Initial file dump from open source releaseHEADmaster

1 files changed, 1269 insertions, 0 deletions

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
new file mode 100644
index 00000000..8cf3b542
--- /dev/null
+++ b/tools/perf/util/symbol.c
@@ -0,0 +1,1269 @@
+#include <dirent.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/param.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include "build-id.h"
+#include "util.h"
+#include "debug.h"
+#include "machine.h"
+#include "symbol.h"
+#include "strlist.h"
+
+#include <elf.h>
+#include <limits.h>
+#include <sys/utsname.h>
+
+#ifndef KSYM_NAME_LEN
+#define KSYM_NAME_LEN 256
+#endif
+
+static int dso__load_kernel_sym(struct dso *dso, struct map *map,
+				symbol_filter_t filter);
+static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
+			symbol_filter_t filter);
+int vmlinux_path__nr_entries;
+char **vmlinux_path;
+
+struct symbol_conf symbol_conf = {
+	.exclude_other	  = true,
+	.use_modules	  = true,
+	.try_vmlinux_path = true,
+	.annotate_src	  = true,
+	.demangle	  = true,
+	.symfs            = "",
+};
+
+static enum dso_binary_type binary_type_symtab[] = {
+	DSO_BINARY_TYPE__KALLSYMS,
+	DSO_BINARY_TYPE__GUEST_KALLSYMS,
+	DSO_BINARY_TYPE__JAVA_JIT,
+	DSO_BINARY_TYPE__DEBUGLINK,
+	DSO_BINARY_TYPE__BUILD_ID_CACHE,
+	DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
+	DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
+	DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
+	DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
+	DSO_BINARY_TYPE__GUEST_KMODULE,
+	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
+	DSO_BINARY_TYPE__NOT_FOUND,
+};
+
+#define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
+
+bool symbol_type__is_a(char symbol_type, enum map_type map_type)
+{
+	symbol_type = toupper(symbol_type);
+
+	switch (map_type) {
+	case MAP__FUNCTION:
+		return symbol_type == 'T' || symbol_type == 'W';
+	case MAP__VARIABLE:
+		return symbol_type == 'D';
+	default:
+		return false;
+	}
+}
+
+static int prefix_underscores_count(const char *str)
+{
+	const char *tail = str;
+
+	while (*tail == '_')
+		tail++;
+
+	return tail - str;
+}
+
+#define SYMBOL_A 0
+#define SYMBOL_B 1
+
+static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
+{
+	s64 a;
+	s64 b;
+
+	/* Prefer a symbol with non zero length */
+	a = syma->end - syma->start;
+	b = symb->end - symb->start;
+	if ((b == 0) && (a > 0))
+		return SYMBOL_A;
+	else if ((a == 0) && (b > 0))
+		return SYMBOL_B;
+
+	/* Prefer a non weak symbol over a weak one */
+	a = syma->binding == STB_WEAK;
+	b = symb->binding == STB_WEAK;
+	if (b && !a)
+		return SYMBOL_A;
+	if (a && !b)
+		return SYMBOL_B;
+
+	/* Prefer a global symbol over a non global one */
+	a = syma->binding == STB_GLOBAL;
+	b = symb->binding == STB_GLOBAL;
+	if (a && !b)
+		return SYMBOL_A;
+	if (b && !a)
+		return SYMBOL_B;
+
+	/* Prefer a symbol with less underscores */
+	a = prefix_underscores_count(syma->name);
+	b = prefix_underscores_count(symb->name);
+	if (b > a)
+		return SYMBOL_A;
+	else if (a > b)
+		return SYMBOL_B;
+
+	/* If all else fails, choose the symbol with the longest name */
+	if (strlen(syma->name) >= strlen(symb->name))
+		return SYMBOL_A;
+	else
+		return SYMBOL_B;
+}
+
+void symbols__fixup_duplicate(struct rb_root *symbols)
+{
+	struct rb_node *nd;
+	struct symbol *curr, *next;
+
+	nd = rb_first(symbols);
+
+	while (nd) {
+		curr = rb_entry(nd, struct symbol, rb_node);
+again:
+		nd = rb_next(&curr->rb_node);
+		next = rb_entry(nd, struct symbol, rb_node);
+
+		if (!nd)
+			break;
+
+		if (curr->start != next->start)
+			continue;
+
+		if (choose_best_symbol(curr, next) == SYMBOL_A) {
+			rb_erase(&next->rb_node, symbols);
+			goto again;
+		} else {
+			nd = rb_next(&curr->rb_node);
+			rb_erase(&curr->rb_node, symbols);
+		}
+	}
+}
+
+void symbols__fixup_end(struct rb_root *symbols)
+{
+	struct rb_node *nd, *prevnd = rb_first(symbols);
+	struct symbol *curr, *prev;
+
+	if (prevnd == NULL)
+		return;
+
+	curr = rb_entry(prevnd, struct symbol, rb_node);
+
+	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
+		prev = curr;
+		curr = rb_entry(nd, struct symbol, rb_node);
+
+		if (prev->end == prev->start && prev->end != curr->start)
+			prev->end = curr->start - 1;
+	}
+
+	/* Last entry */
+	if (curr->end == curr->start)
+		curr->end = roundup(curr->start, 4096);
+}
+
+void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
+{
+	struct map *prev, *curr;
+	struct rb_node *nd, *prevnd = rb_first(&mg->maps[type]);
+
+	if (prevnd == NULL)
+		return;
+
+	curr = rb_entry(prevnd, struct map, rb_node);
+
+	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
+		prev = curr;
+		curr = rb_entry(nd, struct map, rb_node);
+		prev->end = curr->start - 1;
+	}
+
+	/*
+	 * We still haven't the actual symbols, so guess the
+	 * last map final address.
+	 */
+	curr->end = ~0ULL;
+}
+
+struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
+{
+	size_t namelen = strlen(name) + 1;
+	struct symbol *sym = calloc(1, (symbol_conf.priv_size +
+					sizeof(*sym) + namelen));
+	if (sym == NULL)
+		return NULL;
+
+	if (symbol_conf.priv_size)
+		sym = ((void *)sym) + symbol_conf.priv_size;
+
+	sym->start   = start;
+	sym->end     = len ? start + len - 1 : start;
+	sym->binding = binding;
+	sym->namelen = namelen - 1;
+
+	pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
+		  __func__, name, start, sym->end);
+	memcpy(sym->name, name, namelen);
+
+	return sym;
+}
+
+void symbol__delete(struct symbol *sym)
+{
+	free(((void *)sym) - symbol_conf.priv_size);
+}
+
+size_t symbol__fprintf(struct symbol *sym, FILE *fp)
+{
+	return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n",
+		       sym->start, sym->end,
+		       sym->binding == STB_GLOBAL ? 'g' :
+		       sym->binding == STB_LOCAL  ? 'l' : 'w',
+		       sym->name);
+}
+
+size_t symbol__fprintf_symname_offs(const struct symbol *sym,
+				    const struct addr_location *al, FILE *fp)
+{
+	unsigned long offset;
+	size_t length;
+
+	if (sym && sym->name) {
+		length = fprintf(fp, "%s", sym->name);
+		if (al) {
+			offset = al->addr - sym->start;
+			length += fprintf(fp, "+0x%lx", offset);
+		}
+		return length;
+	} else
+		return fprintf(fp, "[unknown]");
+}
+
+size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
+{
+	return symbol__fprintf_symname_offs(sym, NULL, fp);
+}
+
+void symbols__delete(struct rb_root *symbols)
+{
+	struct symbol *pos;
+	struct rb_node *next = rb_first(symbols);
+
+	while (next) {
+		pos = rb_entry(next, struct symbol, rb_node);
+		next = rb_next(&pos->rb_node);
+		rb_erase(&pos->rb_node, symbols);
+		symbol__delete(pos);
+	}
+}
+
+void symbols__insert(struct rb_root *symbols, struct symbol *sym)
+{
+	struct rb_node **p = &symbols->rb_node;
+	struct rb_node *parent = NULL;
+	const u64 ip = sym->start;
+	struct symbol *s;
+
+	while (*p != NULL) {
+		parent = *p;
+		s = rb_entry(parent, struct symbol, rb_node);
+		if (ip < s->start)
+			p = &(*p)->rb_left;
+		else
+			p = &(*p)->rb_right;
+	}
+	rb_link_node(&sym->rb_node, parent, p);
+	rb_insert_color(&sym->rb_node, symbols);
+}
+
+static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
+{
+	struct rb_node *n;
+
+	if (symbols == NULL)
+		return NULL;
+
+	n = symbols->rb_node;
+
+	while (n) {
+		struct symbol *s = rb_entry(n, struct symbol, rb_node);
+
+		if (ip < s->start)
+			n = n->rb_left;
+		else if (ip > s->end)
+			n = n->rb_right;
+		else
+			return s;
+	}
+
+	return NULL;
+}
+
+struct symbol_name_rb_node {
+	struct rb_node	rb_node;
+	struct symbol	sym;
+};
+
+static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym)
+{
+	struct rb_node **p = &symbols->rb_node;
+	struct rb_node *parent = NULL;
+	struct symbol_name_rb_node *symn, *s;
+
+	symn = container_of(sym, struct symbol_name_rb_node, sym);
+
+	while (*p != NULL) {
+		parent = *p;
+		s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
+		if (strcmp(sym->name, s->sym.name) < 0)
+			p = &(*p)->rb_left;
+		else
+			p = &(*p)->rb_right;
+	}
+	rb_link_node(&symn->rb_node, parent, p);
+	rb_insert_color(&symn->rb_node, symbols);
+}
+
+static void symbols__sort_by_name(struct rb_root *symbols,
+				  struct rb_root *source)
+{
+	struct rb_node *nd;
+
+	for (nd = rb_first(source); nd; nd = rb_next(nd)) {
+		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
+		symbols__insert_by_name(symbols, pos);
+	}
+}
+
+static struct symbol *symbols__find_by_name(struct rb_root *symbols,
+					    const char *name)
+{
+	struct rb_node *n;
+
+	if (symbols == NULL)
+		return NULL;
+
+	n = symbols->rb_node;
+
+	while (n) {
+		struct symbol_name_rb_node *s;
+		int cmp;
+
+		s = rb_entry(n, struct symbol_name_rb_node, rb_node);
+		cmp = strcmp(name, s->sym.name);
+
+		if (cmp < 0)
+			n = n->rb_left;
+		else if (cmp > 0)
+			n = n->rb_right;
+		else
+			return &s->sym;
+	}
+
+	return NULL;
+}
+
+struct symbol *dso__find_symbol(struct dso *dso,
+				enum map_type type, u64 addr)
+{
+	return symbols__find(&dso->symbols[type], addr);
+}
+
+struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
+					const char *name)
+{
+	return symbols__find_by_name(&dso->symbol_names[type], name);
+}
+
+void dso__sort_by_name(struct dso *dso, enum map_type type)
+{
+	dso__set_sorted_by_name(dso, type);
+	return symbols__sort_by_name(&dso->symbol_names[type],
+				     &dso->symbols[type]);
+}
+
+size_t dso__fprintf_symbols_by_name(struct dso *dso,
+				    enum map_type type, FILE *fp)
+{
+	size_t ret = 0;
+	struct rb_node *nd;
+	struct symbol_name_rb_node *pos;
+
+	for (nd = rb_first(&dso->symbol_names[type]); nd; nd = rb_next(nd)) {
+		pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
+		fprintf(fp, "%s\n", pos->sym.name);
+	}
+
+	return ret;
+}
+
+int kallsyms__parse(const char *filename, void *arg,
+		    int (*process_symbol)(void *arg, const char *name,
+					  char type, u64 start))
+{
+	char *line = NULL;
+	size_t n;
+	int err = -1;
+	FILE *file = fopen(filename, "r");
+
+	if (file == NULL)
+		goto out_failure;
+
+	err = 0;
+
+	while (!feof(file)) {
+		u64 start;
+		int line_len, len;
+		char symbol_type;
+		char *symbol_name;
+
+		line_len = getline(&line, &n, file);
+		if (line_len < 0 || !line)
+			break;
+
+		line[--line_len] = '\0'; /* \n */
+
+		len = hex2u64(line, &start);
+
+		len++;
+		if (len + 2 >= line_len)
+			continue;
+
+		symbol_type = line[len];
+		len += 2;
+		symbol_name = line + len;
+		len = line_len - len;
+
+		if (len >= KSYM_NAME_LEN) {
+			err = -1;
+			break;
+		}
+
+		err = process_symbol(arg, symbol_name,
+				     symbol_type, start);
+		if (err)
+			break;
+	}
+
+	free(line);
+	fclose(file);
+	return err;
+
+out_failure:
+	return -1;
+}
+
+struct process_kallsyms_args {
+	struct map *map;
+	struct dso *dso;
+};
+
+static u8 kallsyms2elf_type(char type)
+{
+	if (type == 'W')
+		return STB_WEAK;
+
+	return isupper(type) ? STB_GLOBAL : STB_LOCAL;
+}
+
+static int map__process_kallsym_symbol(void *arg, const char *name,
+				       char type, u64 start)
+{
+	struct symbol *sym;
+	struct process_kallsyms_args *a = arg;
+	struct rb_root *root = &a->dso->symbols[a->map->type];
+
+	if (!symbol_type__is_a(type, a->map->type))
+		return 0;
+
+	/*
+	 * module symbols are not sorted so we add all
+	 * symbols, setting length to 0, and rely on
+	 * symbols__fixup_end() to fix it up.
+	 */
+	sym = symbol__new(start, 0, kallsyms2elf_type(type), name);
+	if (sym == NULL)
+		return -ENOMEM;
+	/*
+	 * We will pass the symbols to the filter later, in
+	 * map__split_kallsyms, when we have split the maps per module
+	 */
+	symbols__insert(root, sym);
+
+	return 0;
+}
+
+/*
+ * Loads the function entries in /proc/kallsyms into kernel_map->dso,
+ * so that we can in the next step set the symbol ->end address and then
+ * call kernel_maps__split_kallsyms.
+ */
+static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
+				  struct map *map)
+{
+	struct process_kallsyms_args args = { .map = map, .dso = dso, };
+	return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
+}
+
+/*
+ * Split the symbols into maps, making sure there are no overlaps, i.e. the
+ * kernel range is broken in several maps, named [kernel].N, as we don't have
+ * the original ELF section names vmlinux have.
+ */
+static int dso__split_kallsyms(struct dso *dso, struct map *map,
+			       symbol_filter_t filter)
+{
+	struct map_groups *kmaps = map__kmap(map)->kmaps;
+	struct machine *machine = kmaps->machine;
+	struct map *curr_map = map;
+	struct symbol *pos;
+	int count = 0, moved = 0;	
+	struct rb_root *root = &dso->symbols[map->type];
+	struct rb_node *next = rb_first(root);
+	int kernel_range = 0;
+
+	while (next) {
+		char *module;
+
+		pos = rb_entry(next, struct symbol, rb_node);
+		next = rb_next(&pos->rb_node);
+
+		module = strchr(pos->name, '\t');
+		if (module) {
+			if (!symbol_conf.use_modules)
+				goto discard_symbol;
+
+			*module++ = '\0';
+
+			if (strcmp(curr_map->dso->short_name, module)) {
+				if (curr_map != map &&
+				    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
+				    machine__is_default_guest(machine)) {
+					/*
+					 * We assume all symbols of a module are
+					 * continuous in * kallsyms, so curr_map
+					 * points to a module and all its
+					 * symbols are in its kmap. Mark it as
+					 * loaded.
+					 */
+					dso__set_loaded(curr_map->dso,
+							curr_map->type);
+				}
+
+				curr_map = map_groups__find_by_name(kmaps,
+							map->type, module);
+				if (curr_map == NULL) {
+					pr_debug("%s/proc/{kallsyms,modules} "
+					         "inconsistency while looking "
+						 "for \"%s\" module!\n",
+						 machine->root_dir, module);
+					curr_map = map;
+					goto discard_symbol;
+				}
+
+				if (curr_map->dso->loaded &&
+				    !machine__is_default_guest(machine))
+					goto discard_symbol;
+			}
+			/*
+			 * So that we look just like we get from .ko files,
+			 * i.e. not prelinked, relative to map->start.
+			 */
+			pos->start = curr_map->map_ip(curr_map, pos->start);
+			pos->end   = curr_map->map_ip(curr_map, pos->end);
+		} else if (curr_map != map) {
+			char dso_name[PATH_MAX];
+			struct dso *ndso;
+
+			if (count == 0) {
+				curr_map = map;
+				goto filter_symbol;
+			}
+
+			if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
+				snprintf(dso_name, sizeof(dso_name),
+					"[guest.kernel].%d",
+					kernel_range++);
+			else
+				snprintf(dso_name, sizeof(dso_name),
+					"[kernel].%d",
+					kernel_range++);
+
+			ndso = dso__new(dso_name);
+			if (ndso == NULL)
+				return -1;
+
+			ndso->kernel = dso->kernel;
+
+			curr_map = map__new2(pos->start, ndso, map->type);
+			if (curr_map == NULL) {
+				dso__delete(ndso);
+				return -1;
+			}
+
+			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
+			map_groups__insert(kmaps, curr_map);
+			++kernel_range;
+		}
+filter_symbol:
+		if (filter && filter(curr_map, pos)) {
+discard_symbol:		rb_erase(&pos->rb_node, root);
+			symbol__delete(pos);
+		} else {
+			if (curr_map != map) {
+				rb_erase(&pos->rb_node, root);
+				symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
+				++moved;
+			} else
+				++count;
+		}
+	}
+
+	if (curr_map != map &&
+	    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
+	    machine__is_default_guest(kmaps->machine)) {
+		dso__set_loaded(curr_map->dso, curr_map->type);
+	}
+
+	return count + moved;
+}
+
+bool symbol__restricted_filename(const char *filename,
+				 const char *restricted_filename)
+{
+	bool restricted = false;
+
+	if (symbol_conf.kptr_restrict) {
+		char *r = realpath(filename, NULL);
+
+		if (r != NULL) {
+			restricted = strcmp(r, restricted_filename) == 0;
+			free(r);
+			return restricted;
+		}
+	}
+
+	return restricted;
+}
+
+int dso__load_kallsyms(struct dso *dso, const char *filename,
+		       struct map *map, symbol_filter_t filter)
+{
+	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
+		return -1;
+
+	if (dso__load_all_kallsyms(dso, filename, map) < 0)
+		return -1;
+
+	symbols__fixup_duplicate(&dso->symbols[map->type]);
+	symbols__fixup_end(&dso->symbols[map->type]);
+
+	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
+		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
+	else
+		dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
+
+	return dso__split_kallsyms(dso, map, filter);
+}
+
+static int dso__load_perf_map(struct dso *dso, struct map *map,
+			      symbol_filter_t filter)
+{
+	char *line = NULL;
+	size_t n;
+	FILE *file;
+	int nr_syms = 0;
+
+	file = fopen(dso->long_name, "r");
+	if (file == NULL)
+		goto out_failure;
+
+	while (!feof(file)) {
+		u64 start, size;
+		struct symbol *sym;
+		int line_len, len;
+
+		line_len = getline(&line, &n, file);
+		if (line_len < 0)
+			break;
+
+		if (!line)
+			goto out_failure;
+
+		line[--line_len] = '\0'; /* \n */
+
+		len = hex2u64(line, &start);
+
+		len++;
+		if (len + 2 >= line_len)
+			continue;
+
+		len += hex2u64(line + len, &size);
+
+		len++;
+		if (len + 2 >= line_len)
+			continue;
+
+		sym = symbol__new(start, size, STB_GLOBAL, line + len);
+
+		if (sym == NULL)
+			goto out_delete_line;
+
+		if (filter && filter(map, sym))
+			symbol__delete(sym);
+		else {
+			symbols__insert(&dso->symbols[map->type], sym);
+			nr_syms++;
+		}
+	}
+
+	free(line);
+	fclose(file);
+
+	return nr_syms;
+
+out_delete_line:
+	free(line);
+out_failure:
+	return -1;
+}
+
+int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
+{
+	char *name;
+	int ret = -1;
+	u_int i;
+	struct machine *machine;
+	char *root_dir = (char *) "";
+	int ss_pos = 0;
+	struct symsrc ss_[2];
+	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
+
+	dso__set_loaded(dso, map->type);
+
+	if (dso->kernel == DSO_TYPE_KERNEL)
+		return dso__load_kernel_sym(dso, map, filter);
+	else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
+		return dso__load_guest_kernel_sym(dso, map, filter);
+
+	if (map->groups && map->groups->machine)
+		machine = map->groups->machine;
+	else
+		machine = NULL;
+
+	dso->adjust_symbols = 0;
+
+	if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
+		struct stat st;
+
+		if (lstat(dso->name, &st) < 0)
+			return -1;
+
+		if (st.st_uid && (st.st_uid != geteuid())) {
+			pr_warning("File %s not owned by current user or root, "
+				"ignoring it.\n", dso->name);
+			return -1;
+		}
+
+		ret = dso__load_perf_map(dso, map, filter);
+		dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
+					     DSO_BINARY_TYPE__NOT_FOUND;
+		return ret;
+	}
+
+	if (machine)
+		root_dir = machine->root_dir;
+
+	name = malloc(PATH_MAX);
+	if (!name)
+		return -1;
+
+	/* Iterate over candidate debug images.
+	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
+	 * and/or opd section) for processing.
+	 */
+	for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
+		struct symsrc *ss = &ss_[ss_pos];
+		bool next_slot = false;
+
+		enum dso_binary_type symtab_type = binary_type_symtab[i];
+
+		if (dso__binary_type_file(dso, symtab_type,
+					  root_dir, name, PATH_MAX))
+			continue;
+
+		/* Name is now the name of the next image to try */
+		if (symsrc__init(ss, dso, name, symtab_type) < 0)
+			continue;
+
+		if (!syms_ss && symsrc__has_symtab(ss)) {
+			syms_ss = ss;
+			next_slot = true;
+		}
+
+		if (!runtime_ss && symsrc__possibly_runtime(ss)) {
+			runtime_ss = ss;
+			next_slot = true;
+		}
+
+		if (next_slot) {
+			ss_pos++;
+
+			if (syms_ss && runtime_ss)
+				break;
+		}
+
+	}
+
+	if (!runtime_ss && !syms_ss)
+		goto out_free;
+
+	if (runtime_ss && !syms_ss) {
+		syms_ss = runtime_ss;
+	}
+
+	/* We'll have to hope for the best */
+	if (!runtime_ss && syms_ss)
+		runtime_ss = syms_ss;
+
+	if (syms_ss)
+		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, 0);
+	else
+		ret = -1;
+
+	if (ret > 0) {
+		int nr_plt;
+
+		nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map, filter);
+		if (nr_plt > 0)
+			ret += nr_plt;
+	}
+
+	for (; ss_pos > 0; ss_pos--)
+		symsrc__destroy(&ss_[ss_pos - 1]);
+out_free:
+	free(name);
+	if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
+		return 0;
+	return ret;
+}
+
+struct map *map_groups__find_by_name(struct map_groups *mg,
+				     enum map_type type, const char *name)
+{
+	struct rb_node *nd;
+
+	for (nd = rb_first(&mg->maps[type]); nd; nd = rb_next(nd)) {
+		struct map *map = rb_entry(nd, struct map, rb_node);
+
+		if (map->dso && strcmp(map->dso->short_name, name) == 0)
+			return map;
+	}
+
+	return NULL;
+}
+
+int dso__load_vmlinux(struct dso *dso, struct map *map,
+		      const char *vmlinux, symbol_filter_t filter)
+{
+	int err = -1;
+	struct symsrc ss;
+	char symfs_vmlinux[PATH_MAX];
+	enum dso_binary_type symtab_type;
+
+	snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
+		 symbol_conf.symfs, vmlinux);
+
+	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
+		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
+	else
+		symtab_type = DSO_BINARY_TYPE__VMLINUX;
+
+	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
+		return -1;
+
+	err = dso__load_sym(dso, map, &ss, &ss, filter, 0);
+	symsrc__destroy(&ss);
+
+	if (err > 0) {
+		dso__set_long_name(dso, (char *)vmlinux);
+		dso__set_loaded(dso, map->type);
+		pr_debug("Using %s for symbols\n", symfs_vmlinux);
+	}
+
+	return err;
+}
+
+int dso__load_vmlinux_path(struct dso *dso, struct map *map,
+			   symbol_filter_t filter)
+{
+	int i, err = 0;
+	char *filename;
+
+	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
+		 vmlinux_path__nr_entries + 1);
+
+	filename = dso__build_id_filename(dso, NULL, 0);
+	if (filename != NULL) {
+		err = dso__load_vmlinux(dso, map, filename, filter);
+		if (err > 0) {
+			dso->lname_alloc = 1;
+			goto out;
+		}
+		free(filename);
+	}
+
+	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
+		err = dso__load_vmlinux(dso, map, vmlinux_path[i], filter);
+		if (err > 0) {
+			dso__set_long_name(dso, strdup(vmlinux_path[i]));
+			dso->lname_alloc = 1;
+			break;
+		}
+	}
+out:
+	return err;
+}
+
+static int dso__load_kernel_sym(struct dso *dso, struct map *map,
+				symbol_filter_t filter)
+{
+	int err;
+	const char *kallsyms_filename = NULL;
+	char *kallsyms_allocated_filename = NULL;
+	/*
+	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
+	 * it and only it, reporting errors to the user if it cannot be used.
+	 *
+	 * For instance, try to analyse an ARM perf.data file _without_ a
+	 * build-id, or if the user specifies the wrong path to the right
+	 * vmlinux file, obviously we can't fallback to another vmlinux (a
+	 * x86_86 one, on the machine where analysis is being performed, say),
+	 * or worse, /proc/kallsyms.
+	 *
+	 * If the specified file _has_ a build-id and there is a build-id
+	 * section in the perf.data file, we will still do the expected
+	 * validation in dso__load_vmlinux and will bail out if they don't
+	 * match.
+	 */
+	if (symbol_conf.kallsyms_name != NULL) {
+		kallsyms_filename = symbol_conf.kallsyms_name;
+		goto do_kallsyms;
+	}
+
+	if (symbol_conf.vmlinux_name != NULL) {
+		err = dso__load_vmlinux(dso, map,
+					symbol_conf.vmlinux_name, filter);
+		if (err > 0) {
+			dso__set_long_name(dso,
+					   strdup(symbol_conf.vmlinux_name));
+			dso->lname_alloc = 1;
+			goto out_fixup;
+		}
+		return err;
+	}
+
+	if (vmlinux_path != NULL) {
+		err = dso__load_vmlinux_path(dso, map, filter);
+		if (err > 0)
+			goto out_fixup;
+	}
+
+	/* do not try local files if a symfs was given */
+	if (symbol_conf.symfs[0] != 0)
+		return -1;
+
+	/*
+	 * Say the kernel DSO was created when processing the build-id header table,
+	 * we have a build-id, so check if it is the same as the running kernel,
+	 * using it if it is.
+	 */
+	if (dso->has_build_id) {
+		u8 kallsyms_build_id[BUILD_ID_SIZE];
+		char sbuild_id[BUILD_ID_SIZE * 2 + 1];
+
+		if (sysfs__read_build_id("/sys/kernel/notes", kallsyms_build_id,
+					 sizeof(kallsyms_build_id)) == 0) {
+			if (dso__build_id_equal(dso, kallsyms_build_id)) {
+				kallsyms_filename = "/proc/kallsyms";
+				goto do_kallsyms;
+			}
+		}
+		/*
+		 * Now look if we have it on the build-id cache in
+		 * $HOME/.debug/[kernel.kallsyms].
+		 */
+		build_id__sprintf(dso->build_id, sizeof(dso->build_id),
+				  sbuild_id);
+
+		if (asprintf(&kallsyms_allocated_filename,
+			     "%s/.debug/[kernel.kallsyms]/%s",
+			     getenv("HOME"), sbuild_id) == -1) {
+			pr_err("Not enough memory for kallsyms file lookup\n");
+			return -1;
+		}
+
+		kallsyms_filename = kallsyms_allocated_filename;
+
+		if (access(kallsyms_filename, F_OK)) {
+			pr_err("No kallsyms or vmlinux with build-id %s "
+			       "was found\n", sbuild_id);
+			free(kallsyms_allocated_filename);
+			return -1;
+		}
+	} else {
+		/*
+		 * Last resort, if we don't have a build-id and couldn't find
+		 * any vmlinux file, try the running kernel kallsyms table.
+		 */
+		kallsyms_filename = "/proc/kallsyms";
+	}
+
+do_kallsyms:
+	err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
+	if (err > 0)
+		pr_debug("Using %s for symbols\n", kallsyms_filename);
+	free(kallsyms_allocated_filename);
+
+	if (err > 0) {
+		dso__set_long_name(dso, strdup("[kernel.kallsyms]"));
+out_fixup:
+		map__fixup_start(map);
+		map__fixup_end(map);
+	}
+
+	return err;
+}
+
+static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
+				      symbol_filter_t filter)
+{
+	int err;
+	const char *kallsyms_filename = NULL;
+	struct machine *machine;
+	char path[PATH_MAX];
+
+	if (!map->groups) {
+		pr_debug("Guest kernel map hasn't the point to groups\n");
+		return -1;
+	}
+	machine = map->groups->machine;
+
+	if (machine__is_default_guest(machine)) {
+		/*
+		 * if the user specified a vmlinux filename, use it and only
+		 * it, reporting errors to the user if it cannot be used.
+		 * Or use file guest_kallsyms inputted by user on commandline
+		 */
+		if (symbol_conf.default_guest_vmlinux_name != NULL) {
+			err = dso__load_vmlinux(dso, map,
+				symbol_conf.default_guest_vmlinux_name, filter);
+			goto out_try_fixup;
+		}
+
+		kallsyms_filename = symbol_conf.default_guest_kallsyms;
+		if (!kallsyms_filename)
+			return -1;
+	} else {
+		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
+		kallsyms_filename = path;
+	}
+
+	err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
+	if (err > 0)
+		pr_debug("Using %s for symbols\n", kallsyms_filename);
+
+out_try_fixup:
+	if (err > 0) {
+		if (kallsyms_filename != NULL) {
+			machine__mmap_name(machine, path, sizeof(path));
+			dso__set_long_name(dso, strdup(path));
+		}
+		map__fixup_start(map);
+		map__fixup_end(map);
+	}
+
+	return err;
+}
+
+static void vmlinux_path__exit(void)
+{
+	while (--vmlinux_path__nr_entries >= 0) {
+		free(vmlinux_path[vmlinux_path__nr_entries]);
+		vmlinux_path[vmlinux_path__nr_entries] = NULL;
+	}
+
+	free(vmlinux_path);
+	vmlinux_path = NULL;
+}
+
+static int vmlinux_path__init(void)
+{
+	struct utsname uts;
+	char bf[PATH_MAX];
+
+	vmlinux_path = malloc(sizeof(char *) * 5);
+	if (vmlinux_path == NULL)
+		return -1;
+
+	vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
+	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
+		goto out_fail;
+	++vmlinux_path__nr_entries;
+	vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
+	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
+		goto out_fail;
+	++vmlinux_path__nr_entries;
+
+	/* only try running kernel version if no symfs was given */
+	if (symbol_conf.symfs[0] != 0)
+		return 0;
+
+	if (uname(&uts) < 0)
+		return -1;
+
+	snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
+	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
+	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
+		goto out_fail;
+	++vmlinux_path__nr_entries;
+	snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release);
+	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
+	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
+		goto out_fail;
+	++vmlinux_path__nr_entries;
+	snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
+		 uts.release);
+	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
+	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
+		goto out_fail;
+	++vmlinux_path__nr_entries;
+
+	return 0;
+
+out_fail:
+	vmlinux_path__exit();
+	return -1;
+}
+
+static int setup_list(struct strlist **list, const char *list_str,
+		      const char *list_name)
+{
+	if (list_str == NULL)
+		return 0;
+
+	*list = strlist__new(true, list_str);
+	if (!*list) {
+		pr_err("problems parsing %s list\n", list_name);
+		return -1;
+	}
+	return 0;
+}
+
+static bool symbol__read_kptr_restrict(void)
+{
+	bool value = false;
+
+	if (geteuid() != 0) {
+		FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
+		if (fp != NULL) {
+			char line[8];
+
+			if (fgets(line, sizeof(line), fp) != NULL)
+				value = atoi(line) != 0;
+
+			fclose(fp);
+		}
+	}
+
+	return value;
+}
+
+int symbol__init(void)
+{
+	const char *symfs;
+
+	if (symbol_conf.initialized)
+		return 0;
+
+	symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
+
+	symbol__elf_init();
+
+	if (symbol_conf.sort_by_name)
+		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
+					  sizeof(struct symbol));
+
+	if (symbol_conf.try_vmlinux_path && vmlinux_path__init() < 0)
+		return -1;
+
+	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
+		pr_err("'.' is the only non valid --field-separator argument\n");
+		return -1;
+	}
+
+	if (setup_list(&symbol_conf.dso_list,
+		       symbol_conf.dso_list_str, "dso") < 0)
+		return -1;
+
+	if (setup_list(&symbol_conf.comm_list,
+		       symbol_conf.comm_list_str, "comm") < 0)
+		goto out_free_dso_list;
+
+	if (setup_list(&symbol_conf.sym_list,
+		       symbol_conf.sym_list_str, "symbol") < 0)
+		goto out_free_comm_list;
+
+	/*
+	 * A path to symbols of "/" is identical to ""
+	 * reset here for simplicity.
+	 */
+	symfs = realpath(symbol_conf.symfs, NULL);
+	if (symfs == NULL)
+		symfs = symbol_conf.symfs;
+	if (strcmp(symfs, "/") == 0)
+		symbol_conf.symfs = "";
+	if (symfs != symbol_conf.symfs)
+		free((void *)symfs);
+
+	symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
+
+	symbol_conf.initialized = true;
+	return 0;
+
+out_free_comm_list:
+	strlist__delete(symbol_conf.comm_list);
+out_free_dso_list:
+	strlist__delete(symbol_conf.dso_list);
+	return -1;
+}
+
+void symbol__exit(void)
+{
+	if (!symbol_conf.initialized)
+		return;
+	strlist__delete(symbol_conf.sym_list);
+	strlist__delete(symbol_conf.dso_list);
+	strlist__delete(symbol_conf.comm_list);
+	vmlinux_path__exit();
+	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
+	symbol_conf.initialized = false;
+}