/
p_lx_elf.cpp
5718 lines (5265 loc) · 213 KB
/
p_lx_elf.cpp
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/* p_lx_elf.cpp --
This file is part of the UPX executable compressor.
Copyright (C) 1996-2020 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 1996-2020 Laszlo Molnar
Copyright (C) 2000-2020 John F. Reiser
All Rights Reserved.
UPX and the UCL library are free software; you can redistribute them
and/or modify them under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING.
If not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
Markus F.X.J. Oberhumer Laszlo Molnar
<markus@oberhumer.com> <ezerotven+github@gmail.com>
John F. Reiser
<jreiser@users.sourceforge.net>
*/
#include "conf.h"
#include "file.h"
#include "filter.h"
#include "linker.h"
#include "packer.h"
#include "p_elf.h"
#include "p_unix.h"
#include "p_lx_exc.h"
#include "p_lx_elf.h"
#include "ui.h"
typedef upx_uint32_t u32_t; // easier to type; more narrow
typedef upx_uint64_t u64_t; // easier to type; more narrow
#define PT_LOAD32 Elf32_Phdr::PT_LOAD
#define PT_LOAD64 Elf64_Phdr::PT_LOAD
#define PT_NOTE32 Elf32_Phdr::PT_NOTE
#define PT_NOTE64 Elf64_Phdr::PT_NOTE
#define PT_GNU_STACK32 Elf32_Phdr::PT_GNU_STACK
#define PT_GNU_STACK64 Elf64_Phdr::PT_GNU_STACK
//static unsigned const EF_ARM_HASENTRY = 0x02;
static unsigned const EF_ARM_EABI_VER4 = 0x04000000;
static unsigned const EF_ARM_EABI_VER5 = 0x05000000;
unsigned char PackLinuxElf::o_shstrtab[] = { \
/*start*/ '\0',
/*offset 1*/ '.','n','o','t','e','.','g','n','u','.','b','u','i','l','d','-','i','d','\0',
/*offset 20*/ '.','s','h','s','t','r','t','a','b','\0'
};
static unsigned
umin(unsigned a, unsigned b)
{
return (a < b) ? a : b;
}
static upx_uint64_t
umin64(upx_uint64_t a, upx_uint64_t b)
{
return (a < b) ? a : b;
}
static unsigned
up4(unsigned x)
{
return ~3u & (3+ x);
}
#if 0 //{ unused
static unsigned
up8(unsigned x)
{
return ~7u & (7+ x);
}
#endif //}
static off_t
fpad4(OutputFile *fo)
{
off_t len = fo->st_size();
unsigned d = 3u & (0 - len);
unsigned zero = 0;
fo->write(&zero, d);
return d + len;
}
static off_t
fpad8(OutputFile *fo)
{
off_t len = fo->st_size();
unsigned d = 7u & (0 - len);
upx_uint64_t zero = 0;
fo->write(&zero, d);
return d + len;
}
static unsigned
funpad4(InputFile *fi)
{
unsigned d = 3u & (0 - fi->tell());
if (d)
fi->seek(d, SEEK_CUR);
return d;
}
static void alloc_file_image(MemBuffer &mb, off_t size)
{
assert(mem_size_valid_bytes(size));
if (mb.getVoidPtr() == NULL) {
mb.alloc(size);
} else {
assert((u32_t)size <= mb.getSize());
}
}
int
PackLinuxElf32::checkEhdr(Elf32_Ehdr const *ehdr) const
{
const unsigned char * const buf = ehdr->e_ident;
if (0!=memcmp(buf, "\x7f\x45\x4c\x46", 4) // "\177ELF"
|| buf[Elf32_Ehdr::EI_CLASS]!=ei_class
|| buf[Elf32_Ehdr::EI_DATA] !=ei_data
) {
return -1;
}
if (!memcmp(buf+8, "FreeBSD", 7)) // branded
return 1;
int const type = get_te16(&ehdr->e_type);
if (type != Elf32_Ehdr::ET_EXEC && type != Elf32_Ehdr::ET_DYN)
return 2;
if (get_te16(&ehdr->e_machine) != (unsigned) e_machine)
return 3;
if (get_te32(&ehdr->e_version) != Elf32_Ehdr::EV_CURRENT)
return 4;
if (e_phnum < 1)
return 5;
if (get_te16(&ehdr->e_phentsize) != sizeof(Elf32_Phdr))
return 6;
if (type == Elf32_Ehdr::ET_EXEC) {
// check for Linux kernels
unsigned const entry = get_te32(&ehdr->e_entry);
if (entry == 0xC0100000) // uncompressed vmlinux
return 1000;
if (entry == 0x00001000) // compressed vmlinux
return 1001;
if (entry == 0x00100000) // compressed bvmlinux
return 1002;
}
// FIXME: add more checks for kernels
// FIXME: add special checks for other ELF i386 formats, like
// NetBSD, OpenBSD, Solaris, ....
// success
return 0;
}
int
PackLinuxElf64::checkEhdr(Elf64_Ehdr const *ehdr) const
{
const unsigned char * const buf = ehdr->e_ident;
unsigned char osabi0 = buf[Elf32_Ehdr::EI_OSABI];
if (0==osabi0) {
osabi0 = opt->o_unix.osabi0;
}
if (0!=memcmp(buf, "\x7f\x45\x4c\x46", 4) // "\177ELF"
|| buf[Elf64_Ehdr::EI_CLASS]!=ei_class
|| buf[Elf64_Ehdr::EI_DATA] !=ei_data
|| osabi0!=ei_osabi
) {
return -1;
}
if (!memcmp(buf+8, "FreeBSD", 7)) // branded
return 1;
int const type = get_te16(&ehdr->e_type);
if (type != Elf64_Ehdr::ET_EXEC && type != Elf64_Ehdr::ET_DYN)
return 2;
if (get_te16(&ehdr->e_machine) != (unsigned) e_machine)
return 3;
if (get_te32(&ehdr->e_version) != Elf64_Ehdr::EV_CURRENT)
return 4;
if (e_phnum < 1)
return 5;
if (get_te16(&ehdr->e_phentsize) != sizeof(Elf64_Phdr))
return 6;
if (type == Elf64_Ehdr::ET_EXEC) {
// check for Linux kernels
upx_uint64_t const entry = get_te64(&ehdr->e_entry);
if (entry == 0xC0100000) // uncompressed vmlinux
return 1000;
if (entry == 0x00001000) // compressed vmlinux
return 1001;
if (entry == 0x00100000) // compressed bvmlinux
return 1002;
}
// FIXME: add more checks for kernels
// FIXME: add special checks for other ELF i386 formats, like
// NetBSD, OpenBSD, Solaris, ....
// success
return 0;
}
PackLinuxElf::PackLinuxElf(InputFile *f)
: super(f), e_phnum(0), dynstr(NULL),
sz_phdrs(0), sz_elf_hdrs(0), sz_pack2(0), sz_pack2a(0),
lg2_page(12), page_size(1u<<lg2_page), is_pie(0),
xct_off(0), xct_va(0), jni_onload_va(0),
user_init_va(0), user_init_off(0),
e_machine(0), ei_class(0), ei_data(0), ei_osabi(0), osabi_note(NULL),
o_elf_shnum(0)
{
memset(dt_table, 0, sizeof(dt_table));
}
PackLinuxElf::~PackLinuxElf()
{
}
void
PackLinuxElf32::PackLinuxElf32help1(InputFile *f)
{
e_type = get_te16(&ehdri.e_type);
e_phnum = get_te16(&ehdri.e_phnum);
e_shnum = get_te16(&ehdri.e_shnum);
unsigned const e_phentsize = get_te16(&ehdri.e_phentsize);
if (ehdri.e_ident[Elf32_Ehdr::EI_CLASS]!=Elf32_Ehdr::ELFCLASS32
|| sizeof(Elf32_Phdr) != e_phentsize
|| (Elf32_Ehdr::ELFDATA2MSB == ehdri.e_ident[Elf32_Ehdr::EI_DATA]
&& &N_BELE_RTP::be_policy != bele)
|| (Elf32_Ehdr::ELFDATA2LSB == ehdri.e_ident[Elf32_Ehdr::EI_DATA]
&& &N_BELE_RTP::le_policy != bele)) {
e_phoff = 0;
e_shoff = 0;
sz_phdrs = 0;
return;
}
if (0==e_phnum) throwCantUnpack("0==e_phnum");
e_phoff = get_te32(&ehdri.e_phoff);
unsigned const last_Phdr = e_phoff + e_phnum * sizeof(Elf32_Phdr);
if (last_Phdr < e_phoff || (unsigned long)file_size < last_Phdr) {
throwCantUnpack("bad e_phoff");
}
e_shoff = get_te32(&ehdri.e_shoff);
unsigned const last_Shdr = e_shoff + e_shnum * sizeof(Elf32_Shdr);
if (last_Shdr < e_shoff || (unsigned long)file_size < last_Shdr) {
if (opt->cmd == CMD_COMPRESS) {
throwCantUnpack("bad e_shoff");
}
}
sz_phdrs = e_phnum * e_phentsize;
if (f && Elf32_Ehdr::ET_DYN!=e_type) {
unsigned const len = sz_phdrs + e_phoff;
alloc_file_image(file_image, len);
f->seek(0, SEEK_SET);
f->readx(file_image, len);
phdri= (Elf32_Phdr *)(e_phoff + file_image); // do not free() !!
}
if (f && Elf32_Ehdr::ET_DYN==e_type) {
// The DT_SYMTAB has no designated length. Read the whole file.
alloc_file_image(file_image, file_size);
f->seek(0, SEEK_SET);
f->readx(file_image, file_size);
phdri= (Elf32_Phdr *)(e_phoff + file_image); // do not free() !!
shdri= (Elf32_Shdr *)(e_shoff + file_image); // do not free() !!
if (opt->cmd != CMD_COMPRESS) {
shdri = NULL;
}
sec_dynsym = elf_find_section_type(Elf32_Shdr::SHT_DYNSYM);
if (sec_dynsym) {
unsigned t = get_te32(&sec_dynsym->sh_link);
if (e_shnum <= t)
throwCantPack("bad dynsym->sh_link");
sec_dynstr = &shdri[t];
}
Elf32_Phdr const *phdr= phdri;
for (int j = e_phnum; --j>=0; ++phdr)
if (Elf32_Phdr::PT_DYNAMIC==get_te32(&phdr->p_type)) {
dynseg= (Elf32_Dyn const *)(check_pt_dynamic(phdr) + file_image);
invert_pt_dynamic(dynseg);
}
else if (PT_LOAD32==get_te32(&phdr->p_type)) {
check_pt_load(phdr);
}
// elf_find_dynamic() returns 0 if 0==dynseg.
dynstr = (char const *)elf_find_dynamic(Elf32_Dyn::DT_STRTAB);
dynsym = (Elf32_Sym const *)elf_find_dynamic(Elf32_Dyn::DT_SYMTAB);
gashtab = (unsigned const *)elf_find_dynamic(Elf32_Dyn::DT_GNU_HASH);
hashtab = (unsigned const *)elf_find_dynamic(Elf32_Dyn::DT_HASH);
jni_onload_sym = elf_lookup("JNI_OnLoad");
if (jni_onload_sym) {
jni_onload_va = get_te32(&jni_onload_sym->st_value);
jni_onload_va = 0; // FIXME not understood; need example
}
}
}
off_t PackLinuxElf::pack3(OutputFile *fo, Filter &ft) // return length of output
{
unsigned disp;
unsigned const zero = 0;
unsigned len = sz_pack2a; // after headers and all PT_LOAD
unsigned const t = (4 & len) ^ ((!!xct_off)<<2); // 0 or 4
fo->write(&zero, t);
len += t; // force sz_pack2 (0 mod 8) [see below]
set_te32(&disp, sz_elf_hdrs + sizeof(p_info) + sizeof(l_info) +
(!!xct_off & !!opt->o_unix.android_shlib)); // |1 iff android shlib
fo->write(&disp, sizeof(disp)); // offset(b_info)
len += sizeof(disp);
set_te32(&disp, len); // distance back to beginning (detect dynamic reloc)
fo->write(&disp, sizeof(disp));
len += sizeof(disp);
if (xct_off) { // is_shlib
upx_uint64_t const firstpc_va = (jni_onload_va
? jni_onload_va
: user_init_va);
set_te32(&disp, firstpc_va - load_va);
fo->write(&disp, sizeof(disp)); // DT_INIT.d_val
len += sizeof(disp);
set_te32(&disp, hatch_off);
fo->write(&disp, sizeof(disp)); // offset(hatch)
len += sizeof(disp);
if (opt->o_unix.android_shlib) {
xct_off += asl_delta; // the extra page
}
set_te32(&disp, xct_off);
fo->write(&disp, sizeof(disp)); // offset(dst for f_exp)
len += sizeof(disp);
}
sz_pack2 = len; // 0 mod 8 [see above]
super::pack3(fo, ft); // append the decompressor
set_te16(&linfo.l_lsize, up4( // MATCH03: up4
get_te16(&linfo.l_lsize) + len - sz_pack2a));
return fpad4(fo); // MATCH03
}
off_t PackLinuxElf32::pack3(OutputFile *fo, Filter &ft)
{
off_t flen = super::pack3(fo, ft); // loader follows compressed PT_LOADs
// NOTE: PackLinuxElf::pack3 adjusted xct_off for the extra page
unsigned v_hole = sz_pack2 + lsize;
set_te32(&elfout.phdr[0].p_filesz, v_hole);
set_te32(&elfout.phdr[0].p_memsz, v_hole);
// Then compressed gaps (including debuginfo.)
unsigned total_in = 0, total_out = 0;
for (unsigned k = 0; k < e_phnum; ++k) {
Extent x;
x.size = find_LOAD_gap(phdri, k, e_phnum);
if (x.size) {
x.offset = get_te32(&phdri[k].p_offset) +
get_te32(&phdri[k].p_filesz);
packExtent(x, total_in, total_out, 0, fo);
}
}
// write block end marker (uncompressed size 0)
b_info hdr; memset(&hdr, 0, sizeof(hdr));
set_le32(&hdr.sz_cpr, UPX_MAGIC_LE32);
fo->write(&hdr, sizeof(hdr));
flen = fpad4(fo);
set_te32(&elfout.phdr[0].p_filesz, sz_pack2 + lsize);
set_te32(&elfout.phdr[0].p_memsz, sz_pack2 + lsize);
if (0==xct_off) { // not shared library; adjust PT_LOAD
// .p_align can be big for segments, but Linux uses 4KiB pages.
// This allows [vvar], [vdso], etc to sneak into the gap
// between end_text and data, which we wish to prevent
// because the expanded program will use that space.
// So: pretend 4KiB pages.
unsigned pm = (Elf64_Ehdr::EM_PPC64 == e_machine)
? page_mask // reducing to 4KiB DOES NOT WORK ??
: ((~(unsigned)0)<<12);
pm = page_mask; // Revert until consequences can be analyzed
v_hole = pm & (~pm + v_hole + get_te32(&elfout.phdr[0].p_vaddr));
set_te32(&elfout.phdr[1].p_vaddr, v_hole);
set_te32(&elfout.phdr[1].p_align, ((unsigned)0) - pm);
elfout.phdr[1].p_paddr = elfout.phdr[1].p_vaddr;
elfout.phdr[1].p_offset = 0;
set_te32(&elfout.phdr[1].p_memsz, getbrk(phdri, e_phnum) - v_hole);
set_te32(&elfout.phdr[1].p_flags, Elf32_Phdr::PF_W|Elf32_Phdr::PF_R);
}
if (0!=xct_off) { // shared library
unsigned word = (Elf32_Ehdr::EM_ARM==e_machine) + load_va + sz_pack2; // Thumb mode
set_te32(&file_image[user_init_off], word); // set the hook
Elf32_Phdr *phdr = (Elf32_Phdr *)lowmem.subref(
"bad e_phoff", e_phoff, e_phnum * sizeof(Elf32_Phdr));
unsigned off = fo->st_size();
so_slide = 0;
for (unsigned j = 0; j < e_phnum; ++j, ++phdr) {
unsigned const len = get_te32(&phdr->p_filesz);
unsigned const ioff = get_te32(&phdr->p_offset);
unsigned align= get_te32(&phdr->p_align);
unsigned const type = get_te32(&phdr->p_type);
if (Elf32_Phdr::PT_INTERP==type) {
// Rotate to highest position, so it can be lopped
// by decrementing e_phnum.
memcpy((unsigned char *)ibuf, phdr, sizeof(*phdr)); // extract
memmove(phdr, 1+phdr, (e_phnum - (1+ j))*sizeof(*phdr)); // overlapping
memcpy(&phdr[e_phnum - (1+ j)], (unsigned char *)ibuf, sizeof(*phdr)); // to top
--phdr; --e_phnum;
set_te16(&ehdri.e_phnum, e_phnum);
set_te16(&((Elf32_Ehdr *)(unsigned char *)lowmem)->e_phnum, e_phnum);
continue;
}
if (PT_LOAD32 == type) {
if ((xct_off - ioff) < len) { // Change length of compressed PT_LOAD.
set_te32(&phdr->p_filesz, sz_pack2 + lsize - ioff);
set_te32(&phdr->p_memsz, sz_pack2 + lsize - ioff);
if (user_init_off < xct_off) { // MIPS puts PT_DYNAMIC here
// Allow for DT_INIT in a new [stolen] slot
unsigned off2 = user_init_off - sizeof(word);
fo->seek(off2, SEEK_SET);
fo->rewrite(&file_image[off2], 2*sizeof(word));
}
}
else if (xct_off < ioff) { // Slide subsequent PT_LOAD.
if ((1u<<12) < align) {
align = 1u<<12;
set_te32(&phdr->p_align, align);
}
off += (align-1) & (ioff - off);
fo->seek( off, SEEK_SET);
fo->write(&file_image[ioff], len);
so_slide = off - ioff;
set_te32(&phdr->p_offset, so_slide + ioff);
}
continue; // all done with this PT_LOAD
}
if (xct_off < ioff)
set_te32(&phdr->p_offset, so_slide + ioff);
} // end each Phdr
if (opt->o_unix.android_shlib) {
// Update {DYNAMIC}.sh_offset by so_slide.
Elf32_Shdr *shdr = (Elf32_Shdr *)lowmem.subref(
"bad e_shoff", xct_off - asl_delta, e_shnum * sizeof(Elf32_Shdr));
for (unsigned j = 0; j < e_shnum; ++shdr, ++j) {
unsigned sh_type = get_te32(&shdr->sh_type);
if (Elf32_Shdr::SHT_DYNAMIC == get_te32(&shdr->sh_type)) {
unsigned offset = get_te32(&shdr->sh_offset);
set_te32(&shdr->sh_offset, so_slide + offset );
fo->seek((j * sizeof(Elf32_Shdr)) + xct_off - asl_delta, SEEK_SET);
fo->rewrite(shdr, sizeof(*shdr));
fo->seek(0, SEEK_END);
}
if (Elf32_Shdr::SHT_REL == sh_type
&& n_jmp_slot
&& !strcmp(".rel.plt", get_te32(&shdr->sh_name) + shstrtab)) {
unsigned f_off = elf_get_offset_from_address(plt_off);
fo->seek(so_slide + f_off, SEEK_SET); // FIXME: assumes PT_LOAD[1]
fo->rewrite(&file_image[f_off], n_jmp_slot * 4);
}
}
}
else { // !opt->o_unix.android_shlib)
ehdri.e_shnum = 0;
ehdri.e_shoff = 0;
ehdri.e_shstrndx = 0;
}
}
return flen;
}
off_t PackLinuxElf64::pack3(OutputFile *fo, Filter &ft)
{
off_t flen = super::pack3(fo, ft); // loader follows compressed PT_LOADs
// NOTE: PackLinuxElf::pack3 adjusted xct_off for the extra page
unsigned v_hole = sz_pack2 + lsize;
set_te64(&elfout.phdr[0].p_filesz, v_hole);
set_te64(&elfout.phdr[0].p_memsz, v_hole);
// Then compressed gaps (including debuginfo.)
unsigned total_in = 0, total_out = 0;
for (unsigned k = 0; k < e_phnum; ++k) {
Extent x;
x.size = find_LOAD_gap(phdri, k, e_phnum);
if (x.size) {
x.offset = get_te64(&phdri[k].p_offset) +
get_te64(&phdri[k].p_filesz);
packExtent(x, total_in, total_out, 0, fo);
}
}
// write block end marker (uncompressed size 0)
b_info hdr; memset(&hdr, 0, sizeof(hdr));
set_le32(&hdr.sz_cpr, UPX_MAGIC_LE32);
fo->write(&hdr, sizeof(hdr));
flen = fpad4(fo);
set_te64(&elfout.phdr[0].p_filesz, sz_pack2 + lsize);
set_te64(&elfout.phdr[0].p_memsz, sz_pack2 + lsize);
if (0==xct_off) { // not shared library; adjust PT_LOAD
// On amd64: (2<<20)==.p_align, but Linux uses 4KiB pages.
// This allows [vvar], [vdso], etc to sneak into the gap
// between end_text and data, which we wish to prevent
// because the expanded program will use that space.
// So: pretend 4KiB pages.
upx_uint64_t const pm = (
Elf64_Ehdr::EM_X86_64 ==e_machine
//|| Elf64_Ehdr::EM_AARCH64==e_machine
//|| Elf64_Ehdr::EM_PPC64 ==e_machine /* DOES NOT WORK! */
)
? ((~(upx_uint64_t)0)<<12)
: page_mask;
v_hole = pm & (~pm + v_hole + get_te64(&elfout.phdr[0].p_vaddr));
set_te64(&elfout.phdr[1].p_vaddr, v_hole);
set_te64(&elfout.phdr[1].p_align, ((upx_uint64_t)0) - pm);
elfout.phdr[1].p_paddr = elfout.phdr[1].p_vaddr;
elfout.phdr[1].p_offset = 0;
set_te64(&elfout.phdr[1].p_memsz, getbrk(phdri, e_phnum) - v_hole);
set_te32(&elfout.phdr[1].p_flags, Elf32_Phdr::PF_W|Elf32_Phdr::PF_R);
}
if (0!=xct_off) { // shared library
upx_uint64_t word = load_va + sz_pack2;
set_te64(&file_image[user_init_off], word); // set the hook
Elf64_Phdr *phdr = (Elf64_Phdr *)lowmem.subref(
"bad e_phoff", e_phoff, e_phnum * sizeof(Elf64_Phdr));
unsigned off = fo->st_size();
so_slide = 0;
for (unsigned j = 0; j < e_phnum; ++j, ++phdr) {
upx_uint64_t const len = get_te64(&phdr->p_filesz);
upx_uint64_t const ioff = get_te64(&phdri[j].p_offset);
upx_uint64_t align= get_te64(&phdr->p_align);
unsigned const type = get_te32(&phdr->p_type);
if (Elf64_Phdr::PT_INTERP==type) {
// Rotate to highest position, so it can be lopped
// by decrementing e_phnum.
memcpy((unsigned char *)ibuf, phdr, sizeof(*phdr)); // extract
memmove(phdr, 1+phdr, (e_phnum - (1+ j))*sizeof(*phdr)); // overlapping
memcpy(&phdr[e_phnum - (1+ j)], (unsigned char *)ibuf, sizeof(*phdr)); // to top
--phdr; --e_phnum;
set_te16(&ehdri.e_phnum, e_phnum);
set_te16(&((Elf64_Ehdr *)(unsigned char *)lowmem)->e_phnum, e_phnum);
continue;
}
if (PT_LOAD64 == type) {
if ((xct_off - ioff) < len) { // Change length of compressed PT_LOAD.
set_te64(&phdr->p_filesz, sz_pack2 + lsize - ioff);
set_te64(&phdr->p_memsz, sz_pack2 + lsize - ioff);
if (user_init_off < xct_off) { // MIPS puts PT_DYNAMIC here
// Allow for DT_INIT in a new [stolen] slot
unsigned off2 = user_init_off - sizeof(word);
fo->seek(off2, SEEK_SET);
fo->rewrite(&file_image[off2], 2*sizeof(word));
}
}
else if (xct_off < ioff) { // Slide subsequent PT_LOAD.
// AMD64 chip supports page sizes of 4KiB, 2MiB, and 1GiB;
// the operating system chooses one. .p_align typically
// is a forward-looking 2MiB. In 2009 Linux chooses 4KiB.
// We choose 4KiB to waste less space. If Linux chooses
// 2MiB later, then our output will not run.
if ((1u<<12) < align
&& Elf64_Ehdr::EM_X86_64 ==e_machine
) {
align = 1u<<12;
set_te64(&phdr->p_align, align);
}
off += (align-1) & (ioff - off);
fo->seek( off, SEEK_SET);
fo->write(&file_image[ioff], len);
so_slide = off - ioff;
set_te64(&phdr->p_offset, so_slide + ioff);
}
continue; // all done with this PT_LOAD
}
if (xct_off < ioff)
set_te64(&phdr->p_offset, so_slide + ioff);
} // end each Phdr
if (opt->o_unix.android_shlib) {
// Update {DYNAMIC}.sh_offset by so_slide.
Elf64_Shdr *shdr = (Elf64_Shdr *)lowmem.subref(
"bad e_shoff", xct_off - asl_delta, e_shnum * sizeof(Elf64_Shdr));
for (unsigned j = 0; j < e_shnum; ++shdr, ++j) {
unsigned sh_type = get_te32(&shdr->sh_type);
if (Elf64_Shdr::SHT_DYNAMIC == sh_type) {
upx_uint64_t offset = get_te64(&shdr->sh_offset);
set_te64(&shdr->sh_offset, so_slide + offset);
fo->seek((j * sizeof(Elf64_Shdr)) + xct_off - asl_delta, SEEK_SET);
fo->rewrite(shdr, sizeof(*shdr));
fo->seek(0, SEEK_END);
}
if (Elf64_Shdr::SHT_RELA == sh_type
&& n_jmp_slot
&& !strcmp(".rela.plt", get_te32(&shdr->sh_name) + shstrtab)) {
upx_uint64_t f_off = elf_get_offset_from_address(plt_off);
fo->seek(so_slide + f_off, SEEK_SET); // FIXME: assumes PT_LOAD[1]
fo->rewrite(&file_image[f_off], n_jmp_slot * 8);
}
}
}
else { // !opt->o_unix.android_shlib)
ehdri.e_shnum = 0;
ehdri.e_shoff = 0;
ehdri.e_shstrndx = 0;
}
}
return flen;
}
void
PackLinuxElf::addStubEntrySections(Filter const *)
{
addLoader("ELFMAINX", NULL);
if (hasLoaderSection("ELFMAINXu")) {
// brk() trouble if static
addLoader("ELFMAINXu", NULL);
}
//addLoader(getDecompressorSections(), NULL);
addLoader(
( M_IS_NRV2E(ph.method) ? "NRV_HEAD,NRV2E,NRV_TAIL"
: M_IS_NRV2D(ph.method) ? "NRV_HEAD,NRV2D,NRV_TAIL"
: M_IS_NRV2B(ph.method) ? "NRV_HEAD,NRV2B,NRV_TAIL"
: M_IS_LZMA(ph.method) ? "LZMA_ELF00,LZMA_DEC20,LZMA_DEC30"
: NULL), NULL);
if (hasLoaderSection("CFLUSH"))
addLoader("CFLUSH");
addLoader("ELFMAINY,IDENTSTR", NULL);
if (hasLoaderSection("ELFMAINZe")) { // ppc64 big-endian only
addLoader("ELFMAINZe", NULL);
}
addLoader("+40,ELFMAINZ", NULL);
if (hasLoaderSection("ANDMAJNZ")) { // Android trouble with args to DT_INIT
if (opt->o_unix.android_shlib) {
addLoader("ANDMAJNZ", NULL); // constant PAGE_SIZE
}
else {
addLoader("ELFMAJNZ", NULL); // PAGE_SIZE from AT_PAGESZ
}
addLoader("ELFMAKNZ", NULL);
}
if (hasLoaderSection("ELFMAINZu")) {
addLoader("ELFMAINZu", NULL);
}
addLoader("FOLDEXEC", NULL);
}
void PackLinuxElf::defineSymbols(Filter const *)
{
linker->defineSymbol("O_BINFO", (!!opt->o_unix.is_ptinterp) | o_binfo);
}
void PackLinuxElf32::defineSymbols(Filter const *ft)
{
PackLinuxElf::defineSymbols(ft);
}
void PackLinuxElf64::defineSymbols(Filter const *ft)
{
PackLinuxElf::defineSymbols(ft);
}
PackLinuxElf32::PackLinuxElf32(InputFile *f)
: super(f), phdri(NULL), shdri(NULL),
gnu_stack(NULL), note_body(NULL),
page_mask(~0u<<lg2_page),
dynseg(NULL), hashtab(NULL), gashtab(NULL), dynsym(NULL),
jni_onload_sym(NULL),
shstrtab(NULL),
sec_strndx(NULL), sec_dynsym(NULL), sec_dynstr(NULL)
, symnum_end(0)
{
memset(&ehdri, 0, sizeof(ehdri));
if (f) {
f->seek(0, SEEK_SET);
f->readx(&ehdri, sizeof(ehdri));
}
}
PackLinuxElf32::~PackLinuxElf32()
{
delete[] note_body;
}
PackLinuxElf64::PackLinuxElf64(InputFile *f)
: super(f), phdri(NULL), shdri(NULL),
gnu_stack(NULL), note_body(NULL),
page_mask(~0ull<<lg2_page),
dynseg(NULL), hashtab(NULL), gashtab(NULL), dynsym(NULL),
jni_onload_sym(NULL),
shstrtab(NULL),
sec_strndx(NULL), sec_dynsym(NULL), sec_dynstr(NULL)
, symnum_end(0)
{
memset(&ehdri, 0, sizeof(ehdri));
if (f) {
f->seek(0, SEEK_SET);
f->readx(&ehdri, sizeof(ehdri));
}
}
PackLinuxElf64::~PackLinuxElf64()
{
delete[] note_body;
}
// FIXME: should be templated with PackLinuxElf32help1
void
PackLinuxElf64::PackLinuxElf64help1(InputFile *f)
{
e_type = get_te16(&ehdri.e_type);
e_phnum = get_te16(&ehdri.e_phnum);
e_shnum = get_te16(&ehdri.e_shnum);
unsigned const e_phentsize = get_te16(&ehdri.e_phentsize);
if (ehdri.e_ident[Elf64_Ehdr::EI_CLASS]!=Elf64_Ehdr::ELFCLASS64
|| sizeof(Elf64_Phdr) != e_phentsize
|| (Elf64_Ehdr::ELFDATA2MSB == ehdri.e_ident[Elf64_Ehdr::EI_DATA]
&& &N_BELE_RTP::be_policy != bele)
|| (Elf64_Ehdr::ELFDATA2LSB == ehdri.e_ident[Elf64_Ehdr::EI_DATA]
&& &N_BELE_RTP::le_policy != bele)) {
e_phoff = 0;
e_shoff = 0;
sz_phdrs = 0;
return;
}
if (0==e_phnum) throwCantUnpack("0==e_phnum");
e_phoff = get_te64(&ehdri.e_phoff);
upx_uint64_t const last_Phdr = e_phoff + e_phnum * sizeof(Elf64_Phdr);
if (last_Phdr < e_phoff || (unsigned long)file_size < last_Phdr) {
throwCantUnpack("bad e_phoff");
}
e_shoff = get_te64(&ehdri.e_shoff);
upx_uint64_t const last_Shdr = e_shoff + e_shnum * sizeof(Elf64_Shdr);
if (last_Shdr < e_shoff || (unsigned long)file_size < last_Shdr) {
if (opt->cmd == CMD_COMPRESS) {
throwCantUnpack("bad e_shoff");
}
}
sz_phdrs = e_phnum * e_phentsize;
if (f && Elf64_Ehdr::ET_DYN!=e_type) {
unsigned const len = sz_phdrs + e_phoff;
alloc_file_image(file_image, len);
f->seek(0, SEEK_SET);
f->readx(file_image, len);
phdri= (Elf64_Phdr *)(e_phoff + file_image); // do not free() !!
}
if (f && Elf64_Ehdr::ET_DYN==e_type) {
// The DT_SYMTAB has no designated length. Read the whole file.
alloc_file_image(file_image, file_size);
f->seek(0, SEEK_SET);
f->readx(file_image, file_size);
phdri= (Elf64_Phdr *)(e_phoff + file_image); // do not free() !!
shdri= (Elf64_Shdr *)(e_shoff + file_image); // do not free() !!
if (opt->cmd != CMD_COMPRESS) {
shdri = NULL;
}
sec_dynsym = elf_find_section_type(Elf64_Shdr::SHT_DYNSYM);
if (sec_dynsym) {
unsigned t = get_te32(&sec_dynsym->sh_link);
if (e_shnum <= t)
throwCantPack("bad dynsym->sh_link");
sec_dynstr = &shdri[t];
}
Elf64_Phdr const *phdr= phdri;
for (int j = e_phnum; --j>=0; ++phdr)
if (Elf64_Phdr::PT_DYNAMIC==get_te64(&phdr->p_type)) {
dynseg= (Elf64_Dyn const *)(check_pt_dynamic(phdr) + file_image);
invert_pt_dynamic(dynseg);
}
else if (PT_LOAD64==get_te32(&phdr->p_type)) {
check_pt_load(phdr);
}
// elf_find_dynamic() returns 0 if 0==dynseg.
dynstr = (char const *)elf_find_dynamic(Elf64_Dyn::DT_STRTAB);
dynsym = (Elf64_Sym const *)elf_find_dynamic(Elf64_Dyn::DT_SYMTAB);
gashtab = (unsigned const *)elf_find_dynamic(Elf64_Dyn::DT_GNU_HASH);
hashtab = (unsigned const *)elf_find_dynamic(Elf64_Dyn::DT_HASH);
jni_onload_sym = elf_lookup("JNI_OnLoad");
if (jni_onload_sym) {
jni_onload_va = get_te64(&jni_onload_sym->st_value);
jni_onload_va = 0; // FIXME not understood; need example
}
}
}
Linker* PackLinuxElf64amd::newLinker() const
{
return new ElfLinkerAMD64;
}
Linker* PackLinuxElf64arm::newLinker() const
{
return new ElfLinkerArm64LE;
}
int const *
PackLinuxElf::getCompressionMethods(int method, int level) const
{
// No real dependency on LE32.
return Packer::getDefaultCompressionMethods_le32(method, level);
}
int const *
PackLinuxElf32armLe::getCompressionMethods(int method, int level) const
{
return Packer::getDefaultCompressionMethods_8(method, level);
}
int const *
PackLinuxElf32armBe::getCompressionMethods(int method, int level) const
{
return Packer::getDefaultCompressionMethods_8(method, level);
}
int const *
PackLinuxElf32ppc::getFilters() const
{
static const int filters[] = {
0xd0,
FT_END };
return filters;
}
int const *
PackLinuxElf64ppcle::getFilters() const
{
static const int filters[] = {
0xd0,
FT_END };
return filters;
}
int const *
PackLinuxElf64ppc::getFilters() const
{
static const int filters[] = {
0xd0,
FT_END };
return filters;
}
int const *
PackLinuxElf64amd::getFilters() const
{
static const int filters[] = {
0x49,
FT_END };
return filters;
}
int const *
PackLinuxElf64arm::getFilters() const
{
static const int filters[] = {
0x52,
FT_END };
return filters;
}
void PackLinuxElf32::patchLoader()
{
}
void PackLinuxElf64::patchLoader()
{
}
void PackLinuxElf32::ARM_updateLoader(OutputFile * /*fo*/)
{
set_te32(&elfout.ehdr.e_entry, sz_pack2 +
linker->getSymbolOffset("_start") +
get_te32(&elfout.phdr[0].p_vaddr));
}
void PackLinuxElf32armLe::updateLoader(OutputFile *fo)
{
ARM_updateLoader(fo);
}
void PackLinuxElf32armBe::updateLoader(OutputFile *fo)
{
ARM_updateLoader(fo);
}
void PackLinuxElf32mipsel::updateLoader(OutputFile *fo)
{
ARM_updateLoader(fo); // not ARM specific; (no 32-bit immediates)
}
void PackLinuxElf32mipseb::updateLoader(OutputFile *fo)
{
ARM_updateLoader(fo); // not ARM specific; (no 32-bit immediates)
}
void PackLinuxElf32::updateLoader(OutputFile * /*fo*/)
{
unsigned start = linker->getSymbolOffset("_start");
unsigned vbase = get_te32(&elfout.phdr[0].p_vaddr);
set_te32(&elfout.ehdr.e_entry, start + sz_pack2 + vbase);
}
void PackLinuxElf64::updateLoader(OutputFile * /*fo*/)
{
if (xct_off) {
return; // FIXME elfout has no values at all
}
upx_uint64_t const vbase = get_te64(&elfout.phdr[0].p_vaddr);
unsigned start = linker->getSymbolOffset("_start");
if (get_te16(&elfout.ehdr.e_machine)==Elf64_Ehdr::EM_PPC64
&& elfout.ehdr.e_ident[Elf64_Ehdr::EI_DATA]==Elf64_Ehdr::ELFDATA2MSB) {
unsigned descr = linker->getSymbolOffset("entry_descr");
// External relocation of PPC64 function descriptor.
upx_uint64_t dot_entry = start + sz_pack2 + vbase;
upx_byte *p = getLoader();
set_te64(&p[descr], dot_entry);
set_te64(&elfout.ehdr.e_entry, descr + sz_pack2 + vbase);
}
else {
set_te64(&elfout.ehdr.e_entry, start + sz_pack2 + vbase);
}
}
PackLinuxElf32ppc::PackLinuxElf32ppc(InputFile *f)
: super(f)
{
e_machine = Elf32_Ehdr::EM_PPC;
ei_class = Elf32_Ehdr::ELFCLASS32;
ei_data = Elf32_Ehdr::ELFDATA2MSB;
ei_osabi = Elf32_Ehdr::ELFOSABI_LINUX;
}
PackLinuxElf32ppc::~PackLinuxElf32ppc()
{
}
Linker* PackLinuxElf32ppc::newLinker() const
{
return new ElfLinkerPpc32;
}
PackLinuxElf64ppcle::PackLinuxElf64ppcle(InputFile *f)
: super(f), lg2_page(16), page_size(1u<<lg2_page)
{
e_machine = Elf64_Ehdr::EM_PPC64;
ei_class = Elf64_Ehdr::ELFCLASS64;
ei_data = Elf64_Ehdr::ELFDATA2LSB;
ei_osabi = Elf64_Ehdr::ELFOSABI_LINUX;
}
PackLinuxElf64ppc::PackLinuxElf64ppc(InputFile *f)
: super(f), lg2_page(16), page_size(1u<<lg2_page)
{
e_machine = Elf64_Ehdr::EM_PPC64;
ei_class = Elf64_Ehdr::ELFCLASS64;
ei_data = Elf64_Ehdr::ELFDATA2MSB;
ei_osabi = Elf32_Ehdr::ELFOSABI_LINUX;
}
PackLinuxElf64ppcle::~PackLinuxElf64ppcle()
{
}
PackLinuxElf64ppc::~PackLinuxElf64ppc()
{
}
Linker* PackLinuxElf64ppcle::newLinker() const
{
return new ElfLinkerPpc64le;
}