[GitHub/mt8127/android_kernel_alcatel_ttab.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;

	if (!ss->dynsym)
		return 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;
}

bool symsrc__possibly_runtime(struct symsrc *ss)
{
	return ss->dynsym || ss->opdsec;
}

bool symsrc__has_symtab(struct symsrc *ss)
{
	return ss->symtab != NULL;
}

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 *syms_ss, struct symsrc *runtime_ss,
		  symbol_filter_t filter, int kmodule)
{
	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;
	Elf_Data *syms, *opddata = NULL;
	GElf_Sym sym;
	Elf_Scn *sec, *sec_strndx;
	Elf *elf;
	int nr = 0;

	dso->symtab_type = syms_ss->type;

	if (!syms_ss->symtab) {
		syms_ss->symtab  = syms_ss->dynsym;
		syms_ss->symshdr = syms_ss->dynshdr;
	}

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

	if (runtime_ss->opdsec)
		opddata = elf_rawdata(runtime_ss->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 = runtime_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;
		bool used_opd = false;

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

		sec = elf_getscn(runtime_ss->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 ((used_opd && runtime_ss->adjust_symbols)
				|| (!used_opd && syms_ss->adjust_symbols)) {
			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
f47b58b7 DA	186	if (!ss->dynsym)
	187	return 0;
	188
a44f605b CS	189	elf = ss->elf;
a44f605b CS	190	ehdr = ss->ehdr;
e5a1845f	191
a44f605b CS	192	scn_dynsym = ss->dynsym;
	193	shdr_dynsym = ss->dynshdr;
	194	dynsym_idx = ss->dynsym_idx;
e5a1845f	195
e5a1845f NK	196	if (scn_dynsym == NULL)
	197	goto out_elf_end;
	198
	199	scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
	200	".rela.plt", NULL);
	201	if (scn_plt_rel == NULL) {
	202	scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
	203	".rel.plt", NULL);
	204	if (scn_plt_rel == NULL)
	205	goto out_elf_end;
	206	}
	207
	208	err = -1;
	209
	210	if (shdr_rel_plt.sh_link != dynsym_idx)
	211	goto out_elf_end;
	212
	213	if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
	214	goto out_elf_end;
	215
	216	/*
	217	* Fetch the relocation section to find the idxes to the GOT
	218	* and the symbols in the .dynsym they refer to.
	219	*/
	220	reldata = elf_getdata(scn_plt_rel, NULL);
	221	if (reldata == NULL)
	222	goto out_elf_end;
	223
	224	syms = elf_getdata(scn_dynsym, NULL);
	225	if (syms == NULL)
	226	goto out_elf_end;
	227
	228	scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
	229	if (scn_symstrs == NULL)
	230	goto out_elf_end;
	231
	232	symstrs = elf_getdata(scn_symstrs, NULL);
	233	if (symstrs == NULL)
	234	goto out_elf_end;
	235
52f9ddba CS	236	if (symstrs->d_size == 0)
	237	goto out_elf_end;
	238
e5a1845f NK	239	nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
	240	plt_offset = shdr_plt.sh_offset;
	241
	242	if (shdr_rel_plt.sh_type == SHT_RELA) {
	243	GElf_Rela pos_mem, *pos;
	244
	245	elf_section__for_each_rela(reldata, pos, pos_mem, idx,
	246	nr_rel_entries) {
	247	symidx = GELF_R_SYM(pos->r_info);
	248	plt_offset += shdr_plt.sh_entsize;
	249	gelf_getsym(syms, symidx, &sym);
	250	snprintf(sympltname, sizeof(sympltname),
	251	"%s@plt", elf_sym__name(&sym, symstrs));
	252
	253	f = symbol__new(plt_offset, shdr_plt.sh_entsize,
	254	STB_GLOBAL, sympltname);
	255	if (!f)
	256	goto out_elf_end;
	257
	258	if (filter && filter(map, f))
	259	symbol__delete(f);
	260	else {
	261	symbols__insert(&dso->symbols[map->type], f);
	262	++nr;
	263	}
	264	}
	265	} else if (shdr_rel_plt.sh_type == SHT_REL) {
	266	GElf_Rel pos_mem, *pos;
	267	elf_section__for_each_rel(reldata, pos, pos_mem, idx,
	268	nr_rel_entries) {
	269	symidx = GELF_R_SYM(pos->r_info);
	270	plt_offset += shdr_plt.sh_entsize;
	271	gelf_getsym(syms, symidx, &sym);
	272	snprintf(sympltname, sizeof(sympltname),
	273	"%s@plt", elf_sym__name(&sym, symstrs));
	274
	275	f = symbol__new(plt_offset, shdr_plt.sh_entsize,
	276	STB_GLOBAL, sympltname);
	277	if (!f)
	278	goto out_elf_end;
	279
	280	if (filter && filter(map, f))
	281	symbol__delete(f);
	282	else {
	283	symbols__insert(&dso->symbols[map->type], f);
	284	++nr;
	285	}
	286	}
	287	}
	288
	289	err = 0;
	290	out_elf_end:
e5a1845f NK	291	if (err == 0)
e5a1845f NK	292	return nr;
e5a1845f NK	293	pr_debug("%s: problems reading %s PLT info.\n",
	294	__func__, dso->long_name);
	295	return 0;
	296	}
	297
	298	/*
	299	* Align offset to 4 bytes as needed for note name and descriptor data.
	300	*/
	301	#define NOTE_ALIGN(n) (((n) + 3) & -4U)
	302
	303	static int elf_read_build_id(Elf elf, void bf, size_t size)
	304	{
	305	int err = -1;
	306	GElf_Ehdr ehdr;
	307	GElf_Shdr shdr;
	308	Elf_Data *data;
	309	Elf_Scn *sec;
	310	Elf_Kind ek;
	311	void *ptr;
	312
	313	if (size < BUILD_ID_SIZE)
	314	goto out;
	315
	316	ek = elf_kind(elf);
	317	if (ek != ELF_K_ELF)
	318	goto out;
	319
	320	if (gelf_getehdr(elf, &ehdr) == NULL) {
	321	pr_err("%s: cannot get elf header.\n", __func__);
	322	goto out;
	323	}
	324
	325	/*
	326	* Check following sections for notes:
	327	* '.note.gnu.build-id'
	328	* '.notes'
	329	* '.note' (VDSO specific)
	330	*/
	331	do {
	332	sec = elf_section_by_name(elf, &ehdr, &shdr,
	333	".note.gnu.build-id", NULL);
	334	if (sec)
	335	break;
	336
	337	sec = elf_section_by_name(elf, &ehdr, &shdr,
	338	".notes", NULL);
	339	if (sec)
	340	break;
	341
	342	sec = elf_section_by_name(elf, &ehdr, &shdr,
	343	".note", NULL);
	344	if (sec)
	345	break;
	346
	347	return err;
	348
	349	} while (0);
	350
	351	data = elf_getdata(sec, NULL);
	352	if (data == NULL)
	353	goto out;
	354
	355	ptr = data->d_buf;
	356	while (ptr < (data->d_buf + data->d_size)) {
357	GElf_Nhdr *nhdr = ptr;
358	size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
359	descsz = NOTE_ALIGN(nhdr->n_descsz);
360	const char *name;
361
362	ptr += sizeof(*nhdr);
363	name = ptr;
364	ptr += namesz;
365	if (nhdr->n_type == NT_GNU_BUILD_ID &&
366	nhdr->n_namesz == sizeof("GNU")) {
367	if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
368	size_t sz = min(size, descsz);
369	memcpy(bf, ptr, sz);
370	memset(bf + sz, 0, size - sz);
371	err = descsz;
372	break;
373	}
374	}
375	ptr += descsz;
376	}
377
378	out:
379	return err;
380	}
381
382	int filename__read_build_id(const char filename, void bf, size_t size)
383	{
384	int fd, err = -1;
385	Elf *elf;
386
387	if (size < BUILD_ID_SIZE)
388	goto out;
389
390	fd = open(filename, O_RDONLY);
391	if (fd < 0)
392	goto out;
393
394	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
395	if (elf == NULL) {
396	pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
397	goto out_close;
398	}
399
400	err = elf_read_build_id(elf, bf, size);
401
402	elf_end(elf);
403	out_close:
404	close(fd);
405	out:
406	return err;
407	}
408
409	int sysfs__read_build_id(const char filename, void build_id, size_t size)
410	{
411	int fd, err = -1;
412
413	if (size < BUILD_ID_SIZE)
414	goto out;
415
416	fd = open(filename, O_RDONLY);
417	if (fd < 0)
418	goto out;
419
420	while (1) {
421	char bf[BUFSIZ];
422	GElf_Nhdr nhdr;
423	size_t namesz, descsz;
424
425	if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
426	break;
427
428	namesz = NOTE_ALIGN(nhdr.n_namesz);
429	descsz = NOTE_ALIGN(nhdr.n_descsz);
430	if (nhdr.n_type == NT_GNU_BUILD_ID &&
431	nhdr.n_namesz == sizeof("GNU")) {
432	if (read(fd, bf, namesz) != (ssize_t)namesz)
433	break;
434	if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
435	size_t sz = min(descsz, size);
436	if (read(fd, build_id, sz) == (ssize_t)sz) {
437	memset(build_id + sz, 0, size - sz);
438	err = 0;
439	break;
440	}
441	} else if (read(fd, bf, descsz) != (ssize_t)descsz)
442	break;
443	} else {
444	int n = namesz + descsz;
445	if (read(fd, bf, n) != n)
446	break;
447	}
448	}
449	close(fd);
450	out:
451	return err;
452	}
453
454	int filename__read_debuglink(const char filename, char debuglink,
455	size_t size)
456	{
457	int fd, err = -1;
458	Elf *elf;
459	GElf_Ehdr ehdr;
460	GElf_Shdr shdr;
461	Elf_Data *data;
462	Elf_Scn *sec;
463	Elf_Kind ek;
464
465	fd = open(filename, O_RDONLY);
466	if (fd < 0)
467	goto out;
468
469	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
470	if (elf == NULL) {
471	pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
472	goto out_close;
473	}
474
475	ek = elf_kind(elf);
476	if (ek != ELF_K_ELF)
477	goto out_close;
478
479	if (gelf_getehdr(elf, &ehdr) == NULL) {
480	pr_err("%s: cannot get elf header.\n", __func__);
481	goto out_close;
482	}
483
484	sec = elf_section_by_name(elf, &ehdr, &shdr,
485	".gnu_debuglink", NULL);
486	if (sec == NULL)
487	goto out_close;
488
489	data = elf_getdata(sec, NULL);
490	if (data == NULL)
491	goto out_close;
492
493	/* the start of this section is a zero-terminated string */
494	strncpy(debuglink, data->d_buf, size);
495
496	elf_end(elf);
497
498	out_close:
499	close(fd);
500	out:
501	return err;
502	}
503
504	static int dso__swap_init(struct dso *dso, unsigned char eidata)
505	{
506	static unsigned int const endian = 1;
507
508	dso->needs_swap = DSO_SWAP__NO;
509
510	switch (eidata) {
511	case ELFDATA2LSB:
512	/* We are big endian, DSO is little endian. */
513	if ((unsigned char const )&endian != 1)
514	dso->needs_swap = DSO_SWAP__YES;
515	break;
516
517	case ELFDATA2MSB:
518	/* We are little endian, DSO is big endian. */
519	if ((unsigned char const )&endian != 0)
520	dso->needs_swap = DSO_SWAP__YES;
521	break;
522
523	default:
524	pr_err("unrecognized DSO data encoding %d\n", eidata);
525	return -EINVAL;
526	}
527
528	return 0;
529	}
530
3aafe5ae CS	531	bool symsrc__possibly_runtime(struct symsrc *ss)
	532	{
	533	return ss->dynsym \|\| ss->opdsec;
	534	}
	535
d26cd12b CS	536	bool symsrc__has_symtab(struct symsrc *ss)
	537	{
	538	return ss->symtab != NULL;
	539	}
b68e2f91 CS	540
	541	void symsrc__destroy(struct symsrc *ss)
	542	{
	543	free(ss->name);
	544	elf_end(ss->elf);
	545	close(ss->fd);
	546	}
	547
	548	int symsrc__init(struct symsrc ss, struct dso dso, const char *name,
	549	enum dso_binary_type type)
e5a1845f	550	{
e5a1845f	551	int err = -1;
e5a1845f	552	GElf_Ehdr ehdr;
e5a1845f	553	Elf *elf;
b68e2f91 CS	554	int fd;
	555
	556	fd = open(name, O_RDONLY);
	557	if (fd < 0)
	558	return -1;
e5a1845f NK	559
	560	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
	561	if (elf == NULL) {
	562	pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
	563	goto out_close;
	564	}
	565
	566	if (gelf_getehdr(elf, &ehdr) == NULL) {
	567	pr_debug("%s: cannot get elf header.\n", __func__);
	568	goto out_elf_end;
	569	}
	570
	571	if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
	572	goto out_elf_end;
	573
	574	/* Always reject images with a mismatched build-id: */
	575	if (dso->has_build_id) {
	576	u8 build_id[BUILD_ID_SIZE];
	577
	578	if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0)
	579	goto out_elf_end;
	580
	581	if (!dso__build_id_equal(dso, build_id))
	582	goto out_elf_end;
	583	}
	584
b68e2f91 CS	585	ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
	586	NULL);
	587	if (ss->symshdr.sh_type != SHT_SYMTAB)
	588	ss->symtab = NULL;
	589
	590	ss->dynsym_idx = 0;
	591	ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
	592	&ss->dynsym_idx);
	593	if (ss->dynshdr.sh_type != SHT_DYNSYM)
	594	ss->dynsym = NULL;
	595
	596	ss->opdidx = 0;
	597	ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
	598	&ss->opdidx);
	599	if (ss->opdshdr.sh_type != SHT_PROGBITS)
	600	ss->opdsec = NULL;
	601
	602	if (dso->kernel == DSO_TYPE_USER) {
	603	GElf_Shdr shdr;
	604	ss->adjust_symbols = (ehdr.e_type == ET_EXEC \|\|
	605	elf_section_by_name(elf, &ehdr, &shdr,
	606	".gnu.prelink_undo",
	607	NULL) != NULL);
	608	} else {
	609	ss->adjust_symbols = 0;
	610	}
	611
	612	ss->name = strdup(name);
	613	if (!ss->name)
	614	goto out_elf_end;
	615
	616	ss->elf = elf;
	617	ss->fd = fd;
	618	ss->ehdr = ehdr;
	619	ss->type = type;
	620
	621	return 0;
	622
	623	out_elf_end:
	624	elf_end(elf);
	625	out_close:
	626	close(fd);
	627	return err;
	628	}
	629
261360b6 CS	630	int dso__load_sym(struct dso dso, struct map map,
261360b6 CS	631	struct symsrc syms_ss, struct symsrc runtime_ss,
d26cd12b	632	symbol_filter_t filter, int kmodule)
b68e2f91 CS	633	{
	634	struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
	635	struct map *curr_map = map;
	636	struct dso *curr_dso = dso;
	637	Elf_Data symstrs, secstrs;
	638	uint32_t nr_syms;
	639	int err = -1;
	640	uint32_t idx;
	641	GElf_Ehdr ehdr;
261360b6	642	GElf_Shdr shdr;
b68e2f91 CS	643	Elf_Data syms, opddata = NULL;
b68e2f91 CS	644	GElf_Sym sym;
261360b6	645	Elf_Scn sec, sec_strndx;
b68e2f91 CS	646	Elf *elf;
b68e2f91 CS	647	int nr = 0;
b68e2f91	648
261360b6	649	dso->symtab_type = syms_ss->type;
005f9294	650
261360b6 CS	651	if (!syms_ss->symtab) {
	652	syms_ss->symtab = syms_ss->dynsym;
	653	syms_ss->symshdr = syms_ss->dynshdr;
d26cd12b CS	654	}
d26cd12b CS	655
261360b6 CS	656	elf = syms_ss->elf;
	657	ehdr = syms_ss->ehdr;
	658	sec = syms_ss->symtab;
	659	shdr = syms_ss->symshdr;
b68e2f91	660
261360b6 CS	661	if (runtime_ss->opdsec)
261360b6 CS	662	opddata = elf_rawdata(runtime_ss->opdsec, NULL);
e5a1845f NK	663
	664	syms = elf_getdata(sec, NULL);
	665	if (syms == NULL)
	666	goto out_elf_end;
	667
	668	sec = elf_getscn(elf, shdr.sh_link);
	669	if (sec == NULL)
	670	goto out_elf_end;
	671
	672	symstrs = elf_getdata(sec, NULL);
	673	if (symstrs == NULL)
	674	goto out_elf_end;
	675
	676	sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
	677	if (sec_strndx == NULL)
	678	goto out_elf_end;
	679
	680	secstrs = elf_getdata(sec_strndx, NULL);
	681	if (secstrs == NULL)
	682	goto out_elf_end;
	683
	684	nr_syms = shdr.sh_size / shdr.sh_entsize;
	685
	686	memset(&sym, 0, sizeof(sym));
261360b6	687	dso->adjust_symbols = runtime_ss->adjust_symbols;
e5a1845f NK	688	elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
	689	struct symbol *f;
	690	const char *elf_name = elf_sym__name(&sym, symstrs);
	691	char *demangled = NULL;
	692	int is_label = elf_sym__is_label(&sym);
	693	const char *section_name;
261360b6	694	bool used_opd = false;
e5a1845f NK	695
	696	if (kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
	697	strcmp(elf_name, kmap->ref_reloc_sym->name) == 0)
	698	kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
	699
	700	if (!is_label && !elf_sym__is_a(&sym, map->type))
	701	continue;
	702
	703	/* Reject ARM ELF "mapping symbols": these aren't unique and
	704	* don't identify functions, so will confuse the profile
	705	* output: */
	706	if (ehdr.e_machine == EM_ARM) {
	707	if (!strcmp(elf_name, "$a") \|\|
	708	!strcmp(elf_name, "$d") \|\|
	709	!strcmp(elf_name, "$t"))
	710	continue;
	711	}
	712
261360b6 CS	713	if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
261360b6 CS	714	u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
e5a1845f NK	715	u64 *opd = opddata->d_buf + offset;
e5a1845f NK	716	sym.st_value = DSO__SWAP(dso, u64, *opd);
261360b6 CS	717	sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
	718	sym.st_value);
	719	used_opd = true;
e5a1845f NK	720	}
e5a1845f NK	721
261360b6	722	sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
e5a1845f NK	723	if (!sec)
	724	goto out_elf_end;
	725
	726	gelf_getshdr(sec, &shdr);
	727
	728	if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
	729	continue;
	730
	731	section_name = elf_sec__name(&shdr, secstrs);
	732
	733	/* On ARM, symbols for thumb functions have 1 added to
	734	* the symbol address as a flag - remove it */
	735	if ((ehdr.e_machine == EM_ARM) &&
	736	(map->type == MAP__FUNCTION) &&
	737	(sym.st_value & 1))
	738	--sym.st_value;
	739
	740	if (dso->kernel != DSO_TYPE_USER \|\| kmodule) {
	741	char dso_name[PATH_MAX];
	742
	743	if (strcmp(section_name,
	744	(curr_dso->short_name +
	745	dso->short_name_len)) == 0)
	746	goto new_symbol;
	747
	748	if (strcmp(section_name, ".text") == 0) {
	749	curr_map = map;
	750	curr_dso = dso;
	751	goto new_symbol;
	752	}
	753
	754	snprintf(dso_name, sizeof(dso_name),
	755	"%s%s", dso->short_name, section_name);
	756
	757	curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
	758	if (curr_map == NULL) {
	759	u64 start = sym.st_value;
	760
	761	if (kmodule)
	762	start += map->start + shdr.sh_offset;
	763
	764	curr_dso = dso__new(dso_name);
	765	if (curr_dso == NULL)
	766	goto out_elf_end;
	767	curr_dso->kernel = dso->kernel;
	768	curr_dso->long_name = dso->long_name;
	769	curr_dso->long_name_len = dso->long_name_len;
	770	curr_map = map__new2(start, curr_dso,
	771	map->type);
	772	if (curr_map == NULL) {
	773	dso__delete(curr_dso);
	774	goto out_elf_end;
	775	}
	776	curr_map->map_ip = identity__map_ip;
	777	curr_map->unmap_ip = identity__map_ip;
	778	curr_dso->symtab_type = dso->symtab_type;
	779	map_groups__insert(kmap->kmaps, curr_map);
	780	dsos__add(&dso->node, curr_dso);
	781	dso__set_loaded(curr_dso, map->type);
	782	} else
	783	curr_dso = curr_map->dso;
	784
	785	goto new_symbol;
	786	}
787
261360b6 CS	788	if ((used_opd && runtime_ss->adjust_symbols)
261360b6 CS	789	\|\| (!used_opd && syms_ss->adjust_symbols)) {
e5a1845f NK	790	pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
	791	"sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
	792	(u64)sym.st_value, (u64)shdr.sh_addr,
	793	(u64)shdr.sh_offset);
	794	sym.st_value -= shdr.sh_addr - shdr.sh_offset;
	795	}
	796	/*
	797	* We need to figure out if the object was created from C++ sources
	798	* DWARF DW_compile_unit has this, but we don't always have access
	799	* to it...
	800	*/
	801	demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS \| DMGL_ANSI);
	802	if (demangled != NULL)
	803	elf_name = demangled;
	804	new_symbol:
	805	f = symbol__new(sym.st_value, sym.st_size,
	806	GELF_ST_BIND(sym.st_info), elf_name);
	807	free(demangled);
	808	if (!f)
	809	goto out_elf_end;
	810
	811	if (filter && filter(curr_map, f))
	812	symbol__delete(f);
	813	else {
	814	symbols__insert(&curr_dso->symbols[curr_map->type], f);
	815	nr++;
	816	}
	817	}
	818
	819	/*
	820	* For misannotated, zeroed, ASM function sizes.
	821	*/
	822	if (nr > 0) {
	823	symbols__fixup_duplicate(&dso->symbols[map->type]);
	824	symbols__fixup_end(&dso->symbols[map->type]);
	825	if (kmap) {
	826	/*
	827	* We need to fixup this here too because we create new
	828	* maps here, for things like vsyscall sections.
	829	*/
	830	__map_groups__fixup_end(kmap->kmaps, map->type);
	831	}
	832	}
	833	err = nr;
	834	out_elf_end:
e5a1845f NK	835	return err;
	836	}
	837
	838	void symbol__elf_init(void)
	839	{
	840	elf_version(EV_CURRENT);
	841	}