jory/upx
1
0
Fork 0
Code Issues Pull Requests 1 Actions Packages Projects Releases Wiki Activity

JNI_OnLoad is a pre-DT_INIT in a shared library.

Browse Source
This commit is contained in:
John Reiser
2013-10-26 09:51:25 -07:00
parent 45d2adeb9c
commit caf9af7ae4
2 changed files with 192 additions and 84 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/p_lx_elf.cpp
+177 -77
View File
@@ -195,6 +195,7 @@ PackLinuxElf::PackLinuxElf(InputFile *f)
: super(f), e_phnum(0), file_image(NULL), dynstr(NULL),
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),
jni_onload_va(0),
e_machine(0), ei_class(0), ei_data(0), ei_osabi(0), osabi_note(NULL),
o_elf_shnum(0)
{
@@ -205,6 +206,51 @@ PackLinuxElf::~PackLinuxElf()
delete[] file_image; file_image = NULL;
}
void
PackLinuxElf32::PackLinuxElf32help1(InputFile *f)
{
e_type = get_te16(&ehdri.e_type);
e_phnum = get_te16(&ehdri.e_phnum);
e_shnum = get_te16(&ehdri.e_shnum);
e_phoff = get_te32(&ehdri.e_phoff);
e_shoff = get_te32(&ehdri.e_shoff);
sz_phdrs = e_phnum * get_te16(&ehdri.e_phentsize);
if (f && Elf32_Ehdr::ET_DYN!=e_type) {
unsigned const len = sz_phdrs + e_phoff;
file_image = new char[len];
f->seek(0, SEEK_SET);
f->readx(file_image, len);
phdri= (Elf32_Phdr *)(e_phoff + file_image); // do not free() !!
}
if (f && Elf32_Ehdr::ET_DYN==e_type) {
// The DT_STRTAB has no designated length. Read the whole file.
file_image = new char[file_size];
f->seek(0, SEEK_SET);
f->readx(file_image, file_size);
phdri= (Elf32_Phdr *)(e_phoff + file_image); // do not free() !!
shdri= (Elf32_Shdr const *)(e_shoff + file_image); // do not free() !!
sec_dynsym = elf_find_section_type(Elf32_Shdr::SHT_DYNSYM);
if (sec_dynsym)
sec_dynstr = get_te32(&sec_dynsym->sh_link) + shdri;
Elf32_Phdr const *phdr= phdri;
for (int j = e_phnum; --j>=0; ++phdr)
if (Elf32_Phdr::PT_DYNAMIC==get_te32(&phdr->p_type)) {
dynseg= (Elf32_Dyn const *)(get_te32(&phdr->p_offset) + file_image);
break;
}
// elf_find_dynamic() returns 0 if 0==dynseg.
dynstr = (char const *)elf_find_dynamic(Elf32_Dyn::DT_STRTAB);
dynsym = (Elf32_Sym const *)elf_find_dynamic(Elf32_Dyn::DT_SYMTAB);
gashtab = (unsigned const *)elf_find_dynamic(Elf32_Dyn::DT_GNU_HASH);
hashtab = (unsigned const *)elf_find_dynamic(Elf32_Dyn::DT_HASH);
jni_onload_sym = elf_lookup("JNI_OnLoad");
if (jni_onload_sym)
jni_onload_va = get_te32(&jni_onload_sym->st_value);
}
}
void PackLinuxElf::pack3(OutputFile *fo, Filter &ft)
{
unsigned disp;
@@ -223,7 +269,10 @@ void PackLinuxElf::pack3(OutputFile *fo, Filter &ft)
len += sizeof(disp);
if (xct_off) { // is_shlib
set_te32(&disp, elf_unsigned_dynamic(Elf32_Dyn::DT_INIT) - load_va);
upx_uint64_t const firstpc_va = (jni_onload_va
? jni_onload_va
: elf_unsigned_dynamic(Elf32_Dyn::DT_INIT) );
set_te32(&disp, firstpc_va - load_va);
fo->write(&disp, sizeof(disp));
len += sizeof(disp);
@@ -305,7 +354,7 @@ void PackLinuxElf32::pack3(OutputFile *fo, Filter &ft)
continue; // all done with this PT_LOAD
}
// Compute new offset of &DT_INIT.d_val.
if (phdr->PT_DYNAMIC==type) {
if (0==jni_onload_sym && phdr->PT_DYNAMIC==type) {
off_init = rel + ioff;
fi->seek(ioff, SEEK_SET);
fi->read(ibuf, len);
@@ -475,7 +524,8 @@ PackLinuxElf32::PackLinuxElf32(InputFile *f)
: super(f), phdri(NULL), note_body(NULL), shdri(NULL),
page_mask(~0u<<lg2_page),
dynseg(NULL), hashtab(NULL), gashtab(NULL), dynsym(NULL),
shstrtab(NULL), n_elf_shnum(0),
jni_onload_sym(NULL),
shstrtab(NULL),
sec_strndx(NULL), sec_dynsym(NULL), sec_dynstr(NULL)
{
memset(&ehdri, 0, sizeof(ehdri));
@@ -488,14 +538,14 @@ PackLinuxElf32::PackLinuxElf32(InputFile *f)
PackLinuxElf32::~PackLinuxElf32()
{
delete[] note_body;
delete[] phdri; phdri = NULL;
}
PackLinuxElf64::PackLinuxElf64(InputFile *f)
: super(f), phdri(NULL), note_body(NULL), shdri(NULL),
page_mask(~0ull<<lg2_page),
dynseg(NULL), hashtab(NULL), gashtab(NULL), dynsym(NULL),
shstrtab(NULL), n_elf_shnum(0),
jni_onload_sym(NULL),
shstrtab(NULL),
sec_strndx(NULL), sec_dynsym(NULL), sec_dynstr(NULL)
{
memset(&ehdri, 0, sizeof(ehdri));
@@ -508,7 +558,52 @@ PackLinuxElf64::PackLinuxElf64(InputFile *f)
PackLinuxElf64::~PackLinuxElf64()
{
delete[] note_body;
delete[] phdri; phdri = NULL;
}
// FIXME: should be templated with PackLinuxElf32help1
void
PackLinuxElf64::PackLinuxElf64help1(InputFile *f)
{
e_type = get_te16(&ehdri.e_type);
e_phnum = get_te16(&ehdri.e_phnum);
e_shnum = get_te16(&ehdri.e_shnum);
e_phoff = get_te64(&ehdri.e_phoff);
e_shoff = get_te64(&ehdri.e_shoff);
sz_phdrs = e_phnum * get_te16(&ehdri.e_phentsize);
if (f && Elf64_Ehdr::ET_DYN!=e_type) {
unsigned const len = sz_phdrs + e_phoff;
file_image = new char[len];
f->seek(0, SEEK_SET);
f->readx(file_image, len);
phdri= (Elf64_Phdr *)(e_phoff + file_image); // do not free() !!
}
if (f && Elf64_Ehdr::ET_DYN==e_type) {
// The DT_STRTAB has no designated length. Read the whole file.
file_image = new char[file_size];
f->seek(0, SEEK_SET);
f->readx(file_image, file_size);
phdri= (Elf64_Phdr *)(e_phoff + file_image); // do not free() !!
shdri= (Elf64_Shdr const *)(e_shoff + file_image); // do not free() !!
sec_dynsym = elf_find_section_type(Elf64_Shdr::SHT_DYNSYM);
if (sec_dynsym)
sec_dynstr = get_te64(&sec_dynsym->sh_link) + shdri;
Elf64_Phdr const *phdr= phdri;
for (int j = e_phnum; --j>=0; ++phdr)
if (Elf64_Phdr::PT_DYNAMIC==get_te64(&phdr->p_type)) {
dynseg= (Elf64_Dyn const *)(get_te64(&phdr->p_offset) + file_image);
break;
}
// elf_find_dynamic() returns 0 if 0==dynseg.
dynstr = (char const *)elf_find_dynamic(Elf64_Dyn::DT_STRTAB);
dynsym = (Elf64_Sym const *)elf_find_dynamic(Elf64_Dyn::DT_SYMTAB);
gashtab = (unsigned const *)elf_find_dynamic(Elf64_Dyn::DT_GNU_HASH);
hashtab = (unsigned const *)elf_find_dynamic(Elf64_Dyn::DT_HASH);
jni_onload_sym = elf_lookup("JNI_OnLoad");
if (jni_onload_sym)
jni_onload_va = get_te64(&jni_onload_sym->st_value);
}
}
Linker* PackLinuxElf64amd::newLinker() const
@@ -1168,7 +1263,7 @@ Elf32_Shdr const *PackLinuxElf32::elf_find_section_name(
) const
{
Elf32_Shdr const *shdr = shdri;
int j = n_elf_shnum;
int j = e_shnum;
for (; 0 <=--j; ++shdr) {
if (0==strcmp(name, &shstrtab[get_te32(&shdr->sh_name)])) {
return shdr;
@@ -1182,7 +1277,7 @@ Elf64_Shdr const *PackLinuxElf64::elf_find_section_name(
) const
{
Elf64_Shdr const *shdr = shdri;
int j = n_elf_shnum;
int j = e_shnum;
for (; 0 <=--j; ++shdr) {
unsigned ndx = get_te64(&shdr->sh_name);
if (0==strcmp(name, &shstrtab[ndx])) {
@@ -1197,7 +1292,7 @@ Elf32_Shdr const *PackLinuxElf32::elf_find_section_type(
) const
{
Elf32_Shdr const *shdr = shdri;
int j = n_elf_shnum;
int j = e_shnum;
for (; 0 <=--j; ++shdr) {
if (type==get_te32(&shdr->sh_type)) {
return shdr;
@@ -1211,7 +1306,7 @@ Elf64_Shdr const *PackLinuxElf64::elf_find_section_type(
) const
{
Elf64_Shdr const *shdr = shdri;
int j = n_elf_shnum;
int j = e_shnum;
for (; 0 <=--j; ++shdr) {
if (type==get_te32(&shdr->sh_type)) {
return shdr;
@@ -1242,8 +1337,6 @@ bool PackLinuxElf32::canPack()
throwCantPack("invalid Ehdr e_ehsize; try '--force-execve'");
return false;
}
unsigned const e_shoff = get_te32(&ehdr->e_shoff);
unsigned const e_phoff = get_te32(&ehdr->e_phoff);
if (e_phoff != sizeof(*ehdr)) {// Phdrs not contiguous with Ehdr
throwCantPack("non-contiguous Ehdr/Phdr; try '--force-execve'");
return false;
@@ -1328,31 +1421,7 @@ bool PackLinuxElf32::canPack()
// Also allow __uClibc_main and __uClibc_start_main .
if (Elf32_Ehdr::ET_DYN==get_te16(&ehdr->e_type)) {
// The DT_STRTAB has no designated length. Read the whole file.
file_image = new char[file_size];
fi->seek(0, SEEK_SET);
fi->readx(file_image, file_size);
memcpy(&ehdri, ehdr, sizeof(Elf32_Ehdr));
phdri= (Elf32_Phdr *)(e_phoff + file_image); // do not free() !!
shdri= (Elf32_Shdr const *)(e_shoff + file_image); // do not free() !!
n_elf_shnum = get_te16(&ehdr->e_shnum);
//sec_strndx = &shdri[ehdr->e_shstrndx];
//shstrtab = (char const *)(sec_strndx->sh_offset + file_image);
sec_dynsym = elf_find_section_type(Elf32_Shdr::SHT_DYNSYM);
if (sec_dynsym)
sec_dynstr = get_te32(&sec_dynsym->sh_link) + shdri;
int j= e_phnum;
phdr= phdri;
for (; --j>=0; ++phdr)
if (Elf32_Phdr::PT_DYNAMIC==get_te32(&phdr->p_type)) {
dynseg= (Elf32_Dyn const *)(get_te32(&phdr->p_offset) + file_image);
break;
}
// elf_find_dynamic() returns 0 if 0==dynseg.
dynstr= (char const *)elf_find_dynamic(Elf32_Dyn::DT_STRTAB);
dynsym= (Elf32_Sym const *)elf_find_dynamic(Elf32_Dyn::DT_SYMTAB);
// Modified 2009-10-10 to detect a ProgramLinkageTable relocation
// which references the symbol, because DT_GNU_HASH contains only
@@ -1389,19 +1458,17 @@ bool PackLinuxElf32::canPack()
// 2011-06-01: stub.shlib-init.S works around by installing hatch
// at end of .text.
if (elf_find_dynamic(Elf32_Dyn::DT_INIT)) {
if (jni_onload_sym || elf_find_dynamic(Elf32_Dyn::DT_INIT)) {
if (this->e_machine!=Elf32_Ehdr::EM_386
&& this->e_machine!=Elf32_Ehdr::EM_ARM)
goto abandon; // need stub: EM_MIPS EM_PPC
if (elf_has_dynamic(Elf32_Dyn::DT_TEXTREL)) {
shdri = NULL;
phdri = NULL;
throwCantPack("DT_TEXTREL found; re-compile with -fPIC");
goto abandon;
}
Elf32_Shdr const *shdr = shdri;
xct_va = ~0u;
for (j= n_elf_shnum; --j>=0; ++shdr) {
for (int j= e_shnum; --j>=0; ++shdr) {
if (Elf32_Shdr::SHF_EXECINSTR & get_te32(&shdr->sh_flags)) {
xct_va = umin(xct_va, get_te32(&shdr->sh_addr));
}
@@ -1418,12 +1485,11 @@ bool PackLinuxElf32::canPack()
|| xct_va < elf_unsigned_dynamic(Elf32_Dyn::DT_VERDEF)
|| xct_va < elf_unsigned_dynamic(Elf32_Dyn::DT_VERSYM)
|| xct_va < elf_unsigned_dynamic(Elf32_Dyn::DT_VERNEEDED) ) {
phdri = NULL;
shdri = NULL;
throwCantPack("DT_ tag above stub");
goto abandon;
}
for ((shdr= shdri), (j= n_elf_shnum); --j>=0; ++shdr) {
shdr= shdri;
for (int j= e_shnum; --j>=0; ++shdr) {
unsigned const sh_addr = get_te32(&shdr->sh_addr);
if ( sh_addr==va_gash
|| (sh_addr==va_hash && 0==va_gash) ) {
@@ -1436,14 +1502,10 @@ bool PackLinuxElf32::canPack()
goto proceed; // But proper packing depends on checking xct_va.
}
else
infoWarning("no DT_INIT: %s", fi->getName());
infoWarning("no DT_INIT or JNI_OnLoad: %s", fi->getName());
abandon:
phdri = NULL; // Done with this
shdri = NULL;
return false;
proceed:
phdri = NULL;
shdri = NULL;
proceed: ;
}
// XXX Theoretically the following test should be first,
// but PackUnix::canPack() wants 0!=exetype ?
@@ -1479,8 +1541,6 @@ PackLinuxElf64amd::canPack()
throwCantPack("invalid Ehdr e_ehsize; try '--force-execve'");
return false;
}
upx_uint64_t const e_shoff = get_te64(&ehdr->e_shoff);
upx_uint64_t const e_phoff = get_te64(&ehdr->e_phoff);
if (e_phoff != sizeof(*ehdr)) {// Phdrs not contiguous with Ehdr
throwCantPack("non-contiguous Ehdr/Phdr; try '--force-execve'");
return false;
@@ -1525,7 +1585,6 @@ PackLinuxElf64amd::canPack()
phdri= (Elf64_Phdr *)((size_t)e_phoff + file_image); // do not free() !!
shdri= (Elf64_Shdr const *)((size_t)e_shoff + file_image); // do not free() !!
n_elf_shnum = get_te16(&ehdr->e_shnum);
//sec_strndx = &shdri[ehdr->e_shstrndx];
//shstrtab = (char const *)(sec_strndx->sh_offset + file_image);
sec_dynsym = elf_find_section_type(Elf64_Shdr::SHT_DYNSYM);
@@ -1575,14 +1634,12 @@ PackLinuxElf64amd::canPack()
if (elf_find_dynamic(Elf64_Dyn::DT_INIT)) {
if (elf_has_dynamic(Elf64_Dyn::DT_TEXTREL)) {
shdri = NULL;
phdri = NULL;
throwCantPack("DT_TEXTREL found; re-compile with -fPIC");
goto abandon;
}
Elf64_Shdr const *shdr = shdri;
xct_va = ~0ull;
for (j= n_elf_shnum; --j>=0; ++shdr) {
for (j= e_shnum; --j>=0; ++shdr) {
if (Elf64_Shdr::SHF_EXECINSTR & get_te32(&shdr->sh_flags)) {
xct_va = umin64(xct_va, get_te64(&shdr->sh_addr));
}
@@ -1599,12 +1656,10 @@ PackLinuxElf64amd::canPack()
|| xct_va < elf_unsigned_dynamic(Elf64_Dyn::DT_VERDEF)
|| xct_va < elf_unsigned_dynamic(Elf64_Dyn::DT_VERSYM)
|| xct_va < elf_unsigned_dynamic(Elf64_Dyn::DT_VERNEEDED) ) {
phdri = NULL;
shdri = NULL;
throwCantPack("DT_ tag above stub");
goto abandon;
}
for ((shdr= shdri), (j= n_elf_shnum); --j>=0; ++shdr) {
for ((shdr= shdri), (j= e_shnum); --j>=0; ++shdr) {
upx_uint64_t const sh_addr = get_te64(&shdr->sh_addr);
if ( sh_addr==va_gash
|| (sh_addr==va_hash && 0==va_gash) ) {
@@ -1617,10 +1672,8 @@ PackLinuxElf64amd::canPack()
goto proceed; // But proper packing depends on checking xct_va.
}
abandon:
phdri = 0; // Done with this
return false;
proceed:
phdri = 0;
proceed: ;
}
// XXX Theoretically the following test should be first,
// but PackUnix::canPack() wants 0!=exetype ?
@@ -1978,14 +2031,9 @@ void PackLinuxElf32::pack1(OutputFile *fo, Filter & /*ft*/)
{
fi->seek(0, SEEK_SET);
fi->readx(&ehdri, sizeof(ehdri));
unsigned const e_phoff = get_te32(&ehdri.e_phoff);
assert(e_phoff == sizeof(Elf32_Ehdr)); // checked by canPack()
sz_phdrs = e_phnum * get_te16(&ehdri.e_phentsize);
phdri = new Elf32_Phdr[e_phnum];
fi->seek(e_phoff, SEEK_SET);
fi->readx(phdri, sz_phdrs);
// Remember all PT_NOTE, and find lg2_page from PT_LOAD.
Elf32_Phdr const *phdr = phdri;
note_size = 0;
@@ -2030,13 +2078,12 @@ void PackLinuxElf32::pack1(OutputFile *fo, Filter & /*ft*/)
// if the preserve build-id option was specified
if (opt->o_unix.preserve_build_id) {
n_elf_shnum = ehdri.e_shnum;
Elf32_Shdr *shdr = NULL;
Elf32_Shdr const *tmp = shdri;
if (! shdri) {
shdr = new Elf32_Shdr[n_elf_shnum];
shdr = new Elf32_Shdr[e_shnum];
fi->seek(0,SEEK_SET);
fi->seek(ehdri.e_shoff,SEEK_SET);
@@ -2170,14 +2217,9 @@ void PackLinuxElf64::pack1(OutputFile *fo, Filter & /*ft*/)
{
fi->seek(0, SEEK_SET);
fi->readx(&ehdri, sizeof(ehdri));
unsigned const e_phoff = get_te32(&ehdri.e_phoff);
assert(e_phoff == sizeof(Elf64_Ehdr)); // checked by canPack()
sz_phdrs = e_phnum * get_te16(&ehdri.e_phentsize);
phdri = new Elf64_Phdr[e_phnum];
fi->seek(e_phoff, SEEK_SET);
fi->readx(phdri, sz_phdrs);
Elf64_Phdr const *phdr = phdri;
note_size = 0;
for (unsigned j=0; j < e_phnum; ++phdr, ++j) {
@@ -2222,7 +2264,7 @@ void PackLinuxElf64::pack1(OutputFile *fo, Filter & /*ft*/)
// only execute if option present
if (opt->o_unix.preserve_build_id) {
// set this so we can use elf_find_section_name
n_elf_shnum = ehdri.e_shnum;
e_shnum = ehdri.e_shnum;
// there is a class member similar to this, but I did not
// want to assume it would be available
@@ -2231,7 +2273,7 @@ void PackLinuxElf64::pack1(OutputFile *fo, Filter & /*ft*/)
Elf64_Shdr *shdr = NULL;
if (! shdri) {
shdr = new Elf64_Shdr[n_elf_shnum];
shdr = new Elf64_Shdr[e_shnum];
fi->seek(0,SEEK_SET);
fi->seek(ehdri.e_shoff,SEEK_SET);
@@ -2821,6 +2863,15 @@ void PackLinuxElf32::pack4(OutputFile *fo, Filter &ft)
fo->rewrite(phdri, e_phnum * sizeof(*phdri));
fo->seek(sz_elf_hdrs, SEEK_SET);
fo->rewrite(&linfo, sizeof(linfo));
if (jni_onload_va) {
unsigned tmp = sz_pack2 + get_te32(&elfout.phdr[0].p_vaddr);
tmp |= (Elf32_Ehdr::EM_ARM==e_machine); // THUMB mode
set_te32(&tmp, tmp);
fo->seek((char const *)&jni_onload_sym->st_value - file_image, SEEK_SET);
fo->rewrite(&tmp, sizeof(tmp));
fo->seek(0, SEEK_SET);
}
}
else {
unsigned const reloc = get_te32(&elfout.phdr[0].p_vaddr);
@@ -3283,7 +3334,7 @@ PackLinuxElf64::elf_unsigned_dynamic(unsigned int const key) const
return 0;
}
unsigned PackLinuxElf32::gnu_hash(char const *q)
unsigned PackLinuxElf::gnu_hash(char const *q)
{
unsigned char const *p = (unsigned char const *)q;
unsigned h;
@@ -3294,7 +3345,7 @@ unsigned PackLinuxElf32::gnu_hash(char const *q)
return h;
}
unsigned PackLinuxElf32::elf_hash(char const *p)
unsigned PackLinuxElf::elf_hash(char const *p)
{
unsigned h;
for (h= 0; 0!=*p; ++p) {
@@ -3357,6 +3408,55 @@ Elf32_Sym const *PackLinuxElf32::elf_lookup(char const *name) const
}
Elf64_Sym const *PackLinuxElf64::elf_lookup(char const *name) const
{
if (hashtab && dynsym && dynstr) {
unsigned const nbucket = get_te32(&hashtab[0]);
unsigned const *const buckets = &hashtab[2];
unsigned const *const chains = &buckets[nbucket];
unsigned const m = elf_hash(name) % nbucket;
unsigned si;
for (si= get_te32(&buckets[m]); 0!=si; si= get_te32(&chains[si])) {
char const *const p= get_te64(&dynsym[si].st_name) + dynstr;
if (0==strcmp(name, p)) {
return &dynsym[si];
}
}
}
if (gashtab && dynsym && dynstr) {
unsigned const n_bucket = get_te32(&gashtab[0]);
unsigned const symbias = get_te32(&gashtab[1]);
unsigned const n_bitmask = get_te32(&gashtab[2]);
unsigned const gnu_shift = get_te32(&gashtab[3]);
unsigned long const *const bitmask = (unsigned long const *)&gashtab[4];
unsigned const *const buckets = (unsigned const *)&bitmask[n_bitmask];
unsigned const h = gnu_hash(name);
unsigned const hbit1 = 077& h;
unsigned const hbit2 = 077& (h>>gnu_shift);
unsigned long const w = get_te64(&bitmask[(n_bitmask -1) & (h>>6)]);
if (1& (w>>hbit1) & (w>>hbit2)) {
unsigned bucket = get_te32(&buckets[h % n_bucket]);
if (0!=bucket) {
Elf64_Sym const *dsp = dynsym;
unsigned const *const hasharr = &buckets[n_bucket];
unsigned const *hp = &hasharr[bucket - symbias];
dsp += bucket;
do if (0==((h ^ get_te32(hp))>>1)) {
char const *const p = get_te64(&dsp->st_name) + dynstr;
if (0==strcmp(name, p)) {
return dsp;
}
} while (++dsp, 0==(1u& get_te32(hp++)));
}
}
}
return 0;
}
void PackLinuxElf32::unpack(OutputFile *fo)
{
#define MAX_ELF_HDR 512