Merging upstream version 6.7.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

21 files changed, 462 insertions, 327 deletions

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 1d76f3b01..652c40a14 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -120,6 +120,9 @@ unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
 		 * and don't send kprobe event into ring-buffer,
 		 * so return zero here
 		 */
+		rcu_read_lock();
+		bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array));
+		rcu_read_unlock();
 		ret = 0;
 		goto out;
 	}
@@ -1252,9 +1255,7 @@ static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
 };
 
 #ifdef CONFIG_KEYS
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "kfuncs which will be used in BPF programs");
+__bpf_kfunc_start_defs();
 
 /**
  * bpf_lookup_user_key - lookup a key by its serial
@@ -1404,7 +1405,7 @@ __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
 }
 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
 
-__diag_pop();
+__bpf_kfunc_end_defs();
 
 BTF_SET8_START(key_sig_kfunc_set)
 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
@@ -2387,7 +2388,8 @@ int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
 
 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
 			    u32 *fd_type, const char **buf,
-			    u64 *probe_offset, u64 *probe_addr)
+			    u64 *probe_offset, u64 *probe_addr,
+			    unsigned long *missed)
 {
 	bool is_tracepoint, is_syscall_tp;
 	struct bpf_prog *prog;
@@ -2422,7 +2424,7 @@ int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
 #ifdef CONFIG_KPROBE_EVENTS
 		if (flags & TRACE_EVENT_FL_KPROBE)
 			err = bpf_get_kprobe_info(event, fd_type, buf,
-						  probe_offset, probe_addr,
+						  probe_offset, probe_addr, missed,
 						  event->attr.type == PERF_TYPE_TRACEPOINT);
 #endif
 #ifdef CONFIG_UPROBE_EVENTS
@@ -2617,6 +2619,7 @@ static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
 	info->kprobe_multi.count = kmulti_link->cnt;
 	info->kprobe_multi.flags = kmulti_link->flags;
+	info->kprobe_multi.missed = kmulti_link->fp.nmissed;
 
 	if (!uaddrs)
 		return 0;
@@ -2713,6 +2716,7 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
 	int err;
 
 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
+		bpf_prog_inc_misses_counter(link->link.prog);
 		err = 0;
 		goto out;
 	}
diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
index 881f90f0c..6cd2a4e3a 100644
--- a/kernel/trace/fprobe.c
+++ b/kernel/trace/fprobe.c
@@ -187,7 +187,7 @@ static void fprobe_init(struct fprobe *fp)
 
 static int fprobe_init_rethook(struct fprobe *fp, int num)
 {
-	int i, size;
+	int size;
 
 	if (num <= 0)
 		return -EINVAL;
@@ -205,26 +205,18 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
 	if (size <= 0)
 		return -EINVAL;
 
-	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler);
-	if (!fp->rethook)
-		return -ENOMEM;
-	for (i = 0; i < size; i++) {
-		struct fprobe_rethook_node *node;
-
-		node = kzalloc(sizeof(*node) + fp->entry_data_size, GFP_KERNEL);
-		if (!node) {
-			rethook_free(fp->rethook);
-			fp->rethook = NULL;
-			return -ENOMEM;
-		}
-		rethook_add_node(fp->rethook, &node->node);
-	}
+	/* Initialize rethook */
+	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler,
+				sizeof(struct fprobe_rethook_node), size);
+	if (IS_ERR(fp->rethook))
+		return PTR_ERR(fp->rethook);
+
 	return 0;
 }
 
 static void fprobe_fail_cleanup(struct fprobe *fp)
 {
-	if (fp->rethook) {
+	if (!IS_ERR_OR_NULL(fp->rethook)) {
 		/* Don't need to cleanup rethook->handler because this is not used. */
 		rethook_free(fp->rethook);
 		fp->rethook = NULL;
@@ -379,14 +371,14 @@ int unregister_fprobe(struct fprobe *fp)
 	if (!fprobe_is_registered(fp))
 		return -EINVAL;
 
-	if (fp->rethook)
+	if (!IS_ERR_OR_NULL(fp->rethook))
 		rethook_stop(fp->rethook);
 
 	ret = unregister_ftrace_function(&fp->ops);
 	if (ret < 0)
 		return ret;
 
-	if (fp->rethook)
+	if (!IS_ERR_OR_NULL(fp->rethook))
 		rethook_free(fp->rethook);
 
 	ftrace_free_filter(&fp->ops);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index b01ae7d36..83ba342ae 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5325,7 +5325,17 @@ static LIST_HEAD(ftrace_direct_funcs);
 
 static int register_ftrace_function_nolock(struct ftrace_ops *ops);
 
+/*
+ * If there are multiple ftrace_ops, use SAVE_REGS by default, so that direct
+ * call will be jumped from ftrace_regs_caller. Only if the architecture does
+ * not support ftrace_regs_caller but direct_call, use SAVE_ARGS so that it
+ * jumps from ftrace_caller for multiple ftrace_ops.
+ */
+#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS
 #define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_ARGS)
+#else
+#define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS)
+#endif
 
 static int check_direct_multi(struct ftrace_ops *ops)
 {
diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c
index 3cebcbaf3..fa03094e9 100644
--- a/kernel/trace/rethook.c
+++ b/kernel/trace/rethook.c
@@ -8,7 +8,6 @@
 #include <linux/preempt.h>
 #include <linux/rethook.h>
 #include <linux/slab.h>
-#include <linux/sort.h>
 
 /* Return hook list (shadow stack by list) */
 
@@ -36,21 +35,7 @@ void rethook_flush_task(struct task_struct *tk)
 static void rethook_free_rcu(struct rcu_head *head)
 {
 	struct rethook *rh = container_of(head, struct rethook, rcu);
-	struct rethook_node *rhn;
-	struct freelist_node *node;
-	int count = 1;
-
-	node = rh->pool.head;
-	while (node) {
-		rhn = container_of(node, struct rethook_node, freelist);
-		node = node->next;
-		kfree(rhn);
-		count++;
-	}
-
-	/* The rh->ref is the number of pooled node + 1 */
-	if (refcount_sub_and_test(count, &rh->ref))
-		kfree(rh);
+	objpool_fini(&rh->pool);
 }
 
 /**
@@ -83,6 +68,20 @@ void rethook_free(struct rethook *rh)
 	call_rcu(&rh->rcu, rethook_free_rcu);
 }
 
+static int rethook_init_node(void *nod, void *context)
+{
+	struct rethook_node *node = nod;
+
+	node->rethook = context;
+	return 0;
+}
+
+static int rethook_fini_pool(struct objpool_head *head, void *context)
+{
+	kfree(context);
+	return 0;
+}
+
 static inline rethook_handler_t rethook_get_handler(struct rethook *rh)
 {
 	return (rethook_handler_t)rcu_dereference_check(rh->handler,
@@ -92,51 +91,45 @@ static inline rethook_handler_t rethook_get_handler(struct rethook *rh)
 /**
  * rethook_alloc() - Allocate struct rethook.
  * @data: a data to pass the @handler when hooking the return.
- * @handler: the return hook callback function.
+ * @handler: the return hook callback function, must NOT be NULL
+ * @size: node size: rethook node and additional data
+ * @num: number of rethook nodes to be preallocated
  *
  * Allocate and initialize a new rethook with @data and @handler.
- * Return NULL if memory allocation fails or @handler is NULL.
+ * Return pointer of new rethook, or error codes for failures.
+ *
  * Note that @handler == NULL means this rethook is going to be freed.
  */
-struct rethook *rethook_alloc(void *data, rethook_handler_t handler)
+struct rethook *rethook_alloc(void *data, rethook_handler_t handler,
+			      int size, int num)
 {
-	struct rethook *rh = kzalloc(sizeof(struct rethook), GFP_KERNEL);
+	struct rethook *rh;
 
-	if (!rh || !handler) {
-		kfree(rh);
-		return NULL;
-	}
+	if (!handler || num <= 0 || size < sizeof(struct rethook_node))
+		return ERR_PTR(-EINVAL);
+
+	rh = kzalloc(sizeof(struct rethook), GFP_KERNEL);
+	if (!rh)
+		return ERR_PTR(-ENOMEM);
 
 	rh->data = data;
 	rcu_assign_pointer(rh->handler, handler);
-	rh->pool.head = NULL;
-	refcount_set(&rh->ref, 1);
 
+	/* initialize the objpool for rethook nodes */
+	if (objpool_init(&rh->pool, num, size, GFP_KERNEL, rh,
+			 rethook_init_node, rethook_fini_pool)) {
+		kfree(rh);
+		return ERR_PTR(-ENOMEM);
+	}
 	return rh;
 }
 
-/**
- * rethook_add_node() - Add a new node to the rethook.
- * @rh: the struct rethook.
- * @node: the struct rethook_node to be added.
- *
- * Add @node to @rh. User must allocate @node (as a part of user's
- * data structure.) The @node fields are initialized in this function.
- */
-void rethook_add_node(struct rethook *rh, struct rethook_node *node)
-{
-	node->rethook = rh;
-	freelist_add(&node->freelist, &rh->pool);
-	refcount_inc(&rh->ref);
-}
-
 static void free_rethook_node_rcu(struct rcu_head *head)
 {
 	struct rethook_node *node = container_of(head, struct rethook_node, rcu);
+	struct rethook *rh = node->rethook;
 
-	if (refcount_dec_and_test(&node->rethook->ref))
-		kfree(node->rethook);
-	kfree(node);
+	objpool_drop(node, &rh->pool);
 }
 
 /**
@@ -152,7 +145,7 @@ void rethook_recycle(struct rethook_node *node)
 
 	handler = rethook_get_handler(node->rethook);
 	if (likely(handler))
-		freelist_add(&node->freelist, &node->rethook->pool);
+		objpool_push(node, &node->rethook->pool);
 	else
 		call_rcu(&node->rcu, free_rethook_node_rcu);
 }
@@ -168,7 +161,6 @@ NOKPROBE_SYMBOL(rethook_recycle);
 struct rethook_node *rethook_try_get(struct rethook *rh)
 {
 	rethook_handler_t handler = rethook_get_handler(rh);
-	struct freelist_node *fn;
 
 	/* Check whether @rh is going to be freed. */
 	if (unlikely(!handler))
@@ -183,11 +175,7 @@ struct rethook_node *rethook_try_get(struct rethook *rh)
 	if (unlikely(!rcu_is_watching()))
 		return NULL;
 
-	fn = freelist_try_get(&rh->pool);
-	if (!fn)
-		return NULL;
-
-	return container_of(fn, struct rethook_node, freelist);
+	return (struct rethook_node *)objpool_pop(&rh->pool);
 }
 NOKPROBE_SYMBOL(rethook_try_get);
 
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index f232cf56f..6fa67c297 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1091,7 +1091,7 @@ __poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu,
 		full = 0;
 	} else {
 		if (!cpumask_test_cpu(cpu, buffer->cpumask))
-			return -EINVAL;
+			return EPOLLERR;
 
 		cpu_buffer = buffer->buffers[cpu];
 		work = &cpu_buffer->irq_work;
@@ -2021,7 +2021,7 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer)
 	retries = 10;
 	success = false;
 	while (retries--) {
-		struct list_head *head_page, *prev_page, *r;
+		struct list_head *head_page, *prev_page;
 		struct list_head *last_page, *first_page;
 		struct list_head *head_page_with_bit;
 		struct buffer_page *hpage = rb_set_head_page(cpu_buffer);
@@ -2040,9 +2040,9 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer)
 		last_page->next = head_page_with_bit;
 		first_page->prev = prev_page;
 
-		r = cmpxchg(&prev_page->next, head_page_with_bit, first_page);
-
-		if (r == head_page_with_bit) {
+		/* caution: head_page_with_bit gets updated on cmpxchg failure */
+		if (try_cmpxchg(&prev_page->next,
+				&head_page_with_bit, first_page)) {
 			/*
 			 * yay, we replaced the page pointer to our new list,
 			 * now, we just have to update to head page's prev
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index fc00356a5..3fdc57450 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -39,6 +39,7 @@
 #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>
@@ -54,12 +55,6 @@
 #include "trace.h"
 #include "trace_output.h"
 
-/*
- * On boot up, the ring buffer is set to the minimum size, so that
- * we do not waste memory on systems that are not using tracing.
- */
-bool ring_buffer_expanded;
-
 #ifdef CONFIG_FTRACE_STARTUP_TEST
 /*
  * We need to change this state when a selftest is running.
@@ -202,7 +197,7 @@ static int __init set_cmdline_ftrace(char *str)
 	strscpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
 	default_bootup_tracer = bootup_tracer_buf;
 	/* We are using ftrace early, expand it */
-	ring_buffer_expanded = true;
+	trace_set_ring_buffer_expanded(NULL);
 	return 1;
 }
 __setup("ftrace=", set_cmdline_ftrace);
@@ -247,7 +242,7 @@ static int __init boot_alloc_snapshot(char *str)
 	} else {
 		allocate_snapshot = true;
 		/* We also need the main ring buffer expanded */
-		ring_buffer_expanded = true;
+		trace_set_ring_buffer_expanded(NULL);
 	}
 	return 1;
 }
@@ -490,6 +485,13 @@ static struct trace_array global_trace = {
 	.trace_flags = TRACE_DEFAULT_FLAGS,
 };
 
+void trace_set_ring_buffer_expanded(struct trace_array *tr)
+{
+	if (!tr)
+		tr = &global_trace;
+	tr->ring_buffer_expanded = true;
+}
+
 LIST_HEAD(ftrace_trace_arrays);
 
 int trace_array_get(struct trace_array *this_tr)
@@ -1730,15 +1732,15 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
 {
 	int len;
 
-	if (trace_seq_used(s) <= s->seq.readpos)
+	if (trace_seq_used(s) <= s->readpos)
 		return -EBUSY;
 
-	len = trace_seq_used(s) - s->seq.readpos;
+	len = trace_seq_used(s) - s->readpos;
 	if (cnt > len)
 		cnt = len;
-	memcpy(buf, s->buffer + s->seq.readpos, cnt);
+	memcpy(buf, s->buffer + s->readpos, cnt);
 
-	s->seq.readpos += cnt;
+	s->readpos += cnt;
 	return cnt;
 }
 
@@ -2026,7 +2028,7 @@ static int run_tracer_selftest(struct tracer *type)
 #ifdef CONFIG_TRACER_MAX_TRACE
 	if (type->use_max_tr) {
 		/* If we expanded the buffers, make sure the max is expanded too */
-		if (ring_buffer_expanded)
+		if (tr->ring_buffer_expanded)
 			ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size,
 					   RING_BUFFER_ALL_CPUS);
 		tr->allocated_snapshot = true;
@@ -2052,7 +2054,7 @@ static int run_tracer_selftest(struct tracer *type)
 		tr->allocated_snapshot = false;
 
 		/* Shrink the max buffer again */
-		if (ring_buffer_expanded)
+		if (tr->ring_buffer_expanded)
 			ring_buffer_resize(tr->max_buffer.buffer, 1,
 					   RING_BUFFER_ALL_CPUS);
 	}
@@ -2311,7 +2313,7 @@ struct saved_cmdlines_buffer {
 	unsigned *map_cmdline_to_pid;
 	unsigned cmdline_num;
 	int cmdline_idx;
-	char *saved_cmdlines;
+	char saved_cmdlines[];
 };
 static struct saved_cmdlines_buffer *savedcmd;
 
@@ -2325,47 +2327,60 @@ static inline void set_cmdline(int idx, const char *cmdline)
 	strncpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN);
 }
 
-static int allocate_cmdlines_buffer(unsigned int val,
-				    struct saved_cmdlines_buffer *s)
+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)
-		return -ENOMEM;
-
-	s->saved_cmdlines = kmalloc_array(TASK_COMM_LEN, val, GFP_KERNEL);
-	if (!s->saved_cmdlines) {
-		kfree(s->map_cmdline_to_pid);
-		return -ENOMEM;
+	if (!s->map_cmdline_to_pid) {
+		free_saved_cmdlines_buffer(s);
+		return NULL;
 	}
 
 	s->cmdline_idx = 0;
-	s->cmdline_num = val;
 	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 0;
+	return s;
 }
 
 static int trace_create_savedcmd(void)
 {
-	int ret;
-
-	savedcmd = kmalloc(sizeof(*savedcmd), GFP_KERNEL);
-	if (!savedcmd)
-		return -ENOMEM;
-
-	ret = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT, savedcmd);
-	if (ret < 0) {
-		kfree(savedcmd);
-		savedcmd = NULL;
-		return -ENOMEM;
-	}
+	savedcmd = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT);
 
-	return 0;
+	return savedcmd ? 0 : -ENOMEM;
 }
 
 int is_tracing_stopped(void)
@@ -3374,7 +3389,7 @@ void trace_printk_init_buffers(void)
 	pr_warn("**********************************************************\n");
 
 	/* Expand the buffers to set size */
-	tracing_update_buffers();
+	tracing_update_buffers(&global_trace);
 
 	buffers_allocated = 1;
 
@@ -3798,15 +3813,6 @@ static bool trace_safe_str(struct trace_iterator *iter, const char *str,
 	return false;
 }
 
-static const char *show_buffer(struct trace_seq *s)
-{
-	struct seq_buf *seq = &s->seq;
-
-	seq_buf_terminate(seq);
-
-	return seq->buffer;
-}
-
 static DEFINE_STATIC_KEY_FALSE(trace_no_verify);
 
 static int test_can_verify_check(const char *fmt, ...)
@@ -3946,7 +3952,7 @@ void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
 		 */
 		if (WARN_ONCE(!trace_safe_str(iter, str, star, len),
 			      "fmt: '%s' current_buffer: '%s'",
-			      fmt, show_buffer(&iter->seq))) {
+			      fmt, seq_buf_str(&iter->seq.seq))) {
 			int ret;
 
 			/* Try to safely read the string */
@@ -6056,26 +6062,14 @@ tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf,
 	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 }
 
-static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s)
-{
-	kfree(s->saved_cmdlines);
-	kfree(s->map_cmdline_to_pid);
-	kfree(s);
-}
-
 static int tracing_resize_saved_cmdlines(unsigned int val)
 {
 	struct saved_cmdlines_buffer *s, *savedcmd_temp;
 
-	s = kmalloc(sizeof(*s), GFP_KERNEL);
+	s = allocate_cmdlines_buffer(val);
 	if (!s)
 		return -ENOMEM;
 
-	if (allocate_cmdlines_buffer(val, s) < 0) {
-		kfree(s);
-		return -ENOMEM;
-	}
-
 	preempt_disable();
 	arch_spin_lock(&trace_cmdline_lock);
 	savedcmd_temp = savedcmd;
@@ -6370,7 +6364,7 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr,
 	 * we use the size that was given, and we can forget about
 	 * expanding it later.
 	 */
-	ring_buffer_expanded = true;
+	trace_set_ring_buffer_expanded(tr);
 
 	/* May be called before buffers are initialized */
 	if (!tr->array_buffer.buffer)
@@ -6451,6 +6445,7 @@ out:
 
 /**
  * tracing_update_buffers - used by tracing facility to expand ring buffers
+ * @tr: The tracing instance
  *
  * To save on memory when the tracing is never used on a system with it
  * configured in. The ring buffers are set to a minimum size. But once
@@ -6459,13 +6454,13 @@ out:
  *
  * This function is to be called when a tracer is about to be used.
  */
-int tracing_update_buffers(void)
+int tracing_update_buffers(struct trace_array *tr)
 {
 	int ret = 0;
 
 	mutex_lock(&trace_types_lock);
-	if (!ring_buffer_expanded)
-		ret = __tracing_resize_ring_buffer(&global_trace, trace_buf_size,
+	if (!tr->ring_buffer_expanded)
+		ret = __tracing_resize_ring_buffer(tr, trace_buf_size,
 						RING_BUFFER_ALL_CPUS);
 	mutex_unlock(&trace_types_lock);
 
@@ -6519,7 +6514,7 @@ int tracing_set_tracer(struct trace_array *tr, const char *buf)
 
 	mutex_lock(&trace_types_lock);
 
-	if (!ring_buffer_expanded) {
+	if (!tr->ring_buffer_expanded) {
 		ret = __tracing_resize_ring_buffer(tr, trace_buf_size,
 						RING_BUFFER_ALL_CPUS);
 		if (ret < 0)
@@ -7005,7 +7000,7 @@ waitagain:
 
 	/* Now copy what we have to the user */
 	sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
-	if (iter->seq.seq.readpos >= trace_seq_used(&iter->seq))
+	if (iter->seq.readpos >= trace_seq_used(&iter->seq))
 		trace_seq_init(&iter->seq);
 
 	/*
@@ -7191,7 +7186,7 @@ tracing_entries_read(struct file *filp, char __user *ubuf,
 		}
 
 		if (buf_size_same) {
-			if (!ring_buffer_expanded)
+			if (!tr->ring_buffer_expanded)
 				r = sprintf(buf, "%lu (expanded: %lu)\n",
 					    size >> 10,
 					    trace_buf_size >> 10);
@@ -7248,10 +7243,10 @@ tracing_total_entries_read(struct file *filp, char __user *ubuf,
 	mutex_lock(&trace_types_lock);
 	for_each_tracing_cpu(cpu) {
 		size += per_cpu_ptr(tr->array_buffer.data, cpu)->entries >> 10;
-		if (!ring_buffer_expanded)
+		if (!tr->ring_buffer_expanded)
 			expanded_size += trace_buf_size >> 10;
 	}
-	if (ring_buffer_expanded)
+	if (tr->ring_buffer_expanded)
 		r = sprintf(buf, "%lu\n", size);
 	else
 		r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size);
@@ -7645,7 +7640,7 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
 	unsigned long val;
 	int ret;
 
-	ret = tracing_update_buffers();
+	ret = tracing_update_buffers(tr);
 	if (ret < 0)
 		return ret;
 
@@ -9549,6 +9544,9 @@ static struct trace_array *trace_array_create(const char *name)
 	if (allocate_trace_buffers(tr, trace_buf_size) < 0)
 		goto out_free_tr;
 
+	/* The ring buffer is defaultly expanded */
+	trace_set_ring_buffer_expanded(tr);
+
 	if (ftrace_allocate_ftrace_ops(tr) < 0)
 		goto out_free_tr;
 
@@ -9758,7 +9756,6 @@ static __init void create_trace_instances(struct dentry *d_tracer)
 static void
 init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
 {
-	struct trace_event_file *file;
 	int cpu;
 
 	trace_create_file("available_tracers", TRACE_MODE_READ, d_tracer,
@@ -9791,11 +9788,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
 	trace_create_file("trace_marker", 0220, d_tracer,
 			  tr, &tracing_mark_fops);
 
-	file = __find_event_file(tr, "ftrace", "print");
-	if (file && file->ef)
-		eventfs_add_file("trigger", TRACE_MODE_WRITE, file->ef,
-				  file, &event_trigger_fops);
-	tr->trace_marker_file = file;
+	tr->trace_marker_file = __find_event_file(tr, "ftrace", "print");
 
 	trace_create_file("trace_marker_raw", 0220, d_tracer,
 			  tr, &tracing_mark_raw_fops);
@@ -10443,7 +10436,7 @@ __init static int tracer_alloc_buffers(void)
 		trace_printk_init_buffers();
 
 	/* To save memory, keep the ring buffer size to its minimum */
-	if (ring_buffer_expanded)
+	if (global_trace.ring_buffer_expanded)
 		ring_buf_size = trace_buf_size;
 	else
 		ring_buf_size = 1;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 51c0a9703..0489e72c8 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -381,7 +381,7 @@ struct trace_array {
 	struct dentry		*dir;
 	struct dentry		*options;
 	struct dentry		*percpu_dir;
-	struct dentry		*event_dir;
+	struct eventfs_inode	*event_dir;
 	struct trace_options	*topts;
 	struct list_head	systems;
 	struct list_head	events;
@@ -410,6 +410,11 @@ struct trace_array {
 	struct cond_snapshot	*cond_snapshot;
 #endif
 	struct trace_func_repeats	__percpu *last_func_repeats;
+	/*
+	 * On boot up, the ring buffer is set to the minimum size, so that
+	 * we do not waste memory on systems that are not using tracing.
+	 */
+	bool ring_buffer_expanded;
 };
 
 enum {
@@ -762,7 +767,7 @@ extern int DYN_FTRACE_TEST_NAME(void);
 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
 extern int DYN_FTRACE_TEST_NAME2(void);
 
-extern bool ring_buffer_expanded;
+extern void trace_set_ring_buffer_expanded(struct trace_array *tr);
 extern bool tracing_selftest_disabled;
 
 #ifdef CONFIG_FTRACE_STARTUP_TEST
@@ -1306,7 +1311,7 @@ static inline void trace_branch_disable(void)
 #endif /* CONFIG_BRANCH_TRACER */
 
 /* set ring buffers to default size if not already done so */
-int tracing_update_buffers(void);
+int tracing_update_buffers(struct trace_array *tr);
 
 union trace_synth_field {
 	u8				as_u8;
@@ -1345,7 +1350,7 @@ struct trace_subsystem_dir {
 	struct list_head		list;
 	struct event_subsystem		*subsystem;
 	struct trace_array		*tr;
-	struct eventfs_file             *ef;
+	struct eventfs_inode		*ei;
 	int				ref_count;
 	int				nr_events;
 };
diff --git a/kernel/trace/trace_btf.c b/kernel/trace/trace_btf.c
index ca224d53b..5bbdbcbbd 100644
--- a/kernel/trace/trace_btf.c
+++ b/kernel/trace/trace_btf.c
@@ -91,8 +91,8 @@ retry:
 	for_each_member(i, type, member) {
 		if (!member->name_off) {
 			/* Anonymous union/struct: push it for later use */
-			type = btf_type_skip_modifiers(btf, member->type, &tid);
-			if (type && top < BTF_ANON_STACK_MAX) {
+			if (btf_type_skip_modifiers(btf, member->type, &tid) &&
+			    top < BTF_ANON_STACK_MAX) {
 				anon_stack[top].tid = tid;
 				anon_stack[top++].offset =
 					cur_offset + member->offset;
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 72714cbf4..03c851f57 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -788,12 +788,9 @@ find_and_get_event(const char *system, const char *event_name)
 		name = trace_event_name(tp_event);
 		if (!name || strcmp(event_name, name))
 			continue;
-		if (!trace_event_try_get_ref(tp_event)) {
+		if (!trace_event_try_get_ref(tp_event))
 			return NULL;
-			break;
-		}
 		return tp_event;
-		break;
 	}
 	return NULL;
 }
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 82cb22ad6..f29e815ca 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -984,7 +984,7 @@ static void remove_subsystem(struct trace_subsystem_dir *dir)
 		return;
 
 	if (!--dir->nr_events) {
-		eventfs_remove(dir->ef);
+		eventfs_remove_dir(dir->ei);
 		list_del(&dir->list);
 		__put_system_dir(dir);
 	}
@@ -1013,7 +1013,7 @@ void event_file_put(struct trace_event_file *file)
 
 static void remove_event_file_dir(struct trace_event_file *file)
 {
-	eventfs_remove(file->ef);
+	eventfs_remove_dir(file->ei);
 	list_del(&file->list);
 	remove_subsystem(file->system);
 	free_event_filter(file->filter);
@@ -1188,7 +1188,7 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
 	if (!cnt)
 		return 0;
 
-	ret = tracing_update_buffers();
+	ret = tracing_update_buffers(tr);
 	if (ret < 0)
 		return ret;
 
@@ -1419,18 +1419,20 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 	if (ret)
 		return ret;
 
-	ret = tracing_update_buffers();
-	if (ret < 0)
-		return ret;
-
 	switch (val) {
 	case 0:
 	case 1:
 		ret = -ENODEV;
 		mutex_lock(&event_mutex);
 		file = event_file_data(filp);
-		if (likely(file && !(file->flags & EVENT_FILE_FL_FREED)))
+		if (likely(file && !(file->flags & EVENT_FILE_FL_FREED))) {
+			ret = tracing_update_buffers(file->tr);
+			if (ret < 0) {
+				mutex_unlock(&event_mutex);
+				return ret;
+			}
 			ret = ftrace_event_enable_disable(file, val);
+		}
 		mutex_unlock(&event_mutex);
 		break;
 
@@ -1504,7 +1506,7 @@ system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 	if (ret)
 		return ret;
 
-	ret = tracing_update_buffers();
+	ret = tracing_update_buffers(dir->tr);
 	if (ret < 0)
 		return ret;
 
@@ -1978,7 +1980,7 @@ event_pid_write(struct file *filp, const char __user *ubuf,
 	if (!cnt)
 		return 0;
 
-	ret = tracing_update_buffers();
+	ret = tracing_update_buffers(tr);
 	if (ret < 0)
 		return ret;
 
@@ -2302,14 +2304,40 @@ create_new_subsystem(const char *name)
 	return NULL;
 }
 
-static struct eventfs_file *
+static int system_callback(const char *name, umode_t *mode, void **data,
+		    const struct file_operations **fops)
+{
+	if (strcmp(name, "filter") == 0)
+		*fops = &ftrace_subsystem_filter_fops;
+
+	else if (strcmp(name, "enable") == 0)
+		*fops = &ftrace_system_enable_fops;
+
+	else
+		return 0;
+
+	*mode = TRACE_MODE_WRITE;
+	return 1;
+}
+
+static struct eventfs_inode *
 event_subsystem_dir(struct trace_array *tr, const char *name,
-		    struct trace_event_file *file, struct dentry *parent)
+		    struct trace_event_file *file, struct eventfs_inode *parent)
 {
 	struct event_subsystem *system, *iter;
 	struct trace_subsystem_dir *dir;
-	struct eventfs_file *ef;
-	int res;
+	struct eventfs_inode *ei;
+	int nr_entries;
+	static struct eventfs_entry system_entries[] = {
+		{
+			.name		= "filter",
+			.callback	= system_callback,
+		},
+		{
+			.name		= "enable",
+			.callback	= system_callback,
+		}
+	};
 
 	/* First see if we did not already create this dir */
 	list_for_each_entry(dir, &tr->systems, list) {
@@ -2317,7 +2345,7 @@ event_subsystem_dir(struct trace_array *tr, const char *name,
 		if (strcmp(system->name, name) == 0) {
 			dir->nr_events++;
 			file->system = dir;
-			return dir->ef;
+			return dir->ei;
 		}
 	}
 
@@ -2341,39 +2369,29 @@ event_subsystem_dir(struct trace_array *tr, const char *name,
 	} else
 		__get_system(system);
 
-	ef = eventfs_add_subsystem_dir(name, parent);
-	if (IS_ERR(ef)) {
+	/* ftrace only has directories no files */
+	if (strcmp(name, "ftrace") == 0)
+		nr_entries = 0;
+	else
+		nr_entries = ARRAY_SIZE(system_entries);
+
+	ei = eventfs_create_dir(name, parent, system_entries, nr_entries, dir);
+	if (IS_ERR(ei)) {
 		pr_warn("Failed to create system directory %s\n", name);
 		__put_system(system);
 		goto out_free;
 	}
 
-	dir->ef = ef;
+	dir->ei = ei;
 	dir->tr = tr;
 	dir->ref_count = 1;
 	dir->nr_events = 1;
 	dir->subsystem = system;
 	file->system = dir;
 
-	/* the ftrace system is special, do not create enable or filter files */
-	if (strcmp(name, "ftrace") != 0) {
-
-		res = eventfs_add_file("filter", TRACE_MODE_WRITE,
-					    dir->ef, dir,
-					    &ftrace_subsystem_filter_fops);
-		if (res) {
-			kfree(system->filter);
-			system->filter = NULL;
-			pr_warn("Could not create tracefs '%s/filter' entry\n", name);
-		}
-
-		eventfs_add_file("enable", TRACE_MODE_WRITE, dir->ef, dir,
-				  &ftrace_system_enable_fops);
-	}
-
 	list_add(&dir->list, &tr->systems);
 
-	return dir->ef;
+	return dir->ei;
 
  out_free:
 	kfree(dir);
@@ -2422,15 +2440,134 @@ event_define_fields(struct trace_event_call *call)
 	return ret;
 }
 
+static int event_callback(const char *name, umode_t *mode, void **data,
+			  const struct file_operations **fops)
+{
+	struct trace_event_file *file = *data;
+	struct trace_event_call *call = file->event_call;
+
+	if (strcmp(name, "format") == 0) {
+		*mode = TRACE_MODE_READ;
+		*fops = &ftrace_event_format_fops;
+		*data = call;
+		return 1;
+	}
+
+	/*
+	 * Only event directories that can be enabled should have
+	 * triggers or filters, with the exception of the "print"
+	 * event that can have a "trigger" file.
+	 */
+	if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
+		if (call->class->reg && strcmp(name, "enable") == 0) {
+			*mode = TRACE_MODE_WRITE;
+			*fops = &ftrace_enable_fops;
+			return 1;
+		}
+
+		if (strcmp(name, "filter") == 0) {
+			*mode = TRACE_MODE_WRITE;
+			*fops = &ftrace_event_filter_fops;
+			return 1;
+		}
+	}
+
+	if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) ||
+	    strcmp(trace_event_name(call), "print") == 0) {
+		if (strcmp(name, "trigger") == 0) {
+			*mode = TRACE_MODE_WRITE;
+			*fops = &event_trigger_fops;
+			return 1;
+		}
+	}
+
+#ifdef CONFIG_PERF_EVENTS
+	if (call->event.type && call->class->reg &&
+	    strcmp(name, "id") == 0) {
+		*mode = TRACE_MODE_READ;
+		*data = (void *)(long)call->event.type;
+		*fops = &ftrace_event_id_fops;
+		return 1;
+	}
+#endif
+
+#ifdef CONFIG_HIST_TRIGGERS
+	if (strcmp(name, "hist") == 0) {
+		*mode = TRACE_MODE_READ;
+		*fops = &event_hist_fops;
+		return 1;
+	}
+#endif
+#ifdef CONFIG_HIST_TRIGGERS_DEBUG
+	if (strcmp(name, "hist_debug") == 0) {
+		*mode = TRACE_MODE_READ;
+		*fops = &event_hist_debug_fops;
+		return 1;
+	}
+#endif
+#ifdef CONFIG_TRACE_EVENT_INJECT
+	if (call->event.type && call->class->reg &&
+	    strcmp(name, "inject") == 0) {
+		*mode = 0200;
+		*fops = &event_inject_fops;
+		return 1;
+	}
+#endif
+	return 0;
+}
+
 static int
-event_create_dir(struct dentry *parent, struct trace_event_file *file)
+event_create_dir(struct eventfs_inode *parent, struct trace_event_file *file)
 {
 	struct trace_event_call *call = file->event_call;
-	struct eventfs_file *ef_subsystem = NULL;
 	struct trace_array *tr = file->tr;
-	struct eventfs_file *ef;
+	struct eventfs_inode *e_events;
+	struct eventfs_inode *ei;
 	const char *name;
+	int nr_entries;
 	int ret;
+	static struct eventfs_entry event_entries[] = {
+		{
+			.name		= "enable",
+			.callback	= event_callback,
+		},
+		{
+			.name		= "filter",
+			.callback	= event_callback,
+		},
+		{
+			.name		= "trigger",
+			.callback	= event_callback,
+		},
+		{
+			.name		= "format",
+			.callback	= event_callback,
+		},
+#ifdef CONFIG_PERF_EVENTS
+		{
+			.name		= "id",
+			.callback	= event_callback,
+		},
+#endif
+#ifdef CONFIG_HIST_TRIGGERS
+		{
+			.name		= "hist",
+			.callback	= event_callback,
+		},
+#endif
+#ifdef CONFIG_HIST_TRIGGERS_DEBUG
+		{
+			.name		= "hist_debug",
+			.callback	= event_callback,
+		},
+#endif
+#ifdef CONFIG_TRACE_EVENT_INJECT
+		{
+			.name		= "inject",
+			.callback	= event_callback,
+		},
+#endif
+	};
 
 	/*
 	 * If the trace point header did not define TRACE_SYSTEM
@@ -2440,29 +2577,20 @@ event_create_dir(struct dentry *parent, struct trace_event_file *file)
 	if (WARN_ON_ONCE(strcmp(call->class->system, TRACE_SYSTEM) == 0))
 		return -ENODEV;
 
-	ef_subsystem = event_subsystem_dir(tr, call->class->system, file, parent);
-	if (!ef_subsystem)
+	e_events = event_subsystem_dir(tr, call->class->system, file, parent);
+	if (!e_events)
 		return -ENOMEM;
 
+	nr_entries = ARRAY_SIZE(event_entries);
+
 	name = trace_event_name(call);
-	ef = eventfs_add_dir(name, ef_subsystem);
-	if (IS_ERR(ef)) {
+	ei = eventfs_create_dir(name, e_events, event_entries, nr_entries, file);
+	if (IS_ERR(ei)) {
 		pr_warn("Could not create tracefs '%s' directory\n", name);
 		return -1;
 	}
 
-	file->ef = ef;
-
-	if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
-		eventfs_add_file("enable", TRACE_MODE_WRITE, file->ef, file,
-				  &ftrace_enable_fops);
-
-#ifdef CONFIG_PERF_EVENTS
-	if (call->event.type && call->class->reg)
-		eventfs_add_file("id", TRACE_MODE_READ, file->ef,
-				  (void *)(long)call->event.type,
-				  &ftrace_event_id_fops);
-#endif
+	file->ei = ei;
 
 	ret = event_define_fields(call);
 	if (ret < 0) {
@@ -2470,35 +2598,6 @@ event_create_dir(struct dentry *parent, struct trace_event_file *file)
 		return ret;
 	}
 
-	/*
-	 * Only event directories that can be enabled should have
-	 * triggers or filters.
-	 */
-	if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
-		eventfs_add_file("filter", TRACE_MODE_WRITE, file->ef,
-				  file, &ftrace_event_filter_fops);
-
-		eventfs_add_file("trigger", TRACE_MODE_WRITE, file->ef,
-				  file, &event_trigger_fops);
-	}
-
-#ifdef CONFIG_HIST_TRIGGERS
-	eventfs_add_file("hist", TRACE_MODE_READ, file->ef, file,
-			  &event_hist_fops);
-#endif
-#ifdef CONFIG_HIST_TRIGGERS_DEBUG
-	eventfs_add_file("hist_debug", TRACE_MODE_READ, file->ef, file,
-			  &event_hist_debug_fops);
-#endif
-	eventfs_add_file("format", TRACE_MODE_READ, file->ef, call,
-			  &ftrace_event_format_fops);
-
-#ifdef CONFIG_TRACE_EVENT_INJECT
-	if (call->event.type && call->class->reg)
-		eventfs_add_file("inject", 0200, file->ef, file,
-				  &event_inject_fops);
-#endif
-
 	return 0;
 }
 
@@ -2847,7 +2946,7 @@ static __init int setup_trace_triggers(char *str)
 	int i;
 
 	strscpy(bootup_trigger_buf, str, COMMAND_LINE_SIZE);
-	ring_buffer_expanded = true;
+	trace_set_ring_buffer_expanded(NULL);
 	disable_tracing_selftest("running event triggers");
 
 	buf = bootup_trigger_buf;
@@ -3637,37 +3736,72 @@ static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
 static __init int setup_trace_event(char *str)
 {
 	strscpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
-	ring_buffer_expanded = true;
+	trace_set_ring_buffer_expanded(NULL);
 	disable_tracing_selftest("running event tracing");
 
 	return 1;
 }
 __setup("trace_event=", setup_trace_event);
 
+static int events_callback(const char *name, umode_t *mode, void **data,
+			   const struct file_operations **fops)
+{
+	if (strcmp(name, "enable") == 0) {
+		*mode = TRACE_MODE_WRITE;
+		*fops = &ftrace_tr_enable_fops;
+		return 1;
+	}
+
+	if (strcmp(name, "header_page") == 0)
+		*data = ring_buffer_print_page_header;
+
+	else if (strcmp(name, "header_event") == 0)
+		*data = ring_buffer_print_entry_header;
+
+	else
+		return 0;
+
+	*mode = TRACE_MODE_READ;
+	*fops = &ftrace_show_header_fops;
+	return 1;
+}
+
 /* Expects to have event_mutex held when called */
 static int
 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
 {
-	struct dentry *d_events;
+	struct eventfs_inode *e_events;
 	struct dentry *entry;
-	int error = 0;
+	int nr_entries;
+	static struct eventfs_entry events_entries[] = {
+		{
+			.name		= "enable",
+			.callback	= events_callback,
+		},
+		{
+			.name		= "header_page",
+			.callback	= events_callback,
+		},
+		{
+			.name		= "header_event",
+			.callback	= events_callback,
+		},
+	};
 
 	entry = trace_create_file("set_event", TRACE_MODE_WRITE, parent,
 				  tr, &ftrace_set_event_fops);
 	if (!entry)
 		return -ENOMEM;
 
-	d_events = eventfs_create_events_dir("events", parent);
-	if (IS_ERR(d_events)) {
+	nr_entries = ARRAY_SIZE(events_entries);
+
+	e_events = eventfs_create_events_dir("events", parent, events_entries,
+					     nr_entries, tr);
+	if (IS_ERR(e_events)) {
 		pr_warn("Could not create tracefs 'events' directory\n");
 		return -ENOMEM;
 	}
 
-	error = eventfs_add_events_file("enable", TRACE_MODE_WRITE, d_events,
-				  tr, &ftrace_tr_enable_fops);
-	if (error)
-		return -ENOMEM;
-
 	/* There are not as crucial, just warn if they are not created */
 
 	trace_create_file("set_event_pid", TRACE_MODE_WRITE, parent,
@@ -3677,16 +3811,7 @@ create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
 			  TRACE_MODE_WRITE, parent, tr,
 			  &ftrace_set_event_notrace_pid_fops);
 
-	/* ring buffer internal formats */
-	eventfs_add_events_file("header_page", TRACE_MODE_READ, d_events,
-				  ring_buffer_print_page_header,
-				  &ftrace_show_header_fops);
-
-	eventfs_add_events_file("header_event", TRACE_MODE_READ, d_events,
-				  ring_buffer_print_entry_header,
-				  &ftrace_show_header_fops);
-
-	tr->event_dir = d_events;
+	tr->event_dir = e_events;
 
 	return 0;
 }
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 68aaf0bd7..5ecf3c8bd 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -774,23 +774,16 @@ static void last_cmd_set(struct trace_event_file *file, char *str)
 {
 	const char *system = NULL, *name = NULL;
 	struct trace_event_call *call;
-	int len;
 
 	if (!str)
 		return;
 
-	/* sizeof() contains the nul byte */
-	len = sizeof(HIST_PREFIX) + strlen(str);
 	kfree(last_cmd);
-	last_cmd = kzalloc(len, GFP_KERNEL);
+
+	last_cmd = kasprintf(GFP_KERNEL, HIST_PREFIX "%s", str);
 	if (!last_cmd)
 		return;
 
-	strcpy(last_cmd, HIST_PREFIX);
-	/* Again, sizeof() contains the nul byte */
-	len -= sizeof(HIST_PREFIX);
-	strncat(last_cmd, str, len);
-
 	if (file) {
 		call = file->event_call;
 		system = call->class->system;
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index 846e02c0f..c82b401a2 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -441,8 +441,9 @@ static unsigned int trace_string(struct synth_trace_event *entry,
 	if (is_dynamic) {
 		union trace_synth_field *data = &entry->fields[*n_u64];
 
+		len = fetch_store_strlen((unsigned long)str_val);
 		data->as_dynamic.offset = struct_size(entry, fields, event->n_u64) + data_size;
-		data->as_dynamic.len = fetch_store_strlen((unsigned long)str_val);
+		data->as_dynamic.len = len;
 
 		ret = fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry);
 
@@ -1137,7 +1138,7 @@ EXPORT_SYMBOL_GPL(synth_event_add_fields);
  * @cmd: A pointer to the dynevent_cmd struct representing the new event
  * @name: The name of the synthetic event
  * @mod: The module creating the event, NULL if not created from a module
- * @args: Variable number of arg (pairs), one pair for each field
+ * @...: Variable number of arg (pairs), one pair for each field
  *
  * NOTE: Users normally won't want to call this function directly, but
  * rather use the synth_event_gen_cmd_start() wrapper, which
@@ -1695,7 +1696,7 @@ __synth_event_trace_end(struct synth_event_trace_state *trace_state)
  * synth_event_trace - Trace a synthetic event
  * @file: The trace_event_file representing the synthetic event
  * @n_vals: The number of values in vals
- * @args: Variable number of args containing the event values
+ * @...: Variable number of args containing the event values
  *
  * Trace a synthetic event using the values passed in the variable
  * argument list.
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 46439e3bc..b33c3861f 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -1470,8 +1470,10 @@ register_snapshot_trigger(char *glob,
 			  struct event_trigger_data *data,
 			  struct trace_event_file *file)
 {
-	if (tracing_alloc_snapshot_instance(file->tr) != 0)
-		return 0;
+	int ret = tracing_alloc_snapshot_instance(file->tr);
+
+	if (ret < 0)
+		return ret;
 
 	return register_trigger(glob, data, file);
 }
diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index b87f41187..9365ce407 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -50,18 +50,6 @@
 #define EVENT_STATUS_OTHER BIT(7)
 
 /*
- * User register flags are not allowed yet, keep them here until we are
- * ready to expose them out to the user ABI.
- */
-enum user_reg_flag {
-	/* Event will not delete upon last reference closing */
-	USER_EVENT_REG_PERSIST		= 1U << 0,
-
-	/* This value or above is currently non-ABI */
-	USER_EVENT_REG_MAX		= 1U << 1,
-};
-
-/*
  * Stores the system name, tables, and locks for a group of events. This
  * allows isolation for events by various means.
  */
@@ -220,6 +208,17 @@ static u32 user_event_key(char *name)
 	return jhash(name, strlen(name), 0);
 }
 
+static bool user_event_capable(u16 reg_flags)
+{
+	/* Persistent events require CAP_PERFMON / CAP_SYS_ADMIN */
+	if (reg_flags & USER_EVENT_REG_PERSIST) {
+		if (!perfmon_capable())
+			return false;
+	}
+
+	return true;
+}
+
 static struct user_event *user_event_get(struct user_event *user)
 {
 	refcount_inc(&user->refcnt);
@@ -1811,6 +1810,9 @@ static int user_event_free(struct dyn_event *ev)
 	if (!user_event_last_ref(user))
 		return -EBUSY;
 
+	if (!user_event_capable(user->reg_flags))
+		return -EPERM;
+
 	return destroy_user_event(user);
 }
 
@@ -1926,10 +1928,13 @@ static int user_event_parse(struct user_event_group *group, char *name,
 	int argc = 0;
 	char **argv;
 
-	/* User register flags are not ready yet */
-	if (reg_flags != 0 || flags != NULL)
+	/* Currently don't support any text based flags */
+	if (flags != NULL)
 		return -EINVAL;
 
+	if (!user_event_capable(reg_flags))
+		return -EPERM;
+
 	/* Prevent dyn_event from racing */
 	mutex_lock(&event_mutex);
 	user = find_user_event(group, name, &key);
@@ -2062,6 +2067,9 @@ static int delete_user_event(struct user_event_group *group, char *name)
 	if (!user_event_last_ref(user))
 		return -EBUSY;
 
+	if (!user_event_capable(user->reg_flags))
+		return -EPERM;
+
 	return destroy_user_event(user);
 }
 
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 47812aa16..52f8b537d 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1249,6 +1249,12 @@ static const struct file_operations kprobe_events_ops = {
 	.write		= probes_write,
 };
 
+static unsigned long trace_kprobe_missed(struct trace_kprobe *tk)
+{
+	return trace_kprobe_is_return(tk) ?
+		tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed;
+}
+
 /* Probes profiling interfaces */
 static int probes_profile_seq_show(struct seq_file *m, void *v)
 {
@@ -1260,8 +1266,7 @@ static int probes_profile_seq_show(struct seq_file *m, void *v)
 		return 0;
 
 	tk = to_trace_kprobe(ev);
-	nmissed = trace_kprobe_is_return(tk) ?
-		tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed;
+	nmissed = trace_kprobe_missed(tk);
 	seq_printf(m, "  %-44s %15lu %15lu\n",
 		   trace_probe_name(&tk->tp),
 		   trace_kprobe_nhit(tk),
@@ -1607,7 +1612,8 @@ NOKPROBE_SYMBOL(kretprobe_perf_func);
 
 int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
 			const char **symbol, u64 *probe_offset,
-			u64 *probe_addr, bool perf_type_tracepoint)
+			u64 *probe_addr, unsigned long *missed,
+			bool perf_type_tracepoint)
 {
 	const char *pevent = trace_event_name(event->tp_event);
 	const char *group = event->tp_event->class->system;
@@ -1626,6 +1632,8 @@ int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
 	*probe_addr = kallsyms_show_value(current_cred()) ?
 		      (unsigned long)tk->rp.kp.addr : 0;
 	*symbol = tk->symbol;
+	if (missed)
+		*missed = trace_kprobe_missed(tk);
 	return 0;
 }
 #endif	/* CONFIG_PERF_EVENTS */
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index bd0d01d00..a8e28f9b9 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -2444,6 +2444,9 @@ static int timerlat_fd_open(struct inode *inode, struct file *file)
 	tlat = this_cpu_tmr_var();
 	tlat->count = 0;
 
+	hrtimer_init(&tlat->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD);
+	tlat->timer.function = timerlat_irq;
+
 	migrate_enable();
 	return 0;
 };
@@ -2526,9 +2529,6 @@ timerlat_fd_read(struct file *file, char __user *ubuf, size_t count,
 		tlat->tracing_thread = false;
 		tlat->kthread = current;
 
-		hrtimer_init(&tlat->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD);
-		tlat->timer.function = timerlat_irq;
-
 		/* Annotate now to drift new period */
 		tlat->abs_period = hrtimer_cb_get_time(&tlat->timer);
 
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 3b7d3e9eb..3e7fa44dc 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -404,7 +404,7 @@ static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 			vmstart = vma->vm_start;
 		}
 		if (file) {
-			ret = trace_seq_path(s, &file->f_path);
+			ret = trace_seq_path(s, file_user_path(file));
 			if (ret)
 				trace_seq_printf(s, "[+0x%lx]",
 						 ip - vmstart);
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 4dc74d73f..34289f9c6 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -1159,9 +1159,12 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
 	if (!(ctx->flags & TPARG_FL_TEVENT) &&
 	    (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 ||
 	     strncmp(arg, "\\\"", 2) == 0)) {
-		/* The type of $comm must be "string", and not an array. */
-		if (parg->count || (t && strcmp(t, "string")))
+		/* The type of $comm must be "string", and not an array type. */
+		if (parg->count || (t && strcmp(t, "string"))) {
+			trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
+					NEED_STRING_TYPE);
 			goto out;
+		}
 		parg->type = find_fetch_type("string", ctx->flags);
 	} else
 		parg->type = find_fetch_type(t, ctx->flags);
@@ -1169,18 +1172,6 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
 		trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), BAD_TYPE);
 		goto out;
 	}
-	parg->offset = *size;
-	*size += parg->type->size * (parg->count ?: 1);
-
-	ret = -ENOMEM;
-	if (parg->count) {
-		len = strlen(parg->type->fmttype) + 6;
-		parg->fmt = kmalloc(len, GFP_KERNEL);
-		if (!parg->fmt)
-			goto out;
-		snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
-			 parg->count);
-	}
 
 	code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
 	if (!code)
@@ -1204,6 +1195,19 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
 				goto fail;
 		}
 	}
+	parg->offset = *size;
+	*size += parg->type->size * (parg->count ?: 1);
+
+	if (parg->count) {
+		len = strlen(parg->type->fmttype) + 6;
+		parg->fmt = kmalloc(len, GFP_KERNEL);
+		if (!parg->fmt) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
+			 parg->count);
+	}
 
 	ret = -EINVAL;
 	/* Store operation */
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 850d9ecb6..c1877d018 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -515,7 +515,8 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
 	C(BAD_HYPHEN,		"Failed to parse single hyphen. Forgot '>'?"),	\
 	C(NO_BTF_FIELD,		"This field is not found."),	\
 	C(BAD_BTF_TID,		"Failed to get BTF type info."),\
-	C(BAD_TYPE4STR,		"This type does not fit for string."),
+	C(BAD_TYPE4STR,		"This type does not fit for string."),\
+	C(NEED_STRING_TYPE,	"$comm and immediate-string only accepts string type"),
 
 #undef C
 #define C(a, b)		TP_ERR_##a
diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c
index bac06ee3b..7be97229d 100644
--- a/kernel/trace/trace_seq.c
+++ b/kernel/trace/trace_seq.c
@@ -370,8 +370,12 @@ EXPORT_SYMBOL_GPL(trace_seq_path);
  */
 int trace_seq_to_user(struct trace_seq *s, char __user *ubuf, int cnt)
 {
+	int ret;
 	__trace_seq_init(s);
-	return seq_buf_to_user(&s->seq, ubuf, cnt);
+	ret = seq_buf_to_user(&s->seq, ubuf, s->readpos, cnt);
+	if (ret > 0)
+		s->readpos += ret;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(trace_seq_to_user);
 
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index de753403c..9c581d6da 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -556,7 +556,7 @@ static int perf_call_bpf_enter(struct trace_event_call *call, struct pt_regs *re
 {
 	struct syscall_tp_t {
 		struct trace_entry ent;
-		unsigned long syscall_nr;
+		int syscall_nr;
 		unsigned long args[SYSCALL_DEFINE_MAXARGS];
 	} __aligned(8) param;
 	int i;
@@ -661,7 +661,7 @@ static int perf_call_bpf_exit(struct trace_event_call *call, struct pt_regs *reg
 {
 	struct syscall_tp_t {
 		struct trace_entry ent;
-		unsigned long syscall_nr;
+		int syscall_nr;
 		unsigned long ret;
 	} __aligned(8) param;