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Fix --brute for p_lx_elf.cpp, which compresses multiple pieces

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Force all pieces to use the same de-compressor.
(Future: allow each PT_LOAD to choose its own.)
Has minor wobbles due to page alignment, and size of de-compressor.
64-bit only for now.
https://github.com/upx/upx/issues/570
https://github.com/upx/upx/issues/297
	modified:   p_lx_elf.cpp
	modified:   p_unix.cpp
	modified:   packer.cpp
	modified:   packer.h
This commit is contained in:
John Reiser
2022-03-22 11:46:25 -07:00
committed by Markus F.X.J. Oberhumer
parent 663d6b466b
commit e7ca5c54ff
4 changed files with 150 additions and 34 deletions
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src/p_lx_elf.cpp
+96 -9
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@@ -1266,7 +1266,7 @@ PackLinuxElf64::buildLinuxLoader(
{
unsigned h_sz_cpr = h.sz_cpr;
int r = upx_compress(uncLoader, h.sz_unc, sizeof(h) + cprLoader, &h_sz_cpr,
nullptr, ph.method, 10, nullptr, nullptr );
nullptr, forced_method(ph.method), 10, nullptr, nullptr );
h.sz_cpr = h_sz_cpr;
if (r != UPX_E_OK || h.sz_cpr >= h.sz_unc)
throwInternalError("loader compression failed");
@@ -2808,7 +2808,8 @@ proceed: ;
exetype = 0;
// set options
// .blocksize: avoid over-allocating
// this->blocksize: avoid over-allocating.
// (file_size - max_offset): debug info, non-globl symbols, etc.
opt->o_unix.blocksize = blocksize = UPX_MAX(max_LOADsz, file_size - max_offset);
return true;
}
@@ -3687,7 +3688,7 @@ void PackLinuxElf64ppc::pack1(OutputFile *fo, Filter &ft)
generateElfHdr(fo, stub_powerpc64_linux_elf_fold, getbrk(phdri, e_phnum) );
}
void PackLinuxElf64::pack1(OutputFile *fo, Filter & /*ft*/)
void PackLinuxElf64::pack1(OutputFile *fo, Filter &ft)
{
fi->seek(0, SEEK_SET);
fi->readx(&ehdri, sizeof(ehdri));
@@ -3698,16 +3699,102 @@ void PackLinuxElf64::pack1(OutputFile *fo, Filter & /*ft*/)
// that are not covered by any PT_LOAD), but currently at run time there can be
// only one decompressor method.
// Therefore we must plan ahead because Packer::compressWithFilters tries
// to find the smallest result among the available methods.
// In the future we may allow more than one decompression method at run time,
// but for now we must choose just one, and force compressWithFilters to use it.
// to find the smallest result among the available methods, for one piece only.
// In the future we may allow more than one decompression method at run time.
// For now we must choose only one, and force PackUnix::packExtent
// (==> compressWithFilters) to use it.
int nfilters = 0;
{
int const *fp = getFilters();
while (FT_END != *fp++) {
++nfilters;
}
}
{
int npieces = 1; // tail after highest PT_LOAD
Elf64_Phdr *phdr = phdri;
for (unsigned j=0; j < e_phnum; ++phdr, ++j) {
if (PT_LOAD64 == get_te32(&phdr->p_type)) {
unsigned const flags = get_te32(&phdr->p_flags);
unsigned offset = get_te64(&phdr->p_offset);
if (!xct_off // not shlib
// new-style shlib: PT_LOAD[0] has symbol table
// which must not be compressed, but also lacks PF_X
|| (Elf64_Phdr::PF_X & flags)
// Read-only, non-first PT_LOAD is _assumed_ to be compressible
|| (!(Elf64_Phdr::PF_W & flags) && 0!=offset))
{
++npieces; // will attempt compression of this PT_LOAD
}
}
}
uip->ui_total_passes += npieces;
}
int methods[256];
int nmethods = prepareMethods(methods, ph.method, getCompressionMethods(M_ALL, ph.level));
if (1 < nmethods) {
unsigned nmethods = prepareMethods(methods, ph.method, getCompressionMethods(M_ALL, ph.level));
if (1 < nmethods) { // Many are available, but we must choose only one
uip->ui_total_passes += 1; // the batch for output
uip->ui_total_passes *= nmethods * (1+ nfilters); // finding smallest total
PackHeader orig_ph = ph;
Filter orig_ft = ft;
unsigned max_offset = 0;
unsigned sz_best= ~0u;
int method_best = 0;
for (unsigned k = 0; k < nmethods; ++k) { // FIXME: parallelize; cost: working space
unsigned sz_this = 0;
Elf64_Phdr *phdr = phdri;
for (unsigned j=0; j < e_phnum; ++phdr, ++j) {
if (PT_LOAD64 == get_te32(&phdr->p_type)) {
unsigned const flags = get_te32(&phdr->p_flags);
unsigned offset = get_te64(&phdr->p_offset);
unsigned filesz = get_te64(&phdr->p_filesz);
max_offset = UPX_MAX(max_offset, filesz + offset);
if (!xct_off // not shlib
// new-style shlib: PT_LOAD[0] has symbol table
// which must not be compressed, but also lacks PF_X
|| (Elf64_Phdr::PF_X & flags)
// Read-only, non-first PT_LOAD is _assumed_ to be compressible
|| (!(Elf64_Phdr::PF_W & flags) && 0!=offset))
{
if (xct_off && 0==offset) { // old-style shlib
offset = xct_off;
filesz -= xct_off;
}
fi->seek(offset, SEEK_SET);
fi->readx(ibuf, filesz);
ft = orig_ft;
ph = orig_ph;
ph.method = force_method(methods[k]);
ph.u_len = filesz;
compressWithFilters(&ft, OVERHEAD, NULL_cconf, 10, true);
sz_this += ph.c_len;
}
}
}
unsigned const sz_tail = file_size - max_offset; // debuginfo, etc.
if (sz_tail) {
fi->seek(max_offset, SEEK_SET);
fi->readx(ibuf, sz_tail);
ft = orig_ft;
ph = orig_ph;
ph.method = force_method(methods[k]);
ph.u_len = sz_tail;
compressWithFilters(&ft, OVERHEAD, NULL_cconf, 10, true);
sz_this += ph.c_len;
}
// FIXME: loader size also depends on method
if (sz_best > sz_this) {
sz_best = sz_this;
method_best = methods[k];
}
}
ft = orig_ft;
ph = orig_ph;
ph.method = force_method(method_best);
}
Elf64_Phdr *phdr = phdri;
note_size = 0;
Elf64_Phdr *phdr = phdri;
for (unsigned j=0; j < e_phnum; ++phdr, ++j) {
if (PT_NOTE64 == get_te32(&phdr->p_type)) {
note_size += up4(get_te64(&phdr->p_filesz));