int64_t
private_check_segments(struct bfelf_file_t *ef)
{
bfelf64_xword i = 0;
for (i = 0; i < ef->ehdr->e_phnum; i++)
{
struct bfelf_phdr *phdr = private_get_segment(ef, i);
if (phdr->p_type != bfpt_load)
continue;
if (ef->num_loadable_segments >= BFELF_MAX_SEGMENTS)
return loader_full("increase BFELF_MAX_SEGMENTS");
if (phdr->p_memsz < phdr->p_filesz)
return invalid_segment("segment mem size is less then file size");
if (phdr->p_vaddr != phdr->p_paddr)
return invalid_segment("expect p_vaddr == p_paddr");
if (phdr->p_align != 0x1000 && phdr->p_align != 0x200000)
return invalid_segment("expect 4k or 2M alignment");
if (phdr->p_offset >= ef->fsize)
return invalid_segment("segment offset out of bounds");
ef->loadable_segments[ef->num_loadable_segments] = phdr;
ef->num_loadable_segments++;
}
return BFELF_SUCCESS;
}
static bfelf64_sword
private_check_sections(struct bfelf_file_t *ef)
{
bfelf64_sword i = 0;
bfelf64_sword j = 0;
struct bfelf_shdr *shstrtab = private_get_section(ef, ef->ehdr->e_shstrndx);
for (i = 0; i < ef->ehdr->e_shnum; i++)
{
bfelf64_sword valid_addr = 0;
struct bfelf_shdr *shdr = private_get_section(ef, i);
if (shdr->sh_type != bfsht_nobits)
{
if (shdr->sh_offset + shdr->sh_size > ef->fsize)
return invalid_section("section offset / size is corrupt");
}
if (shdr->sh_name >= shstrtab->sh_size)
return invalid_section("invalid section name offset");
if (shdr->sh_link >= ef->ehdr->e_shnum)
return invalid_section("invalid section link");
for (j = 0; j < ef->ehdr->e_phnum; j++)
{
struct bfelf_phdr *phdr = private_get_segment(ef, j);
if (shdr->sh_addr >= phdr->p_vaddr &&
shdr->sh_addr + shdr->sh_size <= phdr->p_vaddr + phdr->p_memsz)
{
valid_addr = 1;
break;
}
}
if (shdr->sh_addr != 0 && valid_addr == 0)
return invalid_section("section address is out of bounds");
}
return BFELF_SUCCESS;
}
static bfelf64_sword
private_check_segments(struct bfelf_file_t *ef)
{
bfelf64_sword i = 0;
for (i = 0; i < ef->ehdr->e_phnum; i++)
{
struct bfelf_phdr *phdr = private_get_segment(ef, i);
if (phdr->p_type != bfpt_load)
continue;
if (ef->num_loadable_segments >= BFELF_MAX_SEGMENTS)
return loader_full("increase BFELF_MAX_SEGMENTS");
if (phdr->p_memsz < phdr->p_filesz)
return invalid_segment("segment mem size is less then file size");
if (phdr->p_vaddr != phdr->p_paddr)
return invalid_segment("expect p_vaddr == p_paddr");
/*
* At the moment, libc++.so has an alignment of 20, which is really
* strange. Will need to find out why at some point
*
* if (phdr->p_align != 0x1000 && phdr->p_align != 0x200000)
* return invalid_segment("expect 4k or 2M alignment");
*/
if (phdr->p_offset >= ef->fsize)
return invalid_segment("segment offset out of bounds");
ef->loadable_segments[ef->num_loadable_segments] = phdr;
ef->num_loadable_segments++;
}
return BFELF_SUCCESS;
}
static bfelf64_sword
private_check_entry(struct bfelf_file_t *ef)
{
bfelf64_sword i = 0;
bfelf64_sword valid_addr = 0;
for (i = 0; i < ef->ehdr->e_phnum; i++)
{
struct bfelf_phdr *phdr = private_get_segment(ef, i);
if (ef->ehdr->e_entry >= phdr->p_vaddr &&
ef->ehdr->e_entry < phdr->p_vaddr + phdr->p_memsz)
{
valid_addr = 1;
break;
}
}
if (ef->ehdr->e_entry != 0 && valid_addr == 0)
return invalid_file("ELF entry corrupt");
return BFELF_SUCCESS;
}
