static int elf_read_phdr(const char *buf, size_t len, struct elf_info *elf_info,
int idx)
{
/* Override the const in proghdrs, we are the ones doing the loading. */
struct elf_phdr *phdr = (struct elf_phdr *) &elf_info->proghdrs[idx];
const char *pbuf;
struct elf_phdr *buf_phdr;
pbuf = buf + elf_info->ehdr->e_phoff + (idx * sizeof(*buf_phdr));
buf_phdr = (struct elf_phdr *) pbuf;
phdr->p_type = elf32_to_cpu(elf_info->ehdr, buf_phdr->p_type);
phdr->p_offset = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_offset);
phdr->p_paddr = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_paddr);
phdr->p_vaddr = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_vaddr);
phdr->p_flags = elf32_to_cpu(elf_info->ehdr, buf_phdr->p_flags);
/*
* The following fields have a type equivalent to Elf_Addr
* both in 32 bit and 64 bit ELF.
*/
phdr->p_filesz = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_filesz);
phdr->p_memsz = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_memsz);
phdr->p_align = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_align);
return elf_is_phdr_sane(phdr, len) ? 0 : -ENOEXEC;
}
static int build_mem_elf64_phdr(const char *buf, off_t len,
struct mem_ehdr *ehdr, int idx)
{
struct mem_phdr *phdr;
const char *pbuf;
Elf64_Phdr lphdr;
pbuf = buf + ehdr->e_phoff + (idx * sizeof(lphdr));
phdr = &ehdr->e_phdr[idx];
memcpy(&lphdr, pbuf, sizeof(lphdr));
if ( (elf64_to_cpu(ehdr, lphdr.p_filesz) > UINT64_MAX) ||
(elf64_to_cpu(ehdr, lphdr.p_memsz) > UINT64_MAX) ||
(elf64_to_cpu(ehdr, lphdr.p_offset) > UINT64_MAX) ||
(elf64_to_cpu(ehdr, lphdr.p_paddr) > UINT64_MAX) ||
(elf64_to_cpu(ehdr, lphdr.p_vaddr) > UINT64_MAX) ||
(elf64_to_cpu(ehdr, lphdr.p_align) > UINT64_MAX))
{
fprintf(stderr, "Program segment size out of range\n");
return -1;
}
phdr->p_type = elf32_to_cpu(ehdr, lphdr.p_type);
phdr->p_paddr = elf64_to_cpu(ehdr, lphdr.p_paddr);
phdr->p_vaddr = elf64_to_cpu(ehdr, lphdr.p_vaddr);
phdr->p_filesz = elf64_to_cpu(ehdr, lphdr.p_filesz);
phdr->p_memsz = elf64_to_cpu(ehdr, lphdr.p_memsz);
phdr->p_offset = elf64_to_cpu(ehdr, lphdr.p_offset);
phdr->p_flags = elf32_to_cpu(ehdr, lphdr.p_flags);
phdr->p_align = elf64_to_cpu(ehdr, lphdr.p_align);
return 0;
}
static int elf_read_shdr(const char *buf, size_t len, struct elf_info *elf_info,
int idx)
{
struct elf_shdr *shdr = &elf_info->sechdrs[idx];
const struct elfhdr *ehdr = elf_info->ehdr;
const char *sbuf;
struct elf_shdr *buf_shdr;
sbuf = buf + ehdr->e_shoff + idx * sizeof(*buf_shdr);
buf_shdr = (struct elf_shdr *) sbuf;
shdr->sh_name = elf32_to_cpu(ehdr, buf_shdr->sh_name);
shdr->sh_type = elf32_to_cpu(ehdr, buf_shdr->sh_type);
shdr->sh_addr = elf_addr_to_cpu(ehdr, buf_shdr->sh_addr);
shdr->sh_offset = elf_addr_to_cpu(ehdr, buf_shdr->sh_offset);
shdr->sh_link = elf32_to_cpu(ehdr, buf_shdr->sh_link);
shdr->sh_info = elf32_to_cpu(ehdr, buf_shdr->sh_info);
/*
* The following fields have a type equivalent to Elf_Addr
* both in 32 bit and 64 bit ELF.
*/
shdr->sh_flags = elf_addr_to_cpu(ehdr, buf_shdr->sh_flags);
shdr->sh_size = elf_addr_to_cpu(ehdr, buf_shdr->sh_size);
shdr->sh_addralign = elf_addr_to_cpu(ehdr, buf_shdr->sh_addralign);
shdr->sh_entsize = elf_addr_to_cpu(ehdr, buf_shdr->sh_entsize);
return elf_is_shdr_sane(shdr, len) ? 0 : -ENOEXEC;
}
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 void read_nhdr(const struct mem_ehdr *ehdr,
ElfNN_Nhdr *hdr, const unsigned char *note)
{
memcpy(hdr, note, sizeof(*hdr));
hdr->n_namesz = elf32_to_cpu(ehdr, hdr->n_namesz);
hdr->n_descsz = elf32_to_cpu(ehdr, hdr->n_descsz);
hdr->n_type = elf32_to_cpu(ehdr, hdr->n_type);
}
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 struct mem_rela elf_rel(struct mem_ehdr *ehdr, const unsigned char *ptr)
{
struct mem_rela rela = { };
if (ehdr->ei_class == ELFCLASS32) {
Elf32_Rel lrel;
memcpy(&lrel, ptr, sizeof(lrel));
rela.r_offset = elf32_to_cpu(ehdr, lrel.r_offset);
rela.r_sym = ELF32_R_SYM(elf32_to_cpu(ehdr, lrel.r_info));
rela.r_type = ELF32_R_TYPE(elf32_to_cpu(ehdr, lrel.r_info));
rela.r_addend = 0;
}
else if (ehdr->ei_class == ELFCLASS64) {
Elf64_Rel lrel;
memcpy(&lrel, ptr, sizeof(lrel));
rela.r_offset = elf64_to_cpu(ehdr, lrel.r_offset);
rela.r_sym = ELF64_R_SYM(elf64_to_cpu(ehdr, lrel.r_info));
rela.r_type = ELF64_R_TYPE(elf64_to_cpu(ehdr, lrel.r_info));
rela.r_addend = 0;
}
else {
die("Bad elf class");
}
return rela;
}
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;
}
static int build_mem_elf64_shdr(const char *buf, off_t len,
struct mem_ehdr *ehdr, int idx)
{
struct mem_shdr *shdr;
const char *sbuf;
int size_ok;
Elf64_Shdr lshdr;
sbuf = buf + ehdr->e_shoff + (idx * sizeof(lshdr));
shdr = &ehdr->e_shdr[idx];
memcpy(&lshdr, sbuf, sizeof(lshdr));
if ( (elf64_to_cpu(ehdr, lshdr.sh_flags) > UINT64_MAX) ||
(elf64_to_cpu(ehdr, lshdr.sh_addr) > UINT64_MAX) ||
(elf64_to_cpu(ehdr, lshdr.sh_offset) > UINT64_MAX) ||
(elf64_to_cpu(ehdr, lshdr.sh_size) > UINT64_MAX) ||
(elf64_to_cpu(ehdr, lshdr.sh_addralign) > UINT64_MAX) ||
(elf64_to_cpu(ehdr, lshdr.sh_entsize) > UINT64_MAX))
{
fprintf(stderr, "Program section size out of range\n");
return -1;
}
shdr->sh_name = elf32_to_cpu(ehdr, lshdr.sh_name);
shdr->sh_type = elf32_to_cpu(ehdr, lshdr.sh_type);
shdr->sh_flags = elf64_to_cpu(ehdr, lshdr.sh_flags);
shdr->sh_addr = elf64_to_cpu(ehdr, lshdr.sh_addr);
shdr->sh_offset = elf64_to_cpu(ehdr, lshdr.sh_offset);
shdr->sh_size = elf64_to_cpu(ehdr, lshdr.sh_size);
shdr->sh_link = elf32_to_cpu(ehdr, lshdr.sh_link);
shdr->sh_info = elf32_to_cpu(ehdr, lshdr.sh_info);
shdr->sh_addralign = elf64_to_cpu(ehdr, lshdr.sh_addralign);
shdr->sh_entsize = elf64_to_cpu(ehdr, lshdr.sh_entsize);
/* Now verify sh_entsize */
size_ok = 0;
switch(shdr->sh_type) {
case SHT_SYMTAB:
size_ok = shdr->sh_entsize == sizeof(Elf64_Sym);
break;
case SHT_RELA:
size_ok = shdr->sh_entsize == sizeof(Elf64_Rela);
break;
case SHT_DYNAMIC:
size_ok = shdr->sh_entsize == sizeof(Elf64_Dyn);
break;
case SHT_REL:
size_ok = shdr->sh_entsize == sizeof(Elf64_Rel);
break;
case SHT_NOTE:
case SHT_NULL:
case SHT_PROGBITS:
case SHT_HASH:
case SHT_NOBITS:
default:
/* This is a section whose entsize requirements
* I don't care about. If I don't know about
* the section I can't care about it's entsize
* requirements.
*/
size_ok = 1;
break;
}
if (!size_ok) {
fprintf(stderr, "Bad section header(%x) entsize: %ld\n",
shdr->sh_type, shdr->sh_entsize);
return -1;
}
return 0;
}
