[linux-2.6-block.git] / tools / perf / util / symbol-elf.c

#include <libelf.h>
#include <gelf.h>
#include <elf.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <inttypes.h>

#include "symbol.h"
#include "debug.h"

#ifndef NT_GNU_BUILD_ID
#define NT_GNU_BUILD_ID 3
#endif

/**
 * elf_symtab__for_each_symbol - iterate thru all the symbols
 *
 * @syms: struct elf_symtab instance to iterate
 * @idx: uint32_t idx
 * @sym: GElf_Sym iterator
 */
#define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
	for (idx = 0, gelf_getsym(syms, idx, &sym);\
	     idx < nr_syms; \
	     idx++, gelf_getsym(syms, idx, &sym))

static inline uint8_t elf_sym__type(const GElf_Sym *sym)
{
	return GELF_ST_TYPE(sym->st_info);
}

static inline int elf_sym__is_function(const GElf_Sym *sym)
{
	return elf_sym__type(sym) == STT_FUNC &&
	       sym->st_name != 0 &&
	       sym->st_shndx != SHN_UNDEF;
}

static inline bool elf_sym__is_object(const GElf_Sym *sym)
{
	return elf_sym__type(sym) == STT_OBJECT &&
		sym->st_name != 0 &&
		sym->st_shndx != SHN_UNDEF;
}

static inline int elf_sym__is_label(const GElf_Sym *sym)
{
	return elf_sym__type(sym) == STT_NOTYPE &&
		sym->st_name != 0 &&
		sym->st_shndx != SHN_UNDEF &&
		sym->st_shndx != SHN_ABS;
}

static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
{
	switch (type) {
	case MAP__FUNCTION:
		return elf_sym__is_function(sym);
	case MAP__VARIABLE:
		return elf_sym__is_object(sym);
	default:
		return false;
	}
}

static inline const char *elf_sym__name(const GElf_Sym *sym,
					const Elf_Data *symstrs)
{
	return symstrs->d_buf + sym->st_name;
}

static inline const char *elf_sec__name(const GElf_Shdr *shdr,
					const Elf_Data *secstrs)
{
	return secstrs->d_buf + shdr->sh_name;
}

static inline int elf_sec__is_text(const GElf_Shdr *shdr,
					const Elf_Data *secstrs)
{
	return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
}

static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
				    const Elf_Data *secstrs)
{
	return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
}

static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
			  enum map_type type)
{
	switch (type) {
	case MAP__FUNCTION:
		return elf_sec__is_text(shdr, secstrs);
	case MAP__VARIABLE:
		return elf_sec__is_data(shdr, secstrs);
	default:
		return false;
	}
}

static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
{
	Elf_Scn *sec = NULL;
	GElf_Shdr shdr;
	size_t cnt = 1;

	while ((sec = elf_nextscn(elf, sec)) != NULL) {
		gelf_getshdr(sec, &shdr);

		if ((addr >= shdr.sh_addr) &&
		    (addr < (shdr.sh_addr + shdr.sh_size)))
			return cnt;

		++cnt;
	}

	return -1;
}

static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
				    GElf_Shdr *shp, const char *name,
				    size_t *idx)
{
	Elf_Scn *sec = NULL;
	size_t cnt = 1;

	/* Elf is corrupted/truncated, avoid calling elf_strptr. */
	if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
		return NULL;

	while ((sec = elf_nextscn(elf, sec)) != NULL) {
		char *str;

		gelf_getshdr(sec, shp);
		str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
		if (!strcmp(name, str)) {
			if (idx)
				*idx = cnt;
			break;
		}
		++cnt;
	}

	return sec;
}

#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
	for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
	     idx < nr_entries; \
	     ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))

#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
	for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
	     idx < nr_entries; \
	     ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))

/*
 * We need to check if we have a .dynsym, so that we can handle the
 * .plt, synthesizing its symbols, that aren't on the symtabs (be it
 * .dynsym or .symtab).
 * And always look at the original dso, not at debuginfo packages, that
 * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
 */
int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map,
				symbol_filter_t filter)
{
	uint32_t nr_rel_entries, idx;
	GElf_Sym sym;
	u64 plt_offset;
	GElf_Shdr shdr_plt;
	struct symbol *f;
	GElf_Shdr shdr_rel_plt, shdr_dynsym;
	Elf_Data *reldata, *syms, *symstrs;
	Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
	size_t dynsym_idx;
	GElf_Ehdr ehdr;
	char sympltname[1024];
	Elf *elf;
	int nr = 0, symidx, err = 0;

	elf = ss->elf;
	ehdr = ss->ehdr;

	scn_dynsym = ss->dynsym;
	shdr_dynsym = ss->dynshdr;
	dynsym_idx = ss->dynsym_idx;

	if (scn_dynsym == NULL)
		goto out_elf_end;

	scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
					  ".rela.plt", NULL);
	if (scn_plt_rel == NULL) {
		scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
						  ".rel.plt", NULL);
		if (scn_plt_rel == NULL)
			goto out_elf_end;
	}

	err = -1;

	if (shdr_rel_plt.sh_link != dynsym_idx)
		goto out_elf_end;

	if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
		goto out_elf_end;

	/*
	 * Fetch the relocation section to find the idxes to the GOT
	 * and the symbols in the .dynsym they refer to.
	 */
	reldata = elf_getdata(scn_plt_rel, NULL);
	if (reldata == NULL)
		goto out_elf_end;

	syms = elf_getdata(scn_dynsym, NULL);
	if (syms == NULL)
		goto out_elf_end;

	scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
	if (scn_symstrs == NULL)
		goto out_elf_end;

	symstrs = elf_getdata(scn_symstrs, NULL);
	if (symstrs == NULL)
		goto out_elf_end;

	if (symstrs->d_size == 0)
		goto out_elf_end;

	nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
	plt_offset = shdr_plt.sh_offset;

	if (shdr_rel_plt.sh_type == SHT_RELA) {
		GElf_Rela pos_mem, *pos;

		elf_section__for_each_rela(reldata, pos, pos_mem, idx,
					   nr_rel_entries) {
			symidx = GELF_R_SYM(pos->r_info);
			plt_offset += shdr_plt.sh_entsize;
			gelf_getsym(syms, symidx, &sym);
			snprintf(sympltname, sizeof(sympltname),
				 "%s@plt", elf_sym__name(&sym, symstrs));

			f = symbol__new(plt_offset, shdr_plt.sh_entsize,
					STB_GLOBAL, sympltname);
			if (!f)
				goto out_elf_end;

			if (filter && filter(map, f))
				symbol__delete(f);
			else {
				symbols__insert(&dso->symbols[map->type], f);
				++nr;
			}
		}
	} else if (shdr_rel_plt.sh_type == SHT_REL) {
		GElf_Rel pos_mem, *pos;
		elf_section__for_each_rel(reldata, pos, pos_mem, idx,
					  nr_rel_entries) {
			symidx = GELF_R_SYM(pos->r_info);
			plt_offset += shdr_plt.sh_entsize;
			gelf_getsym(syms, symidx, &sym);
			snprintf(sympltname, sizeof(sympltname),
				 "%s@plt", elf_sym__name(&sym, symstrs));

			f = symbol__new(plt_offset, shdr_plt.sh_entsize,
					STB_GLOBAL, sympltname);
			if (!f)
				goto out_elf_end;

			if (filter && filter(map, f))
				symbol__delete(f);
			else {
				symbols__insert(&dso->symbols[map->type], f);
				++nr;
			}
		}
	}

	err = 0;
out_elf_end:
	if (err == 0)
		return nr;
	pr_debug("%s: problems reading %s PLT info.\n",
		 __func__, dso->long_name);
	return 0;
}

/*
 * Align offset to 4 bytes as needed for note name and descriptor data.
 */
#define NOTE_ALIGN(n) (((n) + 3) & -4U)

static int elf_read_build_id(Elf *elf, void *bf, size_t size)
{
	int err = -1;
	GElf_Ehdr ehdr;
	GElf_Shdr shdr;
	Elf_Data *data;
	Elf_Scn *sec;
	Elf_Kind ek;
	void *ptr;

	if (size < BUILD_ID_SIZE)
		goto out;

	ek = elf_kind(elf);
	if (ek != ELF_K_ELF)
		goto out;

	if (gelf_getehdr(elf, &ehdr) == NULL) {
		pr_err("%s: cannot get elf header.\n", __func__);
		goto out;
	}

	/*
	 * Check following sections for notes:
	 *   '.note.gnu.build-id'
	 *   '.notes'
	 *   '.note' (VDSO specific)
	 */
	do {
		sec = elf_section_by_name(elf, &ehdr, &shdr,
					  ".note.gnu.build-id", NULL);
		if (sec)
			break;

		sec = elf_section_by_name(elf, &ehdr, &shdr,
					  ".notes", NULL);
		if (sec)
			break;

		sec = elf_section_by_name(elf, &ehdr, &shdr,
					  ".note", NULL);
		if (sec)
			break;

		return err;

	} while (0);

	data = elf_getdata(sec, NULL);
	if (data == NULL)
		goto out;

	ptr = data->d_buf;
	while (ptr < (data->d_buf + data->d_size)) {
		GElf_Nhdr *nhdr = ptr;
		size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
		       descsz = NOTE_ALIGN(nhdr->n_descsz);
		const char *name;

		ptr += sizeof(*nhdr);
		name = ptr;
		ptr += namesz;
		if (nhdr->n_type == NT_GNU_BUILD_ID &&
		    nhdr->n_namesz == sizeof("GNU")) {
			if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
				size_t sz = min(size, descsz);
				memcpy(bf, ptr, sz);
				memset(bf + sz, 0, size - sz);
				err = descsz;
				break;
			}
		}
		ptr += descsz;
	}

out:
	return err;
}

int filename__read_build_id(const char *filename, void *bf, size_t size)
{
	int fd, err = -1;
	Elf *elf;

	if (size < BUILD_ID_SIZE)
		goto out;

	fd = open(filename, O_RDONLY);
	if (fd < 0)
		goto out;

	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
	if (elf == NULL) {
		pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
		goto out_close;
	}

	err = elf_read_build_id(elf, bf, size);

	elf_end(elf);
out_close:
	close(fd);
out:
	return err;
}

int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
{
	int fd, err = -1;

	if (size < BUILD_ID_SIZE)
		goto out;

	fd = open(filename, O_RDONLY);
	if (fd < 0)
		goto out;

	while (1) {
		char bf[BUFSIZ];
		GElf_Nhdr nhdr;
		size_t namesz, descsz;

		if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
			break;

		namesz = NOTE_ALIGN(nhdr.n_namesz);
		descsz = NOTE_ALIGN(nhdr.n_descsz);
		if (nhdr.n_type == NT_GNU_BUILD_ID &&
		    nhdr.n_namesz == sizeof("GNU")) {
			if (read(fd, bf, namesz) != (ssize_t)namesz)
				break;
			if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
				size_t sz = min(descsz, size);
				if (read(fd, build_id, sz) == (ssize_t)sz) {
					memset(build_id + sz, 0, size - sz);
					err = 0;
					break;
				}
			} else if (read(fd, bf, descsz) != (ssize_t)descsz)
				break;
		} else {
			int n = namesz + descsz;
			if (read(fd, bf, n) != n)
				break;
		}
	}
	close(fd);
out:
	return err;
}

int filename__read_debuglink(const char *filename, char *debuglink,
			     size_t size)
{
	int fd, err = -1;
	Elf *elf;
	GElf_Ehdr ehdr;
	GElf_Shdr shdr;
	Elf_Data *data;
	Elf_Scn *sec;
	Elf_Kind ek;

	fd = open(filename, O_RDONLY);
	if (fd < 0)
		goto out;

	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
	if (elf == NULL) {
		pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
		goto out_close;
	}

	ek = elf_kind(elf);
	if (ek != ELF_K_ELF)
		goto out_close;

	if (gelf_getehdr(elf, &ehdr) == NULL) {
		pr_err("%s: cannot get elf header.\n", __func__);
		goto out_close;
	}

	sec = elf_section_by_name(elf, &ehdr, &shdr,
				  ".gnu_debuglink", NULL);
	if (sec == NULL)
		goto out_close;

	data = elf_getdata(sec, NULL);
	if (data == NULL)
		goto out_close;

	/* the start of this section is a zero-terminated string */
	strncpy(debuglink, data->d_buf, size);

	elf_end(elf);

out_close:
	close(fd);
out:
	return err;
}

static int dso__swap_init(struct dso *dso, unsigned char eidata)
{
	static unsigned int const endian = 1;

	dso->needs_swap = DSO_SWAP__NO;

	switch (eidata) {
	case ELFDATA2LSB:
		/* We are big endian, DSO is little endian. */
		if (*(unsigned char const *)&endian != 1)
			dso->needs_swap = DSO_SWAP__YES;
		break;

	case ELFDATA2MSB:
		/* We are little endian, DSO is big endian. */
		if (*(unsigned char const *)&endian != 0)
			dso->needs_swap = DSO_SWAP__YES;
		break;

	default:
		pr_err("unrecognized DSO data encoding %d\n", eidata);
		return -EINVAL;
	}

	return 0;
}


void symsrc__destroy(struct symsrc *ss)
{
	free(ss->name);
	elf_end(ss->elf);
	close(ss->fd);
}

int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
		 enum dso_binary_type type)
{
	int err = -1;
	GElf_Ehdr ehdr;
	Elf *elf;
	int fd;

	fd = open(name, O_RDONLY);
	if (fd < 0)
		return -1;

	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
	if (elf == NULL) {
		pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
		goto out_close;
	}

	if (gelf_getehdr(elf, &ehdr) == NULL) {
		pr_debug("%s: cannot get elf header.\n", __func__);
		goto out_elf_end;
	}

	if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
		goto out_elf_end;

	/* Always reject images with a mismatched build-id: */
	if (dso->has_build_id) {
		u8 build_id[BUILD_ID_SIZE];

		if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0)
			goto out_elf_end;

		if (!dso__build_id_equal(dso, build_id))
			goto out_elf_end;
	}

	ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
			NULL);
	if (ss->symshdr.sh_type != SHT_SYMTAB)
		ss->symtab = NULL;

	ss->dynsym_idx = 0;
	ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
			&ss->dynsym_idx);
	if (ss->dynshdr.sh_type != SHT_DYNSYM)
		ss->dynsym = NULL;

	ss->opdidx = 0;
	ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
			&ss->opdidx);
	if (ss->opdshdr.sh_type != SHT_PROGBITS)
		ss->opdsec = NULL;

	if (dso->kernel == DSO_TYPE_USER) {
		GElf_Shdr shdr;
		ss->adjust_symbols = (ehdr.e_type == ET_EXEC ||
				elf_section_by_name(elf, &ehdr, &shdr,
						     ".gnu.prelink_undo",
						     NULL) != NULL);
	} else {
		ss->adjust_symbols = 0;
	}

	ss->name   = strdup(name);
	if (!ss->name)
		goto out_elf_end;

	ss->elf    = elf;
	ss->fd     = fd;
	ss->ehdr   = ehdr;
	ss->type   = type;

	return 0;

out_elf_end:
	elf_end(elf);
out_close:
	close(fd);
	return err;
}

int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *ss,
		  symbol_filter_t filter, int kmodule, int want_symtab)
{
	struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
	struct map *curr_map = map;
	struct dso *curr_dso = dso;
	Elf_Data *symstrs, *secstrs;
	uint32_t nr_syms;
	int err = -1;
	uint32_t idx;
	GElf_Ehdr ehdr;
	GElf_Shdr shdr, opdshdr;
	Elf_Data *syms, *opddata = NULL;
	GElf_Sym sym;
	Elf_Scn *sec, *sec_strndx, *opdsec;
	Elf *elf;
	int nr = 0;
	size_t opdidx = 0;

	dso->symtab_type = ss->type;

	elf = ss->elf;
	ehdr = ss->ehdr;
	sec = ss->symtab;
	shdr = ss->symshdr;

	if (sec == NULL) {
		if (want_symtab)
			goto out_elf_end;

		sec  = ss->dynsym;
		shdr = ss->dynshdr;
		if (sec == NULL)
			goto out_elf_end;
	}

	opdsec = ss->opdsec;
	opdshdr = ss->opdshdr;
	opdidx  = ss->opdidx;
	if (opdsec)
		opddata = elf_rawdata(opdsec, NULL);

	syms = elf_getdata(sec, NULL);
	if (syms == NULL)
		goto out_elf_end;

	sec = elf_getscn(elf, shdr.sh_link);
	if (sec == NULL)
		goto out_elf_end;

	symstrs = elf_getdata(sec, NULL);
	if (symstrs == NULL)
		goto out_elf_end;

	sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
	if (sec_strndx == NULL)
		goto out_elf_end;

	secstrs = elf_getdata(sec_strndx, NULL);
	if (secstrs == NULL)
		goto out_elf_end;

	nr_syms = shdr.sh_size / shdr.sh_entsize;

	memset(&sym, 0, sizeof(sym));
	dso->adjust_symbols = ss->adjust_symbols;
	elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
		struct symbol *f;
		const char *elf_name = elf_sym__name(&sym, symstrs);
		char *demangled = NULL;
		int is_label = elf_sym__is_label(&sym);
		const char *section_name;

		if (kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
		    strcmp(elf_name, kmap->ref_reloc_sym->name) == 0)
			kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;

		if (!is_label && !elf_sym__is_a(&sym, map->type))
			continue;

		/* Reject ARM ELF "mapping symbols": these aren't unique and
		 * don't identify functions, so will confuse the profile
		 * output: */
		if (ehdr.e_machine == EM_ARM) {
			if (!strcmp(elf_name, "$a") ||
			    !strcmp(elf_name, "$d") ||
			    !strcmp(elf_name, "$t"))
				continue;
		}

		if (opdsec && sym.st_shndx == opdidx) {
			u32 offset = sym.st_value - opdshdr.sh_addr;
			u64 *opd = opddata->d_buf + offset;
			sym.st_value = DSO__SWAP(dso, u64, *opd);
			sym.st_shndx = elf_addr_to_index(elf, sym.st_value);
		}

		sec = elf_getscn(elf, sym.st_shndx);
		if (!sec)
			goto out_elf_end;

		gelf_getshdr(sec, &shdr);

		if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
			continue;

		section_name = elf_sec__name(&shdr, secstrs);

		/* On ARM, symbols for thumb functions have 1 added to
		 * the symbol address as a flag - remove it */
		if ((ehdr.e_machine == EM_ARM) &&
		    (map->type == MAP__FUNCTION) &&
		    (sym.st_value & 1))
			--sym.st_value;

		if (dso->kernel != DSO_TYPE_USER || kmodule) {
			char dso_name[PATH_MAX];

			if (strcmp(section_name,
				   (curr_dso->short_name +
				    dso->short_name_len)) == 0)
				goto new_symbol;

			if (strcmp(section_name, ".text") == 0) {
				curr_map = map;
				curr_dso = dso;
				goto new_symbol;
			}

			snprintf(dso_name, sizeof(dso_name),
				 "%s%s", dso->short_name, section_name);

			curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
			if (curr_map == NULL) {
				u64 start = sym.st_value;

				if (kmodule)
					start += map->start + shdr.sh_offset;

				curr_dso = dso__new(dso_name);
				if (curr_dso == NULL)
					goto out_elf_end;
				curr_dso->kernel = dso->kernel;
				curr_dso->long_name = dso->long_name;
				curr_dso->long_name_len = dso->long_name_len;
				curr_map = map__new2(start, curr_dso,
						     map->type);
				if (curr_map == NULL) {
					dso__delete(curr_dso);
					goto out_elf_end;
				}
				curr_map->map_ip = identity__map_ip;
				curr_map->unmap_ip = identity__map_ip;
				curr_dso->symtab_type = dso->symtab_type;
				map_groups__insert(kmap->kmaps, curr_map);
				dsos__add(&dso->node, curr_dso);
				dso__set_loaded(curr_dso, map->type);
			} else
				curr_dso = curr_map->dso;

			goto new_symbol;
		}

		if (curr_dso->adjust_symbols && sym.st_value) {
			pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
				  "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
				  (u64)sym.st_value, (u64)shdr.sh_addr,
				  (u64)shdr.sh_offset);
			sym.st_value -= shdr.sh_addr - shdr.sh_offset;
		}
		/*
		 * We need to figure out if the object was created from C++ sources
		 * DWARF DW_compile_unit has this, but we don't always have access
		 * to it...
		 */
		demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS | DMGL_ANSI);
		if (demangled != NULL)
			elf_name = demangled;
new_symbol:
		f = symbol__new(sym.st_value, sym.st_size,
				GELF_ST_BIND(sym.st_info), elf_name);
		free(demangled);
		if (!f)
			goto out_elf_end;

		if (filter && filter(curr_map, f))
			symbol__delete(f);
		else {
			symbols__insert(&curr_dso->symbols[curr_map->type], f);
			nr++;
		}
	}

	/*
	 * For misannotated, zeroed, ASM function sizes.
	 */
	if (nr > 0) {
		symbols__fixup_duplicate(&dso->symbols[map->type]);
		symbols__fixup_end(&dso->symbols[map->type]);
		if (kmap) {
			/*
			 * We need to fixup this here too because we create new
			 * maps here, for things like vsyscall sections.
			 */
			__map_groups__fixup_end(kmap->kmaps, map->type);
		}
	}
	err = nr;
out_elf_end:
	return err;
}

void symbol__elf_init(void)
{
	elf_version(EV_CURRENT);
}
Commit	Line	Data
e5a1845f NK	1	#include <libelf.h>
	2	#include <gelf.h>
	3	#include <elf.h>
	4	#include <fcntl.h>
	5	#include <stdio.h>
	6	#include <errno.h>
	7	#include <string.h>
	8	#include <unistd.h>
	9	#include <inttypes.h>
	10
	11	#include "symbol.h"
	12	#include "debug.h"
	13
	14	#ifndef NT_GNU_BUILD_ID
	15	#define NT_GNU_BUILD_ID 3
	16	#endif
	17
	18	/**
	19	* elf_symtab__for_each_symbol - iterate thru all the symbols
	20	*
	21	* @syms: struct elf_symtab instance to iterate
	22	* @idx: uint32_t idx
	23	* @sym: GElf_Sym iterator
	24	*/
	25	#define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
	26	for (idx = 0, gelf_getsym(syms, idx, &sym);\
	27	idx < nr_syms; \
	28	idx++, gelf_getsym(syms, idx, &sym))
	29
	30	static inline uint8_t elf_sym__type(const GElf_Sym *sym)
	31	{
	32	return GELF_ST_TYPE(sym->st_info);
	33	}
	34
	35	static inline int elf_sym__is_function(const GElf_Sym *sym)
	36	{
	37	return elf_sym__type(sym) == STT_FUNC &&
	38	sym->st_name != 0 &&
	39	sym->st_shndx != SHN_UNDEF;
	40	}
	41
	42	static inline bool elf_sym__is_object(const GElf_Sym *sym)
	43	{
	44	return elf_sym__type(sym) == STT_OBJECT &&
	45	sym->st_name != 0 &&
	46	sym->st_shndx != SHN_UNDEF;
	47	}
	48
	49	static inline int elf_sym__is_label(const GElf_Sym *sym)
	50	{
	51	return elf_sym__type(sym) == STT_NOTYPE &&
	52	sym->st_name != 0 &&
	53	sym->st_shndx != SHN_UNDEF &&
	54	sym->st_shndx != SHN_ABS;
	55	}
	56
	57	static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
	58	{
	59	switch (type) {
	60	case MAP__FUNCTION:
	61	return elf_sym__is_function(sym);
	62	case MAP__VARIABLE:
	63	return elf_sym__is_object(sym);
	64	default:
65	return false;
66	}
67	}
68
69	static inline const char elf_sym__name(const GElf_Sym sym,
70	const Elf_Data *symstrs)
71	{
72	return symstrs->d_buf + sym->st_name;
73	}
74
75	static inline const char elf_sec__name(const GElf_Shdr shdr,
76	const Elf_Data *secstrs)
77	{
78	return secstrs->d_buf + shdr->sh_name;
79	}
80
81	static inline int elf_sec__is_text(const GElf_Shdr *shdr,
82	const Elf_Data *secstrs)
83	{
84	return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
85	}
86
87	static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
88	const Elf_Data *secstrs)
89	{
90	return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
91	}
92
93	static bool elf_sec__is_a(GElf_Shdr shdr, Elf_Data secstrs,
94	enum map_type type)
95	{
96	switch (type) {
97	case MAP__FUNCTION:
98	return elf_sec__is_text(shdr, secstrs);
99	case MAP__VARIABLE:
100	return elf_sec__is_data(shdr, secstrs);
101	default:
102	return false;
103	}
104	}
105
106	static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
107	{
108	Elf_Scn *sec = NULL;
109	GElf_Shdr shdr;
110	size_t cnt = 1;
111
112	while ((sec = elf_nextscn(elf, sec)) != NULL) {
113	gelf_getshdr(sec, &shdr);
114
115	if ((addr >= shdr.sh_addr) &&
116	(addr < (shdr.sh_addr + shdr.sh_size)))
117	return cnt;
118
119	++cnt;
120	}
121
122	return -1;
123	}
124
125	static Elf_Scn elf_section_by_name(Elf elf, GElf_Ehdr *ep,
126	GElf_Shdr shp, const char name,
127	size_t *idx)
128	{
129	Elf_Scn *sec = NULL;
130	size_t cnt = 1;
131
49274654 CS	132	/* Elf is corrupted/truncated, avoid calling elf_strptr. */
	133	if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
	134	return NULL;
	135
e5a1845f NK	136	while ((sec = elf_nextscn(elf, sec)) != NULL) {
	137	char *str;
	138
	139	gelf_getshdr(sec, shp);
	140	str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
	141	if (!strcmp(name, str)) {
	142	if (idx)
	143	*idx = cnt;
	144	break;
	145	}
	146	++cnt;
	147	}
	148
	149	return sec;
	150	}
	151
	152	#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
	153	for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
	154	idx < nr_entries; \
	155	++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
	156
	157	#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
	158	for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
	159	idx < nr_entries; \
	160	++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
	161
	162	/*
	163	* We need to check if we have a .dynsym, so that we can handle the
	164	* .plt, synthesizing its symbols, that aren't on the symtabs (be it
	165	* .dynsym or .symtab).
	166	* And always look at the original dso, not at debuginfo packages, that
	167	* have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
	168	*/
a44f605b	169	int dso__synthesize_plt_symbols(struct dso dso, struct symsrc ss, struct map *map,
e5a1845f NK	170	symbol_filter_t filter)
	171	{
	172	uint32_t nr_rel_entries, idx;
	173	GElf_Sym sym;
	174	u64 plt_offset;
	175	GElf_Shdr shdr_plt;
	176	struct symbol *f;
	177	GElf_Shdr shdr_rel_plt, shdr_dynsym;
	178	Elf_Data reldata, syms, *symstrs;
	179	Elf_Scn scn_plt_rel, scn_symstrs, *scn_dynsym;
	180	size_t dynsym_idx;
	181	GElf_Ehdr ehdr;
	182	char sympltname[1024];
	183	Elf *elf;
a44f605b	184	int nr = 0, symidx, err = 0;
e5a1845f	185
a44f605b CS	186	elf = ss->elf;
a44f605b CS	187	ehdr = ss->ehdr;
e5a1845f	188
a44f605b CS	189	scn_dynsym = ss->dynsym;
	190	shdr_dynsym = ss->dynshdr;
	191	dynsym_idx = ss->dynsym_idx;
e5a1845f	192
e5a1845f NK	193	if (scn_dynsym == NULL)
	194	goto out_elf_end;
	195
	196	scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
	197	".rela.plt", NULL);
	198	if (scn_plt_rel == NULL) {
	199	scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
	200	".rel.plt", NULL);
	201	if (scn_plt_rel == NULL)
	202	goto out_elf_end;
	203	}
	204
	205	err = -1;
	206
	207	if (shdr_rel_plt.sh_link != dynsym_idx)
	208	goto out_elf_end;
	209
	210	if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
	211	goto out_elf_end;
	212
	213	/*
	214	* Fetch the relocation section to find the idxes to the GOT
	215	* and the symbols in the .dynsym they refer to.
	216	*/
	217	reldata = elf_getdata(scn_plt_rel, NULL);
	218	if (reldata == NULL)
	219	goto out_elf_end;
	220
	221	syms = elf_getdata(scn_dynsym, NULL);
	222	if (syms == NULL)
	223	goto out_elf_end;
	224
	225	scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
	226	if (scn_symstrs == NULL)
	227	goto out_elf_end;
	228
	229	symstrs = elf_getdata(scn_symstrs, NULL);
	230	if (symstrs == NULL)
	231	goto out_elf_end;
	232
52f9ddba CS	233	if (symstrs->d_size == 0)
	234	goto out_elf_end;
	235
e5a1845f NK	236	nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
	237	plt_offset = shdr_plt.sh_offset;
	238
	239	if (shdr_rel_plt.sh_type == SHT_RELA) {
	240	GElf_Rela pos_mem, *pos;
	241
	242	elf_section__for_each_rela(reldata, pos, pos_mem, idx,
	243	nr_rel_entries) {
	244	symidx = GELF_R_SYM(pos->r_info);
	245	plt_offset += shdr_plt.sh_entsize;
	246	gelf_getsym(syms, symidx, &sym);
	247	snprintf(sympltname, sizeof(sympltname),
	248	"%s@plt", elf_sym__name(&sym, symstrs));
	249
	250	f = symbol__new(plt_offset, shdr_plt.sh_entsize,
	251	STB_GLOBAL, sympltname);
	252	if (!f)
	253	goto out_elf_end;
	254
	255	if (filter && filter(map, f))
	256	symbol__delete(f);
	257	else {
	258	symbols__insert(&dso->symbols[map->type], f);
	259	++nr;
	260	}
	261	}
	262	} else if (shdr_rel_plt.sh_type == SHT_REL) {
	263	GElf_Rel pos_mem, *pos;
	264	elf_section__for_each_rel(reldata, pos, pos_mem, idx,
	265	nr_rel_entries) {
	266	symidx = GELF_R_SYM(pos->r_info);
	267	plt_offset += shdr_plt.sh_entsize;
	268	gelf_getsym(syms, symidx, &sym);
	269	snprintf(sympltname, sizeof(sympltname),
	270	"%s@plt", elf_sym__name(&sym, symstrs));
	271
	272	f = symbol__new(plt_offset, shdr_plt.sh_entsize,
	273	STB_GLOBAL, sympltname);
	274	if (!f)
	275	goto out_elf_end;
	276
	277	if (filter && filter(map, f))
	278	symbol__delete(f);
	279	else {
	280	symbols__insert(&dso->symbols[map->type], f);
	281	++nr;
	282	}
	283	}
	284	}
	285
	286	err = 0;
	287	out_elf_end:
e5a1845f NK	288	if (err == 0)
e5a1845f NK	289	return nr;
e5a1845f NK	290	pr_debug("%s: problems reading %s PLT info.\n",
	291	__func__, dso->long_name);
	292	return 0;
	293	}
	294
	295	/*
	296	* Align offset to 4 bytes as needed for note name and descriptor data.
	297	*/
	298	#define NOTE_ALIGN(n) (((n) + 3) & -4U)
	299
	300	static int elf_read_build_id(Elf elf, void bf, size_t size)
	301	{
	302	int err = -1;
	303	GElf_Ehdr ehdr;
	304	GElf_Shdr shdr;
	305	Elf_Data *data;
	306	Elf_Scn *sec;
	307	Elf_Kind ek;
	308	void *ptr;
	309
	310	if (size < BUILD_ID_SIZE)
	311	goto out;
	312
	313	ek = elf_kind(elf);
	314	if (ek != ELF_K_ELF)
	315	goto out;
	316
	317	if (gelf_getehdr(elf, &ehdr) == NULL) {
	318	pr_err("%s: cannot get elf header.\n", __func__);
	319	goto out;
	320	}
	321
	322	/*
	323	* Check following sections for notes:
	324	* '.note.gnu.build-id'
	325	* '.notes'
	326	* '.note' (VDSO specific)
	327	*/
	328	do {
	329	sec = elf_section_by_name(elf, &ehdr, &shdr,
	330	".note.gnu.build-id", NULL);
	331	if (sec)
	332	break;
	333
	334	sec = elf_section_by_name(elf, &ehdr, &shdr,
	335	".notes", NULL);
	336	if (sec)
	337	break;
	338
	339	sec = elf_section_by_name(elf, &ehdr, &shdr,
	340	".note", NULL);
	341	if (sec)
	342	break;
	343
	344	return err;
	345
	346	} while (0);
	347
	348	data = elf_getdata(sec, NULL);
	349	if (data == NULL)
	350	goto out;
	351
	352	ptr = data->d_buf;
	353	while (ptr < (data->d_buf + data->d_size)) {
354	GElf_Nhdr *nhdr = ptr;
355	size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
356	descsz = NOTE_ALIGN(nhdr->n_descsz);
357	const char *name;
358
359	ptr += sizeof(*nhdr);
360	name = ptr;
361	ptr += namesz;
362	if (nhdr->n_type == NT_GNU_BUILD_ID &&
363	nhdr->n_namesz == sizeof("GNU")) {
364	if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
365	size_t sz = min(size, descsz);
366	memcpy(bf, ptr, sz);
367	memset(bf + sz, 0, size - sz);
368	err = descsz;
369	break;
370	}
371	}
372	ptr += descsz;
373	}
374
375	out:
376	return err;
377	}
378
379	int filename__read_build_id(const char filename, void bf, size_t size)
380	{
381	int fd, err = -1;
382	Elf *elf;
383
384	if (size < BUILD_ID_SIZE)
385	goto out;
386
387	fd = open(filename, O_RDONLY);
388	if (fd < 0)
389	goto out;
390
391	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
392	if (elf == NULL) {
393	pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
394	goto out_close;
395	}
396
397	err = elf_read_build_id(elf, bf, size);
398
399	elf_end(elf);
400	out_close:
401	close(fd);
402	out:
403	return err;
404	}
405
406	int sysfs__read_build_id(const char filename, void build_id, size_t size)
407	{
408	int fd, err = -1;
409
410	if (size < BUILD_ID_SIZE)
411	goto out;
412
413	fd = open(filename, O_RDONLY);
414	if (fd < 0)
415	goto out;
416
417	while (1) {
418	char bf[BUFSIZ];
419	GElf_Nhdr nhdr;
420	size_t namesz, descsz;
421
422	if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
423	break;
424
425	namesz = NOTE_ALIGN(nhdr.n_namesz);
426	descsz = NOTE_ALIGN(nhdr.n_descsz);
427	if (nhdr.n_type == NT_GNU_BUILD_ID &&
428	nhdr.n_namesz == sizeof("GNU")) {
429	if (read(fd, bf, namesz) != (ssize_t)namesz)
430	break;
431	if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
432	size_t sz = min(descsz, size);
433	if (read(fd, build_id, sz) == (ssize_t)sz) {
434	memset(build_id + sz, 0, size - sz);
435	err = 0;
436	break;
437	}
438	} else if (read(fd, bf, descsz) != (ssize_t)descsz)
439	break;
440	} else {
441	int n = namesz + descsz;
442	if (read(fd, bf, n) != n)
443	break;
444	}
445	}
446	close(fd);
447	out:
448	return err;
449	}
450
451	int filename__read_debuglink(const char filename, char debuglink,
452	size_t size)
453	{
454	int fd, err = -1;
455	Elf *elf;
456	GElf_Ehdr ehdr;
457	GElf_Shdr shdr;
458	Elf_Data *data;
459	Elf_Scn *sec;
460	Elf_Kind ek;
461
462	fd = open(filename, O_RDONLY);
463	if (fd < 0)
464	goto out;
465
466	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
467	if (elf == NULL) {
468	pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
469	goto out_close;
470	}
471
472	ek = elf_kind(elf);
473	if (ek != ELF_K_ELF)
474	goto out_close;
475
476	if (gelf_getehdr(elf, &ehdr) == NULL) {
477	pr_err("%s: cannot get elf header.\n", __func__);
478	goto out_close;
479	}
480
481	sec = elf_section_by_name(elf, &ehdr, &shdr,
482	".gnu_debuglink", NULL);
483	if (sec == NULL)
484	goto out_close;
485
486	data = elf_getdata(sec, NULL);
487	if (data == NULL)
488	goto out_close;
489
490	/* the start of this section is a zero-terminated string */
491	strncpy(debuglink, data->d_buf, size);
492
493	elf_end(elf);
494
495	out_close:
496	close(fd);
497	out:
498	return err;
499	}
500
501	static int dso__swap_init(struct dso *dso, unsigned char eidata)
502	{
503	static unsigned int const endian = 1;
504
505	dso->needs_swap = DSO_SWAP__NO;
506
507	switch (eidata) {
508	case ELFDATA2LSB:
509	/* We are big endian, DSO is little endian. */
510	if ((unsigned char const )&endian != 1)
511	dso->needs_swap = DSO_SWAP__YES;
512	break;
513
514	case ELFDATA2MSB:
515	/* We are little endian, DSO is big endian. */
516	if ((unsigned char const )&endian != 0)
517	dso->needs_swap = DSO_SWAP__YES;
518	break;
519
520	default:
521	pr_err("unrecognized DSO data encoding %d\n", eidata);
522	return -EINVAL;
523	}
524
525	return 0;
526	}
527
b68e2f91 CS	528
	529	void symsrc__destroy(struct symsrc *ss)
	530	{
	531	free(ss->name);
	532	elf_end(ss->elf);
	533	close(ss->fd);
	534	}
	535
	536	int symsrc__init(struct symsrc ss, struct dso dso, const char *name,
	537	enum dso_binary_type type)
e5a1845f	538	{
e5a1845f	539	int err = -1;
e5a1845f	540	GElf_Ehdr ehdr;
e5a1845f	541	Elf *elf;
b68e2f91 CS	542	int fd;
	543
	544	fd = open(name, O_RDONLY);
	545	if (fd < 0)
	546	return -1;
e5a1845f NK	547
	548	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
	549	if (elf == NULL) {
	550	pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
	551	goto out_close;
	552	}
	553
	554	if (gelf_getehdr(elf, &ehdr) == NULL) {
	555	pr_debug("%s: cannot get elf header.\n", __func__);
	556	goto out_elf_end;
	557	}
	558
	559	if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
	560	goto out_elf_end;
	561
	562	/* Always reject images with a mismatched build-id: */
	563	if (dso->has_build_id) {
	564	u8 build_id[BUILD_ID_SIZE];
	565
	566	if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0)
	567	goto out_elf_end;
	568
	569	if (!dso__build_id_equal(dso, build_id))
	570	goto out_elf_end;
	571	}
	572
b68e2f91 CS	573	ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
	574	NULL);
	575	if (ss->symshdr.sh_type != SHT_SYMTAB)
	576	ss->symtab = NULL;
	577
	578	ss->dynsym_idx = 0;
	579	ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
	580	&ss->dynsym_idx);
	581	if (ss->dynshdr.sh_type != SHT_DYNSYM)
	582	ss->dynsym = NULL;
	583
	584	ss->opdidx = 0;
	585	ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
	586	&ss->opdidx);
	587	if (ss->opdshdr.sh_type != SHT_PROGBITS)
	588	ss->opdsec = NULL;
	589
	590	if (dso->kernel == DSO_TYPE_USER) {
	591	GElf_Shdr shdr;
	592	ss->adjust_symbols = (ehdr.e_type == ET_EXEC \|\|
	593	elf_section_by_name(elf, &ehdr, &shdr,
	594	".gnu.prelink_undo",
	595	NULL) != NULL);
	596	} else {
	597	ss->adjust_symbols = 0;
	598	}
	599
	600	ss->name = strdup(name);
	601	if (!ss->name)
	602	goto out_elf_end;
	603
	604	ss->elf = elf;
	605	ss->fd = fd;
	606	ss->ehdr = ehdr;
	607	ss->type = type;
	608
	609	return 0;
	610
	611	out_elf_end:
	612	elf_end(elf);
	613	out_close:
	614	close(fd);
	615	return err;
	616	}
	617
	618	int dso__load_sym(struct dso dso, struct map map, struct symsrc *ss,
	619	symbol_filter_t filter, int kmodule, int want_symtab)
	620	{
	621	struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
	622	struct map *curr_map = map;
	623	struct dso *curr_dso = dso;
	624	Elf_Data symstrs, secstrs;
	625	uint32_t nr_syms;
	626	int err = -1;
	627	uint32_t idx;
	628	GElf_Ehdr ehdr;
	629	GElf_Shdr shdr, opdshdr;
	630	Elf_Data syms, opddata = NULL;
	631	GElf_Sym sym;
	632	Elf_Scn sec, sec_strndx, *opdsec;
	633	Elf *elf;
	634	int nr = 0;
	635	size_t opdidx = 0;
	636
005f9294 CS	637	dso->symtab_type = ss->type;
005f9294 CS	638
b68e2f91 CS	639	elf = ss->elf;
	640	ehdr = ss->ehdr;
	641	sec = ss->symtab;
	642	shdr = ss->symshdr;
	643
e5a1845f NK	644	if (sec == NULL) {
	645	if (want_symtab)
	646	goto out_elf_end;
	647
b68e2f91 CS	648	sec = ss->dynsym;
b68e2f91 CS	649	shdr = ss->dynshdr;
e5a1845f NK	650	if (sec == NULL)
	651	goto out_elf_end;
	652	}
	653
b68e2f91 CS	654	opdsec = ss->opdsec;
	655	opdshdr = ss->opdshdr;
	656	opdidx = ss->opdidx;
e5a1845f NK	657	if (opdsec)
	658	opddata = elf_rawdata(opdsec, NULL);
	659
	660	syms = elf_getdata(sec, NULL);
	661	if (syms == NULL)
	662	goto out_elf_end;
	663
	664	sec = elf_getscn(elf, shdr.sh_link);
	665	if (sec == NULL)
	666	goto out_elf_end;
	667
	668	symstrs = elf_getdata(sec, NULL);
	669	if (symstrs == NULL)
	670	goto out_elf_end;
	671
	672	sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
	673	if (sec_strndx == NULL)
	674	goto out_elf_end;
	675
	676	secstrs = elf_getdata(sec_strndx, NULL);
	677	if (secstrs == NULL)
	678	goto out_elf_end;
	679
	680	nr_syms = shdr.sh_size / shdr.sh_entsize;
	681
	682	memset(&sym, 0, sizeof(sym));
b68e2f91	683	dso->adjust_symbols = ss->adjust_symbols;
e5a1845f NK	684	elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
	685	struct symbol *f;
	686	const char *elf_name = elf_sym__name(&sym, symstrs);
	687	char *demangled = NULL;
	688	int is_label = elf_sym__is_label(&sym);
	689	const char *section_name;
	690
	691	if (kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
	692	strcmp(elf_name, kmap->ref_reloc_sym->name) == 0)
	693	kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
	694
	695	if (!is_label && !elf_sym__is_a(&sym, map->type))
	696	continue;
	697
	698	/* Reject ARM ELF "mapping symbols": these aren't unique and
	699	* don't identify functions, so will confuse the profile
	700	* output: */
	701	if (ehdr.e_machine == EM_ARM) {
	702	if (!strcmp(elf_name, "$a") \|\|
	703	!strcmp(elf_name, "$d") \|\|
	704	!strcmp(elf_name, "$t"))
	705	continue;
	706	}
	707
	708	if (opdsec && sym.st_shndx == opdidx) {
	709	u32 offset = sym.st_value - opdshdr.sh_addr;
	710	u64 *opd = opddata->d_buf + offset;
	711	sym.st_value = DSO__SWAP(dso, u64, *opd);
	712	sym.st_shndx = elf_addr_to_index(elf, sym.st_value);
	713	}
	714
	715	sec = elf_getscn(elf, sym.st_shndx);
	716	if (!sec)
	717	goto out_elf_end;
	718
	719	gelf_getshdr(sec, &shdr);
	720
	721	if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
	722	continue;
	723
	724	section_name = elf_sec__name(&shdr, secstrs);
	725
	726	/* On ARM, symbols for thumb functions have 1 added to
	727	* the symbol address as a flag - remove it */
	728	if ((ehdr.e_machine == EM_ARM) &&
	729	(map->type == MAP__FUNCTION) &&
	730	(sym.st_value & 1))
	731	--sym.st_value;
	732
	733	if (dso->kernel != DSO_TYPE_USER \|\| kmodule) {
	734	char dso_name[PATH_MAX];
	735
	736	if (strcmp(section_name,
	737	(curr_dso->short_name +
	738	dso->short_name_len)) == 0)
	739	goto new_symbol;
	740
	741	if (strcmp(section_name, ".text") == 0) {
	742	curr_map = map;
	743	curr_dso = dso;
	744	goto new_symbol;
	745	}
	746
	747	snprintf(dso_name, sizeof(dso_name),
748	"%s%s", dso->short_name, section_name);
749
750	curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
751	if (curr_map == NULL) {
752	u64 start = sym.st_value;
753
754	if (kmodule)
755	start += map->start + shdr.sh_offset;
756
757	curr_dso = dso__new(dso_name);
758	if (curr_dso == NULL)
759	goto out_elf_end;
760	curr_dso->kernel = dso->kernel;
761	curr_dso->long_name = dso->long_name;
762	curr_dso->long_name_len = dso->long_name_len;
763	curr_map = map__new2(start, curr_dso,
764	map->type);
765	if (curr_map == NULL) {
766	dso__delete(curr_dso);
767	goto out_elf_end;
768	}
769	curr_map->map_ip = identity__map_ip;
770	curr_map->unmap_ip = identity__map_ip;
771	curr_dso->symtab_type = dso->symtab_type;
772	map_groups__insert(kmap->kmaps, curr_map);
773	dsos__add(&dso->node, curr_dso);
774	dso__set_loaded(curr_dso, map->type);
775	} else
776	curr_dso = curr_map->dso;
777
778	goto new_symbol;
779	}
780
8db24c70	781	if (curr_dso->adjust_symbols && sym.st_value) {
e5a1845f NK	782	pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
	783	"sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
	784	(u64)sym.st_value, (u64)shdr.sh_addr,
	785	(u64)shdr.sh_offset);
	786	sym.st_value -= shdr.sh_addr - shdr.sh_offset;
	787	}
	788	/*
	789	* We need to figure out if the object was created from C++ sources
	790	* DWARF DW_compile_unit has this, but we don't always have access
	791	* to it...
	792	*/
	793	demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS \| DMGL_ANSI);
	794	if (demangled != NULL)
	795	elf_name = demangled;
	796	new_symbol:
	797	f = symbol__new(sym.st_value, sym.st_size,
	798	GELF_ST_BIND(sym.st_info), elf_name);
	799	free(demangled);
	800	if (!f)
	801	goto out_elf_end;
	802
	803	if (filter && filter(curr_map, f))
	804	symbol__delete(f);
	805	else {
	806	symbols__insert(&curr_dso->symbols[curr_map->type], f);
	807	nr++;
	808	}
	809	}
	810
	811	/*
	812	* For misannotated, zeroed, ASM function sizes.
	813	*/
	814	if (nr > 0) {
	815	symbols__fixup_duplicate(&dso->symbols[map->type]);
	816	symbols__fixup_end(&dso->symbols[map->type]);
	817	if (kmap) {
	818	/*
	819	* We need to fixup this here too because we create new
	820	* maps here, for things like vsyscall sections.
	821	*/
	822	__map_groups__fixup_end(kmap->kmaps, map->type);
	823	}
	824	}
	825	err = nr;
	826	out_elf_end:
e5a1845f NK	827	return err;
	828	}
	829
	830	void symbol__elf_init(void)
	831	{
	832	elf_version(EV_CURRENT);
	833	}