static struct mem_sym elf_sym(struct mem_ehdr *ehdr, const unsigned char *ptr)
{
struct mem_sym sym = { };
if (ehdr->ei_class == ELFCLASS32) {
Elf32_Sym lsym;
memcpy(&lsym, ptr, sizeof(lsym));
sym.st_name = elf32_to_cpu(ehdr, lsym.st_name);
sym.st_value = elf32_to_cpu(ehdr, lsym.st_value);
sym.st_size = elf32_to_cpu(ehdr, lsym.st_size);
sym.st_info = lsym.st_info;
sym.st_other = lsym.st_other;
sym.st_shndx = elf16_to_cpu(ehdr, lsym.st_shndx);
}
else if (ehdr->ei_class == ELFCLASS64) {
Elf64_Sym lsym;
memcpy(&lsym, ptr, sizeof(lsym));
sym.st_name = elf32_to_cpu(ehdr, lsym.st_name);
sym.st_value = elf64_to_cpu(ehdr, lsym.st_value);
sym.st_size = elf64_to_cpu(ehdr, lsym.st_size);
sym.st_info = lsym.st_info;
sym.st_other = lsym.st_other;
sym.st_shndx = elf16_to_cpu(ehdr, lsym.st_shndx);
}
else {
die("Bad elf class");
}
return sym;
}
static int elf_read_ehdr(const char *buf, size_t len, struct elfhdr *ehdr)
{
struct elfhdr *buf_ehdr;
if (len < sizeof(*buf_ehdr)) {
pr_debug("Buffer is too small to hold ELF header.\n");
return -ENOEXEC;
}
memset(ehdr, 0, sizeof(*ehdr));
memcpy(ehdr->e_ident, buf, sizeof(ehdr->e_ident));
if (!elf_is_elf_file(ehdr)) {
pr_debug("No ELF header magic.\n");
return -ENOEXEC;
}
if (ehdr->e_ident[EI_CLASS] != ELF_CLASS) {
pr_debug("Not a supported ELF class.\n");
return -1;
} else if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB &&
ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
pr_debug("Not a supported ELF data format.\n");
return -ENOEXEC;
}
buf_ehdr = (struct elfhdr *) buf;
if (elf16_to_cpu(ehdr, buf_ehdr->e_ehsize) != sizeof(*buf_ehdr)) {
pr_debug("Bad ELF header size.\n");
return -ENOEXEC;
}
ehdr->e_type = elf16_to_cpu(ehdr, buf_ehdr->e_type);
ehdr->e_machine = elf16_to_cpu(ehdr, buf_ehdr->e_machine);
ehdr->e_version = elf32_to_cpu(ehdr, buf_ehdr->e_version);
ehdr->e_entry = elf_addr_to_cpu(ehdr, buf_ehdr->e_entry);
ehdr->e_phoff = elf_addr_to_cpu(ehdr, buf_ehdr->e_phoff);
ehdr->e_shoff = elf_addr_to_cpu(ehdr, buf_ehdr->e_shoff);
ehdr->e_flags = elf32_to_cpu(ehdr, buf_ehdr->e_flags);
ehdr->e_phentsize = elf16_to_cpu(ehdr, buf_ehdr->e_phentsize);
ehdr->e_phnum = elf16_to_cpu(ehdr, buf_ehdr->e_phnum);
ehdr->e_shentsize = elf16_to_cpu(ehdr, buf_ehdr->e_shentsize);
ehdr->e_shnum = elf16_to_cpu(ehdr, buf_ehdr->e_shnum);
ehdr->e_shstrndx = elf16_to_cpu(ehdr, buf_ehdr->e_shstrndx);
return elf_is_ehdr_sane(ehdr, len) ? 0 : -ENOEXEC;
}
static int build_mem_elf32_ehdr(const char *buf, off_t len, struct mem_ehdr *ehdr)
{
Elf32_Ehdr lehdr;
if (len < sizeof(lehdr)) {
/* Buffer is to small to be an elf executable */
if (probe_debug) {
fprintf(stderr, "Buffer is to small to hold ELF header\n");
}
return -1;
}
memcpy(&lehdr, buf, sizeof(lehdr));
if (elf16_to_cpu(ehdr, lehdr.e_ehsize) != sizeof(Elf32_Ehdr)) {
/* Invalid Elf header size */
if (probe_debug) {
fprintf(stderr, "Bad ELF header size\n");
}
return -1;
}
if (elf32_to_cpu(ehdr, lehdr.e_entry) > UINT32_MAX) {
/* entry is to large */
if (probe_debug) {
fprintf(stderr, "ELF e_entry to large\n");
}
return -1;
}
if (elf32_to_cpu(ehdr, lehdr.e_phoff) > UINT32_MAX) {
/* phoff is to large */
if (probe_debug) {
fprintf(stderr, "ELF e_phoff to large\n");
}
return -1;
}
if (elf32_to_cpu(ehdr, lehdr.e_shoff) > UINT32_MAX) {
/* shoff is to large */
if (probe_debug) {
fprintf(stderr, "ELF e_shoff to large\n");
}
return -1;
}
ehdr->e_type = elf16_to_cpu(ehdr, lehdr.e_type);
ehdr->e_machine = elf16_to_cpu(ehdr, lehdr.e_machine);
ehdr->e_version = elf32_to_cpu(ehdr, lehdr.e_version);
ehdr->e_entry = elf32_to_cpu(ehdr, lehdr.e_entry);
ehdr->e_phoff = elf32_to_cpu(ehdr, lehdr.e_phoff);
ehdr->e_shoff = elf32_to_cpu(ehdr, lehdr.e_shoff);
ehdr->e_flags = elf32_to_cpu(ehdr, lehdr.e_flags);
ehdr->e_phnum = elf16_to_cpu(ehdr, lehdr.e_phnum);
ehdr->e_shnum = elf16_to_cpu(ehdr, lehdr.e_shnum);
ehdr->e_shstrndx = elf16_to_cpu(ehdr, lehdr.e_shstrndx);
if ((ehdr->e_phnum > 0) &&
(elf16_to_cpu(ehdr, lehdr.e_phentsize) != sizeof(Elf32_Phdr)))
{
/* Invalid program header size */
if (probe_debug) {
fprintf(stderr, "ELF bad program header size\n");
}
return -1;
}
if ((ehdr->e_shnum > 0) &&
(elf16_to_cpu(ehdr, lehdr.e_shentsize) != sizeof(Elf32_Shdr)))
{
/* Invalid section header size */
if (probe_debug) {
fprintf(stderr, "ELF bad section header size\n");
}
return -1;
}
return 0;
}
