mirrors/cosmopolitan
1
0
Fork 0
mirror of https://github.com/jart/cosmopolitan.git synced 2025-01-31 03:27:39 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions
cosmopolitan/tool/build/elf2pe.c
Justine Tunney 5bd22aef12
Experiment with supporting Windows Arm64 natively 
So far I haven't found any way to run native Arm64 code on Windows Arm64
without using MSVC. When I build a PE binary from scratch that should be
a valid Windows Arm64 program, the OS refuses to run it. Possibly due to
requiring additional content like XML manifests or relocation or control
flow integrity data that isn't normally required on x64. I've also tried
using VirtualAlloc2() to JIT an Arm64 native function, but VirtualAlloc2
always fails with invalid parameter. I tried using MSVC to create an ARM
DLL that my x64 emulated program can link at runtime, to pass a function
pointer with ARM code, but LoadLibrary() rejects ARM DLLs as invalid exe

The only option left, is likely to write a new program like ape/ape-m1.c
which can be compiled by MSVC to load and run an AARCH64 ELF executable.
The emulated x64 binary would detect emulation using IsWow64Process2 and
then drop the loader executable in a temporary folder, and re-launch the
original executable, using the Arm64 segments of the cosmocc fat binary.
2024-08-16 06:43:59 -07:00

1149 lines
37 KiB
C
Raw Blame History

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2023 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/calls/calls.h"
#include "libc/elf/def.h"
#include "libc/elf/elf.h"
#include "libc/elf/scalar.h"
#include "libc/elf/struct/rela.h"
#include "libc/elf/struct/shdr.h"
#include "libc/fmt/conv.h"
#include "libc/fmt/itoa.h"
#include "libc/intrin/describeflags.h"
#include "libc/intrin/dll.h"
#include "libc/intrin/kprintf.h"
#include "libc/limits.h"
#include "libc/macros.h"
#include "libc/mem/mem.h"
#include "libc/nt/pedef.internal.h"
#include "libc/nt/struct/imagedatadirectory.internal.h"
#include "libc/nt/struct/imagedosheader.internal.h"
#include "libc/nt/struct/imagefileheader.internal.h"
#include "libc/nt/struct/imageimportdescriptor.internal.h"
#include "libc/nt/struct/imageoptionalheader.internal.h"
#include "libc/nt/struct/imagesectionheader.internal.h"
#include "libc/runtime/runtime.h"
#include "libc/serialize.h"
#include "libc/stdckdint.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/prot.h"
#include "third_party/getopt/getopt.internal.h"
// see tool/hello/hello-pe.c for an example program this can link
// make -j8 m=tiny o/tiny/tool/hello/hello-pe
#pragma GCC diagnostic ignored "-Wstringop-overflow"
#define VERSION \
"elf2pe v0.1\n" \
"copyright 2023 justine tunney\n" \
"https://github.com/jart/cosmopolitan\n"
#define MANUAL \
" -o OUTPUT INPUT\n" \
"\n" \
"DESCRIPTION\n" \
"\n" \
" Converts ELF executables to PE\n" \
"\n" \
"FLAGS\n" \
"\n" \
" -h show usage\n" \
" -o OUTPUT set output path\n" \
" -D PATH embed dos/bios stub\n" \
" -S SIZE size of stack commit\n" \
" -R SIZE size of stack reserve\n" \
"\n"
#define MAX_ALIGN 65536
#define ALIGN_VIRT(p, a) ROUNDUP(p, (long)(a))
#define ALIGN_FILE(p, a) (char *)ROUNDUP((uintptr_t)(p), (long)(a))
#define FUNC_CONTAINER(e) DLL_CONTAINER(struct Func, elem, e)
#define LIBRARY_CONTAINER(e) DLL_CONTAINER(struct Library, elem, e)
#define SECTION_CONTAINER(e) DLL_CONTAINER(struct Section, elem, e)
#define SEGMENT_CONTAINER(e) DLL_CONTAINER(struct Segment, elem, e)
struct ImagePointer {
char *fp;
int64_t vp;
};
struct Func {
const char *name;
struct Dll elem;
uint64_t *ilt;
Elf64_Sym *symbol;
};
struct Library {
const char *name;
struct Dll *funcs;
struct Dll elem;
struct NtImageImportDescriptor *idt;
uint64_t *ilt;
size_t iltbytes;
};
struct Section {
int prot;
int index;
char *name;
Elf64_Shdr *shdr;
Elf64_Rela *relas;
Elf64_Xword relacount;
struct Dll elem;
};
struct Segment {
int prot;
char *ptr_new;
bool hasnobits;
bool hasprogbits;
Elf64_Xword align;
Elf64_Off offset_min;
Elf64_Off offset_max;
Elf64_Addr vaddr_min;
Elf64_Addr vaddr_max;
Elf64_Addr vaddr_new_min;
Elf64_Addr vaddr_new_max;
struct Dll *sections;
struct Dll elem;
struct NtImageSectionHeader *pesection;
};
struct Elf {
union {
char *map;
Elf64_Ehdr *ehdr;
};
size_t size;
const char *path;
char *strtab;
char *secstrs;
Elf64_Sym *symtab;
Elf64_Shdr *symhdr;
Elf64_Xword align;
Elf64_Xword symcount;
struct Dll *imports;
struct Dll *segments;
Elf64_Half text_count;
Elf64_Half rdata_count;
Elf64_Half data_count;
Elf64_Half bss_count;
};
static const char *prog;
static const char *outpath;
static const char *stubpath;
static long FLAG_SizeOfStackCommit = 64 * 1024;
static long FLAG_SizeOfStackReserve = 8 * 1024 * 1024;
#define TINYMALLOC_MAX_ALIGN MAX_ALIGN
#include "libc/mem/tinymalloc.inc"
static wontreturn void Die(const char *thing, const char *reason) {
tinyprint(2, thing, ": ", reason, "\n", NULL);
exit(1);
}
static wontreturn void DieSys(const char *thing) {
perror(thing);
exit(1);
}
static wontreturn void ShowUsage(int rc, int fd) {
tinyprint(fd, VERSION, "\nUSAGE\n\n ", prog, MANUAL, NULL);
exit(rc);
}
static wontreturn void DieOom(void) {
Die("makepe", "out of memory");
}
static void *Calloc(size_t n) {
void *p;
if (!(p = calloc(1, n)))
DieOom();
return p;
}
static void *Memalign(size_t a, size_t n) {
void *p;
if (!(p = memalign(a, n)))
DieOom();
return p;
}
static void *Realloc(void *p, size_t n) {
if (!(p = realloc(p, n)))
DieOom();
return p;
}
static struct Func *NewFunc(void) {
struct Func *s;
s = Calloc(sizeof(struct Func));
dll_init(&s->elem);
return s;
}
static struct Library *NewLibrary(void) {
struct Library *s;
s = Calloc(sizeof(struct Library));
dll_init(&s->elem);
return s;
}
static struct Section *NewSection(void) {
struct Section *s;
s = Calloc(sizeof(struct Section));
dll_init(&s->elem);
return s;
}
static struct Segment *NewSegment(void) {
struct Segment *s;
s = Calloc(sizeof(struct Segment));
dll_init(&s->elem);
return s;
}
static int ConvertElfMachineToPe(struct Elf *elf) {
switch (elf->ehdr->e_machine) {
case EM_NEXGEN32E:
return kNtImageFileMachineNexgen32e;
case EM_AARCH64:
return kNtImageFileMachineArm64;
default:
Die(elf->path, "unsupported e_machine");
}
}
static Elf64_Addr RelocateVaddrWithinSegment(struct Elf *elf,
Elf64_Addr vaddr_old,
struct Segment *segment) {
unassert(segment->vaddr_min <= vaddr_old && vaddr_old < segment->vaddr_max);
Elf64_Addr vaddr_new =
vaddr_old + (segment->vaddr_new_min - segment->vaddr_min);
unassert(segment->vaddr_new_min <= vaddr_new &&
vaddr_new < segment->vaddr_new_max);
return vaddr_new;
}
static Elf64_Addr RelocateVaddr(struct Elf *elf, Elf64_Addr vaddr) {
for (struct Dll *e = dll_first(elf->segments); e;
e = dll_next(elf->segments, e)) {
struct Segment *segment = SEGMENT_CONTAINER(e);
if (segment->vaddr_min <= vaddr && vaddr < segment->vaddr_max) {
return RelocateVaddrWithinSegment(elf, vaddr, segment);
}
}
return -1;
}
static Elf64_Phdr *GetTlsPhdr(struct Elf *elf) {
Elf64_Phdr *phdr;
for (int i = 0; i < elf->ehdr->e_phnum; ++i) {
if ((phdr = GetElfProgramHeaderAddress(elf->ehdr, elf->size, i)) &&
phdr->p_type == PT_TLS) {
return phdr;
}
}
Die(elf->path, "ELF has TLS relocations but no PT_TLS program header");
}
static Elf64_Addr RelocateTlsVaddr(struct Elf *elf, Elf64_Addr vaddr) {
Elf64_Addr res;
if ((res = RelocateVaddr(elf, vaddr)) != -1) {
return res;
} else {
Die(elf->path, "ELF PT_TLS program header doesn't overlap with any of "
"the loaded segments we're copying");
}
}
static Elf64_Addr GetTpAddr(struct Elf *elf) {
unassert(elf->ehdr->e_machine == EM_NEXGEN32E ||
elf->ehdr->e_machine == EM_S390);
Elf64_Phdr *p = GetTlsPhdr(elf);
return RelocateTlsVaddr(
elf, (p->p_vaddr + p->p_memsz + (p->p_align - 1)) & -p->p_align);
}
static Elf64_Addr GetDtpAddr(struct Elf *elf) {
unassert(elf->ehdr->e_machine != EM_PPC64 &&
elf->ehdr->e_machine != EM_RISCV);
Elf64_Phdr *p = GetTlsPhdr(elf);
return RelocateTlsVaddr(elf, p->p_vaddr);
}
static void RelocateRela(struct Elf *elf, struct Segment *segment,
struct Section *section, Elf64_Rela *rela) {
Elf64_Addr place_vaddr =
RelocateVaddrWithinSegment(elf, rela->r_offset, segment);
Elf64_Addr symbol_vaddr = elf->symtab[ELF64_R_SYM(rela->r_info)].st_value;
char *place_ptr = segment->ptr_new + (place_vaddr - segment->vaddr_new_min);
switch (ELF64_R_TYPE(rela->r_info)) {
case R_X86_64_NONE: // do nothing
case R_X86_64_COPY: // do nothing
case R_X86_64_SIZE32: // isn't impacted
case R_X86_64_SIZE64: // isn't impacted
break;
case R_X86_64_64: { // S + A
uint64_t abs64;
if (ckd_add(&abs64, symbol_vaddr, rela->r_addend)) {
fprintf(stderr,
"%s: ELF R_X86_64_64 relocation %lx + %ld overflowed "
"at %lx in section %s\n",
elf->path, symbol_vaddr, rela->r_addend, place_vaddr,
section->name);
exit(1);
}
memcpy(place_ptr, &abs64, sizeof(abs64));
break;
}
case R_X86_64_32: { // S + A
uint32_t abs32;
if (ckd_add(&abs32, symbol_vaddr, rela->r_addend)) {
fprintf(stderr,
"%s: ELF R_X86_64_32 relocation %lx + %ld overflowed "
"at %lx in section %s\n",
elf->path, symbol_vaddr, rela->r_addend, place_vaddr,
section->name);
exit(1);
}
memcpy(place_ptr, &abs32, sizeof(abs32));
break;
}
case R_X86_64_32S: { // S + A
int32_t abs32s;
if (ckd_add(&abs32s, symbol_vaddr, rela->r_addend)) {
fprintf(stderr,
"%s: ELF R_X86_64_32S relocation %lx + %ld overflowed "
"at %lx in section %s\n",
elf->path, symbol_vaddr, rela->r_addend, place_vaddr,
section->name);
exit(1);
}
memcpy(place_ptr, &abs32s, sizeof(abs32s));
break;
}
case R_X86_64_16: { // S + A
uint16_t abs16;
if (ckd_add(&abs16, symbol_vaddr, rela->r_addend)) {
fprintf(stderr,
"%s: ELF R_X86_64_16 relocation %lx + %ld overflowed "
"at %lx in section %s\n",
elf->path, symbol_vaddr, rela->r_addend, place_vaddr,
section->name);
exit(1);
}
memcpy(place_ptr, &abs16, sizeof(abs16));
break;
}
case R_X86_64_8: { // S + A
uint8_t abs8;
if (ckd_add(&abs8, symbol_vaddr, rela->r_addend)) {
fprintf(stderr,
"%s: ELF R_X86_64_8 relocation %lx + %ld overflowed "
"at %lx in section %s\n",
elf->path, symbol_vaddr, rela->r_addend, place_vaddr,
section->name);
exit(1);
}
memcpy(place_ptr, &abs8, sizeof(abs8));
break;
}
case R_X86_64_PC64: { // S + A - P
int64_t pc64;
Elf64_Sxword tmp;
if (ckd_add(&tmp, symbol_vaddr, rela->r_addend) ||
ckd_sub(&pc64, tmp, place_vaddr)) {
fprintf(stderr,
"%s: ELF R_X86_64_PC64 relocation %lx + %ld - %lx overflowed "
"at %lx in section %s\n",
elf->path, symbol_vaddr, rela->r_addend, place_vaddr,
place_vaddr, section->name);
exit(1);
}
memcpy(place_ptr, &pc64, sizeof(pc64));
break;
}
case R_X86_64_PC32: // S + A - P
case R_X86_64_PLT32: {
int32_t pc32;
Elf64_Sxword tmp;
if (ckd_add(&tmp, symbol_vaddr, rela->r_addend) ||
ckd_sub(&pc32, tmp, place_vaddr)) {
fprintf(stderr,
"%s: ELF R_X86_64_PC32 relocation %lx + %ld - %lx overflowed "
"at %lx in section %s\n",
elf->path, symbol_vaddr, rela->r_addend, place_vaddr,
place_vaddr, section->name);
exit(1);
}
memcpy(place_ptr, &pc32, sizeof(pc32));
break;
}
case R_X86_64_PC16: { // S + A - P
int16_t pc16;
Elf64_Sxword tmp;
if (ckd_add(&tmp, symbol_vaddr, rela->r_addend) ||
ckd_sub(&pc16, tmp, place_vaddr)) {
fprintf(stderr,
"%s: ELF R_X86_64_PC16 relocation %lx + %ld - %lx overflowed "
"at %lx in section %s\n",
elf->path, symbol_vaddr, rela->r_addend, place_vaddr,
place_vaddr, section->name);
exit(1);
}
memcpy(place_ptr, &pc16, sizeof(pc16));
break;
}
case R_X86_64_PC8: { // S + A - P
int8_t pc8;
Elf64_Sxword tmp;
if (ckd_add(&tmp, symbol_vaddr, rela->r_addend) ||
ckd_sub(&pc8, tmp, place_vaddr)) {
fprintf(stderr,
"%s: ELF R_X86_64_PC8 relocation %lx + %ld - %lx overflowed "
"at %lx in section %s\n",
elf->path, symbol_vaddr, rela->r_addend, place_vaddr,
place_vaddr, section->name);
exit(1);
}
memcpy(place_ptr, &pc8, sizeof(pc8));
break;
}
case R_X86_64_DTPOFF32: { // S + A - T
int32_t pc32;
Elf64_Addr dtp;
Elf64_Sxword tmp;
dtp = GetDtpAddr(elf);
if (ckd_add(&tmp, symbol_vaddr, rela->r_addend) ||
ckd_sub(&pc32, tmp, dtp)) {
fprintf(
stderr,
"%s: ELF R_X86_64_DTPOFF32 relocation %lx + %ld - %lx overflowed "
"at %lx in section %s\n",
elf->path, symbol_vaddr, rela->r_addend, dtp, place_vaddr,
section->name);
exit(1);
}
memcpy(place_ptr, &pc32, sizeof(pc32));
break;
}
case R_X86_64_DTPOFF64: { // S + A - T
int64_t pc64;
Elf64_Addr dtp;
Elf64_Sxword tmp;
dtp = GetDtpAddr(elf);
if (ckd_add(&tmp, symbol_vaddr, rela->r_addend) ||
ckd_sub(&pc64, tmp, dtp)) {
fprintf(
stderr,
"%s: ELF R_X86_64_DTPOFF64 relocation %lx + %ld - %lx overflowed "
"at %lx in section %s\n",
elf->path, symbol_vaddr, rela->r_addend, dtp, place_vaddr,
section->name);
exit(1);
}
memcpy(place_ptr, &pc64, sizeof(pc64));
break;
}
case R_X86_64_TPOFF32: { // S + A - T
int32_t pc32;
Elf64_Addr tp;
Elf64_Sxword tmp;
tp = GetTpAddr(elf);
if (ckd_add(&tmp, symbol_vaddr, rela->r_addend) ||
ckd_sub(&pc32, tmp, tp)) {
fprintf(
stderr,
"%s: ELF R_X86_64_TPOFF32 relocation %lx + %ld - %lx overflowed "
"at %lx in section %s\n",
elf->path, symbol_vaddr, rela->r_addend, tp, place_vaddr,
section->name);
exit(1);
}
memcpy(place_ptr, &pc32, sizeof(pc32));
break;
}
case R_X86_64_TPOFF64: { // S + A - T
int64_t pc64;
Elf64_Addr tp;
Elf64_Sxword tmp;
tp = GetTpAddr(elf);
if (ckd_add(&tmp, symbol_vaddr, rela->r_addend) ||
ckd_sub(&pc64, tmp, tp)) {
fprintf(
stderr,
"%s: ELF R_X86_64_TPOFF64 relocation %lx + %ld - %lx overflowed "
"at %lx in section %s\n",
elf->path, symbol_vaddr, rela->r_addend, tp, place_vaddr,
section->name);
exit(1);
}
memcpy(place_ptr, &pc64, sizeof(pc64));
break;
}
default:
fprintf(stderr, "%s: don't understand ELF relocation type %d\n",
elf->path, ELF64_R_TYPE(rela->r_info));
}
}
static void RelocateSection(struct Elf *elf, struct Segment *segment,
struct Section *section) {
for (Elf64_Xword i = 0; i < section->relacount; ++i) {
RelocateRela(elf, segment, section, section->relas + i);
}
}
static void RelocateSegment(struct Elf *elf, struct Segment *segment) {
unassert(segment->ptr_new);
unassert(segment->hasprogbits);
for (struct Dll *e = dll_first(segment->sections); e;
e = dll_next(segment->sections, e)) {
struct Section *section = SECTION_CONTAINER(e);
RelocateSection(elf, segment, section);
}
}
static void RelocateElf(struct Elf *elf) {
for (Elf64_Xword i = 0; i < elf->symcount; ++i) {
if (elf->symtab[i].st_shndx != SHN_ABS &&
elf->symtab[i].st_shndx != SHN_UNDEF &&
ELF64_ST_TYPE(elf->symtab[i].st_info) != STT_TLS) {
elf->symtab[i].st_value = RelocateVaddr(elf, elf->symtab[i].st_value);
}
}
for (struct Dll *e = dll_first(elf->segments); e;
e = dll_next(elf->segments, e)) {
struct Segment *segment = SEGMENT_CONTAINER(e);
if (segment->hasprogbits) {
RelocateSegment(elf, segment);
}
}
}
static struct Elf64_Sym *FindGlobal(struct Elf *elf, const char *name) {
Elf64_Xword i;
for (i = elf->symhdr->sh_info; i < elf->symcount; ++i) {
if (elf->symtab[i].st_name &&
!strcmp(elf->strtab + elf->symtab[i].st_name, name)) {
return elf->symtab + i;
}
}
return 0;
}
static int GetRelaSectionIndex(struct Elf *elf, int i) {
int j;
Elf64_Shdr *shdr;
for (j = 0; j < elf->ehdr->e_shnum; ++j) {
if ((shdr = GetElfSectionHeaderAddress(elf->ehdr, elf->size, j)) &&
shdr->sh_type == SHT_RELA && shdr->sh_info == i) {
return j;
}
}
return -1;
}
static struct Section *LoadSection(struct Elf *elf, int index,
Elf64_Shdr *shdr) {
int rela_index;
Elf64_Shdr *rela_shdr;
struct Section *section;
section = NewSection();
section->index = index;
section->shdr = shdr;
section->prot = PROT_READ;
section->name = elf->secstrs + shdr->sh_name;
if (shdr->sh_flags & SHF_WRITE) {
section->prot |= PROT_WRITE;
}
if (shdr->sh_flags & SHF_EXECINSTR) {
section->prot |= PROT_EXEC;
}
if ((rela_index = GetRelaSectionIndex(elf, index)) != -1 &&
(rela_shdr =
GetElfSectionHeaderAddress(elf->ehdr, elf->size, rela_index)) &&
(section->relas =
GetElfSectionAddress(elf->ehdr, elf->size, rela_shdr))) {
section->relacount = rela_shdr->sh_size / sizeof(Elf64_Rela);
}
return section;
}
static void LoadSectionsIntoSegments(struct Elf *elf) {
int i;
Elf64_Shdr *shdr;
bool hasdataseg = false;
struct Segment *segment = 0;
for (i = 0; i < elf->ehdr->e_shnum; ++i) {
if ((shdr = GetElfSectionHeaderAddress(elf->ehdr, elf->size, i)) &&
(shdr->sh_type == SHT_PROGBITS || shdr->sh_type == SHT_NOBITS) &&
!((shdr->sh_flags & SHF_TLS) && shdr->sh_type == SHT_NOBITS) &&
(shdr->sh_flags & SHF_ALLOC)) {
struct Section *section;
section = LoadSection(elf, i, shdr);
if (segment && (segment->prot != section->prot ||
(segment->hasnobits && shdr->sh_type == SHT_PROGBITS))) {
dll_make_last(&elf->segments, &segment->elem);
segment = 0;
}
if (!segment) {
segment = NewSegment();
segment->prot = section->prot;
segment->vaddr_min = section->shdr->sh_addr;
if (shdr->sh_type == SHT_PROGBITS)
segment->offset_min = section->shdr->sh_offset;
hasdataseg |= segment->prot == (PROT_READ | PROT_WRITE);
}
segment->hasnobits |= shdr->sh_type == SHT_NOBITS;
segment->hasprogbits |= shdr->sh_type == SHT_PROGBITS;
segment->vaddr_max = section->shdr->sh_addr + section->shdr->sh_size;
if (shdr->sh_type == SHT_PROGBITS)
segment->offset_max = section->shdr->sh_offset + section->shdr->sh_size;
segment->align = MAX(segment->align, section->shdr->sh_addralign);
elf->align = MAX(elf->align, segment->align);
dll_make_last(&segment->sections, &section->elem);
}
}
if (segment) {
dll_make_last(&elf->segments, &segment->elem);
}
if (elf->imports && !hasdataseg) {
// if the program we're linking is really tiny and it doesn't have
// either a .data or .bss section but it does import function from
// libraries, then create a synthetic .data segment for the pe iat
segment = NewSegment();
segment->align = 8;
segment->hasprogbits = true;
segment->prot = PROT_READ | PROT_WRITE;
dll_make_last(&elf->segments, &segment->elem);
}
}
static bool ParseDllImportSymbol(const char *symbol_name,
const char **out_dll_name,
const char **out_func_name) {
size_t n;
char *dll_name;
const char *dolla;
if (!startswith(symbol_name, "dll$"))
return false;
symbol_name += 4;
dolla = strchr(symbol_name, '$');
if (!dolla)
return false;
n = dolla - symbol_name;
dll_name = memcpy(Calloc(n + 1), symbol_name, n);
*out_dll_name = dll_name;
*out_func_name = dolla + 1;
return true;
}
static struct Library *FindImport(struct Elf *elf, const char *name) {
struct Dll *e;
for (e = dll_first(elf->imports); e; e = dll_next(elf->imports, e)) {
struct Library *library = LIBRARY_CONTAINER(e);
if (!strcmp(name, library->name)) {
return library;
}
}
return 0;
}
static void LoadDllImports(struct Elf *elf) {
Elf64_Xword i;
struct Func *func;
const char *dll_name;
const char *func_name;
struct Library *library;
for (i = 0; i < elf->symcount; ++i) {
Elf64_Sym *symbol = elf->symtab + i;
if (symbol->st_name && ParseDllImportSymbol(elf->strtab + symbol->st_name,
&dll_name, &func_name)) {
if (symbol->st_value || symbol->st_shndx != SHN_UNDEF)
Die(elf->path, "ELF executable declared a dll: import symbol without "
"annotating it weak extern");
if (!(library = FindImport(elf, dll_name))) {
library = NewLibrary();
library->name = dll_name;
dll_make_last(&elf->imports, &library->elem);
}
func = NewFunc();
func->name = func_name;
func->symbol = symbol;
dll_make_last(&library->funcs, &func->elem);
}
}
}
static struct Elf *OpenElf(const char *path) {
int fd;
struct Elf *elf;
elf = Calloc(sizeof(*elf));
elf->path = path;
if ((fd = open(path, O_RDONLY)) == -1)
DieSys(path);
if ((elf->size = lseek(fd, 0, SEEK_END)) == -1)
DieSys(path);
elf->map = mmap(0, elf->size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
if (elf->map == MAP_FAILED)
DieSys(path);
if (!IsElf64Binary(elf->ehdr, elf->size))
Die(path, "not an elf64 binary");
elf->symhdr =
GetElfSymbolTable(elf->ehdr, elf->size, SHT_SYMTAB, &elf->symcount);
elf->symtab = GetElfSectionAddress(elf->ehdr, elf->size, elf->symhdr);
if (!elf->symtab)
Die(path, "elf doesn't have symbol table");
elf->strtab = GetElfStringTable(elf->ehdr, elf->size, ".strtab");
if (!elf->strtab)
Die(path, "elf doesn't have string table");
elf->secstrs = GetElfSectionNameStringTable(elf->ehdr, elf->size);
if (!elf->strtab)
Die(path, "elf doesn't have section string table");
LoadDllImports(elf);
LoadSectionsIntoSegments(elf);
close(fd);
return elf;
}
static void PrintElf(struct Elf *elf) {
struct Dll *e, *g;
printf("\n");
printf("%s\n", elf->path);
printf("sections\n");
for (e = dll_first(elf->segments); e; e = dll_next(elf->segments, e)) {
struct Segment *segment = SEGMENT_CONTAINER(e);
for (g = dll_first(segment->sections); g;
g = dll_next(segment->sections, g)) {
struct Section *section = SECTION_CONTAINER(g);
printf("\t%s\n", section->name);
}
printf("\t\talign = %ld\n", segment->align);
printf("\t\tvaddr_old = %lx\n", segment->vaddr_min);
printf("\t\tvaddr_new = %lx\n", segment->vaddr_new_min);
printf("\t\tprot = %s\n", DescribeProtFlags(segment->prot));
}
printf("imports\n");
for (e = dll_first(elf->imports); e; e = dll_next(elf->imports, e)) {
struct Library *library = LIBRARY_CONTAINER(e);
printf("\t%s\n", library->name);
for (g = dll_first(library->funcs); g; g = dll_next(library->funcs, g)) {
struct Func *func = FUNC_CONTAINER(g);
printf("\t\t%s\n", func->name);
}
}
}
static void PickPeSectionName(char *p, struct Elf *elf,
struct Segment *segment) {
int n;
switch (segment->prot) {
case PROT_EXEC:
case PROT_EXEC | PROT_READ:
case PROT_EXEC | PROT_READ | PROT_WRITE:
p = stpcpy(p, ".text");
n = ++elf->text_count;
break;
case PROT_READ:
p = stpcpy(p, ".rdata");
n = ++elf->rdata_count;
break;
case PROT_READ | PROT_WRITE:
if (segment->hasprogbits) {
p = stpcpy(p, ".data");
n = ++elf->data_count;
} else {
p = stpcpy(p, ".bss");
n = ++elf->bss_count;
}
break;
default:
notpossible;
}
if (n > 1) {
FormatInt32(p, n);
}
}
static uint32_t GetPeSectionCharacteristics(struct Segment *s) {
uint32_t x = 0;
if (s->prot & PROT_EXEC) {
x |= kNtPeSectionCntCode | kNtPeSectionMemExecute;
} else if (s->hasprogbits) {
x |= kNtPeSectionCntInitializedData;
}
if (s->prot & PROT_READ) {
x |= kNtPeSectionMemRead;
}
if (s->prot & PROT_WRITE) {
x |= kNtPeSectionMemWrite;
}
if (s->hasnobits) {
x |= kNtPeSectionCntUninitializedData;
}
return x;
}
// converts static elf executable to portable executable
//
// the trick to generating a portable executable is to maintain the file
// pointer and virtual address pointers separately, as the image is made
//
// during this process, we're going to be inserting and removing padding
// to both the file layout and virtual address space, that weren't there
// originally in the elf image that ld linked. in order for this to work
// the executable needs to be linked in `ld -q` mode, since it'll retain
// the .rela sections we'll need later to fixup the binary.
static struct ImagePointer GeneratePe(struct Elf *elf, char *fp) {
int64_t vp = 0;
Elf64_Phdr *phdr;
for (int i = 0; i < elf->ehdr->e_phnum; ++i) {
if ((phdr = GetElfProgramHeaderAddress(elf->ehdr, elf->size, i)) &&
phdr->p_type == PT_LOAD) {
vp = phdr->p_vaddr;
break;
}
}
Elf64_Sym *entry;
if (!(entry = FindGlobal(elf, "__win32_start")) &&
!(entry = FindGlobal(elf, "WinMain")))
Die(elf->path, "ELF didn't define global `__win32_start` PE entrypoint or "
"alternatively a `WinMain` function");
if (elf->align > MAX_ALIGN)
Die(elf->path, "ELF specified an alignment greater than 64k which isn't "
"supported by the PE format");
vp = ALIGN_VIRT(vp, 65536);
struct NtImageDosHeader *mzhdr;
mzhdr = (struct NtImageDosHeader *)fp;
fp += sizeof(struct NtImageDosHeader);
memcpy(mzhdr, "MZ", 2);
// embed the ms-dos stub and/or bios bootloader
if (stubpath) {
int fd = open(stubpath, O_RDONLY);
if (fd == -1)
DieSys(stubpath);
for (;;) {
ssize_t got = read(fd, fp, 512);
if (got == -1)
DieSys(stubpath);
if (!got)
break;
fp += got;
}
if (close(fd))
DieSys(stubpath);
}
// output portable executable magic
fp = ALIGN_FILE(fp, 8);
mzhdr->e_lfanew = fp - (char *)mzhdr;
fp = WRITE32LE(fp, 'P' | 'E' << 8);
// output coff header
struct NtImageFileHeader *filehdr;
filehdr = (struct NtImageFileHeader *)fp;
fp += sizeof(struct NtImageFileHeader);
filehdr->Machine = ConvertElfMachineToPe(elf);
filehdr->TimeDateStamp = 1690072024;
filehdr->Characteristics =
kNtPeFileExecutableImage | kNtImageFileLargeAddressAware |
kNtPeFileRelocsStripped | kNtPeFileLineNumsStripped |
kNtPeFileLocalSymsStripped;
// output "optional" header
struct NtImageOptionalHeader *opthdr;
opthdr = (struct NtImageOptionalHeader *)fp;
fp += sizeof(struct NtImageOptionalHeader);
opthdr->Magic = kNtPe64bit;
opthdr->MajorLinkerVersion = 14;
opthdr->MinorLinkerVersion = 35;
opthdr->ImageBase = vp;
opthdr->FileAlignment = 512;
opthdr->SectionAlignment = MAX(4096, elf->align);
opthdr->MajorOperatingSystemVersion = 6;
opthdr->MinorOperatingSystemVersion = 2;
opthdr->MajorSubsystemVersion = 6;
opthdr->MinorSubsystemVersion = 2;
opthdr->Subsystem = kNtImageSubsystemWindowsCui;
opthdr->DllCharacteristics = kNtImageDllcharacteristicsNxCompat |
kNtImageDllcharacteristicsHighEntropyVa;
opthdr->SizeOfStackReserve =
MAX(FLAG_SizeOfStackReserve, FLAG_SizeOfStackCommit);
opthdr->SizeOfStackCommit = FLAG_SizeOfStackCommit;
// output data directory entries
if (elf->imports) {
opthdr->NumberOfRvaAndSizes = 2;
fp += opthdr->NumberOfRvaAndSizes * sizeof(struct NtImageDataDirectory);
}
// finish optional header
filehdr->SizeOfOptionalHeader = fp - (char *)opthdr;
// output section headers
struct NtImageSectionHeader *sections;
sections = (struct NtImageSectionHeader *)fp;
struct NtImageSectionHeader *idata_section;
idata_section = (struct NtImageSectionHeader *)fp;
if (elf->imports) {
fp += sizeof(struct NtImageSectionHeader);
++filehdr->NumberOfSections;
}
for (struct Dll *e = dll_first(elf->segments); e;
e = dll_next(elf->segments, e)) {
struct Segment *segment = SEGMENT_CONTAINER(e);
segment->pesection = (struct NtImageSectionHeader *)fp;
fp += sizeof(struct NtImageSectionHeader);
++filehdr->NumberOfSections;
}
// finish headers
fp = ALIGN_FILE(fp, opthdr->FileAlignment);
opthdr->SizeOfHeaders = fp - (char *)mzhdr;
vp += opthdr->SizeOfHeaders;
// output .idata section
if (elf->imports) {
vp = ALIGN_VIRT(vp, opthdr->SectionAlignment);
char *fbegin = fp;
int64_t vbegin = vp;
idata_section->VirtualAddress = vp - opthdr->ImageBase;
idata_section->PointerToRawData = fbegin - (char *)mzhdr;
//////////////////////////////////////////////////////////////////////
strcpy(idata_section->Name, ".idata");
idata_section->Characteristics =
kNtPeSectionMemRead | kNtPeSectionCntInitializedData;
// output import descriptor for each dll
for (struct Dll *e = dll_first(elf->imports); e;
e = dll_next(elf->imports, e)) {
struct Library *library = LIBRARY_CONTAINER(e);
library->idt = (struct NtImageImportDescriptor *)fp;
fp += sizeof(struct NtImageImportDescriptor);
vp += sizeof(struct NtImageImportDescriptor);
}
fp += sizeof(struct NtImageImportDescriptor);
vp += sizeof(struct NtImageImportDescriptor);
opthdr->DataDirectory[kNtImageDirectoryEntryImport].VirtualAddress =
idata_section->VirtualAddress;
opthdr->DataDirectory[kNtImageDirectoryEntryImport].Size = vp - vbegin;
// output import lookup table for each dll
for (struct Dll *e = dll_first(elf->imports); e;
e = dll_next(elf->imports, e)) {
struct Library *library = LIBRARY_CONTAINER(e);
library->idt->ImportLookupTable = vp - opthdr->ImageBase;
library->ilt = (uint64_t *)fp;
for (struct Dll *g = dll_first(library->funcs); g;
g = dll_next(library->funcs, g)) {
struct Func *func = FUNC_CONTAINER(g);
func->ilt = (uint64_t *)fp;
fp += sizeof(uint64_t);
vp += sizeof(uint64_t);
}
fp += sizeof(uint64_t);
vp += sizeof(uint64_t);
library->iltbytes = fp - (char *)library->ilt;
}
// output the hint name table
for (struct Dll *e = dll_first(elf->imports); e;
e = dll_next(elf->imports, e)) {
struct Library *library = LIBRARY_CONTAINER(e);
for (struct Dll *g = dll_first(library->funcs); g;
g = dll_next(library->funcs, g)) {
struct Func *func = FUNC_CONTAINER(g);
*func->ilt = vp - opthdr->ImageBase;
fp += sizeof(uint16_t); // hint
vp += sizeof(uint16_t);
size_t n = strlen(func->name);
fp = mempcpy(fp, func->name, n + 1);
vp += n + 1;
fp = ALIGN_FILE(fp, 2);
vp = ALIGN_VIRT(vp, 2);
}
}
// output the dll names
for (struct Dll *e = dll_first(elf->imports); e;
e = dll_next(elf->imports, e)) {
struct Library *library = LIBRARY_CONTAINER(e);
size_t n = strlen(library->name);
library->idt->DllNameRva = vp - opthdr->ImageBase;
fp = mempcpy(fp, library->name, n + 1);
vp += n + 1;
}
//////////////////////////////////////////////////////////////////////
idata_section->Misc.VirtualSize = vp - vbegin;
fp = ALIGN_FILE(fp, opthdr->FileAlignment);
idata_section->SizeOfRawData = fp - fbegin;
}
// output elf segment sections
for (struct Dll *e = dll_first(elf->segments); e;
e = dll_next(elf->segments, e)) {
struct Segment *segment = SEGMENT_CONTAINER(e);
vp = ALIGN_VIRT(vp, opthdr->SectionAlignment);
char *fbegin = fp;
int64_t vbegin = vp;
segment->pesection->VirtualAddress = vp - opthdr->ImageBase;
segment->pesection->PointerToRawData = fbegin - (char *)mzhdr;
//////////////////////////////////////////////////////////////////////
if (segment->prot == (PROT_READ | PROT_WRITE)) {
// sneak InputAddressTable into .data or .bss section
for (struct Dll *e = dll_first(elf->imports); e;
e = dll_next(elf->imports, e)) {
struct Library *library = LIBRARY_CONTAINER(e);
library->idt->ImportAddressTable = vp - opthdr->ImageBase;
fp = mempcpy(fp, library->ilt, library->iltbytes);
segment->hasprogbits = true;
for (struct Dll *g = dll_first(library->funcs); g;
g = dll_next(library->funcs, g)) {
struct Func *func = FUNC_CONTAINER(g);
func->symbol->st_value = vp;
vp += 8;
}
vp += 8;
}
fp = ALIGN_FILE(fp, segment->align);
vp = ALIGN_VIRT(vp, segment->align);
}
PickPeSectionName(segment->pesection->Name, elf, segment);
segment->vaddr_new_min = vp;
if (segment->vaddr_min <= entry->st_value &&
entry->st_value < segment->vaddr_max) {
opthdr->AddressOfEntryPoint =
vp + (entry->st_value - segment->vaddr_min) - opthdr->ImageBase;
}
if (segment->hasprogbits) {
segment->ptr_new = fp;
fp = mempcpy(fp, elf->map + segment->offset_min,
segment->offset_max - segment->offset_min);
}
vp += segment->vaddr_max - segment->vaddr_min;
segment->vaddr_new_max = vp;
segment->pesection->Characteristics = GetPeSectionCharacteristics(segment);
//////////////////////////////////////////////////////////////////////
segment->pesection->Misc.VirtualSize = vp - vbegin;
fp = ALIGN_FILE(fp, opthdr->FileAlignment);
segment->pesection->SizeOfRawData = fp - fbegin;
}
// compute relocations
RelocateElf(elf);
// compute informative sizes
// the windows executive ignores these fields, but they can't hurt.
for (int i = 0; i < filehdr->NumberOfSections; ++i) {
if (sections[i].Characteristics & kNtPeSectionCntCode) {
opthdr->SizeOfCode += sections[i].SizeOfRawData;
if (!opthdr->BaseOfCode) {
opthdr->BaseOfCode = sections[i].VirtualAddress;
}
}
if (sections[i].Characteristics & kNtPeSectionCntInitializedData) {
opthdr->SizeOfInitializedData += sections[i].SizeOfRawData;
}
if ((sections[i].Characteristics & kNtPeSectionCntUninitializedData) &&
sections[i].Misc.VirtualSize > sections[i].SizeOfRawData) {
opthdr->SizeOfUninitializedData +=
sections[i].Misc.VirtualSize - sections[i].SizeOfRawData;
}
}
// finish image
vp = ALIGN_VIRT(vp, opthdr->SectionAlignment);
opthdr->SizeOfImage = vp - opthdr->ImageBase;
return (struct ImagePointer){fp, vp};
}
static void GetOpts(int argc, char *argv[]) {
int opt;
while ((opt = getopt(argc, argv, "ho:D:R:S:")) != -1) {
switch (opt) {
case 'o':
outpath = optarg;
break;
case 'D':
stubpath = optarg;
break;
case 'S':
FLAG_SizeOfStackCommit = sizetol(optarg, 1024);
break;
case 'R':
FLAG_SizeOfStackReserve = sizetol(optarg, 1024);
break;
case 'h':
ShowUsage(0, 1);
default:
ShowUsage(1, 2);
}
}
if (!outpath) {
Die(prog, "need output path");
}
if (optind == argc) {
Die(prog, "missing input argument");
}
}
static void Pwrite(int fd, const void *data, size_t size, uint64_t offset) {
ssize_t rc;
const char *p, *e;
for (p = data, e = p + size; p < e; p += (size_t)rc, offset += (size_t)rc) {
if ((rc = pwrite(fd, p, e - p, offset)) == -1) {
DieSys(outpath);
}
}
}
int main(int argc, char *argv[]) {
#ifdef MODE_DBG
ShowCrashReports();
#endif
// get program name
prog = argv[0];
if (!prog)
prog = "elf2pe";
// process flags
GetOpts(argc, argv);
// translate executable
struct Elf *elf = OpenElf(argv[optind]);
char *buf = Memalign(MAX_ALIGN, 134217728);
struct ImagePointer ip = GeneratePe(elf, buf);
if (creat(outpath, 0755) == -1)
DieSys(elf->path);
Pwrite(3, buf, ip.fp - buf, 0);
if (close(3))
DieSys(elf->path);
// PrintElf(elf);
}
Reference in a new issue View git blame Copy permalink