diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 3fff4adfd431..68cbb8e10aea 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -177,9 +177,8 @@ struct trace_options {
 };
 
 struct trace_pid_list {
-	unsigned int			nr_pids;
-	int				order;
-	pid_t				*pids;
+	int				pid_max;
+	unsigned long			*pids;
 };
 
 /*
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 598a18675a6b..45f7cc72bf25 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -15,7 +15,7 @@
 #include <linux/kthread.h>
 #include <linux/tracefs.h>
 #include <linux/uaccess.h>
-#include <linux/bsearch.h>
+#include <linux/vmalloc.h>
 #include <linux/module.h>
 #include <linux/ctype.h>
 #include <linux/sort.h>
@@ -471,23 +471,13 @@ static void ftrace_clear_events(struct trace_array *tr)
 	mutex_unlock(&event_mutex);
 }
 
-static int cmp_pid(const void *key, const void *elt)
-{
-	const pid_t *search_pid = key;
-	const pid_t *pid = elt;
-
-	if (*search_pid == *pid)
-		return 0;
-	if (*search_pid < *pid)
-		return -1;
-	return 1;
-}
+/* Shouldn't this be in a header? */
+extern int pid_max;
 
 static bool
 ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task)
 {
-	pid_t search_pid;
-	pid_t *pid;
+	pid_t pid;
 
 	/*
 	 * Return false, because if filtered_pids does not exist,
@@ -496,15 +486,16 @@ ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task)
 	if (!filtered_pids)
 		return false;
 
-	search_pid = task->pid;
+	pid = task->pid;
 
-	pid = bsearch(&search_pid, filtered_pids->pids,
-		      filtered_pids->nr_pids, sizeof(pid_t),
-		      cmp_pid);
-	if (!pid)
+	/*
+	 * If pid_max changed after filtered_pids was created, we
+	 * by default ignore all pids greater than the previous pid_max.
+	 */
+	if (task->pid >= filtered_pids->pid_max)
 		return true;
 
-	return false;
+	return !test_bit(task->pid, filtered_pids->pids);
 }
 
 static void
@@ -602,7 +593,7 @@ static void __ftrace_clear_event_pids(struct trace_array *tr)
 	/* Wait till all users are no longer using pid filtering */
 	synchronize_sched();
 
-	free_pages((unsigned long)pid_list->pids, pid_list->order);
+	vfree(pid_list->pids);
 	kfree(pid_list);
 }
 
@@ -946,11 +937,32 @@ static void t_stop(struct seq_file *m, void *p)
 	mutex_unlock(&event_mutex);
 }
 
+static void *
+p_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	struct trace_array *tr = m->private;
+	struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
+	unsigned long pid = (unsigned long)v;
+
+	(*pos)++;
+
+	/* pid already is +1 of the actual prevous bit */
+	pid = find_next_bit(pid_list->pids, pid_list->pid_max, pid);
+
+	/* Return pid + 1 to allow zero to be represented */
+	if (pid < pid_list->pid_max)
+		return (void *)(pid + 1);
+
+	return NULL;
+}
+
 static void *p_start(struct seq_file *m, loff_t *pos)
 	__acquires(RCU)
 {
 	struct trace_pid_list *pid_list;
 	struct trace_array *tr = m->private;
+	unsigned long pid;
+	loff_t l = 0;
 
 	/*
 	 * Grab the mutex, to keep calls to p_next() having the same
@@ -963,10 +975,18 @@ static void *p_start(struct seq_file *m, loff_t *pos)
 
 	pid_list = rcu_dereference_sched(tr->filtered_pids);
 
-	if (!pid_list || *pos >= pid_list->nr_pids)
+	if (!pid_list)
 		return NULL;
 
-	return (void *)&pid_list->pids[*pos];
+	pid = find_first_bit(pid_list->pids, pid_list->pid_max);
+	if (pid >= pid_list->pid_max)
+		return NULL;
+
+	/* Return pid + 1 so that zero can be the exit value */
+	for (pid++; pid && l < *pos;
+	     pid = (unsigned long)p_next(m, (void *)pid, &l))
+		;
+	return (void *)pid;
 }
 
 static void p_stop(struct seq_file *m, void *p)
@@ -976,25 +996,11 @@ static void p_stop(struct seq_file *m, void *p)
 	mutex_unlock(&event_mutex);
 }
 
-static void *
-p_next(struct seq_file *m, void *v, loff_t *pos)
-{
-	struct trace_array *tr = m->private;
-	struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
-
-	(*pos)++;
-
-	if (*pos >= pid_list->nr_pids)
-		return NULL;
-
-	return (void *)&pid_list->pids[*pos];
-}
-
 static int p_show(struct seq_file *m, void *v)
 {
-	pid_t *pid = v;
+	unsigned long pid = (unsigned long)v - 1;
 
-	seq_printf(m, "%d\n", *pid);
+	seq_printf(m, "%lu\n", pid);
 	return 0;
 }
 
@@ -1543,11 +1549,6 @@ show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 	return r;
 }
 
-static int max_pids(struct trace_pid_list *pid_list)
-{
-	return (PAGE_SIZE << pid_list->order) / sizeof(pid_t);
-}
-
 static void ignore_task_cpu(void *data)
 {
 	struct trace_array *tr = data;
@@ -1571,7 +1572,7 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
 	struct seq_file *m = filp->private_data;
 	struct trace_array *tr = m->private;
 	struct trace_pid_list *filtered_pids = NULL;
-	struct trace_pid_list *pid_list = NULL;
+	struct trace_pid_list *pid_list;
 	struct trace_event_file *file;
 	struct trace_parser parser;
 	unsigned long val;
@@ -1579,7 +1580,7 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
 	ssize_t read = 0;
 	ssize_t ret = 0;
 	pid_t pid;
-	int i;
+	int nr_pids = 0;
 
 	if (!cnt)
 		return 0;
@@ -1592,10 +1593,43 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
 		return -ENOMEM;
 
 	mutex_lock(&event_mutex);
+	filtered_pids = rcu_dereference_protected(tr->filtered_pids,
+					     lockdep_is_held(&event_mutex));
+
 	/*
-	 * Load as many pids into the array before doing a
-	 * swap from the tr->filtered_pids to the new list.
+	 * Always recreate a new array. The write is an all or nothing
+	 * operation. Always create a new array when adding new pids by
+	 * the user. If the operation fails, then the current list is
+	 * not modified.
 	 */
+	pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
+	if (!pid_list) {
+		read = -ENOMEM;
+		goto out;
+	}
+	pid_list->pid_max = READ_ONCE(pid_max);
+	/* Only truncating will shrink pid_max */
+	if (filtered_pids && filtered_pids->pid_max > pid_list->pid_max)
+		pid_list->pid_max = filtered_pids->pid_max;
+	pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3);
+	if (!pid_list->pids) {
+		kfree(pid_list);
+		read = -ENOMEM;
+		goto out;
+	}
+	if (filtered_pids) {
+		/* copy the current bits to the new max */
+		pid = find_first_bit(filtered_pids->pids,
+				     filtered_pids->pid_max);
+		while (pid < filtered_pids->pid_max) {
+			set_bit(pid, pid_list->pids);
+			pid = find_next_bit(filtered_pids->pids,
+					    filtered_pids->pid_max,
+					    pid + 1);
+			nr_pids++;
+		}
+	}
+
 	while (cnt > 0) {
 
 		this_pos = 0;
@@ -1613,92 +1647,35 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
 		ret = -EINVAL;
 		if (kstrtoul(parser.buffer, 0, &val))
 			break;
-		if (val > INT_MAX)
+		if (val >= pid_list->pid_max)
 			break;
 
 		pid = (pid_t)val;
 
-		ret = -ENOMEM;
-		if (!pid_list) {
-			pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
-			if (!pid_list)
-				break;
+		set_bit(pid, pid_list->pids);
+		nr_pids++;
 
-			filtered_pids = rcu_dereference_protected(tr->filtered_pids,
-							lockdep_is_held(&event_mutex));
-			if (filtered_pids)
-				pid_list->order = filtered_pids->order;
-			else
-				pid_list->order = 0;
-
-			pid_list->pids = (void *)__get_free_pages(GFP_KERNEL,
-								  pid_list->order);
-			if (!pid_list->pids)
-				break;
-
-			if (filtered_pids) {
-				pid_list->nr_pids = filtered_pids->nr_pids;
-				memcpy(pid_list->pids, filtered_pids->pids,
-				       pid_list->nr_pids * sizeof(pid_t));
-			} else
-				pid_list->nr_pids = 0;
-		}
-
-		if (pid_list->nr_pids >= max_pids(pid_list)) {
-			pid_t *pid_page;
-
-			pid_page = (void *)__get_free_pages(GFP_KERNEL,
-							    pid_list->order + 1);
-			if (!pid_page)
-				break;
-			memcpy(pid_page, pid_list->pids,
-			       pid_list->nr_pids * sizeof(pid_t));
-			free_pages((unsigned long)pid_list->pids, pid_list->order);
-
-			pid_list->order++;
-			pid_list->pids = pid_page;
-		}
-
-		pid_list->pids[pid_list->nr_pids++] = pid;
 		trace_parser_clear(&parser);
 		ret = 0;
 	}
 	trace_parser_put(&parser);
 
 	if (ret < 0) {
-		if (pid_list)
-			free_pages((unsigned long)pid_list->pids, pid_list->order);
+		vfree(pid_list->pids);
 		kfree(pid_list);
-		mutex_unlock(&event_mutex);
-		return ret;
+		read = ret;
+		goto out;
 	}
 
-	if (!pid_list) {
-		mutex_unlock(&event_mutex);
-		return ret;
+	if (!nr_pids) {
+		/* Cleared the list of pids */
+		vfree(pid_list->pids);
+		kfree(pid_list);
+		read = ret;
+		if (!filtered_pids)
+			goto out;
+		pid_list = NULL;
 	}
-
-	sort(pid_list->pids, pid_list->nr_pids, sizeof(pid_t), cmp_pid, NULL);
-
-	/* Remove duplicates */
-	for (i = 1; i < pid_list->nr_pids; i++) {
-		int start = i;
-
-		while (i < pid_list->nr_pids &&
-		       pid_list->pids[i - 1] == pid_list->pids[i])
-			i++;
-
-		if (start != i) {
-			if (i < pid_list->nr_pids) {
-				memmove(&pid_list->pids[start], &pid_list->pids[i],
-					(pid_list->nr_pids - i) * sizeof(pid_t));
-				pid_list->nr_pids -= i - start;
-				i = start;
-			} else
-				pid_list->nr_pids = start;
-		}
-	}
-
 	rcu_assign_pointer(tr->filtered_pids, pid_list);
 
 	list_for_each_entry(file, &tr->events, list) {
@@ -1708,7 +1685,7 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
 	if (filtered_pids) {
 		synchronize_sched();
 
-		free_pages((unsigned long)filtered_pids->pids, filtered_pids->order);
+		vfree(filtered_pids->pids);
 		kfree(filtered_pids);
 	} else {
 		/*
@@ -1745,10 +1722,12 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
 	 */
 	on_each_cpu(ignore_task_cpu, tr, 1);
 
+ out:
 	mutex_unlock(&event_mutex);
 
 	ret = read;
-	*ppos += read;
+	if (read > 0)
+		*ppos += read;
 
 	return ret;
 }