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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_wcle.cpp
+31 -30
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@@ -181,7 +181,7 @@ void PackWcle::encodeObjectTable() {
OOT(0, base_address) = IOT(0, base_address);
ic = IOT(objects - 1, my_base_address) + IOT(objects - 1, virtual_size);
jc = pages * mps + sofixups + 1024;
jc = mem_size(mps, pages, sofixups, 1024);
if (ic < jc)
ic = jc;
@@ -247,14 +247,14 @@ void PackWcle::preprocessFixups() {
throwCantPack("files without relocations are not supported");
}
MemBuffer rl_membuf(jc);
MemBuffer mb_relocs(jc);
ByteArray(srf, counts[objects + 0] + 1);
ByteArray(slf, counts[objects + 1] + 1);
SPAN_S_VAR(upx_byte, rl, rl_membuf);
SPAN_S_VAR(upx_byte, relocs, mb_relocs);
SPAN_S_VAR(upx_byte, selector_fixups, srf_membuf);
SPAN_S_VAR(upx_byte, selfrel_fixups, slf_membuf);
unsigned rc = 0;
unsigned relocnum = 0;
upx_byte *fix = ifixups;
for (ic = jc = 0; ic < pages; ic++) {
@@ -295,7 +295,7 @@ void PackWcle::preprocessFixups() {
}
dputc('p', stdout);
memcpy(iimage + jc + fixp2, fix + 5, (fix[1] & 0x10) ? 4 : 2);
set_le32(rl + 4 * rc++, jc + fixp2);
set_le32(relocs + 4 * relocnum++, jc + fixp2);
set_le32(iimage + jc + fixp2,
get_le32(iimage + jc + fixp2) + IOT(fix[4] - 1, my_base_address));
@@ -316,8 +316,8 @@ void PackWcle::preprocessFixups() {
// work around a pmwunlite bug: remove duplicated fixups
// FIXME: fix the other cases too
if (rc == 0 || get_le32(rl + 4 * rc - 4) != jc + fixp2) {
set_le32(rl + 4 * rc++, jc + fixp2);
if (relocnum == 0 || get_le32(relocs + 4 * relocnum - 4) != jc + fixp2) {
set_le32(relocs + 4 * relocnum++, jc + fixp2);
set_le32(iimage + jc + fixp2,
get_le32(iimage + jc + fixp2) + IOT(fix[4] - 1, my_base_address));
}
@@ -348,11 +348,14 @@ void PackWcle::preprocessFixups() {
}
// resize ifixups if it's too small
if (sofixups < 1000) {
if (sofixups < 4 * relocnum + 8192) {
delete[] ifixups;
ifixups = new upx_byte[1000];
sofixups = 4 * relocnum + 8192;
ifixups = New(upx_byte, sofixups);
}
fix = ifixups + optimizeReloc32(rl, rc, ifixups, iimage, file_size, 1, &big_relocs);
SPAN_S_VAR(upx_byte, orelocs, ifixups, sofixups);
fix =
ifixups + optimizeReloc(relocnum, relocs, orelocs, iimage, soimage, 32, true, &big_relocs);
has_extra_code = ptr_udiff_bytes(selector_fixups, srf) != 0;
// FIXME: this could be removed if has_extra_code = false
// but then we'll need a flag
@@ -380,7 +383,7 @@ void PackWcle::encodeImage(Filter *ft) {
ifixups = nullptr;
mb_oimage.allocForCompression(isize, RESERVED + 512);
oimage = mb_oimage;
oimage = mb_oimage; // => now a SPAN_S
// prepare packheader
ph.u_len = isize;
// prepare filter [already done]
@@ -424,7 +427,7 @@ void PackWcle::pack(OutputFile *fo) {
preprocessFixups();
const unsigned text_size = IOT(ih.init_cs_object - 1, npages) * mps;
const unsigned text_size = mem_size(mps, IOT(ih.init_cs_object - 1, npages));
const unsigned text_vaddr = IOT(ih.init_cs_object - 1, my_base_address);
// attach some useful data at the end of preprocessed fixups
@@ -437,7 +440,8 @@ void PackWcle::pack(OutputFile *fo) {
set_le32(ifixups + sofixups,
ih.init_esp_offset + IOT(ih.init_ss_object - 1, my_base_address)); // old stack pointer
set_le32(ifixups + sofixups + 4, ih.init_eip_offset + text_vaddr); // real entry point
set_le32(ifixups + sofixups + 8, mps * pages); // virtual address of unpacked relocations
set_le32(ifixups + sofixups + 8,
mem_size(mps, pages)); // virtual address of unpacked relocations
ifixups[sofixups + 12] = (unsigned char) (unsigned) objects;
sofixups += 13;
@@ -478,7 +482,7 @@ void PackWcle::pack(OutputFile *fo) {
linker->defineSymbol("original_entry", ih.init_eip_offset + text_vaddr);
linker->defineSymbol("original_stack",
ih.init_esp_offset + IOT(ih.init_ss_object - 1, my_base_address));
linker->defineSymbol("start_of_relocs", mps * pages);
linker->defineSymbol("start_of_relocs", mem_size(mps, pages));
defineDecompressorSymbols();
defineFilterSymbols(&ft);
linker->defineSymbol("filter_buffer_start", text_vaddr);
@@ -518,19 +522,17 @@ void PackWcle::pack(OutputFile *fo) {
**************************************************************************/
void PackWcle::decodeFixups() {
SPAN_P_VAR(upx_byte, p, oimage + soimage);
// assert(p.raw_size_in_bytes() == mb_oimage.getSize()); // Span sanity check
mb_iimage.dealloc();
iimage = nullptr;
MemBuffer tmpbuf;
unsigned const fixupn = unoptimizeReloc32(p, oimage, tmpbuf, true);
SPAN_S_VAR(const upx_byte, p, oimage + soimage);
MemBuffer mb_relocs;
unsigned const fixupn = unoptimizeReloc(p, mb_relocs, oimage, soimage, 32, true);
MemBuffer wrkmem(8 * fixupn + 8);
unsigned ic, jc, o, r;
for (ic = 0; ic < fixupn; ic++) {
jc = get_le32(tmpbuf + 4 * ic);
jc = get_le32(mb_relocs + 4 * ic);
set_le32(wrkmem + ic * 8, jc);
o = soobject_table;
r = get_le32(oimage + jc);
@@ -539,13 +541,13 @@ void PackWcle::decodeFixups() {
set_le32(oimage + jc, r);
}
set_le32(wrkmem + ic * 8, 0xFFFFFFFF); // end of 32-bit offset fixups
tmpbuf.dealloc();
mb_relocs.dealloc(); // done
// selector fixups then self-relative fixups
SPAN_P_VAR(const upx_byte, selector_fixups, p);
SPAN_S_VAR(const upx_byte, selector_fixups, p);
// Find selfrel_fixups by skipping over selector_fixups.
SPAN_P_VAR(const upx_byte, q, selector_fixups);
SPAN_S_VAR(const upx_byte, q, selector_fixups);
// The code is a subroutine that ends in RET (0xC3).
while (*q != 0xC3) {
// Defend against tampered selector_fixups; see PackWcle::preprocessFixups().
@@ -563,10 +565,9 @@ void PackWcle::decodeFixups() {
}
// Guard against run-away.
static unsigned char const blank[9] = {0};
if (ptr_diff_bytes(oimage + ph.u_len - sizeof(blank), raw_bytes(q, 0)) <
0 // catastrophic worst case
|| !memcmp(blank, q, sizeof(blank)) // no-good early warning
) {
// catastrophic worst case or no-good early warning
if (ptr_diff_bytes(oimage + ph.u_len - sizeof(blank), raw_bytes(q, 0)) < 0 ||
!memcmp(blank, q, sizeof(blank))) {
char msg[50];
snprintf(msg, sizeof(msg), "bad selector_fixups %d",
ptr_diff_bytes(q, selector_fixups));
@@ -575,7 +576,7 @@ void PackWcle::decodeFixups() {
q += 9;
}
unsigned selectlen = ptr_udiff_bytes(q, selector_fixups) / 9;
SPAN_P_VAR(const upx_byte, selfrel_fixups, q + 1); // Skip the 0xC3
SPAN_S_VAR(const upx_byte, selfrel_fixups, q + 1); // Skip the 0xC3
const unsigned fbytes = fixupn * 9 + 1000 + selectlen * 5;
ofixups = New(upx_byte, fbytes);
@@ -611,7 +612,7 @@ void PackWcle::decodeFixups() {
dputc('s', stdout);
}
// 32 bit offset fixups
while (get_le32(wrkmem + 4 * jc) < ic * mps) {
while (get_le32(wrkmem + 4 * jc) < mem_size(mps, ic)) {
if (jc > 1 &&
((get_le32(wrkmem + 4 * (jc - 2)) + 3) & (mps - 1)) < 3) // cross page fixup?
{
@@ -770,7 +771,7 @@ void PackWcle::unpack(OutputFile *fo) {
// unfilter
if (ph.filter) {
const unsigned text_size = OOT(oh.init_cs_object - 1, npages) * mps;
const unsigned text_size = mem_size(mps, OOT(oh.init_cs_object - 1, npages));
const unsigned text_vaddr = OOT(oh.init_cs_object - 1, my_base_address);
Filter ft(ph.level);