symbol.c 39.9 KB
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#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>
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#include <inttypes.h>
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#include "build-id.h"
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#include "util.h"
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#include "debug.h"
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#include "machine.h"
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#include "symbol.h"
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#include "strlist.h"
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#include <elf.h>
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#include <limits.h>
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#include <sys/utsname.h>
P
Peter Zijlstra 已提交
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#ifndef KSYM_NAME_LEN
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#define KSYM_NAME_LEN 256
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#endif

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static int dso__load_kernel_sym(struct dso *dso, struct map *map,
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				symbol_filter_t filter);
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static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
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			symbol_filter_t filter);
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int vmlinux_path__nr_entries;
char **vmlinux_path;
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struct symbol_conf symbol_conf = {
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	.use_modules	  = true,
	.try_vmlinux_path = true,
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	.annotate_src	  = true,
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	.demangle	  = true,
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	.symfs            = "",
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};

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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,
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	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
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	DSO_BINARY_TYPE__NOT_FOUND,
};

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#define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
59

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bool symbol_type__is_a(char symbol_type, enum map_type map_type)
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{
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	symbol_type = toupper(symbol_type);

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	switch (map_type) {
	case MAP__FUNCTION:
		return symbol_type == 'T' || symbol_type == 'W';
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	case MAP__VARIABLE:
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		return symbol_type == 'D';
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	default:
		return false;
	}
}

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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;
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	size_t na, nb;
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	/* 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;

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	/* Choose the symbol with the longest name */
	na = strlen(syma->name);
	nb = strlen(symb->name);
	if (na > nb)
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		return SYMBOL_A;
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	else if (na < nb)
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		return SYMBOL_B;
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	/* Avoid "SyS" kernel syscall aliases */
	if (na >= 3 && !strncmp(syma->name, "SyS", 3))
		return SYMBOL_B;
	if (na >= 10 && !strncmp(syma->name, "compat_SyS", 10))
		return SYMBOL_B;

	return SYMBOL_A;
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}

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void symbols__fixup_duplicate(struct rb_root *symbols)
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{
	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);
		}
	}
}

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void symbols__fixup_end(struct rb_root *symbols)
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{
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	struct rb_node *nd, *prevnd = rb_first(symbols);
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	struct symbol *curr, *prev;
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	if (prevnd == NULL)
		return;

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	curr = rb_entry(prevnd, struct symbol, rb_node);

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	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
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		prev = curr;
		curr = rb_entry(nd, struct symbol, rb_node);
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		if (prev->end == prev->start && prev->end != curr->start)
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			prev->end = curr->start - 1;
	}
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	/* Last entry */
	if (curr->end == curr->start)
		curr->end = roundup(curr->start, 4096);
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}

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void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
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{
	struct map *prev, *curr;
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	struct rb_node *nd, *prevnd = rb_first(&mg->maps[type]);
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	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;
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	}
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	/*
	 * We still haven't the actual symbols, so guess the
	 * last map final address.
	 */
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	curr->end = ~0ULL;
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}

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struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
218
{
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	size_t namelen = strlen(name) + 1;
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	struct symbol *sym = calloc(1, (symbol_conf.priv_size +
					sizeof(*sym) + namelen));
	if (sym == NULL)
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		return NULL;

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	if (symbol_conf.priv_size)
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		sym = ((void *)sym) + symbol_conf.priv_size;
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	sym->start   = start;
	sym->end     = len ? start + len - 1 : start;
	sym->binding = binding;
	sym->namelen = namelen - 1;
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	pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
		  __func__, name, start, sym->end);
	memcpy(sym->name, name, namelen);
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	return sym;
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}

240
void symbol__delete(struct symbol *sym)
241
{
242
	free(((void *)sym) - symbol_conf.priv_size);
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}

245
size_t symbol__fprintf(struct symbol *sym, FILE *fp)
246
{
247
	return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n",
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		       sym->start, sym->end,
		       sym->binding == STB_GLOBAL ? 'g' :
		       sym->binding == STB_LOCAL  ? 'l' : 'w',
		       sym->name);
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}

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size_t symbol__fprintf_symname_offs(const struct symbol *sym,
				    const struct addr_location *al, FILE *fp)
256
{
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	unsigned long offset;
	size_t length;

	if (sym && sym->name) {
		length = fprintf(fp, "%s", sym->name);
		if (al) {
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			if (al->addr < sym->end)
				offset = al->addr - sym->start;
			else
				offset = al->addr - al->map->start - sym->start;
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			length += fprintf(fp, "+0x%lx", offset);
		}
		return length;
	} else
		return fprintf(fp, "[unknown]");
}
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size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
{
	return symbol__fprintf_symname_offs(sym, NULL, fp);
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}

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void symbols__delete(struct rb_root *symbols)
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{
	struct symbol *pos;
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	struct rb_node *next = rb_first(symbols);
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	while (next) {
		pos = rb_entry(next, struct symbol, rb_node);
		next = rb_next(&pos->rb_node);
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		rb_erase(&pos->rb_node, symbols);
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		symbol__delete(pos);
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	}
}

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void symbols__insert(struct rb_root *symbols, struct symbol *sym)
293
{
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	struct rb_node **p = &symbols->rb_node;
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	struct rb_node *parent = NULL;
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	const u64 ip = sym->start;
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	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);
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	rb_insert_color(&sym->rb_node, symbols);
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}

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static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
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{
	struct rb_node *n;

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	if (symbols == NULL)
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		return NULL;

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	n = symbols->rb_node;
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	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;
}

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static struct symbol *symbols__first(struct rb_root *symbols)
{
	struct rb_node *n = rb_first(symbols);

	if (n)
		return rb_entry(n, struct symbol, rb_node);

	return NULL;
}

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struct symbol_name_rb_node {
	struct rb_node	rb_node;
	struct symbol	sym;
};

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static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym)
350
{
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	struct rb_node **p = &symbols->rb_node;
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	struct rb_node *parent = NULL;
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	struct symbol_name_rb_node *symn, *s;

	symn = container_of(sym, struct symbol_name_rb_node, sym);
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	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);
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	rb_insert_color(&symn->rb_node, symbols);
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}

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static void symbols__sort_by_name(struct rb_root *symbols,
				  struct rb_root *source)
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{
	struct rb_node *nd;

	for (nd = rb_first(source); nd; nd = rb_next(nd)) {
		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
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		symbols__insert_by_name(symbols, pos);
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	}
}

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static struct symbol *symbols__find_by_name(struct rb_root *symbols,
					    const char *name)
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{
	struct rb_node *n;

385
	if (symbols == NULL)
386 387
		return NULL;

388
	n = symbols->rb_node;
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	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;
}

408
struct symbol *dso__find_symbol(struct dso *dso,
409
				enum map_type type, u64 addr)
410
{
411
	return symbols__find(&dso->symbols[type], addr);
412 413
}

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struct symbol *dso__first_symbol(struct dso *dso, enum map_type type)
{
	return symbols__first(&dso->symbols[type]);
}

419
struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
420 421
					const char *name)
{
422
	return symbols__find_by_name(&dso->symbol_names[type], name);
423 424
}

425
void dso__sort_by_name(struct dso *dso, enum map_type type)
426
{
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	dso__set_sorted_by_name(dso, type);
	return symbols__sort_by_name(&dso->symbol_names[type],
				     &dso->symbols[type]);
430 431
}

432 433
size_t dso__fprintf_symbols_by_name(struct dso *dso,
				    enum map_type type, FILE *fp)
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{
	size_t ret = 0;
	struct rb_node *nd;
	struct symbol_name_rb_node *pos;

439
	for (nd = rb_first(&dso->symbol_names[type]); nd; nd = rb_next(nd)) {
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		pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
		fprintf(fp, "%s\n", pos->sym.name);
	}

	return ret;
}

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int kallsyms__parse(const char *filename, void *arg,
		    int (*process_symbol)(void *arg, const char *name,
449
					  char type, u64 start))
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{
	char *line = NULL;
	size_t n;
453
	int err = -1;
454
	FILE *file = fopen(filename, "r");
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	if (file == NULL)
		goto out_failure;

459 460
	err = 0;

461
	while (!feof(file)) {
462
		u64 start;
463 464
		int line_len, len;
		char symbol_type;
465
		char *symbol_name;
466 467

		line_len = getline(&line, &n, file);
468
		if (line_len < 0 || !line)
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			break;

		line[--line_len] = '\0'; /* \n */

473
		len = hex2u64(line, &start);
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		len++;
		if (len + 2 >= line_len)
			continue;

479
		symbol_type = line[len];
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		len += 2;
		symbol_name = line + len;
		len = line_len - len;
483

484 485
		if (len >= KSYM_NAME_LEN) {
			err = -1;
486
			break;
487 488
		}

489
		err = process_symbol(arg, symbol_name,
490
				     symbol_type, start);
491 492
		if (err)
			break;
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	}

	free(line);
	fclose(file);
497
	return err;
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out_failure:
	return -1;
}

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int modules__parse(const char *filename, void *arg,
		   int (*process_module)(void *arg, const char *name,
					 u64 start))
{
	char *line = NULL;
	size_t n;
	FILE *file;
	int err = 0;

	file = fopen(filename, "r");
	if (file == NULL)
		return -1;

	while (1) {
		char name[PATH_MAX];
		u64 start;
		char *sep;
		ssize_t line_len;

		line_len = getline(&line, &n, file);
		if (line_len < 0) {
			if (feof(file))
				break;
			err = -1;
			goto out;
		}

		if (!line) {
			err = -1;
			goto out;
		}

		line[--line_len] = '\0'; /* \n */

		sep = strrchr(line, 'x');
		if (sep == NULL)
			continue;

		hex2u64(sep + 1, &start);

		sep = strchr(line, ' ');
		if (sep == NULL)
			continue;

		*sep = '\0';

		scnprintf(name, sizeof(name), "[%s]", line);

		err = process_module(arg, name, start);
		if (err)
			break;
	}
out:
	free(line);
	fclose(file);
	return err;
}

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struct process_kallsyms_args {
	struct map *map;
	struct dso *dso;
};

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static u8 kallsyms2elf_type(char type)
{
	if (type == 'W')
		return STB_WEAK;

	return isupper(type) ? STB_GLOBAL : STB_LOCAL;
}

574
static int map__process_kallsym_symbol(void *arg, const char *name,
575
				       char type, u64 start)
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{
	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;

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	/*
	 * 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);
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	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);
597

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	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.
 */
606
static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
607
				  struct map *map)
608
{
609
	struct process_kallsyms_args args = { .map = map, .dso = dso, };
610
	return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
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}

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static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map,
					 symbol_filter_t filter)
{
	struct map_groups *kmaps = map__kmap(map)->kmaps;
	struct map *curr_map;
	struct symbol *pos;
	int count = 0, moved = 0;
	struct rb_root *root = &dso->symbols[map->type];
	struct rb_node *next = rb_first(root);

	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)
			*module = '\0';

		curr_map = map_groups__find(kmaps, map->type, pos->start);

		if (!curr_map || (filter && filter(curr_map, pos))) {
			rb_erase(&pos->rb_node, root);
			symbol__delete(pos);
		} else {
			pos->start -= curr_map->start - curr_map->pgoff;
			if (pos->end)
				pos->end -= curr_map->start - curr_map->pgoff;
			if (curr_map != map) {
				rb_erase(&pos->rb_node, root);
				symbols__insert(
					&curr_map->dso->symbols[curr_map->type],
					pos);
				++moved;
			} else {
				++count;
			}
		}
	}

	/* Symbols have been adjusted */
	dso->adjust_symbols = 1;

	return count + moved;
}

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/*
 * 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.
 */
665
static int dso__split_kallsyms(struct dso *dso, struct map *map,
666
			       symbol_filter_t filter)
667
{
668
	struct map_groups *kmaps = map__kmap(map)->kmaps;
669
	struct machine *machine = kmaps->machine;
670
	struct map *curr_map = map;
671
	struct symbol *pos;
672
	int count = 0, moved = 0;	
673
	struct rb_root *root = &dso->symbols[map->type];
674
	struct rb_node *next = rb_first(root);
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	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) {
685
			if (!symbol_conf.use_modules)
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				goto discard_symbol;

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			*module++ = '\0';

690
			if (strcmp(curr_map->dso->short_name, module)) {
691
				if (curr_map != map &&
692
				    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
693
				    machine__is_default_guest(machine)) {
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					/*
					 * 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);
707
				if (curr_map == NULL) {
708
					pr_debug("%s/proc/{kallsyms,modules} "
709
					         "inconsistency while looking "
710
						 "for \"%s\" module!\n",
711
						 machine->root_dir, module);
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					curr_map = map;
					goto discard_symbol;
714
				}
715

716
				if (curr_map->dso->loaded &&
717
				    !machine__is_default_guest(machine))
718
					goto discard_symbol;
719
			}
720 721 722 723
			/*
			 * So that we look just like we get from .ko files,
			 * i.e. not prelinked, relative to map->start.
			 */
724 725 726
			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) {
727
			char dso_name[PATH_MAX];
728
			struct dso *ndso;
729

730 731 732 733 734
			if (count == 0) {
				curr_map = map;
				goto filter_symbol;
			}

735
			if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
736 737 738 739 740 741 742
				snprintf(dso_name, sizeof(dso_name),
					"[guest.kernel].%d",
					kernel_range++);
			else
				snprintf(dso_name, sizeof(dso_name),
					"[kernel].%d",
					kernel_range++);
743

744 745
			ndso = dso__new(dso_name);
			if (ndso == NULL)
746 747
				return -1;

748
			ndso->kernel = dso->kernel;
749

750
			curr_map = map__new2(pos->start, ndso, map->type);
751
			if (curr_map == NULL) {
752
				dso__delete(ndso);
753 754
				return -1;
			}
755

756
			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
757
			map_groups__insert(kmaps, curr_map);
758 759
			++kernel_range;
		}
760
filter_symbol:
761
		if (filter && filter(curr_map, pos)) {
762
discard_symbol:		rb_erase(&pos->rb_node, root);
763
			symbol__delete(pos);
764
		} else {
765 766 767
			if (curr_map != map) {
				rb_erase(&pos->rb_node, root);
				symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
768 769 770
				++moved;
			} else
				++count;
771
		}
772 773
	}

774
	if (curr_map != map &&
775
	    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
776
	    machine__is_default_guest(kmaps->machine)) {
777 778 779
		dso__set_loaded(curr_map->dso, curr_map->type);
	}

780
	return count + moved;
781
}
782

783 784
bool symbol__restricted_filename(const char *filename,
				 const char *restricted_filename)
785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800
{
	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;
}

801 802 803 804
struct module_info {
	struct rb_node rb_node;
	char *name;
	u64 start;
805 806
};

807
static void add_module(struct module_info *mi, struct rb_root *modules)
808
{
809 810 811
	struct rb_node **p = &modules->rb_node;
	struct rb_node *parent = NULL;
	struct module_info *m;
812

813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867
	while (*p != NULL) {
		parent = *p;
		m = rb_entry(parent, struct module_info, rb_node);
		if (strcmp(mi->name, m->name) < 0)
			p = &(*p)->rb_left;
		else
			p = &(*p)->rb_right;
	}
	rb_link_node(&mi->rb_node, parent, p);
	rb_insert_color(&mi->rb_node, modules);
}

static void delete_modules(struct rb_root *modules)
{
	struct module_info *mi;
	struct rb_node *next = rb_first(modules);

	while (next) {
		mi = rb_entry(next, struct module_info, rb_node);
		next = rb_next(&mi->rb_node);
		rb_erase(&mi->rb_node, modules);
		free(mi->name);
		free(mi);
	}
}

static struct module_info *find_module(const char *name,
				       struct rb_root *modules)
{
	struct rb_node *n = modules->rb_node;

	while (n) {
		struct module_info *m;
		int cmp;

		m = rb_entry(n, struct module_info, rb_node);
		cmp = strcmp(name, m->name);
		if (cmp < 0)
			n = n->rb_left;
		else if (cmp > 0)
			n = n->rb_right;
		else
			return m;
	}

	return NULL;
}

static int __read_proc_modules(void *arg, const char *name, u64 start)
{
	struct rb_root *modules = arg;
	struct module_info *mi;

	mi = zalloc(sizeof(struct module_info));
	if (!mi)
868 869
		return -ENOMEM;

870 871
	mi->name = strdup(name);
	mi->start = start;
872

873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891
	if (!mi->name) {
		free(mi);
		return -ENOMEM;
	}

	add_module(mi, modules);

	return 0;
}

static int read_proc_modules(const char *filename, struct rb_root *modules)
{
	if (symbol__restricted_filename(filename, "/proc/modules"))
		return -1;

	if (modules__parse(filename, modules, __read_proc_modules)) {
		delete_modules(modules);
		return -1;
	}
892 893 894 895

	return 0;
}

896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936
int compare_proc_modules(const char *from, const char *to)
{
	struct rb_root from_modules = RB_ROOT;
	struct rb_root to_modules = RB_ROOT;
	struct rb_node *from_node, *to_node;
	struct module_info *from_m, *to_m;
	int ret = -1;

	if (read_proc_modules(from, &from_modules))
		return -1;

	if (read_proc_modules(to, &to_modules))
		goto out_delete_from;

	from_node = rb_first(&from_modules);
	to_node = rb_first(&to_modules);
	while (from_node) {
		if (!to_node)
			break;

		from_m = rb_entry(from_node, struct module_info, rb_node);
		to_m = rb_entry(to_node, struct module_info, rb_node);

		if (from_m->start != to_m->start ||
		    strcmp(from_m->name, to_m->name))
			break;

		from_node = rb_next(from_node);
		to_node = rb_next(to_node);
	}

	if (!from_node && !to_node)
		ret = 0;

	delete_modules(&to_modules);
out_delete_from:
	delete_modules(&from_modules);

	return ret;
}

937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972
static int do_validate_kcore_modules(const char *filename, struct map *map,
				  struct map_groups *kmaps)
{
	struct rb_root modules = RB_ROOT;
	struct map *old_map;
	int err;

	err = read_proc_modules(filename, &modules);
	if (err)
		return err;

	old_map = map_groups__first(kmaps, map->type);
	while (old_map) {
		struct map *next = map_groups__next(old_map);
		struct module_info *mi;

		if (old_map == map || old_map->start == map->start) {
			/* The kernel map */
			old_map = next;
			continue;
		}

		/* Module must be in memory at the same address */
		mi = find_module(old_map->dso->short_name, &modules);
		if (!mi || mi->start != old_map->start) {
			err = -EINVAL;
			goto out;
		}

		old_map = next;
	}
out:
	delete_modules(&modules);
	return err;
}

973
/*
974
 * If kallsyms is referenced by name then we look for filename in the same
975 976
 * directory.
 */
977 978 979
static bool filename_from_kallsyms_filename(char *filename,
					    const char *base_name,
					    const char *kallsyms_filename)
980 981 982
{
	char *name;

983 984
	strcpy(filename, kallsyms_filename);
	name = strrchr(filename, '/');
985 986 987
	if (!name)
		return false;

988 989 990 991
	name += 1;

	if (!strcmp(name, "kallsyms")) {
		strcpy(name, base_name);
992 993 994 995 996 997
		return true;
	}

	return false;
}

998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036
static int validate_kcore_modules(const char *kallsyms_filename,
				  struct map *map)
{
	struct map_groups *kmaps = map__kmap(map)->kmaps;
	char modules_filename[PATH_MAX];

	if (!filename_from_kallsyms_filename(modules_filename, "modules",
					     kallsyms_filename))
		return -EINVAL;

	if (do_validate_kcore_modules(modules_filename, map, kmaps))
		return -EINVAL;

	return 0;
}

struct kcore_mapfn_data {
	struct dso *dso;
	enum map_type type;
	struct list_head maps;
};

static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
{
	struct kcore_mapfn_data *md = data;
	struct map *map;

	map = map__new2(start, md->dso, md->type);
	if (map == NULL)
		return -ENOMEM;

	map->end = map->start + len;
	map->pgoff = pgoff;

	list_add(&map->node, &md->maps);

	return 0;
}

1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052
static int dso__load_kcore(struct dso *dso, struct map *map,
			   const char *kallsyms_filename)
{
	struct map_groups *kmaps = map__kmap(map)->kmaps;
	struct machine *machine = kmaps->machine;
	struct kcore_mapfn_data md;
	struct map *old_map, *new_map, *replacement_map = NULL;
	bool is_64_bit;
	int err, fd;
	char kcore_filename[PATH_MAX];
	struct symbol *sym;

	/* This function requires that the map is the kernel map */
	if (map != machine->vmlinux_maps[map->type])
		return -EINVAL;

1053 1054 1055 1056 1057 1058
	if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
					     kallsyms_filename))
		return -EINVAL;

	/* All modules must be present at their original addresses */
	if (validate_kcore_modules(kallsyms_filename, map))
1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150
		return -EINVAL;

	md.dso = dso;
	md.type = map->type;
	INIT_LIST_HEAD(&md.maps);

	fd = open(kcore_filename, O_RDONLY);
	if (fd < 0)
		return -EINVAL;

	/* Read new maps into temporary lists */
	err = file__read_maps(fd, md.type == MAP__FUNCTION, kcore_mapfn, &md,
			      &is_64_bit);
	if (err)
		goto out_err;

	if (list_empty(&md.maps)) {
		err = -EINVAL;
		goto out_err;
	}

	/* Remove old maps */
	old_map = map_groups__first(kmaps, map->type);
	while (old_map) {
		struct map *next = map_groups__next(old_map);

		if (old_map != map)
			map_groups__remove(kmaps, old_map);
		old_map = next;
	}

	/* Find the kernel map using the first symbol */
	sym = dso__first_symbol(dso, map->type);
	list_for_each_entry(new_map, &md.maps, node) {
		if (sym && sym->start >= new_map->start &&
		    sym->start < new_map->end) {
			replacement_map = new_map;
			break;
		}
	}

	if (!replacement_map)
		replacement_map = list_entry(md.maps.next, struct map, node);

	/* Add new maps */
	while (!list_empty(&md.maps)) {
		new_map = list_entry(md.maps.next, struct map, node);
		list_del(&new_map->node);
		if (new_map == replacement_map) {
			map->start	= new_map->start;
			map->end	= new_map->end;
			map->pgoff	= new_map->pgoff;
			map->map_ip	= new_map->map_ip;
			map->unmap_ip	= new_map->unmap_ip;
			map__delete(new_map);
			/* Ensure maps are correctly ordered */
			map_groups__remove(kmaps, map);
			map_groups__insert(kmaps, map);
		} else {
			map_groups__insert(kmaps, new_map);
		}
	}

	/*
	 * Set the data type and long name so that kcore can be read via
	 * dso__data_read_addr().
	 */
	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
		dso->data_type = DSO_BINARY_TYPE__GUEST_KCORE;
	else
		dso->data_type = DSO_BINARY_TYPE__KCORE;
	dso__set_long_name(dso, strdup(kcore_filename));

	close(fd);

	if (map->type == MAP__FUNCTION)
		pr_debug("Using %s for kernel object code\n", kcore_filename);
	else
		pr_debug("Using %s for kernel data\n", kcore_filename);

	return 0;

out_err:
	while (!list_empty(&md.maps)) {
		map = list_entry(md.maps.next, struct map, node);
		list_del(&map->node);
		map__delete(map);
	}
	close(fd);
	return -EINVAL;
}

1151
int dso__load_kallsyms(struct dso *dso, const char *filename,
1152
		       struct map *map, symbol_filter_t filter)
1153
{
1154 1155 1156
	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
		return -1;

1157
	if (dso__load_all_kallsyms(dso, filename, map) < 0)
1158 1159
		return -1;

1160
	symbols__fixup_duplicate(&dso->symbols[map->type]);
1161 1162
	symbols__fixup_end(&dso->symbols[map->type]);

1163
	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1164
		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1165
	else
1166
		dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1167

1168 1169 1170 1171
	if (!dso__load_kcore(dso, map, filename))
		return dso__split_kallsyms_for_kcore(dso, map, filter);
	else
		return dso__split_kallsyms(dso, map, filter);
1172 1173
}

1174
static int dso__load_perf_map(struct dso *dso, struct map *map,
1175
			      symbol_filter_t filter)
1176 1177 1178 1179 1180 1181
{
	char *line = NULL;
	size_t n;
	FILE *file;
	int nr_syms = 0;

1182
	file = fopen(dso->long_name, "r");
1183 1184 1185 1186
	if (file == NULL)
		goto out_failure;

	while (!feof(file)) {
1187
		u64 start, size;
1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211
		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;

1212
		sym = symbol__new(start, size, STB_GLOBAL, line + len);
1213 1214 1215 1216

		if (sym == NULL)
			goto out_delete_line;

1217
		if (filter && filter(map, sym))
1218
			symbol__delete(sym);
1219
		else {
1220
			symbols__insert(&dso->symbols[map->type], sym);
1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235
			nr_syms++;
		}
	}

	free(line);
	fclose(file);

	return nr_syms;

out_delete_line:
	free(line);
out_failure:
	return -1;
}

1236
int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
1237
{
1238
	char *name;
1239
	int ret = -1;
1240
	u_int i;
1241
	struct machine *machine;
1242
	char *root_dir = (char *) "";
1243 1244 1245
	int ss_pos = 0;
	struct symsrc ss_[2];
	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1246

1247
	dso__set_loaded(dso, map->type);
1248

1249 1250 1251 1252
	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);
1253

1254 1255
	if (map->groups && map->groups->machine)
		machine = map->groups->machine;
1256
	else
1257
		machine = NULL;
1258

1259
	dso->adjust_symbols = 0;
1260

1261
	if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
1262 1263
		struct stat st;

1264
		if (lstat(dso->name, &st) < 0)
1265 1266 1267 1268 1269 1270 1271 1272
			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;
		}

1273
		ret = dso__load_perf_map(dso, map, filter);
1274 1275
		dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
					     DSO_BINARY_TYPE__NOT_FOUND;
1276 1277 1278
		return ret;
	}

1279 1280 1281
	if (machine)
		root_dir = machine->root_dir;

1282 1283 1284 1285
	name = malloc(PATH_MAX);
	if (!name)
		return -1;

1286
	/* Iterate over candidate debug images.
1287 1288
	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
	 * and/or opd section) for processing.
1289
	 */
1290
	for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1291 1292
		struct symsrc *ss = &ss_[ss_pos];
		bool next_slot = false;
1293

1294
		enum dso_binary_type symtab_type = binary_type_symtab[i];
1295

1296
		if (dso__binary_type_file(dso, symtab_type,
1297 1298
					  root_dir, name, PATH_MAX))
			continue;
1299 1300

		/* Name is now the name of the next image to try */
1301
		if (symsrc__init(ss, dso, name, symtab_type) < 0)
1302
			continue;
1303

1304 1305 1306
		if (!syms_ss && symsrc__has_symtab(ss)) {
			syms_ss = ss;
			next_slot = true;
1307 1308
		}

1309 1310 1311
		if (!runtime_ss && symsrc__possibly_runtime(ss)) {
			runtime_ss = ss;
			next_slot = true;
1312
		}
1313

1314 1315
		if (next_slot) {
			ss_pos++;
1316

1317 1318
			if (syms_ss && runtime_ss)
				break;
1319
		}
1320

1321
	}
1322

1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333
	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;

1334 1335 1336 1337 1338 1339 1340
	if (syms_ss) {
		int km;

		km = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
		     dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE;
		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, km);
	} else {
1341
		ret = -1;
1342
	}
1343

1344
	if (ret > 0) {
1345 1346 1347 1348 1349
		int nr_plt;

		nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map, filter);
		if (nr_plt > 0)
			ret += nr_plt;
1350 1351
	}

1352 1353 1354
	for (; ss_pos > 0; ss_pos--)
		symsrc__destroy(&ss_[ss_pos - 1]);
out_free:
1355
	free(name);
1356
	if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1357
		return 0;
1358 1359 1360
	return ret;
}

1361
struct map *map_groups__find_by_name(struct map_groups *mg,
1362
				     enum map_type type, const char *name)
1363 1364 1365
{
	struct rb_node *nd;

1366
	for (nd = rb_first(&mg->maps[type]); nd; nd = rb_next(nd)) {
1367 1368
		struct map *map = rb_entry(nd, struct map, rb_node);

1369
		if (map->dso && strcmp(map->dso->short_name, name) == 0)
1370 1371 1372 1373 1374 1375
			return map;
	}

	return NULL;
}

1376
int dso__load_vmlinux(struct dso *dso, struct map *map,
1377
		      const char *vmlinux, symbol_filter_t filter)
1378
{
1379 1380
	int err = -1;
	struct symsrc ss;
1381
	char symfs_vmlinux[PATH_MAX];
1382
	enum dso_binary_type symtab_type;
1383

1384 1385 1386 1387 1388
	if (vmlinux[0] == '/')
		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
	else
		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
			 symbol_conf.symfs, vmlinux);
1389

1390
	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1391
		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1392
	else
1393
		symtab_type = DSO_BINARY_TYPE__VMLINUX;
1394

1395
	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
1396 1397
		return -1;

1398
	err = dso__load_sym(dso, map, &ss, &ss, filter, 0);
1399
	symsrc__destroy(&ss);
1400

1401
	if (err > 0) {
1402 1403 1404 1405
		if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
			dso->data_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
		else
			dso->data_type = DSO_BINARY_TYPE__VMLINUX;
1406 1407
		dso__set_long_name(dso, (char *)vmlinux);
		dso__set_loaded(dso, map->type);
1408
		pr_debug("Using %s for symbols\n", symfs_vmlinux);
1409
	}
1410

1411 1412 1413
	return err;
}

1414
int dso__load_vmlinux_path(struct dso *dso, struct map *map,
1415
			   symbol_filter_t filter)
1416 1417
{
	int i, err = 0;
1418
	char *filename;
1419 1420

	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
1421 1422
		 vmlinux_path__nr_entries + 1);

1423
	filename = dso__build_id_filename(dso, NULL, 0);
1424
	if (filename != NULL) {
1425
		err = dso__load_vmlinux(dso, map, filename, filter);
1426 1427
		if (err > 0) {
			dso->lname_alloc = 1;
1428
			goto out;
1429
		}
1430 1431
		free(filename);
	}
1432 1433

	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
1434
		err = dso__load_vmlinux(dso, map, vmlinux_path[i], filter);
1435
		if (err > 0) {
1436
			dso__set_long_name(dso, strdup(vmlinux_path[i]));
1437
			dso->lname_alloc = 1;
1438 1439 1440
			break;
		}
	}
1441
out:
1442 1443 1444
	return err;
}

1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543
static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
{
	char kallsyms_filename[PATH_MAX];
	struct dirent *dent;
	int ret = -1;
	DIR *d;

	d = opendir(dir);
	if (!d)
		return -1;

	while (1) {
		dent = readdir(d);
		if (!dent)
			break;
		if (dent->d_type != DT_DIR)
			continue;
		scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
			  "%s/%s/kallsyms", dir, dent->d_name);
		if (!validate_kcore_modules(kallsyms_filename, map)) {
			strlcpy(dir, kallsyms_filename, dir_sz);
			ret = 0;
			break;
		}
	}

	closedir(d);

	return ret;
}

static char *dso__find_kallsyms(struct dso *dso, struct map *map)
{
	u8 host_build_id[BUILD_ID_SIZE];
	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
	bool is_host = false;
	char path[PATH_MAX];

	if (!dso->has_build_id) {
		/*
		 * Last resort, if we don't have a build-id and couldn't find
		 * any vmlinux file, try the running kernel kallsyms table.
		 */
		goto proc_kallsyms;
	}

	if (sysfs__read_build_id("/sys/kernel/notes", host_build_id,
				 sizeof(host_build_id)) == 0)
		is_host = dso__build_id_equal(dso, host_build_id);

	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);

	/* Use /proc/kallsyms if possible */
	if (is_host) {
		DIR *d;
		int fd;

		/* If no cached kcore go with /proc/kallsyms */
		scnprintf(path, sizeof(path), "%s/[kernel.kcore]/%s",
			  buildid_dir, sbuild_id);
		d = opendir(path);
		if (!d)
			goto proc_kallsyms;
		closedir(d);

		/*
		 * Do not check the build-id cache, until we know we cannot use
		 * /proc/kcore.
		 */
		fd = open("/proc/kcore", O_RDONLY);
		if (fd != -1) {
			close(fd);
			/* If module maps match go with /proc/kallsyms */
			if (!validate_kcore_modules("/proc/kallsyms", map))
				goto proc_kallsyms;
		}

		/* Find kallsyms in build-id cache with kcore */
		if (!find_matching_kcore(map, path, sizeof(path)))
			return strdup(path);

		goto proc_kallsyms;
	}

	scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s",
		  buildid_dir, sbuild_id);

	if (access(path, F_OK)) {
		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
		       sbuild_id);
		return NULL;
	}

	return strdup(path);

proc_kallsyms:
	return strdup("/proc/kallsyms");
}

1544
static int dso__load_kernel_sym(struct dso *dso, struct map *map,
1545
				symbol_filter_t filter)
1546
{
1547
	int err;
1548 1549
	const char *kallsyms_filename = NULL;
	char *kallsyms_allocated_filename = NULL;
1550
	/*
1551 1552
	 * 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.
1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564
	 *
	 * 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.
	 */
1565 1566 1567 1568 1569
	if (symbol_conf.kallsyms_name != NULL) {
		kallsyms_filename = symbol_conf.kallsyms_name;
		goto do_kallsyms;
	}

1570
	if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
1571
		err = dso__load_vmlinux(dso, map,
1572
					symbol_conf.vmlinux_name, filter);
1573
		if (err > 0) {
1574
			dso__set_long_name(dso,
1575
					   strdup(symbol_conf.vmlinux_name));
1576
			dso->lname_alloc = 1;
1577
			return err;
1578 1579
		}
		return err;
1580
	}
1581

1582
	if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
1583
		err = dso__load_vmlinux_path(dso, map, filter);
1584
		if (err > 0)
1585
			return err;
1586 1587
	}

1588 1589 1590 1591
	/* do not try local files if a symfs was given */
	if (symbol_conf.symfs[0] != 0)
		return -1;

1592 1593 1594
	kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
	if (!kallsyms_allocated_filename)
		return -1;
1595

1596
	kallsyms_filename = kallsyms_allocated_filename;
1597

1598
do_kallsyms:
1599
	err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1600 1601
	if (err > 0)
		pr_debug("Using %s for symbols\n", kallsyms_filename);
1602
	free(kallsyms_allocated_filename);
1603

1604
	if (err > 0 && !dso__is_kcore(dso)) {
1605
		dso__set_long_name(dso, strdup("[kernel.kallsyms]"));
1606 1607
		map__fixup_start(map);
		map__fixup_end(map);
1608
	}
1609

1610 1611 1612
	return err;
}

1613 1614
static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
				      symbol_filter_t filter)
1615 1616 1617
{
	int err;
	const char *kallsyms_filename = NULL;
1618
	struct machine *machine;
1619 1620 1621 1622 1623 1624
	char path[PATH_MAX];

	if (!map->groups) {
		pr_debug("Guest kernel map hasn't the point to groups\n");
		return -1;
	}
1625
	machine = map->groups->machine;
1626

1627
	if (machine__is_default_guest(machine)) {
1628 1629 1630 1631 1632 1633
		/*
		 * 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) {
1634
			err = dso__load_vmlinux(dso, map,
1635
				symbol_conf.default_guest_vmlinux_name, filter);
1636
			return err;
1637 1638 1639 1640 1641 1642
		}

		kallsyms_filename = symbol_conf.default_guest_kallsyms;
		if (!kallsyms_filename)
			return -1;
	} else {
1643
		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
1644 1645 1646
		kallsyms_filename = path;
	}

1647
	err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1648
	if (err > 0)
1649
		pr_debug("Using %s for symbols\n", kallsyms_filename);
1650
	if (err > 0 && !dso__is_kcore(dso)) {
1651 1652
		machine__mmap_name(machine, path, sizeof(path));
		dso__set_long_name(dso, strdup(path));
1653 1654 1655 1656 1657 1658
		map__fixup_start(map);
		map__fixup_end(map);
	}

	return err;
}
1659

1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687
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;
1688 1689 1690 1691 1692 1693 1694 1695

	/* only try running kernel version if no symfs was given */
	if (symbol_conf.symfs[0] != 0)
		return 0;

	if (uname(&uts) < 0)
		return -1;

1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719
	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;
}

1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733
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;
}

1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752
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;
}

1753
int symbol__init(void)
1754
{
1755 1756
	const char *symfs;

1757 1758 1759
	if (symbol_conf.initialized)
		return 0;

1760
	symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
1761

1762 1763
	symbol__elf_init();

1764 1765 1766
	if (symbol_conf.sort_by_name)
		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
					  sizeof(struct symbol));
1767

1768
	if (symbol_conf.try_vmlinux_path && vmlinux_path__init() < 0)
1769 1770
		return -1;

1771 1772 1773 1774 1775
	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
		pr_err("'.' is the only non valid --field-separator argument\n");
		return -1;
	}

1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787
	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;

1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799
	/*
	 * 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);

1800 1801
	symbol_conf.kptr_restrict = symbol__read_kptr_restrict();

1802
	symbol_conf.initialized = true;
1803
	return 0;
1804 1805 1806

out_free_comm_list:
	strlist__delete(symbol_conf.comm_list);
1807 1808
out_free_dso_list:
	strlist__delete(symbol_conf.dso_list);
1809
	return -1;
1810 1811
}

1812 1813
void symbol__exit(void)
{
1814 1815
	if (!symbol_conf.initialized)
		return;
1816 1817 1818 1819 1820
	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;
1821
	symbol_conf.initialized = false;
1822
}