#include "dso.h"
#include "symbol.h"
#include "symsrc.h"
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <byteswap.h>
#include <sys/stat.h>
#include <linux/zalloc.h>
#include <internal/lib.h>
static bool check_need_swap(int file_endian)
{
const int data = 1;
u8 *check = (u8 *)&data;
int host_endian;
if (check[0] == 1)
host_endian = ELFDATA2LSB;
else
host_endian = ELFDATA2MSB;
return host_endian != file_endian;
}
#define NOTE_ALIGN(sz) (((sz) + 3) & ~3)
#define NT_GNU_BUILD_ID 3
static int read_build_id(void *note_data, size_t note_len, struct build_id *bid,
bool need_swap)
{
size_t size = sizeof(bid->data);
struct {
u32 n_namesz;
u32 n_descsz;
u32 n_type;
} *nhdr;
void *ptr;
ptr = note_data;
while ((ptr + sizeof(*nhdr)) < (note_data + note_len)) {
const char *name;
size_t namesz, descsz;
nhdr = ptr;
if (need_swap) {
nhdr->n_namesz = bswap_32(nhdr->n_namesz);
nhdr->n_descsz = bswap_32(nhdr->n_descsz);
nhdr->n_type = bswap_32(nhdr->n_type);
}
namesz = NOTE_ALIGN(nhdr->n_namesz);
descsz = NOTE_ALIGN(nhdr->n_descsz);
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(bid->data, ptr, sz);
memset(bid->data + sz, 0, size - sz);
bid->size = sz;
return 0;
}
}
ptr += descsz;
}
return -1;
}
int filename__read_debuglink(const char *filename __maybe_unused,
char *debuglink __maybe_unused,
size_t size __maybe_unused)
{
return -1;
}
int filename__read_build_id(const char *filename, struct build_id *bid)
{
int fd, ret = -1;
bool need_swap = false, elf32;
union {
struct {
Elf32_Ehdr ehdr32;
Elf32_Phdr *phdr32;
};
struct {
Elf64_Ehdr ehdr64;
Elf64_Phdr *phdr64;
};
} hdrs;
void *phdr, *buf = NULL;
ssize_t phdr_size, ehdr_size, buf_size = 0;
if (!filename)
return -EFAULT;
errno = 0;
if (!is_regular_file(filename))
return errno == 0 ? -EWOULDBLOCK : -errno;
fd = open(filename, O_RDONLY);
if (fd < 0)
return -1;
if (read(fd, hdrs.ehdr32.e_ident, EI_NIDENT) != EI_NIDENT)
goto out;
if (memcmp(hdrs.ehdr32.e_ident, ELFMAG, SELFMAG) ||
hdrs.ehdr32.e_ident[EI_VERSION] != EV_CURRENT)
goto out;
need_swap = check_need_swap(hdrs.ehdr32.e_ident[EI_DATA]);
elf32 = hdrs.ehdr32.e_ident[EI_CLASS] == ELFCLASS32;
ehdr_size = (elf32 ? sizeof(hdrs.ehdr32) : sizeof(hdrs.ehdr64)) - EI_NIDENT;
if (read(fd,
(elf32 ? (void *)&hdrs.ehdr32 : (void *)&hdrs.ehdr64) + EI_NIDENT,
ehdr_size) != ehdr_size)
goto out;
if (need_swap) {
if (elf32) {
hdrs.ehdr32.e_phoff = bswap_32(hdrs.ehdr32.e_phoff);
hdrs.ehdr32.e_phentsize = bswap_16(hdrs.ehdr32.e_phentsize);
hdrs.ehdr32.e_phnum = bswap_16(hdrs.ehdr32.e_phnum);
} else {
hdrs.ehdr64.e_phoff = bswap_64(hdrs.ehdr64.e_phoff);
hdrs.ehdr64.e_phentsize = bswap_16(hdrs.ehdr64.e_phentsize);
hdrs.ehdr64.e_phnum = bswap_16(hdrs.ehdr64.e_phnum);
}
}
if ((elf32 && hdrs.ehdr32.e_phentsize != sizeof(Elf32_Phdr)) ||
(!elf32 && hdrs.ehdr64.e_phentsize != sizeof(Elf64_Phdr)))
goto out;
phdr_size = elf32 ? sizeof(Elf32_Phdr) * hdrs.ehdr32.e_phnum
: sizeof(Elf64_Phdr) * hdrs.ehdr64.e_phnum;
phdr = malloc(phdr_size);
if (phdr == NULL)
goto out;
lseek(fd, elf32 ? hdrs.ehdr32.e_phoff : hdrs.ehdr64.e_phoff, SEEK_SET);
if (read(fd, phdr, phdr_size) != phdr_size)
goto out_free;
if (elf32)
hdrs.phdr32 = phdr;
else
hdrs.phdr64 = phdr;
for (int i = 0; i < (elf32 ? hdrs.ehdr32.e_phnum : hdrs.ehdr64.e_phnum); i++) {
ssize_t p_filesz;
if (need_swap) {
if (elf32) {
hdrs.phdr32[i].p_type = bswap_32(hdrs.phdr32[i].p_type);
hdrs.phdr32[i].p_offset = bswap_32(hdrs.phdr32[i].p_offset);
hdrs.phdr32[i].p_filesz = bswap_32(hdrs.phdr32[i].p_offset);
} else {
hdrs.phdr64[i].p_type = bswap_32(hdrs.phdr64[i].p_type);
hdrs.phdr64[i].p_offset = bswap_64(hdrs.phdr64[i].p_offset);
hdrs.phdr64[i].p_filesz = bswap_64(hdrs.phdr64[i].p_filesz);
}
}
if ((elf32 ? hdrs.phdr32[i].p_type : hdrs.phdr64[i].p_type) != PT_NOTE)
continue;
p_filesz = elf32 ? hdrs.phdr32[i].p_filesz : hdrs.phdr64[i].p_filesz;
if (p_filesz > buf_size) {
void *tmp;
buf_size = p_filesz;
tmp = realloc(buf, buf_size);
if (tmp == NULL)
goto out_free;
buf = tmp;
}
lseek(fd, elf32 ? hdrs.phdr32[i].p_offset : hdrs.phdr64[i].p_offset, SEEK_SET);
if (read(fd, buf, p_filesz) != p_filesz)
goto out_free;
ret = read_build_id(buf, p_filesz, bid, need_swap);
if (ret == 0) {
ret = bid->size;
break;
}
}
out_free:
free(buf);
free(phdr);
out:
close(fd);
return ret;
}
int sysfs__read_build_id(const char *filename, struct build_id *bid)
{
int fd;
int ret = -1;
struct stat stbuf;
size_t buf_size;
void *buf;
fd = open(filename, O_RDONLY);
if (fd < 0)
return -1;
if (fstat(fd, &stbuf) < 0)
goto out;
buf_size = stbuf.st_size;
buf = malloc(buf_size);
if (buf == NULL)
goto out;
if (read(fd, buf, buf_size) != (ssize_t) buf_size)
goto out_free;
ret = read_build_id(buf, buf_size, bid, false);
out_free:
free(buf);
out:
close(fd);
return ret;
}
int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
enum dso_binary_type type)
{
int fd = open(name, O_RDONLY);
if (fd < 0)
goto out_errno;
ss->name = strdup(name);
if (!ss->name)
goto out_close;
ss->fd = fd;
ss->type = type;
return 0;
out_close:
close(fd);
out_errno:
RC_CHK_ACCESS(dso)->load_errno = errno;
return -1;
}
bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused)
{
return true;
}
bool symsrc__has_symtab(struct symsrc *ss __maybe_unused)
{
return false;
}
void symsrc__destroy(struct symsrc *ss)
{
zfree(&ss->name);
close(ss->fd);
}
int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused,
struct symsrc *ss __maybe_unused)
{
return 0;
}
static int fd__is_64_bit(int fd)
{
u8 e_ident[EI_NIDENT];
if (lseek(fd, 0, SEEK_SET))
return -1;
if (readn(fd, e_ident, sizeof(e_ident)) != sizeof(e_ident))
return -1;
if (memcmp(e_ident, ELFMAG, SELFMAG) ||
e_ident[EI_VERSION] != EV_CURRENT)
return -1;
return e_ident[EI_CLASS] == ELFCLASS64;
}
enum dso_type dso__type_fd(int fd)
{
Elf64_Ehdr ehdr;
int ret;
ret = fd__is_64_bit(fd);
if (ret < 0)
return DSO__TYPE_UNKNOWN;
if (ret)
return DSO__TYPE_64BIT;
if (readn(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
return DSO__TYPE_UNKNOWN;
if (ehdr.e_machine == EM_X86_64)
return DSO__TYPE_X32BIT;
return DSO__TYPE_32BIT;
}
int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,
struct symsrc *ss,
struct symsrc *runtime_ss __maybe_unused,
int kmodule __maybe_unused)
{
struct build_id bid = { .size = 0, };
int ret;
ret = fd__is_64_bit(ss->fd);
if (ret >= 0)
RC_CHK_ACCESS(dso)->is_64_bit = ret;
if (filename__read_build_id(ss->name, &bid) > 0)
dso__set_build_id(dso, &bid);
return 0;
}
int file__read_maps(int fd __maybe_unused, bool exe __maybe_unused,
mapfn_t mapfn __maybe_unused, void *data __maybe_unused,
bool *is_64_bit __maybe_unused)
{
return -1;
}
int kcore_extract__create(struct kcore_extract *kce __maybe_unused)
{
return -1;
}
void kcore_extract__delete(struct kcore_extract *kce __maybe_unused)
{
}
int kcore_copy(const char *from_dir __maybe_unused,
const char *to_dir __maybe_unused)
{
return -1;
}
void symbol__elf_init(void)
{
}
bool filename__has_section(const char *filename __maybe_unused, const char *sec __maybe_unused)
{
return false;
}
