bool elf_validate_header(elf_header* hdr) {
if (!elf_check_magic(hdr)) {
return false;
}
if (!elf_check_supported(hdr)) {
return false;
}
return true;
}
/* not secure */
void elf_loader(const char * file) {
int filelen=0;
char * addr = load(file, &filelen);
if(!addr) {
TRACE("Could not read file");
kernel_freeze();
return;
}
Elf64_Ehdr *hdr = (Elf64_Ehdr *)addr;
if(!elf_check_supported(hdr)) {
TRACE("ELF File cannot be loaded");
kernel_freeze();
return;
}
TRACE("e_entry:%lX e_phnum:%d e_shnum:%d", hdr->e_entry, hdr->e_phnum, hdr->e_shnum);
size_t allocsize = 0;
for(int i=0; i<hdr->e_phnum; i++) {
Elf64_Phdr *seg = elf_segment(hdr, i);
#if 0
TRACE("SGMT: type:%X flags:%X offset:%lX vaddr:%lX filesz:%lX memsz:%lX align:%lX",
seg->p_type, seg->p_flags, seg->p_offset, seg->p_vaddr,
seg->p_filesz, seg->p_memsz, seg->p_align);
#endif
if(seg->p_type == 1) {
allocsize = imax(allocsize, seg->p_vaddr + seg->p_memsz);
}
}
char *prgmp = kernel_calloc(allocsize, 1); //TODO:align this correctly
bzero(prgmp, allocsize);
if(!prgmp) {
TRACE("Malloc failed");
kernel_freeze();
return;
}
for(int i=0; i<hdr->e_phnum; i++) {
Elf64_Phdr *seg = elf_segment(hdr, i);
memcpy(prgmp+seg->p_vaddr, addr + seg->p_offset, seg->p_filesz);
}
size_t pid = kernel_exec((uintptr_t)(prgmp + hdr->e_entry), 0x465);
tmp_exec_stuff(pid, (size_t)prgmp, hdr->e_entry, allocsize);
}
cap_pair elf_loader_mem(Elf_Env *env, void *p, size_t *minaddr, size_t *maxaddr, size_t *entry) {
char *addr = (char *)p;
size_t lowaddr = (size_t)(-1);
Elf64_Ehdr *hdr = (Elf64_Ehdr *)addr;
if(!elf_check_supported(env, hdr)) {
ERROR("ELF File cannot be loaded");
return NULL_PAIR;
}
Elf64_Addr e_entry = hdr->e_entry;
TRACE("e_entry:%lX e_phnum:%d e_shnum:%d", hdr->e_entry, hdr->e_phnum, hdr->e_shnum);
size_t allocsize = 0;
for(int i=0; i<hdr->e_phnum; i++) {
Elf64_Phdr *seg = elf_segment(hdr, i);
TRACE("SGMT: type:%X flags:%X offset:%lX vaddr:%lX filesz:%lX memsz:%lX align:%lX",
seg->p_type, seg->p_flags, seg->p_offset, seg->p_vaddr,
seg->p_filesz, seg->p_memsz, seg->p_align);
if(seg->p_filesz > seg->p_memsz) {
ERROR("Section is larger in file than in memory");
return NULL_PAIR;
}
if(seg->p_type == PT_LOAD) {
size_t bound = seg->p_vaddr + seg->p_memsz;
allocsize = umax(allocsize, bound);
lowaddr = umin(lowaddr, seg->p_vaddr);
TRACE("lowaddr:%lx allocsize:%lx bound:%lx", lowaddr, allocsize, bound);
} else if(seg->p_type == PT_GNUSTACK || seg->p_type == PT_PHDR || seg->p_type == PT_GNURELRO) {
/* Ignore these headers */
} else {
ERROR("Unknown section");
return NULL_PAIR;
}
}
cap_pair pair = env->alloc(allocsize);
char *prgmp = pair.data;
if(!prgmp) {
ERROR("alloc failed");
return NULL_PAIR;
}
TRACE("Allocated %lx bytes of target memory", allocsize);
ENV_PRINT_CAP(env, prgmp);
for(int i=0; i<hdr->e_phnum; i++) {
Elf64_Phdr *seg = elf_segment(hdr, i);
if(seg->p_type == 1) {
TRACE("memcpy: [%lx %lx] <-- [%lx %lx] (%lx bytes)",
seg->p_vaddr, seg->p_vaddr + seg->p_filesz,
seg->p_offset, seg->p_offset + seg->p_filesz,
seg->p_filesz);
env->memcpy(prgmp+seg->p_vaddr, addr + seg->p_offset, seg->p_filesz);
}
}
env->free(addr);
if(minaddr) *minaddr = lowaddr;
if(maxaddr) *maxaddr = allocsize;
if(entry) *entry = e_entry;
return pair;
}
