jory/upx
1
0
Fork 0
Code Issues Pull Requests 1 Actions Packages Projects Releases Wiki Activity

i386: new stub strategy to avoid problems with early mmap layout

Browse Source 
The stub occupies the same region that execve() would create
for the original progam.  The stub copies everything to a new area,
erases the original region, replaces it with the de-compressed
program, and erases the copy of itself via the escape hatch.
The copy is inexpensive via mmap() of /proc/self/exe.

	modified:   stub/src/i386-linux.elf-entry.S
	modified:   stub/src/i386-linux.elf-fold.S
	modified:   stub/src/i386-linux.elf-main.c

	modified:   p_lx_elf.cpp
	modified:   p_lx_elf.h
	modified:   p_lx_interp.cpp
	modified:   p_lx_interp.h
	modified:   p_lx_sh.cpp
	modified:   p_lx_sh.h
	modified:   p_mach.cpp
	modified:   p_mach.h
	modified:   p_unix.cpp
	modified:   p_unix.h
	modified:   p_vmlinx.cpp

	plus .h, .map, .dump
This commit is contained in:
John Reiser
2017-10-01 15:56:34 -07:00
parent 26be845563
commit 9e8de4abe5
30 changed files with 2943 additions and 3118 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/p_lx_elf.cpp
+37 -31
View File
@@ -77,20 +77,20 @@ up4(unsigned x)
return ~3u & (3+ x);
}
static unsigned
static off_t
fpad4(OutputFile *fo)
{
unsigned len = fo->st_size();
off_t len = fo->st_size();
unsigned d = 3u & (0 - len);
unsigned zero = 0;
fo->write(&zero, d);
return d + len;
}
static unsigned
static off_t
fpad8(OutputFile *fo)
{
unsigned len = fo->st_size();
off_t len = fo->st_size();
unsigned d = 7u & (0 - len);
upx_uint64_t zero = 0;
fo->write(&zero, d);
@@ -286,7 +286,7 @@ PackLinuxElf32::PackLinuxElf32help1(InputFile *f)
}
}
void PackLinuxElf::pack3(OutputFile *fo, Filter &ft)
off_t PackLinuxElf::pack3(OutputFile *fo, Filter &ft) // return length of output
{
unsigned disp;
unsigned const zero = 0;
@@ -325,13 +325,15 @@ void PackLinuxElf::pack3(OutputFile *fo, Filter &ft)
set_te16(&linfo.l_lsize, up4( // MATCH03: up4
get_te16(&linfo.l_lsize) + len - sz_pack2a));
len = fpad4(fo); // MATCH03
ACC_UNUSED(len);
return fpad4(fo); // MATCH03
}
void PackLinuxElf32::pack3(OutputFile *fo, Filter &ft)
off_t PackLinuxElf32::pack3(OutputFile *fo, Filter &ft)
{
super::pack3(fo, ft); // loader follows compressed PT_LOADs
off_t flen = super::pack3(fo, ft); // loader follows compressed PT_LOADs
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) {
@@ -347,10 +349,16 @@ void PackLinuxElf32::pack3(OutputFile *fo, Filter &ft)
b_info hdr; memset(&hdr, 0, sizeof(hdr));
set_le32(&hdr.sz_cpr, UPX_MAGIC_LE32);
fo->write(&hdr, sizeof(hdr));
fpad4(fo);
flen = fpad4(fo);
set_te32(&elfout.phdr[0].p_filesz, sz_pack2 + lsize);
set_te32(&elfout.phdr[0].p_memsz, sz_pack2 + lsize);
v_hole = page_mask & (~page_mask + v_hole + get_te32(&elfout.phdr[0].p_vaddr));
if (0==xct_off) { // not shared library; adjust PT_LOAD
set_te32(&elfout.phdr[1].p_vaddr, v_hole);
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
Elf32_Phdr *phdr = phdri;
unsigned off = fo->st_size();
@@ -412,17 +420,18 @@ void PackLinuxElf32::pack3(OutputFile *fo, Filter &ft)
va_init |= (Elf32_Ehdr::EM_ARM==e_machine); // THUMB mode
unsigned word; set_te32(&word, va_init);
fo->rewrite(&word, sizeof(word));
fo->seek(0, SEEK_END);
flen = fo->seek(0, SEEK_END);
}
ehdri.e_shnum = 0;
ehdri.e_shoff = 0;
ehdri.e_shstrndx = 0;
}
return flen;
}
void PackLinuxElf64::pack3(OutputFile *fo, Filter &ft)
off_t PackLinuxElf64::pack3(OutputFile *fo, Filter &ft)
{
super::pack3(fo, ft); // loader follows compressed PT_LOADs
unsigned flen = super::pack3(fo, ft); // loader follows compressed PT_LOADs
// Then compressed gaps (including debuginfo.)
unsigned total_in = 0, total_out = 0;
for (unsigned k = 0; k < e_phnum; ++k) {
@@ -438,7 +447,7 @@ void PackLinuxElf64::pack3(OutputFile *fo, Filter &ft)
b_info hdr; memset(&hdr, 0, sizeof(hdr));
set_le32(&hdr.sz_cpr, UPX_MAGIC_LE32);
fo->write(&hdr, sizeof(hdr));
fpad4(fo);
flen = fpad4(fo);
set_te64(&elfout.phdr[0].p_filesz, sz_pack2 + lsize);
set_te64(&elfout.phdr[0].p_memsz, sz_pack2 + lsize);
@@ -510,12 +519,13 @@ void PackLinuxElf64::pack3(OutputFile *fo, Filter &ft)
fo->seek(off_init, SEEK_SET);
upx_uint64_t word; set_te64(&word, va_init);
fo->rewrite(&word, sizeof(word));
fo->seek(0, SEEK_END);
flen = fo->seek(0, SEEK_END);
}
ehdri.e_shnum = 0;
ehdri.e_shoff = 0;
ehdri.e_shstrndx = 0;
}
return flen;
}
void
@@ -1005,13 +1015,6 @@ void PackLinuxElf32x86::addStubEntrySections(Filter const *ft)
addLoader("IDENTSTR", NULL);
addLoader("LEXEC020", NULL);
if (Elf32_Ehdr::ET_DYN==get_te16(&ehdri.e_type)) {
addLoader("LEXECDYN", NULL);
}
else {
addLoader("LEXECEXE", NULL);
}
addLoader("LEXEC025", NULL);
addLoader("FOLDEXEC", NULL);
}
@@ -2083,15 +2086,16 @@ PackLinuxElf32::generateElfHdr(
// Info for OS kernel to set the brk()
if (brka) {
// linux-2.6.14 binfmt_elf.c: SIGKILL if (0==.p_memsz) on a page boundary
unsigned const brkb = brka | ((0==(~page_mask & brka)) ? 0x20 : 0);
h2->phdr[0].p_paddr = phdri[0].p_paddr;
h2->phdr[0].p_vaddr = phdri[0].p_vaddr;
unsigned const brkb = page_mask & (~page_mask +
get_te32(&h2->phdr[0].p_vaddr) + get_te32(&h2->phdr[0].p_memsz));
set_te32(&h2->phdr[1].p_type, PT_LOAD32); // be sure
set_te32(&h2->phdr[1].p_offset, ~page_mask & brkb);
h2->phdr[1].p_offset = 0;
set_te32(&h2->phdr[1].p_vaddr, brkb);
set_te32(&h2->phdr[1].p_paddr, brkb);
h2->phdr[1].p_filesz = 0;
h2->phdr[1].p_memsz = 0;
if (ARM_is_QNX())
set_te32(&h2->phdr[1].p_memsz, 1); // 0==.p_memsz invalid on QNX 6.3.0
set_te32(&h2->phdr[1].p_memsz, brka - brkb);
set_te32(&h2->phdr[1].p_flags, Elf32_Phdr::PF_R | Elf32_Phdr::PF_W);
}
if (ph.format==getFormat()) {
@@ -2273,7 +2277,8 @@ PackOpenBSDElf32x86::generateElfHdr(
set_te32(&h3->phdr[1].p_vaddr, brkb);
set_te32(&h3->phdr[1].p_paddr, brkb);
h3->phdr[1].p_filesz = 0;
h3->phdr[1].p_memsz = 0;
// Too many kernels have bugs when 0==.p_memsz
set_te32(&h3->phdr[1].p_memsz, 1);
set_te32(&h3->phdr[1].p_flags, Elf32_Phdr::PF_R | Elf32_Phdr::PF_W);
if (ph.format==getFormat()) {
@@ -2361,7 +2366,8 @@ PackLinuxElf64::generateElfHdr(
set_te64(&h2->phdr[1].p_vaddr, brkb);
set_te64(&h2->phdr[1].p_paddr, brkb);
h2->phdr[1].p_filesz = 0;
h2->phdr[1].p_memsz = 0;
// Too many Linux kernels have bugs when 0==.p_memsz
set_te64(&h2->phdr[1].p_memsz, 1);
set_te32(&h2->phdr[1].p_flags, Elf64_Phdr::PF_R | Elf64_Phdr::PF_W);
}
if (ph.format==getFormat()) {