bool load(std::istream &in, Memory& mem, addr_t img_base) {
if (virt_sz > 0) {
addr_t sect_addr_va = img_base + virt_addr;
int prot = get_prot(charac);
mem.alloc_protect(sect_addr_va , virt_sz, prot | Memory::Write);
//TODO check for file_sz > virt_sz (explained in spec)
if (file_sz > 0) {
std::istream::streampos pos_orig = in.tellg();
if (pos_orig == std::istream::pos_type(std::istream::off_type(-1)))
return false;
in.seekg(file_pos, std::ios_base::beg);
// TODO is "bad()" the right thing to check?
if (in.bad())
return false;
char *sect_data = new char[file_sz];
in.read(sect_data, file_sz);
if (std::size_t(in.gcount()) < file_sz) {
delete[] sect_data;
return false;
}
// perhaps change "write" interface to accept const char * to
// avoid this copying madness?
mem.write(sect_addr_va, std::string(sect_data, file_sz));
delete[] sect_data;
if (!(prot & Memory::Write))
mem.alloc_protect(sect_addr_va, virt_sz, prot);
in.seekg(pos_orig);
if (in.bad())
return false;
}
}
return true;
}
void *elf_file_load_ram(int pid, char *pfile) {
elf64_hdr *pelf_header;
elf64_phdr *prog_hdr;
void *seg_addr;
void *elf_offset;
int ph;
uintptr_t start, end;
int sizeof_phdrs;
int err;
pelf_header = (elf64_hdr *)pfile;
if (strncmp((const char *)pelf_header->e_ident, "\x7f" "ELF", 4)) {
anvil_syslog(0, "Incorrect ELF identifier\n");
return NULL;
}
if (pelf_header->e_ident[4] != 2) {
anvil_syslog(0, "Elf file is not 64 bit\n");
return NULL;
}
if (pelf_header->e_type != 2) {
anvil_syslog(0, "Elf file is not executable\n");
return NULL;
}
if (pelf_header->e_phnum > 3) {
anvil_syslog(0, "Elf file has too many segments\n");
return NULL;
}
//anvil_syslog(0, "Elf OK\n");
sizeof_phdrs = pelf_header->e_phentsize * pelf_header->e_phnum;
prog_hdr = (elf64_phdr *)((char *)pelf_header + pelf_header->e_phoff);
for (ph=0; ph<pelf_header->e_phnum; ++ph) {
int prot;
if (prog_hdr->p_type != 1) {
anvil_syslog(0, "Elf file segment is not loadable\n");
return NULL;
}
prot = get_prot(prog_hdr->p_flags);
/* We found a loadable segment so create a mapping */
start = prog_hdr->p_vaddr;
end = start + prog_hdr->p_memsz;
start &= ~0xfff;
end = __PAGEROUND(end);
if (_Mmap(0, 0, end - start, PROT_READ,
MAP_ANON, -1, 0, &seg_addr) != 0) {
anvil_syslog(0, "Out of memory\n");
return NULL;
}
//anvil_syslog(0, "seg_addr = %016lx\n", seg_addr);
/* Find where, in the elf image the section is */
elf_offset = (void *)(pfile + prog_hdr->p_offset);
//anvil_syslog(0, "File image addr = %08x\n", elf_offset);
/* The segment is zero filled by the _Mmap system call */
//anvil_syslog(0, "%016lx %016lx %016lx\n",
// seg_addr + prog_hdr->p_vaddr - start,
// elf_offset,
// prog_hdr->p_filesz);
memcpy(seg_addr + prog_hdr->p_vaddr - start,
elf_offset, prog_hdr->p_filesz);
//anvil_syslog(0, "_Vmm_send: %d %016lx %016lx %018x\n",
// pid, start, seg_addr, end - start);
_Vmm_send(pid, (void *)start, seg_addr, end - start, prot);
prog_hdr = (elf64_phdr *)
((uint64_t)prog_hdr + pelf_header->e_phentsize);
}
return (void *)pelf_header->e_entry;
}
int se_virtual_protect(void* address, size_t size, uint32_t prot)
{
return !mprotect(address, size, (int)get_prot(prot));
}
void *elf_file_load(int pid, int fd) {
elf64_hdr elf_header;
elf64_hdr *pelf_header;
elf64_phdr *pprog_hdr;
void *seg_addr;
void *elf_offset;
int ph;
uintptr_t start, end;
int sizeof_phdrs;
int err;
char *p;
char *interp_name;
elf64_dyn *dyn_seg;
int ndyn_items;
int interp_fd;
uintptr_t entry_offs;
int prot;
interp_name = NULL;
dyn_seg = NULL;
entry_offs = 0;
if (read(fd, &elf_header, sizeof(elf_header)) != sizeof(elf_header)) {
anvil_syslog(0, "Bad ELF header\n");
while (1);
}
pelf_header = &elf_header;
if (strncmp((const char *)pelf_header->e_ident, "\x7f" "ELF", 4)) {
anvil_syslog(0, "Incorrect ELF identifier\n");
return NULL;
}
if (pelf_header->e_ident[4] != 2) {
anvil_syslog(0, "Elf file is not 64 bit\n");
return NULL;
}
if (pelf_header->e_type != 2) {
anvil_syslog(0, "Elf file is not executable\n");
return NULL;
}
// if (pelf_header->e_phnum > 3) {
// anvil_syslog(0, "Elf file has too many segments\n");
// return NULL;
// }
//anvil_syslog(0, "Elf OK\n");
sizeof_phdrs = pelf_header->e_phentsize * pelf_header->e_phnum;
pprog_hdr = (elf64_phdr *)alloca(sizeof_phdrs);
memset(pprog_hdr, 0, sizeof_phdrs);
if (pread(fd, pprog_hdr, sizeof_phdrs, elf_header.e_phoff) == -1) {
anvil_syslog(0, "Bad prog_hdr header\n");
while (1);
}
for (ph=0; ph<pelf_header->e_phnum; ++ph) {
switch (pprog_hdr->p_type) {
case PT_LOAD:
if (pprog_hdr->p_type != 1) {
anvil_syslog(0, "Elf file segment is not loadable\n");
return NULL;
}
prot = get_prot(pprog_hdr->p_flags);
/* We found a loadable segment so create a mapping */
start = pprog_hdr->p_vaddr;
end = start + pprog_hdr->p_memsz;
start &= ~0xfff;
end = __PAGEROUND(end);
//anvil_syslog(0, "\nstart=%016lx end=%016lx\n", start, end);
/* Make a mapping in the address of the exec-svr */
if (_Mmap(0, 0, end - start, PROT_READ,
MAP_ANON, -1, 0, &seg_addr) != 0) {
anvil_syslog(0, "Out of memory\n");
return NULL;
}
/*
* seg_addr (from the mmap call) is the address in the
* exec-svr where we will load the section
*/
/* Load the segment from the file */
//anvil_syslog(0, "pread to %016lx %016lx\n", pprog_hdr->p_filesz, pprog_hdr->p_offset);
if (pread(fd, seg_addr + pprog_hdr->p_vaddr - start, pprog_hdr->p_filesz, pprog_hdr->p_offset) == -1) {
anvil_syslog(0, "Bad load of segment\n");
while (1);
}
/* Send it to the new process space */
//anvil_syslog(0, "_Vmm_send: %d %016lx %016lx %018x\n",
// pid, start, seg_addr, end - start);
_Vmm_send(pid, (void *)start, seg_addr, end - start, prot);
break;
case PT_INTERP:
/*
* Just record the name of the interpreter. We'll load it in
* a minute
*/
//anvil_syslog(0, "PT_INTERP %d\n", pprog_hdr->p_filesz);
interp_name = alloca(pprog_hdr->p_filesz + 1);
if (pread(fd, interp_name, pprog_hdr->p_filesz, pprog_hdr->p_offset) == -1) {
anvil_syslog(0, "Bad load of interp\n");
while (1);
}
interp_name[pprog_hdr->p_filesz] = 0;
//anvil_syslog(0, "PT_INTERP is %s\n", interp_name);
break;
case PT_DYNAMIC:
/*
*/
//anvil_syslog(0, "PT_DYNAMIC\n");
dyn_seg = alloca(pprog_hdr->p_filesz);
if (pread(fd, dyn_seg, pprog_hdr->p_filesz, pprog_hdr->p_offset) == -1) {
anvil_syslog(0, "Bad load of dyn_seg\n");
while (1);
}
ndyn_items = pprog_hdr->p_filesz / sizeof(elf64_dyn);
//anvil_syslog(0, "PT_DYNAMIC %d items\n", ndyn_items);
/* Now parse the dyn seg */
while (ndyn_items) {
//anvil_syslog(0, " items %d %016lx\n", dyn_seg->d_tag, dyn_seg->d_un.d_ptr);
++dyn_seg;
--ndyn_items;
}
break;
case PT_TLS:
// anvil_syslog(0, "PT_TLS\n");
// anvil_syslog(0, "p_type %016lx\n",pprog_hdr->p_type);
// anvil_syslog(0, "p_flags %016lx\n",pprog_hdr->p_flags);
// anvil_syslog(0, "p_offset %016lx\n",pprog_hdr->p_offset);
// anvil_syslog(0, "p_vaddr %016lx\n",pprog_hdr->p_vaddr);
// anvil_syslog(0, "p_paddr %016lx\n",pprog_hdr->p_paddr);
// anvil_syslog(0, "p_filesz %016lx\n",pprog_hdr->p_filesz);
// anvil_syslog(0, "p_memsz %016lx\n",pprog_hdr->p_memsz);
// anvil_syslog(0, "p_align %016lx\n",pprog_hdr->p_align);
//*ptls_bss_len += pprog_hdr->p_memsz;
break;
default:
anvil_syslog(0, "Unknown Load type %d\n", pprog_hdr->p_type);
break;
}
pprog_hdr = (elf64_phdr *)
((uint64_t)pprog_hdr + pelf_header->e_phentsize);
}
if (interp_name != NULL) {
interp_name = "/lib/libc.so";
//anvil_syslog(0, "Loading interpreter %s\n", interp_name);
if ((interp_fd = open(interp_name, 0, 0)) == -1) {
anvil_syslog(0, "Couldn't open interpreter %s\n", interp_name);
return NULL;
}
/*
* Now load the interpreter into memory. The interpreter should be
* entirely PIC so we can load it anywhere.
*/
if (read(interp_fd, &elf_header, sizeof(elf_header)) != sizeof(elf_header)) {
anvil_syslog(0, "Bad ELF header\n");
while (1);
}
pelf_header = &elf_header;
if (strncmp((const char *)pelf_header->e_ident, "\x7f" "ELF", 4)) {
anvil_syslog(0, "Interp: Incorrect ELF identifier\n");
return NULL;
}
if (pelf_header->e_ident[4] != 2) {
anvil_syslog(0, "Interp: Elf file is not 64 bit\n");
return NULL;
}
if (pelf_header->e_type != 3) {
anvil_syslog(0, "Interp: Elf file is not a so\n");
return NULL;
}
anvil_syslog(0, "Interp OK\n");
sizeof_phdrs = pelf_header->e_phentsize * pelf_header->e_phnum;
pprog_hdr = (elf64_phdr *)alloca(sizeof_phdrs);
memset(pprog_hdr, 0, sizeof_phdrs);
if (pread(interp_fd, pprog_hdr, sizeof_phdrs, elf_header.e_phoff) == -1) {
anvil_syslog(0, "Interp: Bad prog_hdr header\n");
while (1);
}
for (ph=0; ph<pelf_header->e_phnum; ++ph) {
switch (pprog_hdr->p_type) {
case PT_LOAD:
if (pprog_hdr->p_type != 1) {
anvil_syslog(0, "Interp: Elf file segment is not loadable\n");
return NULL;
}
prot = get_prot(pprog_hdr->p_flags);
/* We found a loadable segment so create a mapping */
start = pprog_hdr->p_vaddr;
end = start + pprog_hdr->p_memsz;
start &= ~0xfff;
end = __PAGEROUND(end);
//anvil_syslog(0, "\nstart=%016lx end=%016lx\n", start, end);
/* Make a mapping in the address of the exec-svr */
if (_Mmap(0, 0, end - start, PROT_EXEC|PROT_READ|PROT_WRITE,
MAP_ANON, -1, 0, &seg_addr) != 0) {
anvil_syslog(0, "Interp: Out of memory\n");
return NULL;
}
/*
* seg_addr (from the mmap call) is the address in the
* exec-svr where we will load the section
*/
/* Load the segment from the file */
//anvil_syslog(0, "pread to %016lx %016lx\n", pprog_hdr->p_filesz, pprog_hdr->p_offset);
if (pread(interp_fd, seg_addr + pprog_hdr->p_vaddr - start, pprog_hdr->p_filesz, pprog_hdr->p_offset) == -1) {
anvil_syslog(0, "Interp: Bad load of segment\n");
while (1);
}
/* Send it to the new process space */
//anvil_syslog(0, "_Vmm_send: %d %016lx %016lx %018x\n",
// pid, start, seg_addr, end - start);
_Vmm_send(pid, (void *)start+0x100000000, seg_addr, end - start, prot);
break;
default:
anvil_syslog(0, "Unknown Load type %d\n", pprog_hdr->p_type);
break;
}
pprog_hdr = (elf64_phdr *)
((uint64_t)pprog_hdr + pelf_header->e_phentsize);
}
entry_offs += 0x100000000;
close(interp_fd);
}
//anvil_syslog(0, "Start address at %016lx\n", elf_header.e_entry+entry_offs);
return (void *)elf_header.e_entry + entry_offs;
}
void load_elf(const char* fn, elf_info* info)
{
file_t* file = file_open(fn, O_RDONLY, 0);
if (IS_ERR_VALUE(file))
goto fail;
Elf_Ehdr eh;
ssize_t ehdr_size = file_pread(file, &eh, sizeof(eh), 0);
if (ehdr_size < (ssize_t)sizeof(eh) ||
!(eh.e_ident[0] == '\177' && eh.e_ident[1] == 'E' &&
eh.e_ident[2] == 'L' && eh.e_ident[3] == 'F'))
goto fail;
#if __riscv_xlen == 64
assert(IS_ELF64(eh));
#else
assert(IS_ELF32(eh));
#endif
#ifndef __riscv_compressed
assert(!(eh.e_flags & EF_RISCV_RVC));
#endif
size_t phdr_size = eh.e_phnum * sizeof(Elf_Phdr);
if (phdr_size > info->phdr_size)
goto fail;
ssize_t ret = file_pread(file, (void*)info->phdr, phdr_size, eh.e_phoff);
if (ret < (ssize_t)phdr_size)
goto fail;
info->phnum = eh.e_phnum;
info->phent = sizeof(Elf_Phdr);
Elf_Phdr* ph = (typeof(ph))info->phdr;
// compute highest VA in ELF
uintptr_t max_vaddr = 0;
for (int i = 0; i < eh.e_phnum; i++)
if (ph[i].p_type == PT_LOAD && ph[i].p_memsz)
max_vaddr = MAX(max_vaddr, ph[i].p_vaddr + ph[i].p_memsz);
max_vaddr = ROUNDUP(max_vaddr, RISCV_PGSIZE);
// don't load dynamic linker at 0, else we can't catch NULL pointer derefs
uintptr_t bias = 0;
if (eh.e_type == ET_DYN)
bias = RISCV_PGSIZE;
info->entry = eh.e_entry + bias;
int flags = MAP_FIXED | MAP_PRIVATE;
for (int i = eh.e_phnum - 1; i >= 0; i--) {
if(ph[i].p_type == PT_LOAD && ph[i].p_memsz) {
uintptr_t prepad = ph[i].p_vaddr % RISCV_PGSIZE;
uintptr_t vaddr = ph[i].p_vaddr + bias;
if (vaddr + ph[i].p_memsz > info->brk_min)
info->brk_min = vaddr + ph[i].p_memsz;
int flags2 = flags | (prepad ? MAP_POPULATE : 0);
int prot = get_prot(ph[i].p_flags);
if (__do_mmap(vaddr - prepad, ph[i].p_filesz + prepad, prot | PROT_WRITE, flags2, file, ph[i].p_offset - prepad) != vaddr - prepad)
goto fail;
memset((void*)vaddr - prepad, 0, prepad);
if (!(prot & PROT_WRITE))
if (do_mprotect(vaddr - prepad, ph[i].p_filesz + prepad, prot))
goto fail;
size_t mapped = ROUNDUP(ph[i].p_filesz + prepad, RISCV_PGSIZE) - prepad;
if (ph[i].p_memsz > mapped)
if (__do_mmap(vaddr + mapped, ph[i].p_memsz - mapped, prot, flags|MAP_ANONYMOUS, 0, 0) != vaddr + mapped)
goto fail;
}
}
file_decref(file);
return;
fail:
panic("couldn't open ELF program: %s!", fn);
}