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src: rework optimizeReloc handling; cleanups

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This commit is contained in:
Markus F.X.J. Oberhumer
2023-02-21 15:19:24 +01:00
parent 8d364c82e2
commit 4a8efd2e2f
23 changed files with 430 additions and 381 deletions
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src/p_tmt.cpp
+51 -47
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@@ -35,8 +35,6 @@
static const CLANG_FORMAT_DUMMY_STATEMENT
#include "stub/i386-dos32.tmt.h"
#define EXTRA_INFO 4 // original entry point
/*************************************************************************
//
**************************************************************************/
@@ -100,7 +98,7 @@ int PackTmt::readFileHeader() {
fi->seek(adam_offset, SEEK_SET);
fi->readx(h, sizeof(h));
if (memcmp(h, "MZ", 2) == 0) // dos exe
if (memcmp(h, "MZ", 2) == 0) // dos/exe
{
exe_offset = adam_offset;
adam_offset += H(2) * 512 + H(1);
@@ -135,14 +133,15 @@ int PackTmt::readFileHeader() {
fi->seek(adam_offset, SEEK_SET);
fi->readx(&ih, sizeof(ih));
// FIXME: should add more checks for the values in 'ih'
unsigned const imagesize = ih.imagesize;
unsigned const entry = ih.entry;
unsigned const relocsize = ih.relocsize;
if (imagesize < sizeof(ih) || entry < sizeof(ih) || file_size_u <= imagesize ||
file_size_u <= entry || file_size_u <= relocsize) {
printWarn(getName(), "bad header; imagesize=%#x entry=%#x relocsize=%#x", imagesize,
entry, relocsize);
// TODO: could add more checks for the values in 'ih'
const unsigned imagesize = ih.imagesize;
const unsigned entry = ih.entry;
const unsigned rsize = ih.relocsize;
if (imagesize < sizeof(ih) || imagesize >= file_size_u || entry >= file_size_u ||
rsize >= file_size_u) {
throwCantPack("%s: bad header: imagesize=%#x entry=%#x relocsize=%#x", getName(), imagesize,
entry, rsize);
return 0;
}
@@ -168,44 +167,47 @@ void PackTmt::pack(OutputFile *fo) {
const unsigned usize = ih.imagesize;
const unsigned rsize = ih.relocsize;
const unsigned relocnum = rsize / 4;
ibuf.alloc(usize + rsize + 128);
obuf.allocForCompression(usize + rsize + 128);
MemBuffer mb_wrkmem;
mb_wrkmem.alloc(rsize + EXTRA_INFO + 4); // relocations + original entry point + relocsize
SPAN_S_VAR(upx_byte, wrkmem, mb_wrkmem);
fi->seek(adam_offset + sizeof(ih), SEEK_SET);
fi->readx(ibuf, usize);
fi->readx(wrkmem + 4, rsize);
const unsigned overlay = file_size - fi->tell();
if (find_le32(ibuf, UPX_MIN(128u, usize), get_le32("UPX ")) >= 0)
throwAlreadyPacked();
if (rsize == 0)
throwCantPack("file is already compressed with another packer");
MemBuffer mb_relocs(rsize);
SPAN_S_VAR(upx_byte, relocs, mb_relocs);
fi->readx(relocs, rsize);
const unsigned overlay = file_size - fi->tell();
checkOverlay(overlay);
unsigned relocsize = 0;
// if (rsize)
{
for (unsigned ic = 4; ic <= rsize; ic += 4)
set_le32(wrkmem + ic, get_le32(wrkmem + ic) - 4);
relocsize =
optimizeReloc32(wrkmem + 4, rsize / 4, wrkmem, ibuf, file_size, true, &big_relocs);
}
for (unsigned ic = 0; ic < relocnum; ic++)
set_le32(relocs + ic * 4, get_le32(relocs + ic * 4) - 4);
wrkmem[relocsize++] = 0;
set_le32(wrkmem + relocsize, ih.entry); // save original entry point
relocsize += 4;
set_le32(wrkmem + relocsize, relocsize + 4);
relocsize += 4;
memcpy(raw_index_bytes(ibuf, usize, relocsize), wrkmem, relocsize);
MemBuffer mb_orelocs(4 * relocnum + 8192); // relocations + extra_info
SPAN_S_VAR(upx_byte, orelocs, mb_orelocs);
unsigned orelocsize =
optimizeReloc(relocnum, relocs, orelocs, ibuf, usize, 32, true, &big_relocs);
relocs.destroy(); // done
mb_relocs.dealloc(); // done
// extra_info
orelocs[orelocsize++] = 0; // why is this needed - historical oversight ???
set_le32(orelocs + orelocsize, ih.entry); // save original entry point
orelocsize += 4;
set_le32(orelocs + orelocsize, orelocsize + 4); // save orelocsize
orelocsize += 4;
memcpy(raw_index_bytes(ibuf, usize, orelocsize), orelocs, orelocsize);
orelocs.destroy(); // done
mb_orelocs.dealloc(); // done
// prepare packheader
ph.u_len = usize + relocsize;
ph.u_len = usize + orelocsize;
// prepare filter
Filter ft(ph.level);
ft.buf_len = usize;
@@ -247,7 +249,7 @@ void PackTmt::pack(OutputFile *fo) {
fo->write(loader, e_len);
fo->write(obuf, ph.c_len);
fo->write(loader + lsize - d_len, d_len); // decompressor
char rel_entry[4];
unsigned char rel_entry[4];
set_le32(rel_entry, 5 + s_point);
fo->write(rel_entry, sizeof(rel_entry));
@@ -281,10 +283,10 @@ void PackTmt::unpack(OutputFile *fo) {
// decompress
decompress(ibuf, obuf);
// decode relocations
const unsigned osize = ph.u_len - get_le32(obuf + (ph.u_len - 4));
SPAN_P_VAR(upx_byte, relocs, obuf + osize);
const unsigned origstart = get_le32(obuf + (ph.u_len - 8));
// read extra_info
const unsigned orig_entry = mem_size(1, get_le32(obuf + ph.u_len - 8));
const unsigned orelocsize = mem_size(1, get_le32(obuf + ph.u_len - 4));
const unsigned osize = mem_size(1, ph.u_len - orelocsize);
// unfilter
if (ph.filter) {
@@ -292,21 +294,23 @@ void PackTmt::unpack(OutputFile *fo) {
ft.init(ph.filter, 0);
ft.cto = (unsigned char) ph.filter_cto;
if (ph.version < 11)
ft.cto = (unsigned char) (get_le32(obuf + (ph.u_len - 12)) >> 24);
ft.unfilter(obuf, ptr_udiff_bytes(relocs, obuf));
ft.cto = (unsigned char) (get_le32(obuf + ph.u_len - 12) >> 24);
ft.unfilter(obuf, osize);
}
// decode relocations
MemBuffer mb_wrkmem;
const unsigned relocn = unoptimizeReloc32(relocs, obuf, mb_wrkmem, true);
SPAN_S_VAR(upx_byte, wrkmem, mb_wrkmem);
for (unsigned ic = 0; ic < relocn; ic++)
set_le32(wrkmem + ic * 4, get_le32(wrkmem + ic * 4) + 4);
SPAN_S_VAR(const upx_byte, orelocs, raw_index_bytes(obuf, osize, orelocsize), orelocsize);
SPAN_S_VAR(upx_byte, reloc_image, raw_index_bytes(obuf, 0, osize), osize);
MemBuffer mb_relocs;
const unsigned relocnum = unoptimizeReloc(orelocs, mb_relocs, reloc_image, osize, 32, true);
SPAN_S_VAR(upx_byte, relocs, mb_relocs);
for (unsigned ic = 0; ic < relocnum; ic++)
set_le32(relocs + ic * 4, get_le32(relocs + ic * 4) + 4);
memcpy(&oh, &ih, sizeof(oh));
oh.imagesize = osize;
oh.entry = origstart;
oh.relocsize = relocn * 4;
oh.entry = orig_entry;
oh.relocsize = relocnum * 4;
const unsigned overlay = file_size - adam_offset - ih.imagesize - ih.relocsize - sizeof(ih);
checkOverlay(overlay);
@@ -315,7 +319,7 @@ void PackTmt::unpack(OutputFile *fo) {
if (fo) {
fo->write(&oh, sizeof(oh));
fo->write(obuf, osize);
fo->write(raw_bytes(wrkmem, relocn * 4), relocn * 4);
fo->write(relocs, relocnum * 4);
}
// copy the overlay