Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 943 insertions, 0 deletions

diff --git a/tools/perf/ui/stdio/hist.c b/tools/perf/ui/stdio/hist.c
new file mode 100644
index 000000000..8c4c8925d
--- /dev/null
+++ b/tools/perf/ui/stdio/hist.c
@@ -0,0 +1,943 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <linux/string.h>
+
+#include "../../util/callchain.h"
+#include "../../util/debug.h"
+#include "../../util/event.h"
+#include "../../util/hist.h"
+#include "../../util/map.h"
+#include "../../util/maps.h"
+#include "../../util/symbol.h"
+#include "../../util/sort.h"
+#include "../../util/evsel.h"
+#include "../../util/srcline.h"
+#include "../../util/string2.h"
+#include "../../util/thread.h"
+#include "../../util/block-info.h"
+#include <linux/ctype.h>
+#include <linux/zalloc.h>
+
+static size_t callchain__fprintf_left_margin(FILE *fp, int left_margin)
+{
+	int i;
+	int ret = fprintf(fp, "            ");
+
+	if (left_margin > USHRT_MAX)
+		left_margin = USHRT_MAX;
+
+	for (i = 0; i < left_margin; i++)
+		ret += fprintf(fp, " ");
+
+	return ret;
+}
+
+static size_t ipchain__fprintf_graph_line(FILE *fp, int depth, int depth_mask,
+					  int left_margin)
+{
+	int i;
+	size_t ret = callchain__fprintf_left_margin(fp, left_margin);
+
+	for (i = 0; i < depth; i++)
+		if (depth_mask & (1 << i))
+			ret += fprintf(fp, "|          ");
+		else
+			ret += fprintf(fp, "           ");
+
+	ret += fprintf(fp, "\n");
+
+	return ret;
+}
+
+static size_t ipchain__fprintf_graph(FILE *fp, struct callchain_node *node,
+				     struct callchain_list *chain,
+				     int depth, int depth_mask, int period,
+				     u64 total_samples, int left_margin)
+{
+	int i;
+	size_t ret = 0;
+	char bf[1024], *alloc_str = NULL;
+	char buf[64];
+	const char *str;
+
+	ret += callchain__fprintf_left_margin(fp, left_margin);
+	for (i = 0; i < depth; i++) {
+		if (depth_mask & (1 << i))
+			ret += fprintf(fp, "|");
+		else
+			ret += fprintf(fp, " ");
+		if (!period && i == depth - 1) {
+			ret += fprintf(fp, "--");
+			ret += callchain_node__fprintf_value(node, fp, total_samples);
+			ret += fprintf(fp, "--");
+		} else
+			ret += fprintf(fp, "%s", "          ");
+	}
+
+	str = callchain_list__sym_name(chain, bf, sizeof(bf), false);
+
+	if (symbol_conf.show_branchflag_count) {
+		callchain_list_counts__printf_value(chain, NULL,
+						    buf, sizeof(buf));
+
+		if (asprintf(&alloc_str, "%s%s", str, buf) < 0)
+			str = "Not enough memory!";
+		else
+			str = alloc_str;
+	}
+
+	fputs(str, fp);
+	fputc('\n', fp);
+	free(alloc_str);
+
+	return ret;
+}
+
+static struct symbol *rem_sq_bracket;
+static struct callchain_list rem_hits;
+
+static void init_rem_hits(void)
+{
+	rem_sq_bracket = malloc(sizeof(*rem_sq_bracket) + 6);
+	if (!rem_sq_bracket) {
+		fprintf(stderr, "Not enough memory to display remaining hits\n");
+		return;
+	}
+
+	strcpy(rem_sq_bracket->name, "[...]");
+	rem_hits.ms.sym = rem_sq_bracket;
+}
+
+static size_t __callchain__fprintf_graph(FILE *fp, struct rb_root *root,
+					 u64 total_samples, int depth,
+					 int depth_mask, int left_margin)
+{
+	struct rb_node *node, *next;
+	struct callchain_node *child = NULL;
+	struct callchain_list *chain;
+	int new_depth_mask = depth_mask;
+	u64 remaining;
+	size_t ret = 0;
+	int i;
+	uint entries_printed = 0;
+	int cumul_count = 0;
+
+	remaining = total_samples;
+
+	node = rb_first(root);
+	while (node) {
+		u64 new_total;
+		u64 cumul;
+
+		child = rb_entry(node, struct callchain_node, rb_node);
+		cumul = callchain_cumul_hits(child);
+		remaining -= cumul;
+		cumul_count += callchain_cumul_counts(child);
+
+		/*
+		 * The depth mask manages the output of pipes that show
+		 * the depth. We don't want to keep the pipes of the current
+		 * level for the last child of this depth.
+		 * Except if we have remaining filtered hits. They will
+		 * supersede the last child
+		 */
+		next = rb_next(node);
+		if (!next && (callchain_param.mode != CHAIN_GRAPH_REL || !remaining))
+			new_depth_mask &= ~(1 << (depth - 1));
+
+		/*
+		 * But we keep the older depth mask for the line separator
+		 * to keep the level link until we reach the last child
+		 */
+		ret += ipchain__fprintf_graph_line(fp, depth, depth_mask,
+						   left_margin);
+		i = 0;
+		list_for_each_entry(chain, &child->val, list) {
+			ret += ipchain__fprintf_graph(fp, child, chain, depth,
+						      new_depth_mask, i++,
+						      total_samples,
+						      left_margin);
+		}
+
+		if (callchain_param.mode == CHAIN_GRAPH_REL)
+			new_total = child->children_hit;
+		else
+			new_total = total_samples;
+
+		ret += __callchain__fprintf_graph(fp, &child->rb_root, new_total,
+						  depth + 1,
+						  new_depth_mask | (1 << depth),
+						  left_margin);
+		node = next;
+		if (++entries_printed == callchain_param.print_limit)
+			break;
+	}
+
+	if (callchain_param.mode == CHAIN_GRAPH_REL &&
+		remaining && remaining != total_samples) {
+		struct callchain_node rem_node = {
+			.hit = remaining,
+		};
+
+		if (!rem_sq_bracket)
+			return ret;
+
+		if (callchain_param.value == CCVAL_COUNT && child && child->parent) {
+			rem_node.count = child->parent->children_count - cumul_count;
+			if (rem_node.count <= 0)
+				return ret;
+		}
+
+		new_depth_mask &= ~(1 << (depth - 1));
+		ret += ipchain__fprintf_graph(fp, &rem_node, &rem_hits, depth,
+					      new_depth_mask, 0, total_samples,
+					      left_margin);
+	}
+
+	return ret;
+}
+
+/*
+ * If have one single callchain root, don't bother printing
+ * its percentage (100 % in fractal mode and the same percentage
+ * than the hist in graph mode). This also avoid one level of column.
+ *
+ * However when percent-limit applied, it's possible that single callchain
+ * node have different (non-100% in fractal mode) percentage.
+ */
+static bool need_percent_display(struct rb_node *node, u64 parent_samples)
+{
+	struct callchain_node *cnode;
+
+	if (rb_next(node))
+		return true;
+
+	cnode = rb_entry(node, struct callchain_node, rb_node);
+	return callchain_cumul_hits(cnode) != parent_samples;
+}
+
+static size_t callchain__fprintf_graph(FILE *fp, struct rb_root *root,
+				       u64 total_samples, u64 parent_samples,
+				       int left_margin)
+{
+	struct callchain_node *cnode;
+	struct callchain_list *chain;
+	u32 entries_printed = 0;
+	bool printed = false;
+	struct rb_node *node;
+	int i = 0;
+	int ret = 0;
+	char bf[1024];
+
+	node = rb_first(root);
+	if (node && !need_percent_display(node, parent_samples)) {
+		cnode = rb_entry(node, struct callchain_node, rb_node);
+		list_for_each_entry(chain, &cnode->val, list) {
+			/*
+			 * If we sort by symbol, the first entry is the same than
+			 * the symbol. No need to print it otherwise it appears as
+			 * displayed twice.
+			 */
+			if (!i++ && field_order == NULL &&
+			    sort_order && strstarts(sort_order, "sym"))
+				continue;
+
+			if (!printed) {
+				ret += callchain__fprintf_left_margin(fp, left_margin);
+				ret += fprintf(fp, "|\n");
+				ret += callchain__fprintf_left_margin(fp, left_margin);
+				ret += fprintf(fp, "---");
+				left_margin += 3;
+				printed = true;
+			} else
+				ret += callchain__fprintf_left_margin(fp, left_margin);
+
+			ret += fprintf(fp, "%s",
+				       callchain_list__sym_name(chain, bf,
+								sizeof(bf),
+								false));
+
+			if (symbol_conf.show_branchflag_count)
+				ret += callchain_list_counts__printf_value(
+						chain, fp, NULL, 0);
+			ret += fprintf(fp, "\n");
+
+			if (++entries_printed == callchain_param.print_limit)
+				break;
+		}
+		root = &cnode->rb_root;
+	}
+
+	if (callchain_param.mode == CHAIN_GRAPH_REL)
+		total_samples = parent_samples;
+
+	ret += __callchain__fprintf_graph(fp, root, total_samples,
+					  1, 1, left_margin);
+	if (ret) {
+		/* do not add a blank line if it printed nothing */
+		ret += fprintf(fp, "\n");
+	}
+
+	return ret;
+}
+
+static size_t __callchain__fprintf_flat(FILE *fp, struct callchain_node *node,
+					u64 total_samples)
+{
+	struct callchain_list *chain;
+	size_t ret = 0;
+	char bf[1024];
+
+	if (!node)
+		return 0;
+
+	ret += __callchain__fprintf_flat(fp, node->parent, total_samples);
+
+
+	list_for_each_entry(chain, &node->val, list) {
+		if (chain->ip >= PERF_CONTEXT_MAX)
+			continue;
+		ret += fprintf(fp, "                %s\n", callchain_list__sym_name(chain,
+					bf, sizeof(bf), false));
+	}
+
+	return ret;
+}
+
+static size_t callchain__fprintf_flat(FILE *fp, struct rb_root *tree,
+				      u64 total_samples)
+{
+	size_t ret = 0;
+	u32 entries_printed = 0;
+	struct callchain_node *chain;
+	struct rb_node *rb_node = rb_first(tree);
+
+	while (rb_node) {
+		chain = rb_entry(rb_node, struct callchain_node, rb_node);
+
+		ret += fprintf(fp, "           ");
+		ret += callchain_node__fprintf_value(chain, fp, total_samples);
+		ret += fprintf(fp, "\n");
+		ret += __callchain__fprintf_flat(fp, chain, total_samples);
+		ret += fprintf(fp, "\n");
+		if (++entries_printed == callchain_param.print_limit)
+			break;
+
+		rb_node = rb_next(rb_node);
+	}
+
+	return ret;
+}
+
+static size_t __callchain__fprintf_folded(FILE *fp, struct callchain_node *node)
+{
+	const char *sep = symbol_conf.field_sep ?: ";";
+	struct callchain_list *chain;
+	size_t ret = 0;
+	char bf[1024];
+	bool first;
+
+	if (!node)
+		return 0;
+
+	ret += __callchain__fprintf_folded(fp, node->parent);
+
+	first = (ret == 0);
+	list_for_each_entry(chain, &node->val, list) {
+		if (chain->ip >= PERF_CONTEXT_MAX)
+			continue;
+		ret += fprintf(fp, "%s%s", first ? "" : sep,
+			       callchain_list__sym_name(chain,
+						bf, sizeof(bf), false));
+		first = false;
+	}
+
+	return ret;
+}
+
+static size_t callchain__fprintf_folded(FILE *fp, struct rb_root *tree,
+					u64 total_samples)
+{
+	size_t ret = 0;
+	u32 entries_printed = 0;
+	struct callchain_node *chain;
+	struct rb_node *rb_node = rb_first(tree);
+
+	while (rb_node) {
+
+		chain = rb_entry(rb_node, struct callchain_node, rb_node);
+
+		ret += callchain_node__fprintf_value(chain, fp, total_samples);
+		ret += fprintf(fp, " ");
+		ret += __callchain__fprintf_folded(fp, chain);
+		ret += fprintf(fp, "\n");
+		if (++entries_printed == callchain_param.print_limit)
+			break;
+
+		rb_node = rb_next(rb_node);
+	}
+
+	return ret;
+}
+
+static size_t hist_entry_callchain__fprintf(struct hist_entry *he,
+					    u64 total_samples, int left_margin,
+					    FILE *fp)
+{
+	u64 parent_samples = he->stat.period;
+
+	if (symbol_conf.cumulate_callchain)
+		parent_samples = he->stat_acc->period;
+
+	switch (callchain_param.mode) {
+	case CHAIN_GRAPH_REL:
+		return callchain__fprintf_graph(fp, &he->sorted_chain, total_samples,
+						parent_samples, left_margin);
+		break;
+	case CHAIN_GRAPH_ABS:
+		return callchain__fprintf_graph(fp, &he->sorted_chain, total_samples,
+						parent_samples, left_margin);
+		break;
+	case CHAIN_FLAT:
+		return callchain__fprintf_flat(fp, &he->sorted_chain, total_samples);
+		break;
+	case CHAIN_FOLDED:
+		return callchain__fprintf_folded(fp, &he->sorted_chain, total_samples);
+		break;
+	case CHAIN_NONE:
+		break;
+	default:
+		pr_err("Bad callchain mode\n");
+	}
+
+	return 0;
+}
+
+int __hist_entry__snprintf(struct hist_entry *he, struct perf_hpp *hpp,
+			   struct perf_hpp_list *hpp_list)
+{
+	const char *sep = symbol_conf.field_sep;
+	struct perf_hpp_fmt *fmt;
+	char *start = hpp->buf;
+	int ret;
+	bool first = true;
+
+	if (symbol_conf.exclude_other && !he->parent)
+		return 0;
+
+	perf_hpp_list__for_each_format(hpp_list, fmt) {
+		if (perf_hpp__should_skip(fmt, he->hists))
+			continue;
+
+		/*
+		 * If there's no field_sep, we still need
+		 * to display initial '  '.
+		 */
+		if (!sep || !first) {
+			ret = scnprintf(hpp->buf, hpp->size, "%s", sep ?: "  ");
+			advance_hpp(hpp, ret);
+		} else
+			first = false;
+
+		if (perf_hpp__use_color() && fmt->color)
+			ret = fmt->color(fmt, hpp, he);
+		else
+			ret = fmt->entry(fmt, hpp, he);
+
+		ret = hist_entry__snprintf_alignment(he, hpp, fmt, ret);
+		advance_hpp(hpp, ret);
+	}
+
+	return hpp->buf - start;
+}
+
+static int hist_entry__snprintf(struct hist_entry *he, struct perf_hpp *hpp)
+{
+	return __hist_entry__snprintf(he, hpp, he->hists->hpp_list);
+}
+
+static int hist_entry__hierarchy_fprintf(struct hist_entry *he,
+					 struct perf_hpp *hpp,
+					 struct hists *hists,
+					 FILE *fp)
+{
+	const char *sep = symbol_conf.field_sep;
+	struct perf_hpp_fmt *fmt;
+	struct perf_hpp_list_node *fmt_node;
+	char *buf = hpp->buf;
+	size_t size = hpp->size;
+	int ret, printed = 0;
+	bool first = true;
+
+	if (symbol_conf.exclude_other && !he->parent)
+		return 0;
+
+	ret = scnprintf(hpp->buf, hpp->size, "%*s", he->depth * HIERARCHY_INDENT, "");
+	advance_hpp(hpp, ret);
+
+	/* the first hpp_list_node is for overhead columns */
+	fmt_node = list_first_entry(&hists->hpp_formats,
+				    struct perf_hpp_list_node, list);
+	perf_hpp_list__for_each_format(&fmt_node->hpp, fmt) {
+		/*
+		 * If there's no field_sep, we still need
+		 * to display initial '  '.
+		 */
+		if (!sep || !first) {
+			ret = scnprintf(hpp->buf, hpp->size, "%s", sep ?: "  ");
+			advance_hpp(hpp, ret);
+		} else
+			first = false;
+
+		if (perf_hpp__use_color() && fmt->color)
+			ret = fmt->color(fmt, hpp, he);
+		else
+			ret = fmt->entry(fmt, hpp, he);
+
+		ret = hist_entry__snprintf_alignment(he, hpp, fmt, ret);
+		advance_hpp(hpp, ret);
+	}
+
+	if (!sep)
+		ret = scnprintf(hpp->buf, hpp->size, "%*s",
+				(hists->nr_hpp_node - 2) * HIERARCHY_INDENT, "");
+	advance_hpp(hpp, ret);
+
+	printed += fprintf(fp, "%s", buf);
+
+	perf_hpp_list__for_each_format(he->hpp_list, fmt) {
+		hpp->buf  = buf;
+		hpp->size = size;
+
+		/*
+		 * No need to call hist_entry__snprintf_alignment() since this
+		 * fmt is always the last column in the hierarchy mode.
+		 */
+		if (perf_hpp__use_color() && fmt->color)
+			fmt->color(fmt, hpp, he);
+		else
+			fmt->entry(fmt, hpp, he);
+
+		/*
+		 * dynamic entries are right-aligned but we want left-aligned
+		 * in the hierarchy mode
+		 */
+		printed += fprintf(fp, "%s%s", sep ?: "  ", skip_spaces(buf));
+	}
+	printed += putc('\n', fp);
+
+	if (he->leaf && hist_entry__has_callchains(he) && symbol_conf.use_callchain) {
+		u64 total = hists__total_period(hists);
+
+		printed += hist_entry_callchain__fprintf(he, total, 0, fp);
+		goto out;
+	}
+
+out:
+	return printed;
+}
+
+static int hist_entry__block_fprintf(struct hist_entry *he,
+				     char *bf, size_t size,
+				     FILE *fp)
+{
+	struct block_hist *bh = container_of(he, struct block_hist, he);
+	int ret = 0;
+
+	for (unsigned int i = 0; i < bh->block_hists.nr_entries; i++) {
+		struct perf_hpp hpp = {
+			.buf		= bf,
+			.size		= size,
+			.skip		= false,
+		};
+
+		bh->block_idx = i;
+		hist_entry__snprintf(he, &hpp);
+
+		if (!hpp.skip)
+			ret += fprintf(fp, "%s\n", bf);
+	}
+
+	return ret;
+}
+
+static int hist_entry__individual_block_fprintf(struct hist_entry *he,
+						char *bf, size_t size,
+						FILE *fp)
+{
+	int ret = 0;
+
+	struct perf_hpp hpp = {
+		.buf		= bf,
+		.size		= size,
+		.skip		= false,
+	};
+
+	hist_entry__snprintf(he, &hpp);
+	if (!hpp.skip)
+		ret += fprintf(fp, "%s\n", bf);
+
+	return ret;
+}
+
+static int hist_entry__fprintf(struct hist_entry *he, size_t size,
+			       char *bf, size_t bfsz, FILE *fp,
+			       bool ignore_callchains)
+{
+	int ret;
+	int callchain_ret = 0;
+	struct perf_hpp hpp = {
+		.buf		= bf,
+		.size		= size,
+	};
+	struct hists *hists = he->hists;
+	u64 total_period = hists->stats.total_period;
+
+	if (size == 0 || size > bfsz)
+		size = hpp.size = bfsz;
+
+	if (symbol_conf.report_hierarchy)
+		return hist_entry__hierarchy_fprintf(he, &hpp, hists, fp);
+
+	if (symbol_conf.report_block)
+		return hist_entry__block_fprintf(he, bf, size, fp);
+
+	if (symbol_conf.report_individual_block)
+		return hist_entry__individual_block_fprintf(he, bf, size, fp);
+
+	hist_entry__snprintf(he, &hpp);
+
+	ret = fprintf(fp, "%s\n", bf);
+
+	if (hist_entry__has_callchains(he) && !ignore_callchains)
+		callchain_ret = hist_entry_callchain__fprintf(he, total_period,
+							      0, fp);
+
+	ret += callchain_ret;
+
+	return ret;
+}
+
+static int print_hierarchy_indent(const char *sep, int indent,
+				  const char *line, FILE *fp)
+{
+	int width;
+
+	if (sep != NULL || indent < 2)
+		return 0;
+
+	width = (indent - 2) * HIERARCHY_INDENT;
+
+	return fprintf(fp, "%-*.*s", width, width, line);
+}
+
+static int hists__fprintf_hierarchy_headers(struct hists *hists,
+					    struct perf_hpp *hpp, FILE *fp)
+{
+	bool first_node, first_col;
+	int indent;
+	int depth;
+	unsigned width = 0;
+	unsigned header_width = 0;
+	struct perf_hpp_fmt *fmt;
+	struct perf_hpp_list_node *fmt_node;
+	struct perf_hpp_list *hpp_list = hists->hpp_list;
+	const char *sep = symbol_conf.field_sep;
+
+	indent = hists->nr_hpp_node;
+
+	/* the first hpp_list_node is for overhead columns */
+	fmt_node = list_first_entry(&hists->hpp_formats,
+				    struct perf_hpp_list_node, list);
+
+	for (int line = 0; line < hpp_list->nr_header_lines; line++) {
+		/* first # is displayed one level up */
+		if (line)
+			fprintf(fp, "# ");
+
+		/* preserve max indent depth for column headers */
+		print_hierarchy_indent(sep, indent, " ", fp);
+
+		perf_hpp_list__for_each_format(&fmt_node->hpp, fmt) {
+			fmt->header(fmt, hpp, hists, line, NULL);
+			fprintf(fp, "%s%s", hpp->buf, sep ?: "  ");
+		}
+
+		if (line < hpp_list->nr_header_lines - 1)
+			goto next_line;
+
+		/* combine sort headers with ' / ' */
+		first_node = true;
+		list_for_each_entry_continue(fmt_node, &hists->hpp_formats, list) {
+			if (!first_node)
+				header_width += fprintf(fp, " / ");
+			first_node = false;
+
+			first_col = true;
+			perf_hpp_list__for_each_format(&fmt_node->hpp, fmt) {
+				if (perf_hpp__should_skip(fmt, hists))
+					continue;
+
+				if (!first_col)
+					header_width += fprintf(fp, "+");
+				first_col = false;
+
+				fmt->header(fmt, hpp, hists, line, NULL);
+
+				header_width += fprintf(fp, "%s", strim(hpp->buf));
+			}
+		}
+
+next_line:
+		fprintf(fp, "\n");
+	}
+
+	fprintf(fp, "# ");
+
+	/* preserve max indent depth for initial dots */
+	print_hierarchy_indent(sep, indent, dots, fp);
+
+	/* the first hpp_list_node is for overhead columns */
+	fmt_node = list_first_entry(&hists->hpp_formats,
+				    struct perf_hpp_list_node, list);
+
+	first_col = true;
+	perf_hpp_list__for_each_format(&fmt_node->hpp, fmt) {
+		if (!first_col)
+			fprintf(fp, "%s", sep ?: "..");
+		first_col = false;
+
+		width = fmt->width(fmt, hpp, hists);
+		fprintf(fp, "%.*s", width, dots);
+	}
+
+	depth = 0;
+	list_for_each_entry_continue(fmt_node, &hists->hpp_formats, list) {
+		first_col = true;
+		width = depth * HIERARCHY_INDENT;
+
+		perf_hpp_list__for_each_format(&fmt_node->hpp, fmt) {
+			if (perf_hpp__should_skip(fmt, hists))
+				continue;
+
+			if (!first_col)
+				width++;  /* for '+' sign between column header */
+			first_col = false;
+
+			width += fmt->width(fmt, hpp, hists);
+		}
+
+		if (width > header_width)
+			header_width = width;
+
+		depth++;
+	}
+
+	fprintf(fp, "%s%-.*s", sep ?: "  ", header_width, dots);
+
+	fprintf(fp, "\n#\n");
+
+	return 2;
+}
+
+static void fprintf_line(struct hists *hists, struct perf_hpp *hpp,
+			 int line, FILE *fp)
+{
+	struct perf_hpp_fmt *fmt;
+	const char *sep = symbol_conf.field_sep;
+	bool first = true;
+	int span = 0;
+
+	hists__for_each_format(hists, fmt) {
+		if (perf_hpp__should_skip(fmt, hists))
+			continue;
+
+		if (!first && !span)
+			fprintf(fp, "%s", sep ?: "  ");
+		else
+			first = false;
+
+		fmt->header(fmt, hpp, hists, line, &span);
+
+		if (!span)
+			fprintf(fp, "%s", hpp->buf);
+	}
+}
+
+static int
+hists__fprintf_standard_headers(struct hists *hists,
+				struct perf_hpp *hpp,
+				FILE *fp)
+{
+	struct perf_hpp_list *hpp_list = hists->hpp_list;
+	struct perf_hpp_fmt *fmt;
+	unsigned int width;
+	const char *sep = symbol_conf.field_sep;
+	bool first = true;
+	int line;
+
+	for (line = 0; line < hpp_list->nr_header_lines; line++) {
+		/* first # is displayed one level up */
+		if (line)
+			fprintf(fp, "# ");
+		fprintf_line(hists, hpp, line, fp);
+		fprintf(fp, "\n");
+	}
+
+	if (sep)
+		return hpp_list->nr_header_lines;
+
+	first = true;
+
+	fprintf(fp, "# ");
+
+	hists__for_each_format(hists, fmt) {
+		unsigned int i;
+
+		if (perf_hpp__should_skip(fmt, hists))
+			continue;
+
+		if (!first)
+			fprintf(fp, "%s", sep ?: "  ");
+		else
+			first = false;
+
+		width = fmt->width(fmt, hpp, hists);
+		for (i = 0; i < width; i++)
+			fprintf(fp, ".");
+	}
+
+	fprintf(fp, "\n");
+	fprintf(fp, "#\n");
+	return hpp_list->nr_header_lines + 2;
+}
+
+int hists__fprintf_headers(struct hists *hists, FILE *fp)
+{
+	char bf[1024];
+	struct perf_hpp dummy_hpp = {
+		.buf	= bf,
+		.size	= sizeof(bf),
+	};
+
+	fprintf(fp, "# ");
+
+	if (symbol_conf.report_hierarchy)
+		return hists__fprintf_hierarchy_headers(hists, &dummy_hpp, fp);
+	else
+		return hists__fprintf_standard_headers(hists, &dummy_hpp, fp);
+
+}
+
+size_t hists__fprintf(struct hists *hists, bool show_header, int max_rows,
+		      int max_cols, float min_pcnt, FILE *fp,
+		      bool ignore_callchains)
+{
+	struct rb_node *nd;
+	size_t ret = 0;
+	const char *sep = symbol_conf.field_sep;
+	int nr_rows = 0;
+	size_t linesz;
+	char *line = NULL;
+	unsigned indent;
+
+	init_rem_hits();
+
+	hists__reset_column_width(hists);
+
+	if (symbol_conf.col_width_list_str)
+		perf_hpp__set_user_width(symbol_conf.col_width_list_str);
+
+	if (show_header)
+		nr_rows += hists__fprintf_headers(hists, fp);
+
+	if (max_rows && nr_rows >= max_rows)
+		goto out;
+
+	linesz = hists__sort_list_width(hists) + 3 + 1;
+	linesz += perf_hpp__color_overhead();
+	line = malloc(linesz);
+	if (line == NULL) {
+		ret = -1;
+		goto out;
+	}
+
+	indent = hists__overhead_width(hists) + 4;
+
+	for (nd = rb_first_cached(&hists->entries); nd;
+	     nd = __rb_hierarchy_next(nd, HMD_FORCE_CHILD)) {
+		struct hist_entry *h = rb_entry(nd, struct hist_entry, rb_node);
+		float percent;
+
+		if (h->filtered)
+			continue;
+
+		if (symbol_conf.report_individual_block)
+			percent = block_info__total_cycles_percent(h);
+		else
+			percent = hist_entry__get_percent_limit(h);
+
+		if (percent < min_pcnt)
+			continue;
+
+		ret += hist_entry__fprintf(h, max_cols, line, linesz, fp, ignore_callchains);
+
+		if (max_rows && ++nr_rows >= max_rows)
+			break;
+
+		/*
+		 * If all children are filtered out or percent-limited,
+		 * display "no entry >= x.xx%" message.
+		 */
+		if (!h->leaf && !hist_entry__has_hierarchy_children(h, min_pcnt)) {
+			int depth = hists->nr_hpp_node + h->depth + 1;
+
+			print_hierarchy_indent(sep, depth, " ", fp);
+			fprintf(fp, "%*sno entry >= %.2f%%\n", indent, "", min_pcnt);
+
+			if (max_rows && ++nr_rows >= max_rows)
+				break;
+		}
+
+		if (h->ms.map == NULL && verbose > 1) {
+			maps__fprintf(thread__maps(h->thread), fp);
+			fprintf(fp, "%.10s end\n", graph_dotted_line);
+		}
+	}
+
+	free(line);
+out:
+	zfree(&rem_sq_bracket);
+
+	return ret;
+}
+
+size_t events_stats__fprintf(struct events_stats *stats, FILE *fp)
+{
+	int i;
+	size_t ret = 0;
+	u32 total = stats->nr_events[0];
+
+	for (i = 0; i < PERF_RECORD_HEADER_MAX; ++i) {
+		const char *name;
+
+		name = perf_event__name(i);
+		if (!strcmp(name, "UNKNOWN"))
+			continue;
+		if (symbol_conf.skip_empty && !stats->nr_events[i])
+			continue;
+
+		if (i && total) {
+			ret += fprintf(fp, "%20s events: %10d  (%4.1f%%)\n",
+				       name, stats->nr_events[i],
+				       100.0 * stats->nr_events[i] / total);
+		} else {
+			ret += fprintf(fp, "%20s events: %10d\n",
+				       name, stats->nr_events[i]);
+		}
+	}
+
+	return ret;
+}