v4.19.13 snapshot.
diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
new file mode 100644
index 0000000..5ac1570
--- /dev/null
+++ b/tools/perf/util/config.c
@@ -0,0 +1,830 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * config.c
+ *
+ * Helper functions for parsing config items.
+ * Originally copied from GIT source.
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ * Copyright (C) Johannes Schindelin, 2005
+ *
+ */
+#include <errno.h>
+#include <sys/param.h>
+#include "util.h"
+#include "cache.h"
+#include <subcmd/exec-cmd.h>
+#include "util/hist.h"  /* perf_hist_config */
+#include "util/llvm-utils.h"   /* perf_llvm_config */
+#include "config.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <linux/string.h>
+
+#include "sane_ctype.h"
+
+#define MAXNAME (256)
+
+#define DEBUG_CACHE_DIR ".debug"
+
+
+char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
+
+static FILE *config_file;
+static const char *config_file_name;
+static int config_linenr;
+static int config_file_eof;
+static struct perf_config_set *config_set;
+
+const char *config_exclusive_filename;
+
+static int get_next_char(void)
+{
+	int c;
+	FILE *f;
+
+	c = '\n';
+	if ((f = config_file) != NULL) {
+		c = fgetc(f);
+		if (c == '\r') {
+			/* DOS like systems */
+			c = fgetc(f);
+			if (c != '\n') {
+				ungetc(c, f);
+				c = '\r';
+			}
+		}
+		if (c == '\n')
+			config_linenr++;
+		if (c == EOF) {
+			config_file_eof = 1;
+			c = '\n';
+		}
+	}
+	return c;
+}
+
+static char *parse_value(void)
+{
+	static char value[1024];
+	int quote = 0, comment = 0, space = 0;
+	size_t len = 0;
+
+	for (;;) {
+		int c = get_next_char();
+
+		if (len >= sizeof(value) - 1)
+			return NULL;
+		if (c == '\n') {
+			if (quote)
+				return NULL;
+			value[len] = 0;
+			return value;
+		}
+		if (comment)
+			continue;
+		if (isspace(c) && !quote) {
+			space = 1;
+			continue;
+		}
+		if (!quote) {
+			if (c == ';' || c == '#') {
+				comment = 1;
+				continue;
+			}
+		}
+		if (space) {
+			if (len)
+				value[len++] = ' ';
+			space = 0;
+		}
+		if (c == '\\') {
+			c = get_next_char();
+			switch (c) {
+			case '\n':
+				continue;
+			case 't':
+				c = '\t';
+				break;
+			case 'b':
+				c = '\b';
+				break;
+			case 'n':
+				c = '\n';
+				break;
+			/* Some characters escape as themselves */
+			case '\\': case '"':
+				break;
+			/* Reject unknown escape sequences */
+			default:
+				return NULL;
+			}
+			value[len++] = c;
+			continue;
+		}
+		if (c == '"') {
+			quote = 1-quote;
+			continue;
+		}
+		value[len++] = c;
+	}
+}
+
+static inline int iskeychar(int c)
+{
+	return isalnum(c) || c == '-' || c == '_';
+}
+
+static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
+{
+	int c;
+	char *value;
+
+	/* Get the full name */
+	for (;;) {
+		c = get_next_char();
+		if (config_file_eof)
+			break;
+		if (!iskeychar(c))
+			break;
+		name[len++] = c;
+		if (len >= MAXNAME)
+			return -1;
+	}
+	name[len] = 0;
+	while (c == ' ' || c == '\t')
+		c = get_next_char();
+
+	value = NULL;
+	if (c != '\n') {
+		if (c != '=')
+			return -1;
+		value = parse_value();
+		if (!value)
+			return -1;
+	}
+	return fn(name, value, data);
+}
+
+static int get_extended_base_var(char *name, int baselen, int c)
+{
+	do {
+		if (c == '\n')
+			return -1;
+		c = get_next_char();
+	} while (isspace(c));
+
+	/* We require the format to be '[base "extension"]' */
+	if (c != '"')
+		return -1;
+	name[baselen++] = '.';
+
+	for (;;) {
+		int ch = get_next_char();
+
+		if (ch == '\n')
+			return -1;
+		if (ch == '"')
+			break;
+		if (ch == '\\') {
+			ch = get_next_char();
+			if (ch == '\n')
+				return -1;
+		}
+		name[baselen++] = ch;
+		if (baselen > MAXNAME / 2)
+			return -1;
+	}
+
+	/* Final ']' */
+	if (get_next_char() != ']')
+		return -1;
+	return baselen;
+}
+
+static int get_base_var(char *name)
+{
+	int baselen = 0;
+
+	for (;;) {
+		int c = get_next_char();
+		if (config_file_eof)
+			return -1;
+		if (c == ']')
+			return baselen;
+		if (isspace(c))
+			return get_extended_base_var(name, baselen, c);
+		if (!iskeychar(c) && c != '.')
+			return -1;
+		if (baselen > MAXNAME / 2)
+			return -1;
+		name[baselen++] = tolower(c);
+	}
+}
+
+static int perf_parse_file(config_fn_t fn, void *data)
+{
+	int comment = 0;
+	int baselen = 0;
+	static char var[MAXNAME];
+
+	/* U+FEFF Byte Order Mark in UTF8 */
+	static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
+	const unsigned char *bomptr = utf8_bom;
+
+	for (;;) {
+		int line, c = get_next_char();
+
+		if (bomptr && *bomptr) {
+			/* We are at the file beginning; skip UTF8-encoded BOM
+			 * if present. Sane editors won't put this in on their
+			 * own, but e.g. Windows Notepad will do it happily. */
+			if ((unsigned char) c == *bomptr) {
+				bomptr++;
+				continue;
+			} else {
+				/* Do not tolerate partial BOM. */
+				if (bomptr != utf8_bom)
+					break;
+				/* No BOM at file beginning. Cool. */
+				bomptr = NULL;
+			}
+		}
+		if (c == '\n') {
+			if (config_file_eof)
+				return 0;
+			comment = 0;
+			continue;
+		}
+		if (comment || isspace(c))
+			continue;
+		if (c == '#' || c == ';') {
+			comment = 1;
+			continue;
+		}
+		if (c == '[') {
+			baselen = get_base_var(var);
+			if (baselen <= 0)
+				break;
+			var[baselen++] = '.';
+			var[baselen] = 0;
+			continue;
+		}
+		if (!isalpha(c))
+			break;
+		var[baselen] = tolower(c);
+
+		/*
+		 * The get_value function might or might not reach the '\n',
+		 * so saving the current line number for error reporting.
+		 */
+		line = config_linenr;
+		if (get_value(fn, data, var, baselen+1) < 0) {
+			config_linenr = line;
+			break;
+		}
+	}
+	pr_err("bad config file line %d in %s\n", config_linenr, config_file_name);
+	return -1;
+}
+
+static int parse_unit_factor(const char *end, unsigned long *val)
+{
+	if (!*end)
+		return 1;
+	else if (!strcasecmp(end, "k")) {
+		*val *= 1024;
+		return 1;
+	}
+	else if (!strcasecmp(end, "m")) {
+		*val *= 1024 * 1024;
+		return 1;
+	}
+	else if (!strcasecmp(end, "g")) {
+		*val *= 1024 * 1024 * 1024;
+		return 1;
+	}
+	return 0;
+}
+
+static int perf_parse_llong(const char *value, long long *ret)
+{
+	if (value && *value) {
+		char *end;
+		long long val = strtoll(value, &end, 0);
+		unsigned long factor = 1;
+
+		if (!parse_unit_factor(end, &factor))
+			return 0;
+		*ret = val * factor;
+		return 1;
+	}
+	return 0;
+}
+
+static int perf_parse_long(const char *value, long *ret)
+{
+	if (value && *value) {
+		char *end;
+		long val = strtol(value, &end, 0);
+		unsigned long factor = 1;
+		if (!parse_unit_factor(end, &factor))
+			return 0;
+		*ret = val * factor;
+		return 1;
+	}
+	return 0;
+}
+
+static void bad_config(const char *name)
+{
+	if (config_file_name)
+		pr_warning("bad config value for '%s' in %s, ignoring...\n", name, config_file_name);
+	else
+		pr_warning("bad config value for '%s', ignoring...\n", name);
+}
+
+int perf_config_u64(u64 *dest, const char *name, const char *value)
+{
+	long long ret = 0;
+
+	if (!perf_parse_llong(value, &ret)) {
+		bad_config(name);
+		return -1;
+	}
+
+	*dest = ret;
+	return 0;
+}
+
+int perf_config_int(int *dest, const char *name, const char *value)
+{
+	long ret = 0;
+	if (!perf_parse_long(value, &ret)) {
+		bad_config(name);
+		return -1;
+	}
+	*dest = ret;
+	return 0;
+}
+
+static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
+{
+	int ret;
+
+	*is_bool = 1;
+	if (!value)
+		return 1;
+	if (!*value)
+		return 0;
+	if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
+		return 1;
+	if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
+		return 0;
+	*is_bool = 0;
+	return perf_config_int(&ret, name, value) < 0 ? -1 : ret;
+}
+
+int perf_config_bool(const char *name, const char *value)
+{
+	int discard;
+	return !!perf_config_bool_or_int(name, value, &discard);
+}
+
+static const char *perf_config_dirname(const char *name, const char *value)
+{
+	if (!name)
+		return NULL;
+	return value;
+}
+
+static int perf_buildid_config(const char *var, const char *value)
+{
+	/* same dir for all commands */
+	if (!strcmp(var, "buildid.dir")) {
+		const char *dir = perf_config_dirname(var, value);
+
+		if (!dir) {
+			pr_err("Invalid buildid directory!\n");
+			return -1;
+		}
+		strncpy(buildid_dir, dir, MAXPATHLEN-1);
+		buildid_dir[MAXPATHLEN-1] = '\0';
+	}
+
+	return 0;
+}
+
+static int perf_default_core_config(const char *var __maybe_unused,
+				    const char *value __maybe_unused)
+{
+	/* Add other config variables here. */
+	return 0;
+}
+
+static int perf_ui_config(const char *var, const char *value)
+{
+	/* Add other config variables here. */
+	if (!strcmp(var, "ui.show-headers"))
+		symbol_conf.show_hist_headers = perf_config_bool(var, value);
+
+	return 0;
+}
+
+int perf_default_config(const char *var, const char *value,
+			void *dummy __maybe_unused)
+{
+	if (strstarts(var, "core."))
+		return perf_default_core_config(var, value);
+
+	if (strstarts(var, "hist."))
+		return perf_hist_config(var, value);
+
+	if (strstarts(var, "ui."))
+		return perf_ui_config(var, value);
+
+	if (strstarts(var, "call-graph."))
+		return perf_callchain_config(var, value);
+
+	if (strstarts(var, "llvm."))
+		return perf_llvm_config(var, value);
+
+	if (strstarts(var, "buildid."))
+		return perf_buildid_config(var, value);
+
+	/* Add other config variables here. */
+	return 0;
+}
+
+static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
+{
+	int ret;
+	FILE *f = fopen(filename, "r");
+
+	ret = -1;
+	if (f) {
+		config_file = f;
+		config_file_name = filename;
+		config_linenr = 1;
+		config_file_eof = 0;
+		ret = perf_parse_file(fn, data);
+		fclose(f);
+		config_file_name = NULL;
+	}
+	return ret;
+}
+
+const char *perf_etc_perfconfig(void)
+{
+	static const char *system_wide;
+	if (!system_wide)
+		system_wide = system_path(ETC_PERFCONFIG);
+	return system_wide;
+}
+
+static int perf_env_bool(const char *k, int def)
+{
+	const char *v = getenv(k);
+	return v ? perf_config_bool(k, v) : def;
+}
+
+static int perf_config_system(void)
+{
+	return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
+}
+
+static int perf_config_global(void)
+{
+	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
+}
+
+static struct perf_config_section *find_section(struct list_head *sections,
+						const char *section_name)
+{
+	struct perf_config_section *section;
+
+	list_for_each_entry(section, sections, node)
+		if (!strcmp(section->name, section_name))
+			return section;
+
+	return NULL;
+}
+
+static struct perf_config_item *find_config_item(const char *name,
+						 struct perf_config_section *section)
+{
+	struct perf_config_item *item;
+
+	list_for_each_entry(item, &section->items, node)
+		if (!strcmp(item->name, name))
+			return item;
+
+	return NULL;
+}
+
+static struct perf_config_section *add_section(struct list_head *sections,
+					       const char *section_name)
+{
+	struct perf_config_section *section = zalloc(sizeof(*section));
+
+	if (!section)
+		return NULL;
+
+	INIT_LIST_HEAD(&section->items);
+	section->name = strdup(section_name);
+	if (!section->name) {
+		pr_debug("%s: strdup failed\n", __func__);
+		free(section);
+		return NULL;
+	}
+
+	list_add_tail(&section->node, sections);
+	return section;
+}
+
+static struct perf_config_item *add_config_item(struct perf_config_section *section,
+						const char *name)
+{
+	struct perf_config_item *item = zalloc(sizeof(*item));
+
+	if (!item)
+		return NULL;
+
+	item->name = strdup(name);
+	if (!item->name) {
+		pr_debug("%s: strdup failed\n", __func__);
+		free(item);
+		return NULL;
+	}
+
+	list_add_tail(&item->node, &section->items);
+	return item;
+}
+
+static int set_value(struct perf_config_item *item, const char *value)
+{
+	char *val = strdup(value);
+
+	if (!val)
+		return -1;
+
+	zfree(&item->value);
+	item->value = val;
+	return 0;
+}
+
+static int collect_config(const char *var, const char *value,
+			  void *perf_config_set)
+{
+	int ret = -1;
+	char *ptr, *key;
+	char *section_name, *name;
+	struct perf_config_section *section = NULL;
+	struct perf_config_item *item = NULL;
+	struct perf_config_set *set = perf_config_set;
+	struct list_head *sections;
+
+	if (set == NULL)
+		return -1;
+
+	sections = &set->sections;
+	key = ptr = strdup(var);
+	if (!key) {
+		pr_debug("%s: strdup failed\n", __func__);
+		return -1;
+	}
+
+	section_name = strsep(&ptr, ".");
+	name = ptr;
+	if (name == NULL || value == NULL)
+		goto out_free;
+
+	section = find_section(sections, section_name);
+	if (!section) {
+		section = add_section(sections, section_name);
+		if (!section)
+			goto out_free;
+	}
+
+	item = find_config_item(name, section);
+	if (!item) {
+		item = add_config_item(section, name);
+		if (!item)
+			goto out_free;
+	}
+
+	/* perf_config_set can contain both user and system config items.
+	 * So we should know where each value is from.
+	 * The classification would be needed when a particular config file
+	 * is overwrited by setting feature i.e. set_config().
+	 */
+	if (strcmp(config_file_name, perf_etc_perfconfig()) == 0) {
+		section->from_system_config = true;
+		item->from_system_config = true;
+	} else {
+		section->from_system_config = false;
+		item->from_system_config = false;
+	}
+
+	ret = set_value(item, value);
+	return ret;
+
+out_free:
+	free(key);
+	return -1;
+}
+
+int perf_config_set__collect(struct perf_config_set *set, const char *file_name,
+			     const char *var, const char *value)
+{
+	config_file_name = file_name;
+	return collect_config(var, value, set);
+}
+
+static int perf_config_set__init(struct perf_config_set *set)
+{
+	int ret = -1;
+	const char *home = NULL;
+	char *user_config;
+	struct stat st;
+
+	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
+	if (config_exclusive_filename)
+		return perf_config_from_file(collect_config, config_exclusive_filename, set);
+	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
+		if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
+			goto out;
+	}
+
+	home = getenv("HOME");
+
+	/*
+	 * Skip reading user config if:
+	 *   - there is no place to read it from (HOME)
+	 *   - we are asked not to (PERF_CONFIG_NOGLOBAL=1)
+	 */
+	if (!home || !*home || !perf_config_global())
+		return 0;
+
+	user_config = strdup(mkpath("%s/.perfconfig", home));
+	if (user_config == NULL) {
+		pr_warning("Not enough memory to process %s/.perfconfig, ignoring it.", home);
+		goto out;
+	}
+
+	if (stat(user_config, &st) < 0) {
+		if (errno == ENOENT)
+			ret = 0;
+		goto out_free;
+	}
+
+	ret = 0;
+
+	if (st.st_uid && (st.st_uid != geteuid())) {
+		pr_warning("File %s not owned by current user or root, ignoring it.", user_config);
+		goto out_free;
+	}
+
+	if (st.st_size)
+		ret = perf_config_from_file(collect_config, user_config, set);
+
+out_free:
+	free(user_config);
+out:
+	return ret;
+}
+
+struct perf_config_set *perf_config_set__new(void)
+{
+	struct perf_config_set *set = zalloc(sizeof(*set));
+
+	if (set) {
+		INIT_LIST_HEAD(&set->sections);
+		perf_config_set__init(set);
+	}
+
+	return set;
+}
+
+static int perf_config__init(void)
+{
+	if (config_set == NULL)
+		config_set = perf_config_set__new();
+
+	return config_set == NULL;
+}
+
+int perf_config(config_fn_t fn, void *data)
+{
+	int ret = 0;
+	char key[BUFSIZ];
+	struct perf_config_section *section;
+	struct perf_config_item *item;
+
+	if (config_set == NULL && perf_config__init())
+		return -1;
+
+	perf_config_set__for_each_entry(config_set, section, item) {
+		char *value = item->value;
+
+		if (value) {
+			scnprintf(key, sizeof(key), "%s.%s",
+				  section->name, item->name);
+			ret = fn(key, value, data);
+			if (ret < 0) {
+				pr_err("Error: wrong config key-value pair %s=%s\n",
+				       key, value);
+				break;
+			}
+		}
+	}
+
+	return ret;
+}
+
+void perf_config__exit(void)
+{
+	perf_config_set__delete(config_set);
+	config_set = NULL;
+}
+
+void perf_config__refresh(void)
+{
+	perf_config__exit();
+	perf_config__init();
+}
+
+static void perf_config_item__delete(struct perf_config_item *item)
+{
+	zfree(&item->name);
+	zfree(&item->value);
+	free(item);
+}
+
+static void perf_config_section__purge(struct perf_config_section *section)
+{
+	struct perf_config_item *item, *tmp;
+
+	list_for_each_entry_safe(item, tmp, &section->items, node) {
+		list_del_init(&item->node);
+		perf_config_item__delete(item);
+	}
+}
+
+static void perf_config_section__delete(struct perf_config_section *section)
+{
+	perf_config_section__purge(section);
+	zfree(&section->name);
+	free(section);
+}
+
+static void perf_config_set__purge(struct perf_config_set *set)
+{
+	struct perf_config_section *section, *tmp;
+
+	list_for_each_entry_safe(section, tmp, &set->sections, node) {
+		list_del_init(&section->node);
+		perf_config_section__delete(section);
+	}
+}
+
+void perf_config_set__delete(struct perf_config_set *set)
+{
+	if (set == NULL)
+		return;
+
+	perf_config_set__purge(set);
+	free(set);
+}
+
+/*
+ * Call this to report error for your variable that should not
+ * get a boolean value (i.e. "[my] var" means "true").
+ */
+int config_error_nonbool(const char *var)
+{
+	pr_err("Missing value for '%s'", var);
+	return -1;
+}
+
+void set_buildid_dir(const char *dir)
+{
+	if (dir)
+		scnprintf(buildid_dir, MAXPATHLEN-1, "%s", dir);
+
+	/* default to $HOME/.debug */
+	if (buildid_dir[0] == '\0') {
+		char *home = getenv("HOME");
+
+		if (home) {
+			snprintf(buildid_dir, MAXPATHLEN-1, "%s/%s",
+				 home, DEBUG_CACHE_DIR);
+		} else {
+			strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
+		}
+		buildid_dir[MAXPATHLEN-1] = '\0';
+	}
+	/* for communicating with external commands */
+	setenv("PERF_BUILDID_DIR", buildid_dir, 1);
+}