543,7 @@ int tracing_snapshot_cond_disable(struct trace_array *tr)
 }
 EXPORT_SYMBOL_GPL(tracing_snapshot_cond_disable);
 #define free_snapshot(tr)	do { } while (0)
+#define tracing_arm_snapshot_locked(tr) ({ -EBUSY; })
 #endif /* CONFIG_TRACER_SNAPSHOT */
 
 void tracer_tracing_off(struct trace_array *tr)
@@ -2320,98 +2382,6 @@ void tracing_reset_all_online_cpus(void)
 	mutex_unlock(&trace_types_lock);
 }
 
-/*
- * The tgid_map array maps from pid to tgid; i.e. the value stored at index i
- * is the tgid last observed corresponding to pid=i.
- */
-static int *tgid_map;
-
-/* The maximum valid index into tgid_map. */
-static size_t tgid_map_max;
-
-#define SAVED_CMDLINES_DEFAULT 128
-#define NO_CMDLINE_MAP UINT_MAX
-/*
- * Preemption must be disabled before acquiring trace_cmdline_lock.
- * The various trace_arrays' max_lock must be acquired in a context
- * where interrupt is disabled.
- */
-static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED;
-struct saved_cmdlines_buffer {
-	unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
-	unsigned *map_cmdline_to_pid;
-	unsigned cmdline_num;
-	int cmdline_idx;
-	char saved_cmdlines[];
-};
-static struct saved_cmdlines_buffer *savedcmd;
-
-static inline char *get_saved_cmdlines(int idx)
-{
-	return &savedcmd->saved_cmdlines[idx * TASK_COMM_LEN];
-}
-
-static inline void set_cmdline(int idx, const char *cmdline)
-{
-	strncpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN);
-}
-
-static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s)
-{
-	int order = get_order(sizeof(*s) + s->cmdline_num * TASK_COMM_LEN);
-
-	kfree(s->map_cmdline_to_pid);
-	kmemleak_free(s);
-	free_pages((unsigned long)s, order);
-}
-
-static struct saved_cmdlines_buffer *allocate_cmdlines_buffer(unsigned int val)
-{
-	struct saved_cmdlines_buffer *s;
-	struct page *page;
-	int orig_size, size;
-	int order;
-
-	/* Figure out how much is needed to hold the given number of cmdlines */
-	orig_size = sizeof(*s) + val * TASK_COMM_LEN;
-	order = get_order(orig_size);
-	size = 1 << (order + PAGE_SHIFT);
-	page = alloc_pages(GFP_KERNEL, order);
-	if (!page)
-		return NULL;
-
-	s = page_address(page);
-	kmemleak_alloc(s, size, 1, GFP_KERNEL);
-	memset(s, 0, sizeof(*s));
-
-	/* Round up to actual allocation */
-	val = (size - sizeof(*s)) / TASK_COMM_LEN;
-	s->cmdline_num = val;
-
-	s->map_cmdline_to_pid = kmalloc_array(val,
-					      sizeof(*s->map_cmdline_to_pid),
-					      GFP_KERNEL);
-	if (!s->map_cmdline_to_pid) {
-		free_saved_cmdlines_buffer(s);
-		return NULL;
-	}
-
-	s->cmdline_idx = 0;
-	memset(&s->map_pid_to_cmdline, NO_CMDLINE_MAP,
-	       sizeof(s->map_pid_to_cmdline));
-	memset(s->map_cmdline_to_pid, NO_CMDLINE_MAP,
-	       val * sizeof(*s->map_cmdline_to_pid));
-
-	return s;
-}
-
-static int trace_create_savedcmd(void)
-{
-	savedcmd = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT);
-
-	return savedcmd ? 0 : -ENOMEM;
-}
-
 int is_tracing_stopped(void)
 {
 	return global_trace.stop_count;
@@ -2504,201 +2474,6 @@ void tracing_stop(void)
 	return tracing_stop_tr(&global_trace);
 }
 
-static int trace_save_cmdline(struct task_struct *tsk)
-{
-	unsigned tpid, idx;
-
-	/* treat recording of idle task as a success */
-	if (!tsk->pid)
-		return 1;
-
-	tpid = tsk->pid & (PID_MAX_DEFAULT - 1);
-
-	/*
-	 * It's not the end of the world if we don't get
-	 * the lock, but we also don't want to spin
-	 * nor do we want to disable interrupts,
-	 * so if we miss here, then better luck next time.
-	 *
-	 * This is called within the scheduler and wake up, so interrupts
-	 * had better been disabled and run queue lock been held.
-	 */
-	lockdep_assert_preemption_disabled();
-	if (!arch_spin_trylock(&trace_cmdline_lock))
-		return 0;
-
-	idx = savedcmd->map_pid_to_cmdline[tpid];
-	if (idx == NO_CMDLINE_MAP) {
-		idx = (savedcmd->cmdline_idx + 1) % savedcmd->cmdline_num;
-
-		savedcmd->map_pid_to_cmdline[tpid] = idx;
-		savedcmd->cmdline_idx = idx;
-	}
-
-	savedcmd->map_cmdline_to_pid[idx] = tsk->pid;
-	set_cmdline(idx, tsk->comm);
-
-	arch_spin_unlock(&trace_cmdline_lock);
-
-	return 1;
-}
-
-static void __trace_find_cmdline(int pid, char comm[])
-{
-	unsigned map;
-	int tpid;
-
-	if (!pid) {
-		strcpy(comm, "<idle>");
-		return;
-	}
-
-	if (WARN_ON_ONCE(pid < 0)) {
-		strcpy(comm, "<XXX>");
-		return;
-	}
-
-	tpid = pid & (PID_MAX_DEFAULT - 1);
-	map = savedcmd->map_pid_to_cmdline[tpid];
-	if (map != NO_CMDLINE_MAP) {
-		tpid = savedcmd->map_cmdline_to_pid[map];
-		if (tpid == pid) {
-			strscpy(comm, get_saved_cmdlines(map), TASK_COMM_LEN);
-			return;
-		}
-	}
-	strcpy(comm, "<...>");
-}
-
-void trace_find_cmdline(int pid, char comm[])
-{
-	preempt_disable();
-	arch_spin_lock(&trace_cmdline_lock);
-
-	__trace_find_cmdline(pid, comm);
-
-	arch_spin_unlock(&trace_cmdline_lock);
-	preempt_enable();
-}
-
-static int *trace_find_tgid_ptr(int pid)
-{
-	/*
-	 * Pairs with the smp_store_release in set_tracer_flag() to ensure that
-	 * if we observe a non-NULL tgid_map then we also observe the correct
-	 * tgid_map_max.
-	 */
-	int *map = smp_load_acquire(&tgid_map);
-
-	if (unlikely(!map || pid > tgid_map_max))
-		return NULL;
-
-	return &map[pid];
-}
-
-int trace_find_tgid(int pid)
-{
-	int *ptr = trace_find_tgid_ptr(pid);
-
-	return ptr ? *ptr : 0;
-}
-
-static int trace_save_tgid(struct task_struct *tsk)
-{
-	int *ptr;
-
-	/* treat recording of idle task as a success */
-	if (!tsk->pid)
-		return 1;
-
-	ptr = trace_find_tgid_ptr(tsk->pid);
-	if (!ptr)
-		return 0;
-
-	*ptr = tsk->tgid;
-	return 1;
-}
-
-static bool tracing_record_taskinfo_skip(int flags)
-{
-	if (unlikely(!(flags & (TRACE_RECORD_CMDLINE | TRACE_RECORD_TGID))))
-		return true;
-	if (!__this_cpu_read(trace_taskinfo_save))
-		return true;
-	return false;
-}
-
-/**
- * tracing_record_taskinfo - record the task info of a task
- *
- * @task:  task to record
- * @flags: TRACE_RECORD_CMDLINE for recording comm
- *         TRACE_RECORD_TGID for recording tgid
- */
-void tracing_record_taskinfo(struct task_struct *task, int flags)
-{
-	bool done;
-
-	if (tracing_record_taskinfo_skip(flags))
-		return;
-
-	/*
-	 * Record as much task information as possible. If some fail, continue
-	 * to try to record the others.
-	 */
-	done = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(task);
-	done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(task);
-
-	/* If recording any information failed, retry again soon. */
-	if (!done)
-		return;
-
-	__this_cpu_write(trace_taskinfo_save, false);
-}
-
-/**
- * tracing_record_taskinfo_sched_switch - record task info for sched_switch
- *
- * @prev: previous task during sched_switch
- * @next: next task during sched_switch
- * @flags: TRACE_RECORD_CMDLINE for recording comm
- *         TRACE_RECORD_TGID for recording tgid
- */
-void tracing_record_taskinfo_sched_switch(struct task_struct *prev,
-					  struct task_struct *next, int flags)
-{
-	bool done;
-
-	if (tracing_record_taskinfo_skip(flags))
-		return;
-
-	/*
-	 * Record as much task information as possible. If some fail, continue
-	 * to try to record the others.
-	 */
-	done  = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(prev);
-	done &= !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(next);
-	done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(prev);
-	done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(next);
-
-	/* If recording any information failed, retry again soon. */
-	if (!done)
-		return;
-
-	__this_cpu_write(trace_taskinfo_save, false);
-}
-
-/* Helpers to record a specific task information */
-void tracing_record_cmdline(struct task_struct *task)
-{
-	tracing_record_taskinfo(task, TRACE_RECORD_CMDLINE);
-}
-
-void tracing_record_tgid(struct task_struct *task)
-{
-	tracing_record_taskinfo(task, TRACE_RECORD_TGID);
-}
-
 /*
  * Several functions return TRACE_TYPE_PARTIAL_LINE if the trace_seq
  * overflowed, and TRACE_TYPE_HANDLED otherwise. This helper function
@@ -4389,7 +4164,7 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
 	get_total_entries(buf, &total, &entries);
 
 	seq_printf(m, "# %s latency trace v1.1.5 on %s\n",
-		   name, UTS_RELEASE);
+		   name, init_utsname()->release);
 	seq_puts(m, "# -----------------------------------"
 		 "---------------------------------\n");
 	seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |"
@@ -5457,8 +5232,6 @@ int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set)
 
 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
 {
-	int *map;
-
 	if ((mask == TRACE_ITER_RECORD_TGID) ||
 	    (mask == TRACE_ITER_RECORD_CMD))
 		lockdep_assert_held(&event_mutex);
@@ -5481,20 +5254,8 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
 		trace_event_enable_cmd_record(enabled);
 
 	if (mask == TRACE_ITER_RECORD_TGID) {
-		if (!tgid_map) {
-			tgid_map_max = pid_max;
-			map = kvcalloc(tgid_map_max + 1, sizeof(*tgid_map),
-				       GFP_KERNEL);
 
-			/*
-			 * Pairs with smp_load_acquire() in
-			 * trace_find_tgid_ptr() to ensure that if it observes
-			 * the tgid_map we just allocated then it also observes
-			 * the corresponding tgid_map_max value.
-			 */
-			smp_store_release(&tgid_map, map);
-		}
-		if (!tgid_map) {
+		if (trace_alloc_tgid_map() < 0) {
 			tr->trace_flags &= ~TRACE_ITER_RECORD_TGID;
 			return -ENOMEM;
 		}
@@ -5938,207 +5699,6 @@ static const struct file_operations tracing_readme_fops = {
 	.llseek		= generic_file_llseek,
 };
 
-static void *saved_tgids_next(struct seq_file *m, void *v, loff_t *pos)
-{
-	int pid = ++(*pos);
-
-	return trace_find_tgid_ptr(pid);
-}
-
-static void *saved_tgids_start(struct seq_file *m, loff_t *pos)
-{
-	int pid = *pos;
-
-	return trace_find_tgid_ptr(pid);
-}
-
-static void saved_tgids_stop(struct seq_file *m, void *v)
-{
-}
-
-static int saved_tgids_show(struct seq_file *m, void *v)
-{
-	int *entry = (int *)v;
-	int pid = entry - tgid_map;
-	int tgid = *entry;
-
-	if (tgid == 0)
-		return SEQ_SKIP;
-
-	seq_printf(m, "%d %d\n", pid, tgid);
-	return 0;
-}
-
-static const struct seq_operations tracing_saved_tgids_seq_ops = {
-	.start		= saved_tgids_start,
-	.stop		= saved_tgids_stop,
-	.next		= saved_tgids_next,
-	.show		= saved_tgids_show,
-};
-
-static int tracing_saved_tgids_open(struct inode *inode, struct file *filp)
-{
-	int ret;
-
-	ret = tracing_check_open_get_tr(NULL);
-	if (ret)
-		return ret;
-
-	return seq_open(filp, &tracing_saved_tgids_seq_ops);
-}
-
-
-static const struct file_operations tracing_saved_tgids_fops = {
-	.open		= tracing_saved_tgids_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release,
-};
-
-static void *saved_cmdlines_next(struct seq_file *m, void *v, loff_t *pos)
-{
-	unsigned int *ptr = v;
-
-	if (*pos || m->count)
-		ptr++;
-
-	(*pos)++;
-
-	for (; ptr < &savedcmd->map_cmdline_to_pid[savedcmd->cmdline_num];
-	     ptr++) {
-		if (*ptr == -1 || *ptr == NO_CMDLINE_MAP)
-			continue;
-
-		return ptr;
-	}
-
-	return NULL;
-}
-
-static void *saved_cmdlines_start(struct seq_file *m, loff_t *pos)
-{
-	void *v;
-	loff_t l = 0;
-
-	preempt_disable();
-	arch_spin_lock(&trace_cmdline_lock);
-
-	v = &savedcmd->map_cmdline_to_pid[0];
-	while (l <= *pos) {
-		v = saved_cmdlines_next(m, v, &l);
-		if (!v)
-			return NULL;
-	}
-
-	return v;
-}
-
-static void saved_cmdlines_stop(struct seq_file *m, void *v)
-{
-	arch_spin_unlock(&trace_cmdline_lock);
-	preempt_enable();
-}
-
-static int saved_cmdlines_show(struct seq_file *m, void *v)
-{
-	char buf[TASK_COMM_LEN];
-	unsigned int *pid = v;
-
-	__trace_find_cmdline(*pid, buf);
-	seq_printf(m, "%d %s\n", *pid, buf);
-	return 0;
-}
-
-static const struct seq_operations tracing_saved_cmdlines_seq_ops = {
-	.start		= saved_cmdlines_start,
-	.next		= saved_cmdlines_next,
-	.stop		= saved_cmdlines_stop,
-	.show		= saved_cmdlines_show,
-};
-
-static int tracing_saved_cmdlines_open(struct inode *inode, struct file *filp)
-{
-	int ret;
-
-	ret = tracing_check_open_get_tr(NULL);
-	if (ret)
-		return ret;
-
-	return seq_open(filp, &tracing_saved_cmdlines_seq_ops);
-}
-
-static const struct file_operations tracing_saved_cmdlines_fops = {
-	.open		= tracing_saved_cmdlines_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release,
-};
-
-static ssize_t
-tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf,
-				 size_t cnt, loff_t *ppos)
-{
-	char buf[64];
-	int r;
-
-	preempt_disable();
-	arch_spin_lock(&trace_cmdline_lock);
-	r = scnprintf(buf, sizeof(buf), "%u\n", savedcmd->cmdline_num);
-	arch_spin_unlock(&trace_cmdline_lock);
-	preempt_enable();
-
-	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
-}
-
-static int tracing_resize_saved_cmdlines(unsigned int val)
-{
-	struct saved_cmdlines_buffer *s, *savedcmd_temp;
-
-	s = allocate_cmdlines_buffer(val);
-	if (!s)
-		return -ENOMEM;
-
-	preempt_disable();
-	arch_spin_lock(&trace_cmdline_lock);
-	savedcmd_temp = savedcmd;
-	savedcmd = s;
-	arch_spin_unlock(&trace_cmdline_lock);
-	preempt_enable();
-	free_saved_cmdlines_buffer(savedcmd_temp);
-
-	return 0;
-}
-
-static ssize_t
-tracing_saved_cmdlines_size_write(struct file *filp, const char __user *ubuf,
-				  size_t cnt, loff_t *ppos)
-{
-	unsigned long val;
-	int ret;
-
-	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
-	if (ret)
-		return ret;
-
-	/* must have at least 1 entry or less than PID_MAX_DEFAULT */
-	if (!val || val > PID_MAX_DEFAULT)
-		return -EINVAL;
-
-	ret = tracing_resize_saved_cmdlines((unsigned int)val);
-	if (ret < 0)
-		return ret;
-
-	*ppos += cnt;
-
-	return cnt;
-}
-
-static const struct file_operations tracing_saved_cmdlines_size_fops = {
-	.open		= tracing_open_generic,
-	.read		= tracing_saved_cmdlines_size_read,
-	.write		= tracing_saved_cmdlines_size_write,
-};
-
 #ifdef CONFIG_TRACE_EVAL_MAP_FILE
 static union trace_eval_map_item *
 update_eval_map(union trace_eval_map_item *ptr)
@@ -6615,11 +6175,12 @@ int tracing_set_tracer(struct trace_array *tr, const char *buf)
 		 */
 		synchronize_rcu();
 		free_snapshot(tr);
+		tracing_disarm_snapshot(tr);
 	}
 
-	if (t->use_max_tr && !tr->allocated_snapshot) {
-		ret = tracing_alloc_snapshot_instance(tr);
-		if (ret < 0)
+	if (!had_max_tr && t->use_max_tr) {
+		ret = tracing_arm_snapshot_locked(tr);
+		if (ret)
 			goto out;
 	}
 #else
@@ -6628,8 +6189,13 @@ int tracing_set_tracer(struct trace_array *tr, const char *buf)
 
 	if (t->init) {
 		ret = tracer_init(t, tr);
-		if (ret)
+		if (ret) {
+#ifdef CONFIG_TRACER_MAX_TRACE
+			if (t->use_max_tr)
+				tracing_disarm_snapshot(tr);
+#endif
 			goto out;
+		}
 	}
 
 	tr->current_trace = t;
@@ -7731,10 +7297,11 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
 		if (tr->allocated_snapshot)
 			ret = resize_buffer_duplicate_size(&tr->max_buffer,
 					&tr->array_buffer, iter->cpu_file);
-		else
-			ret = tracing_alloc_snapshot_instance(tr);
-		if (ret < 0)
+
+		ret = tracing_arm_snapshot_locked(tr);
+		if (ret)
 			break;
+
 		/* Now, we're going to swap */
 		if (iter->cpu_file == RING_BUFFER_ALL_CPUS) {
 			local_irq_disable();
@@ -7744,6 +7311,7 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
 			smp_call_function_single(iter->cpu_file, tracing_swap_cpu_buffer,
 						 (void *)tr, 1);
 		}
+		tracing_disarm_snapshot(tr);
 		break;
 	default:
 		if (tr->allocated_snapshot) {
@@ -8875,8 +8443,13 @@ ftrace_trace_snapshot_callback(struct trace_array *tr, struct ftrace_hash *hash,
 
 	ops = param ? &snapshot_count_probe_ops :  &snapshot_probe_ops;
 
-	if (glob[0] == '!')
-		return unregister_ftrace_function_probe_func(glob+1, tr, ops);
+	if (glob[0] == '!') {
+		ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
+		if (!ret)
+			tracing_disarm_snapshot(tr);
+
+		return ret;
+	}
 
 	if (!param)
 		goto out_reg;
@@ -8895,12 +8468,13 @@ ftrace_trace_snapshot_callback(struct trace_array *tr, struct ftrace_hash *hash,
 		return ret;
 
  out_reg:
-	ret = tracing_alloc_snapshot_instance(tr);
+	ret = tracing_arm_snapshot(tr);
 	if (ret < 0)
 		goto out;
 
 	ret = register_ftrace_function_probe(glob, tr, ops, count);
-
+	if (ret < 0)
+		tracing_disarm_snapshot(tr);
  out:
 	return ret < 0 ? ret : 0;
 }
@@ -9707,7 +9281,9 @@ trace_array_create_systems(const char *name, const char *systems)
 	raw_spin_lock_init(&tr->start_lock);
 
 	tr->max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
-
+#ifdef CONFIG_TRACER_MAX_TRACE
+	spin_lock_init(&tr->snapshot_trigger_lock);
+#endif
 	tr->current_trace = &nop_trace;
 
 	INIT_LIST_HEAD(&tr->systems);
@@ -10272,14 +9848,14 @@ static struct notifier_block trace_die_notifier = {
 static int trace_die_panic_handler(struct notifier_block *self,
 				unsigned long ev, void *unused)
 {
-	if (!ftrace_dump_on_oops)
+	if (!ftrace_dump_on_oops_enabled())
 		return NOTIFY_DONE;
 
 	/* The die notifier requires DIE_OOPS to trigger */
 	if (self == &trace_die_notifier && ev != DIE_OOPS)
 		return NOTIFY_DONE;
 
-	ftrace_dump(ftrace_dump_on_oops);
+	ftrace_dump(DUMP_PARAM);
 
 	return NOTIFY_DONE;
 }
@@ -10320,12 +9896,12 @@ trace_printk_seq(struct trace_seq *s)
 	trace_seq_init(s);
 }
 
-void trace_init_global_iter(struct trace_iterator *iter)
+static void trace_init_iter(struct trace_iterator *iter, struct trace_array *tr)
 {
-	iter->tr = &global_trace;
+	iter->tr = tr;
 	iter->trace = iter->tr->current_trace;
 	iter->cpu_file = RING_BUFFER_ALL_CPUS;
-	iter->array_buffer = &global_trace.array_buffer;
+	iter->array_buffer = &tr->array_buffer;
 
 	if (iter->trace && iter->trace->open)
 		iter->trace->open(iter);
@@ -10345,22 +9921,19 @@ void trace_init_global_iter(struct trace_iterator *iter)
 	iter->fmt_size = STATIC_FMT_BUF_SIZE;
 }
 
-void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
+void trace_init_global_iter(struct trace_iterator *iter)
+{
+	trace_init_iter(iter, &global_trace);
+}
+
+static void ftrace_dump_one(struct trace_array *tr, enum ftrace_dump_mode dump_mode)
 {
 	/* use static because iter can be a bit big for the stack */
 	static struct trace_iterator iter;
-	static atomic_t dump_running;
-	struct trace_array *tr = &global_trace;
 	unsigned int old_userobj;
 	unsigned long flags;
 	int cnt = 0, cpu;
 
-	/* Only allow one dump user at a time. */
-	if (atomic_inc_return(&dump_running) != 1) {
-		atomic_dec(&dump_running);
-		return;
-	}
-
 	/*
 	 * Always turn off tracing when we dump.
 	 * We don't need to show trace output of what happens
@@ -10369,12 +9942,12 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
 	 * If the user does a sysrq-z, then they can re-enable
 	 * tracing with echo 1 > tracing_on.
 	 */
-	tracing_off();
+	tracer_tracing_off(tr);
 
 	local_irq_save(flags);
 
 	/* Simulate the iterator */
-	trace_init_global_iter(&iter);
+	trace_init_iter(&iter, tr);
 
 	for_each_tracing_cpu(cpu) {
 		atomic_inc(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled);
@@ -10385,21 +9958,15 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
 	/* don't look at user memory in panic mode */
 	tr->trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
 
-	switch (oops_dump_mode) {
-	case DUMP_ALL:
-		iter.cpu_file = RING_BUFFER_ALL_CPUS;
-		break;
-	case DUMP_ORIG:
+	if (dump_mode == DUMP_ORIG)
 		iter.cpu_file = raw_smp_processor_id();
-		break;
-	case DUMP_NONE:
-		goto out_enable;
-	default:
-		printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n");
+	else
 		iter.cpu_file = RING_BUFFER_ALL_CPUS;
-	}
 
-	printk(KERN_TRACE "Dumping ftrace buffer:\n");
+	if (tr == &global_trace)
+		printk(KERN_TRACE "Dumping ftrace buffer:\n");
+	else
+		printk(KERN_TRACE "Dumping ftrace instance %s buffer:\n", tr->name);
 
 	/* Did function tracer already get disabled? */
 	if (ftrace_is_dead()) {
@@ -10441,15 +10008,84 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
 	else
 		printk(KERN_TRACE "---------------------------------\n");
 
- out_enable:
 	tr->trace_flags |= old_userobj;
 
 	for_each_tracing_cpu(cpu) {
 		atomic_dec(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled);
 	}
-	atomic_dec(&dump_running);
 	local_irq_restore(flags);
 }
+
+static void ftrace_dump_by_param(void)
+{
+	bool first_param = true;
+	char dump_param[MAX_TRACER_SIZE];
+	char *buf, *token, *inst_name;
+	struct trace_array *tr;
+
+	strscpy(dump_param, ftrace_dump_on_oops, MAX_TRACER_SIZE);
+	buf = dump_param;
+
+	while ((token = strsep(&buf, ",")) != NULL) {
+		if (first_param) {
+			first_param = false;
+			if (!strcmp("0", token))
+				continue;
+			else if (!strcmp("1", token)) {
+				ftrace_dump_one(&global_trace, DUMP_ALL);
+				continue;
+			}
+			else if (!strcmp("2", token) ||
+			  !strcmp("orig_cpu", token)) {
+				ftrace_dump_one(&global_trace, DUMP_ORIG);
+				continue;
+			}
+		}
+
+		inst_name = strsep(&token, "=");
+		tr = trace_array_find(inst_name);
+		if (!tr) {
+			printk(KERN_TRACE "Instance %s not found\n", inst_name);
+			continue;
+		}
+
+		if (token && (!strcmp("2", token) ||
+			  !strcmp("orig_cpu", token)))
+			ftrace_dump_one(tr, DUMP_ORIG);
+		else
+			ftrace_dump_one(tr, DUMP_ALL);
+	}
+}
+
+void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
+{
+	static atomic_t dump_running;
+
+	/* Only allow one dump user at a time. */
+	if (atomic_inc_return(&dump_running) != 1) {
+		atomic_dec(&dump_running);
+		return;
+	}
+
+	switch (oops_dump_mode) {
+	case DUMP_ALL:
+		ftrace_dump_one(&global_trace, DUMP_ALL);
+		break;
+	case DUMP_ORIG:
+		ftrace_dump_one(&global_trace, DUMP_ORIG);
+		break;
+	case DUMP_PARAM:
+		ftrace_dump_by_param();
+		break;
+	case DUMP_NONE:
+		break;
+	default:
+		printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n");
+		ftrace_dump_one(&global_trace, DUMP_ALL);
+	}
+
+	atomic_dec(&dump_running);
+}
 EXPORT_SYMBOL_GPL(ftrace_dump);
 
 #define WRITE_BUFSIZE  4096
@@ -10677,7 +10313,9 @@ __init static int tracer_alloc_buffers(void)
 	global_trace.current_trace = &nop_trace;
 
 	global_trace.max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
-
+#ifdef CONFIG_TRACER_MAX_TRACE
+	spin_lock_init(&global_trace.snapshot_trigger_lock);
+#endif
 	ftrace_init_global_array_ops(&global_trace);
 
 	init_trace_flags_index(&global_trace);
@@ -10714,7 +10352,7 @@ __init static int tracer_alloc_buffers(void)
 out_free_pipe_cpumask:
 	free_cpumask_var(global_trace.pipe_cpumask);
 out_free_savedcmd:
-	free_saved_cmdlines_buffer(savedcmd);
+	trace_free_saved_cmdlines_buffer();
 out_free_temp_buffer:
 	ring_buffer_free(temp_buffer);
 out_rm_hp_state: