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WIP: un_shlib_1

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modified:   p_lx_elf.cpp
	modified:   p_lx_elf.h
This commit is contained in:
John Reiser 2021-02-27 19:27:12 -08:00 committed by Markus F.X.J. Oberhumer
parent 214dd0a522
commit 2be03028f4
2 changed files with 64 additions and 20 deletions
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83
src/p_lx_elf.cpp
View File

@ -4569,7 +4569,6 @@ void PackLinuxElf64::un_shlib_1(
OutputFile *const fo,
unsigned &c_adler,
unsigned &u_adler,
Elf64_Ehdr const *ehdr,
Elf64_Phdr const *const dynhdr,
unsigned const orig_file_size,
unsigned const szb_info
@ -4577,12 +4576,14 @@ void PackLinuxElf64::un_shlib_1(
{
// The first PT_LOAD. Part is not compressed (for benefit of rtld.)
fi->seek(0, SEEK_SET);
fi->readx(ibuf, get_te64(&dynhdr->p_offset) + get_te64(&dynhdr->p_filesz));
unsigned const limit_dynhdr = get_te64(&dynhdr->p_offset) + get_te64(&dynhdr->p_filesz);
fi->readx(ibuf, limit_dynhdr);
overlay_offset -= sizeof(linfo);
xct_off = overlay_offset;
e_shoff = get_te64(&ehdri.e_shoff);
ibuf.subref("bad .e_shoff %#lx for %#lx", e_shoff, sizeof(Elf64_Shdr) * e_shnum);
if (e_shoff && e_shnum) { // --android-shlib
if (e_shoff && e_shnum
&& (e_shoff + sizeof(Elf64_Shdr) * e_shnum) <= limit_dynhdr) { // --android-shlib
ibuf.subref("bad .e_shoff %#lx for %#lx", e_shoff, sizeof(Elf64_Shdr) * e_shnum);
shdri = (Elf64_Shdr /*const*/ *)ibuf.subref(
"bad Shdr table", e_shoff, sizeof(Elf64_Shdr)*e_shnum);
upx_uint64_t xct_off2 = get_te64(&shdri->sh_offset);
@ -4618,26 +4619,70 @@ void PackLinuxElf64::un_shlib_1(
}
}
if (fo) {
fo->write(ibuf + ph.u_len, xct_off - ph.u_len);
fo->write(ibuf, xct_off);
}
total_in = xct_off;
total_out = xct_off;
ph.u_len = 0;
// Position the input for next unpackExtent.
fi->seek(sizeof(linfo) + overlay_offset + sizeof(p_info) + szb_info + ph.c_len, SEEK_SET);
// Decompress and unfilter the tail of first PT_LOAD.
Elf64_Phdr const *phdr = (Elf64_Phdr const *) (void const *) (1+ ehdr);
unsigned const u_phnum = get_te16(&ehdr->e_phnum);
for (unsigned j=0; j < u_phnum; ++phdr, ++j) {
if (PT_LOAD64==get_te32(&phdr->p_type)) {
ph.u_len = get_te64(&phdr->p_filesz) - xct_off;
break;
}
}
// Decompress and unfilter the tail of PT_LOAD containing xct_off
fi->seek(xct_off + sizeof(linfo) + sizeof(p_info), SEEK_SET);
struct b_info hdr;
fi->readx(&hdr, sizeof(hdr)); // Peek at b_info
fi->seek(-(off_t)sizeof(hdr), SEEK_CUR);
ph.c_len = get_te32(&hdr.sz_cpr);
ph.u_len = get_te32(&hdr.sz_unc);
unpackExtent(ph.u_len, fo,
c_adler, u_adler, false, szb_info);
// Copy (slide) the remaining PT_LOAD; they are not compressed
Elf64_Phdr *phdr = phdri;
unsigned gap_offset = 0;
unsigned slide = 0;
int first = 0;
for (unsigned k = 0; k < e_phnum; ++k, ++phdr) {
if (PT_LOAD64==get_te32(&phdr->p_type)) {
unsigned vaddr = get_te64(&phdr->p_vaddr);
if (xct_off <= vaddr) {
unsigned offset = get_te64(&phdr->p_offset);
unsigned filesz = get_te64(&phdr->p_filesz);
if (0==first++) { // the partially-compressed PT_LOAD
gap_offset = up4(filesz) + offset;
set_te64(&phdr->p_filesz, ph.u_len + xct_off - vaddr);
set_te64(&phdr->p_memsz, ph.u_len + xct_off - vaddr);
}
else { // subsequent PT_LOAD
fi->seek(offset, SEEK_SET);
fi->readx(ibuf, filesz);
if (0==slide) {
slide = vaddr - offset;
}
set_te64(&phdr->p_offset, slide + offset);
fo->seek(slide + offset, SEEK_SET);
fo->write(ibuf, filesz);
}
}
}
}
// The compressed gaps (including to EOF: debuginfo.)
fi->seek(gap_offset, SEEK_SET);
phdr = phdri;
for (unsigned k = 0; k < e_phnum; ++k, ++phdr) {
if (PT_LOAD64==get_te32(&phdr->p_type)) {
unsigned vaddr = get_te64(&phdr->p_vaddr);
if (xct_off <= vaddr) {
unsigned gap = find_LOAD_gap(phdri, k, e_phnum);
if (gap) {
unsigned offset = get_te64(&phdr->p_offset);
unsigned filesz = get_te64(&phdr->p_filesz);
fo->seek(filesz + offset, SEEK_SET);
unpackExtent(gap, fo, c_adler, u_adler, false, szb_info);
}
}
}
}
}
void PackLinuxElf64::un_DT_INIT(
@ -4815,7 +4860,7 @@ void PackLinuxElf64::unpack(OutputFile *fo)
// Packed shlib? (ET_DYN without -fPIE)
if (!(Elf64_Dyn::DF_1_PIE & elf_unsigned_dynamic(Elf64_Dyn::DT_FLAGS_1))) {
is_shlib = 1;
un_shlib_1(fo, c_adler, u_adler, ehdr, dynhdr, orig_file_size, szb_info);
un_shlib_1(fo, c_adler, u_adler, dynhdr, orig_file_size, szb_info);
}
}
else { // main executable

1
src/p_lx_elf.h
View File

@ -273,7 +273,6 @@ protected:
OutputFile *const fo,
unsigned &c_adler,
unsigned &u_adler,
Elf64_Ehdr const *ehdr,
Elf64_Phdr const *const dynhdr,
unsigned const orig_file_size,
unsigned const szb_info