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Code Issues Releases Wiki Activity

fix brk() problem when is_big: stub must munmap all_pages

Browse Source 
https://github.com/upx/upx/issues/5
	modified:   p_lx_elf.cpp
	modified:   p_lx_elf.h
This commit is contained in:
John Reiser 2016-10-15 14:06:56 -07:00
parent f606b5879b
commit 44328aee76
2 changed files with 12 additions and 10 deletions
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21
src/p_lx_elf.cpp
View File

@ -204,8 +204,8 @@ PackLinuxElf64::checkEhdr(Elf64_Ehdr const *ehdr) const
PackLinuxElf::PackLinuxElf(InputFile *f) PackLinuxElf::PackLinuxElf(InputFile *f)
: super(f), e_phnum(0), dynstr(NULL), : super(f), e_phnum(0), dynstr(NULL),
sz_phdrs(0), sz_elf_hdrs(0), sz_pack2(0), sz_pack2a(0), sz_phdrs(0), sz_elf_hdrs(0), sz_pack2(0), sz_pack2a(0),
lg2_page(12), page_size(1u<<lg2_page), xct_off(0), xct_va(0), lg2_page(12), page_size(1u<<lg2_page), is_big(0),
jni_onload_va(0), xct_off(0), xct_va(0), jni_onload_va(0),
e_machine(0), ei_class(0), ei_data(0), ei_osabi(0), osabi_note(NULL), e_machine(0), ei_class(0), ei_data(0), ei_osabi(0), osabi_note(NULL),
o_elf_shnum(0) o_elf_shnum(0)
{ {
@ -516,11 +516,11 @@ void PackLinuxElf64::pack3(OutputFile *fo, Filter &ft)
void void
PackLinuxElf::addStubEntrySections(Filter const *) PackLinuxElf::addStubEntrySections(Filter const *)
{ {
int all_pages = opt->o_unix.unmap_all_pages | is_big;
addLoader("ELFMAINX", NULL); addLoader("ELFMAINX", NULL);
if (hasLoaderSection("ELFMAINXu")) { if (hasLoaderSection("ELFMAINXu")) {
int const all_pages = opt->o_unix.unmap_all_pages ||
// brk() trouble if static // brk() trouble if static
(Elf32_Ehdr::EM_ARM==e_machine && 0x8000==load_va); all_pages |= (Elf32_Ehdr::EM_ARM==e_machine && 0x8000==load_va);
addLoader((all_pages ? "LUNMP000" : "LUNMP001"), "ELFMAINXu", NULL); addLoader((all_pages ? "LUNMP000" : "LUNMP001"), "ELFMAINXu", NULL);
} }
//addLoader(getDecompressorSections(), NULL); //addLoader(getDecompressorSections(), NULL);
@ -534,7 +534,7 @@ PackLinuxElf::addStubEntrySections(Filter const *)
addLoader("CFLUSH"); addLoader("CFLUSH");
addLoader("ELFMAINY,IDENTSTR,+40,ELFMAINZ", NULL); addLoader("ELFMAINY,IDENTSTR,+40,ELFMAINZ", NULL);
if (hasLoaderSection("ELFMAINZu")) { if (hasLoaderSection("ELFMAINZu")) {
addLoader((opt->o_unix.unmap_all_pages ? "LUNMP000" : "LUNMP001"), "ELFMAINZu", NULL); addLoader((all_pages ? "LUNMP000" : "LUNMP001"), "ELFMAINZu", NULL);
} }
addLoader("FOLDEXEC", NULL); addLoader("FOLDEXEC", NULL);
} }
@ -881,7 +881,8 @@ void PackLinuxElf32x86::addStubEntrySections(Filter const *ft)
if (Elf32_Ehdr::ET_DYN==get_te16(&ehdri.e_type)) { if (Elf32_Ehdr::ET_DYN==get_te16(&ehdri.e_type)) {
addLoader("LEXECDYN", NULL); addLoader("LEXECDYN", NULL);
} }
addLoader((opt->o_unix.unmap_all_pages ? "LUNMP000" : "LUNMP001"), "LEXEC025", NULL); addLoader(((opt->o_unix.unmap_all_pages|is_big) ? "LUNMP000" : "LUNMP001"),
"LEXEC025", NULL);
addLoader("FOLDEXEC", NULL); addLoader("FOLDEXEC", NULL);
} }
@ -1041,7 +1042,7 @@ PackLinuxElf64amd::defineSymbols(Filter const *)
unsigned lenm; unsigned lenm;
unsigned lenu; unsigned lenu;
len += (7&-lsize) + lsize; len += (7&-lsize) + lsize;
bool const is_big = (lo_va_user < (lo_va_stub + len + 2*page_size)); is_big = (lo_va_user < (lo_va_stub + len + 2*page_size));
if (is_big && ehdri.ET_EXEC==get_te16(&ehdri.e_type)) { if (is_big && ehdri.ET_EXEC==get_te16(&ehdri.e_type)) {
set_te64( &elfout.ehdr.e_entry, set_te64( &elfout.ehdr.e_entry,
get_te64(&elfout.ehdr.e_entry) + lo_va_user - lo_va_stub); get_te64(&elfout.ehdr.e_entry) + lo_va_user - lo_va_stub);
@ -2958,7 +2959,7 @@ void PackLinuxElf32::ARM_defineSymbols(Filter const * /*ft*/)
unsigned adrc; unsigned adrc;
unsigned adrm; unsigned adrm;
bool const is_big = true; // kernel disallows mapping below 0x8000. is_big = true; // kernel disallows mapping below 0x8000.
if (is_big) { if (is_big) {
set_te32( &elfout.ehdr.e_entry, linker->getSymbolOffset("_start") + set_te32( &elfout.ehdr.e_entry, linker->getSymbolOffset("_start") +
get_te32(&elfout.ehdr.e_entry) + lo_va_user - lo_va_stub); get_te32(&elfout.ehdr.e_entry) + lo_va_user - lo_va_stub);
@ -3026,7 +3027,7 @@ void PackLinuxElf32mipseb::defineSymbols(Filter const * /*ft*/)
unsigned lenm; unsigned lenm;
unsigned lenu; unsigned lenu;
len += (7&-lsize) + lsize; len += (7&-lsize) + lsize;
bool const is_big = (lo_va_user < (lo_va_stub + len + 2*page_size)); is_big = (lo_va_user < (lo_va_stub + len + 2*page_size));
if (is_big) { if (is_big) {
set_te32( &elfout.ehdr.e_entry, set_te32( &elfout.ehdr.e_entry,
get_te32(&elfout.ehdr.e_entry) + lo_va_user - lo_va_stub); get_te32(&elfout.ehdr.e_entry) + lo_va_user - lo_va_stub);
@ -3099,7 +3100,7 @@ void PackLinuxElf32mipsel::defineSymbols(Filter const * /*ft*/)
unsigned lenm; unsigned lenm;
unsigned lenu; unsigned lenu;
len += (7&-lsize) + lsize; len += (7&-lsize) + lsize;
bool const is_big = (lo_va_user < (lo_va_stub + len + 2*page_size)); is_big = (lo_va_user < (lo_va_stub + len + 2*page_size));
if (is_big) { if (is_big) {
set_te32( &elfout.ehdr.e_entry, set_te32( &elfout.ehdr.e_entry,
get_te32(&elfout.ehdr.e_entry) + lo_va_user - lo_va_stub); get_te32(&elfout.ehdr.e_entry) + lo_va_user - lo_va_stub);

1
src/p_lx_elf.h
View File

@ -81,6 +81,7 @@ protected:
unsigned sz_pack2a; // after pack2() of all PT_LOAD unsigned sz_pack2a; // after pack2() of all PT_LOAD
unsigned lg2_page; // log2(PAGE_SIZE) unsigned lg2_page; // log2(PAGE_SIZE)
unsigned page_size; // 1u<<lg2_page unsigned page_size; // 1u<<lg2_page
unsigned is_big; // stub style: must use area above the brk
unsigned xct_off; // shared library: file offset of SHT_EXECINSTR unsigned xct_off; // shared library: file offset of SHT_EXECINSTR
unsigned hatch_off; // file offset of escape hatch unsigned hatch_off; // file offset of escape hatch
upx_uint64_t load_va; // PT_LOAD[0].p_vaddr upx_uint64_t load_va; // PT_LOAD[0].p_vaddr