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am 8a1007db: Merge "Add realpath for soinfo"

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* commit '8a1007dbababa6c4812c267ca9119cf0765afc3f':
  Add realpath for soinfo
This commit is contained in:
Dmitriy Ivanov 2015-04-07 00:32:46 +00:00 committed by Android Git Automerger
commit 0e67ab32f2
7 changed files with 313 additions and 136 deletions
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35
linker/dlfcn.cpp
View File

@ -136,7 +136,7 @@ int dladdr(const void* addr, Dl_info* info) {
memset(info, 0, sizeof(Dl_info));
info->dli_fname = si->name;
info->dli_fname = si->get_realpath();
// Address at which the shared object is loaded.
info->dli_fbase = reinterpret_cast<void*>(si->base);
@ -228,23 +228,28 @@ static unsigned g_libdl_chains[] = { 0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 0 };
static unsigned g_libdl_chains[] = { 0, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
#endif
static soinfo __libdl_info("libdl.so", nullptr, 0, RTLD_GLOBAL);
static uint8_t __libdl_info_buf[sizeof(soinfo)] __attribute__((aligned(8)));
static soinfo* __libdl_info = nullptr;
// This is used by the dynamic linker. Every process gets these symbols for free.
soinfo* get_libdl_info() {
if ((__libdl_info.flags_ & FLAG_LINKED) == 0) {
__libdl_info.flags_ |= FLAG_LINKED;
__libdl_info.strtab_ = ANDROID_LIBDL_STRTAB;
__libdl_info.symtab_ = g_libdl_symtab;
__libdl_info.nbucket_ = sizeof(g_libdl_buckets)/sizeof(unsigned);
__libdl_info.nchain_ = sizeof(g_libdl_chains)/sizeof(unsigned);
__libdl_info.bucket_ = g_libdl_buckets;
__libdl_info.chain_ = g_libdl_chains;
__libdl_info.ref_count_ = 1;
__libdl_info.strtab_size_ = sizeof(ANDROID_LIBDL_STRTAB);
__libdl_info.local_group_root_ = &__libdl_info;
__libdl_info.soname_ = "libdl.so";
if (__libdl_info == nullptr) {
__libdl_info = new (__libdl_info_buf) soinfo("libdl.so", nullptr, 0, RTLD_GLOBAL);
__libdl_info->flags_ |= FLAG_LINKED;
__libdl_info->strtab_ = ANDROID_LIBDL_STRTAB;
__libdl_info->symtab_ = g_libdl_symtab;
__libdl_info->nbucket_ = sizeof(g_libdl_buckets)/sizeof(unsigned);
__libdl_info->nchain_ = sizeof(g_libdl_chains)/sizeof(unsigned);
__libdl_info->bucket_ = g_libdl_buckets;
__libdl_info->chain_ = g_libdl_chains;
__libdl_info->ref_count_ = 1;
__libdl_info->strtab_size_ = sizeof(ANDROID_LIBDL_STRTAB);
__libdl_info->local_group_root_ = __libdl_info;
__libdl_info->soname_ = "libdl.so";
#if defined(__arm__)
strlcpy(__libdl_info->old_name_, __libdl_info->soname_, sizeof(__libdl_info->old_name_));
#endif
}
return &__libdl_info;
return __libdl_info;
}

246
linker/linker.cpp
View File

@ -153,7 +153,8 @@ static void insert_soinfo_into_debug_map(soinfo* info) {
// Copy the necessary fields into the debug structure.
link_map* map = &(info->link_map_head);
map->l_addr = info->load_bias;
map->l_name = info->name;
// link_map l_name field is not const.
map->l_name = const_cast<char*>(info->get_realpath());
map->l_ld = info->dynamic;
// Stick the new library at the end of the list.
@ -238,7 +239,7 @@ void SoinfoListAllocator::free(LinkedListEntry<soinfo>* entry) {
static soinfo* soinfo_alloc(const char* name, struct stat* file_stat,
off64_t file_offset, uint32_t rtld_flags) {
if (strlen(name) >= SOINFO_NAME_LEN) {
if (strlen(name) >= PATH_MAX) {
DL_ERR("library name \"%s\" too long", name);
return nullptr;
}
@ -263,7 +264,7 @@ static void soinfo_free(soinfo* si) {
soinfo *prev = nullptr, *trav;
TRACE("name %s: freeing soinfo @ %p", si->name, si);
TRACE("name %s: freeing soinfo @ %p", si->get_soname(), si);
for (trav = solist; trav != nullptr; trav = trav->next) {
if (trav == si) {
@ -274,7 +275,7 @@ static void soinfo_free(soinfo* si) {
if (trav == nullptr) {
// si was not in solist
DL_ERR("name \"%s\"@%p is not in solist!", si->name, si);
DL_ERR("name \"%s\"@%p is not in solist!", si->get_soname(), si);
return;
}
@ -324,6 +325,17 @@ static void parse_LD_PRELOAD(const char* path) {
parse_path(path, " :", &g_ld_preload_names);
}
static bool realpath_fd(int fd, std::string* realpath) {
std::vector<char> buf(PATH_MAX), proc_self_fd(PATH_MAX);
snprintf(&proc_self_fd[0], proc_self_fd.size(), "/proc/self/fd/%d", fd);
if (readlink(&proc_self_fd[0], &buf[0], buf.size()) == -1) {
return false;
}
*realpath = std::string(&buf[0]);
return true;
}
#if defined(__arm__)
// For a given PC, find the .so that it belongs to.
@ -377,7 +389,7 @@ static bool is_symbol_global_and_defined(const soinfo* si, const ElfW(Sym)* s) {
return s->st_shndx != SHN_UNDEF;
} else if (ELF_ST_BIND(s->st_info) != STB_LOCAL) {
DL_WARN("unexpected ST_BIND value: %d for '%s' in '%s'",
ELF_ST_BIND(s->st_info), si->get_string(s->st_name), si->name);
ELF_ST_BIND(s->st_info), si->get_string(s->st_name), si->get_soname());
}
return false;
@ -392,12 +404,12 @@ ElfW(Sym)* soinfo::gnu_lookup(SymbolName& symbol_name) {
ElfW(Addr) bloom_word = gnu_bloom_filter_[word_num];
TRACE_TYPE(LOOKUP, "SEARCH %s in %s@%p (gnu)",
symbol_name.get_name(), name, reinterpret_cast<void*>(base));
symbol_name.get_name(), get_soname(), reinterpret_cast<void*>(base));
// test against bloom filter
if ((1 & (bloom_word >> (hash % bloom_mask_bits)) & (bloom_word >> (h2 % bloom_mask_bits))) == 0) {
TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p",
symbol_name.get_name(), name, reinterpret_cast<void*>(base));
symbol_name.get_name(), get_soname(), reinterpret_cast<void*>(base));
return nullptr;
}
@ -407,7 +419,7 @@ ElfW(Sym)* soinfo::gnu_lookup(SymbolName& symbol_name) {
if (n == 0) {
TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p",
symbol_name.get_name(), name, reinterpret_cast<void*>(base));
symbol_name.get_name(), get_soname(), reinterpret_cast<void*>(base));
return nullptr;
}
@ -418,14 +430,14 @@ ElfW(Sym)* soinfo::gnu_lookup(SymbolName& symbol_name) {
strcmp(get_string(s->st_name), symbol_name.get_name()) == 0 &&
is_symbol_global_and_defined(this, s)) {
TRACE_TYPE(LOOKUP, "FOUND %s in %s (%p) %zd",
symbol_name.get_name(), name, reinterpret_cast<void*>(s->st_value),
symbol_name.get_name(), get_soname(), reinterpret_cast<void*>(s->st_value),
static_cast<size_t>(s->st_size));
return s;
}
} while ((gnu_chain_[n++] & 1) == 0);
TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p",
symbol_name.get_name(), name, reinterpret_cast<void*>(base));
symbol_name.get_name(), get_soname(), reinterpret_cast<void*>(base));
return nullptr;
}
@ -434,30 +446,36 @@ ElfW(Sym)* soinfo::elf_lookup(SymbolName& symbol_name) {
uint32_t hash = symbol_name.elf_hash();
TRACE_TYPE(LOOKUP, "SEARCH %s in %s@%p h=%x(elf) %zd",
symbol_name.get_name(), name, reinterpret_cast<void*>(base), hash, hash % nbucket_);
symbol_name.get_name(), get_soname(),
reinterpret_cast<void*>(base), hash, hash % nbucket_);
for (uint32_t n = bucket_[hash % nbucket_]; n != 0; n = chain_[n]) {
ElfW(Sym)* s = symtab_ + n;
if (strcmp(get_string(s->st_name), symbol_name.get_name()) == 0 &&
is_symbol_global_and_defined(this, s)) {
TRACE_TYPE(LOOKUP, "FOUND %s in %s (%p) %zd",
symbol_name.get_name(), name, reinterpret_cast<void*>(s->st_value),
symbol_name.get_name(), get_soname(),
reinterpret_cast<void*>(s->st_value),
static_cast<size_t>(s->st_size));
return s;
}
}
TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p %x %zd",
symbol_name.get_name(), name, reinterpret_cast<void*>(base), hash, hash % nbucket_);
symbol_name.get_name(), get_soname(),
reinterpret_cast<void*>(base), hash, hash % nbucket_);
return nullptr;
}
soinfo::soinfo(const char* name, const struct stat* file_stat,
soinfo::soinfo(const char* realpath, const struct stat* file_stat,
off64_t file_offset, int rtld_flags) {
memset(this, 0, sizeof(*this));
strlcpy(this->name, name, sizeof(this->name));
if (realpath != nullptr) {
realpath_ = realpath;
}
flags_ = FLAG_NEW_SOINFO;
version_ = SOINFO_VERSION;
@ -473,7 +491,7 @@ soinfo::soinfo(const char* name, const struct stat* file_stat,
uint32_t SymbolName::elf_hash() {
if (!has_elf_hash_) {
const unsigned char* name = reinterpret_cast<const unsigned char*>(name_);
const uint8_t* name = reinterpret_cast<const uint8_t*>(name_);
uint32_t h = 0, g;
while (*name) {
@ -493,7 +511,7 @@ uint32_t SymbolName::elf_hash() {
uint32_t SymbolName::gnu_hash() {
if (!has_gnu_hash_) {
uint32_t h = 5381;
const unsigned char* name = reinterpret_cast<const unsigned char*>(name_);
const uint8_t* name = reinterpret_cast<const uint8_t*>(name_);
while (*name != 0) {
h += (h << 5) + *name++; // h*33 + c = h + h * 32 + c = h + h << 5 + c
}
@ -522,7 +540,7 @@ ElfW(Sym)* soinfo_do_lookup(soinfo* si_from, const char* name, soinfo** si_found
* relocations for -Bsymbolic linked dynamic executables.
*/
if (si_from->has_DT_SYMBOLIC) {
DEBUG("%s: looking up %s in local scope (DT_SYMBOLIC)", si_from->name, name);
DEBUG("%s: looking up %s in local scope (DT_SYMBOLIC)", si_from->get_soname(), name);
s = si_from->find_symbol_by_name(symbol_name);
if (s != nullptr) {
*si_found_in = si_from;
@ -532,7 +550,8 @@ ElfW(Sym)* soinfo_do_lookup(soinfo* si_from, const char* name, soinfo** si_found
// 1. Look for it in global_group
if (s == nullptr) {
global_group.visit([&](soinfo* global_si) {
DEBUG("%s: looking up %s in %s (from global group)", si_from->name, name, global_si->name);
DEBUG("%s: looking up %s in %s (from global group)",
si_from->get_soname(), name, global_si->get_soname());
s = global_si->find_symbol_by_name(symbol_name);
if (s != nullptr) {
*si_found_in = global_si;
@ -551,7 +570,8 @@ ElfW(Sym)* soinfo_do_lookup(soinfo* si_from, const char* name, soinfo** si_found
return true;
}
DEBUG("%s: looking up %s in %s (from local group)", si_from->name, name, local_si->name);
DEBUG("%s: looking up %s in %s (from local group)",
si_from->get_soname(), name, local_si->get_soname());
s = local_si->find_symbol_by_name(symbol_name);
if (s != nullptr) {
*si_found_in = local_si;
@ -565,8 +585,8 @@ ElfW(Sym)* soinfo_do_lookup(soinfo* si_from, const char* name, soinfo** si_found
if (s != nullptr) {
TRACE_TYPE(LOOKUP, "si %s sym %s s->st_value = %p, "
"found in %s, base = %p, load bias = %p",
si_from->name, name, reinterpret_cast<void*>(s->st_value),
(*si_found_in)->name, reinterpret_cast<void*>((*si_found_in)->base),
si_from->get_soname(), name, reinterpret_cast<void*>(s->st_value),
(*si_found_in)->get_soname(), reinterpret_cast<void*>((*si_found_in)->base),
reinterpret_cast<void*>((*si_found_in)->load_bias));
}
@ -922,7 +942,7 @@ static bool format_path(char* buf, size_t buf_size, const char* path, const char
static int open_library_on_default_path(const char* name, off64_t* file_offset) {
for (size_t i = 0; kDefaultLdPaths[i] != nullptr; ++i) {
char buf[512];
if(!format_path(buf, sizeof(buf), kDefaultLdPaths[i], name)) {
if (!format_path(buf, sizeof(buf), kDefaultLdPaths[i], name)) {
continue;
}
@ -1053,7 +1073,7 @@ static soinfo* load_library(LoadTaskList& load_tasks,
si->get_st_ino() == file_stat.st_ino &&
si->get_file_offset() == file_offset) {
TRACE("library \"%s\" is already loaded under different name/path \"%s\" - "
"will return existing soinfo", name, si->name);
"will return existing soinfo", name, si->get_realpath());
return si;
}
}
@ -1064,13 +1084,19 @@ static soinfo* load_library(LoadTaskList& load_tasks,
return nullptr;
}
std::string realpath = name;
if (!realpath_fd(fd, &realpath)) {
PRINT("cannot resolve realpath for the library \"%s\": %s", name, strerror(errno));
realpath = name;
}
// Read the ELF header and load the segments.
ElfReader elf_reader(name, fd, file_offset);
ElfReader elf_reader(realpath.c_str(), fd, file_offset);
if (!elf_reader.Load(extinfo)) {
return nullptr;
}
soinfo* si = soinfo_alloc(name, &file_stat, file_offset, rtld_flags);
soinfo* si = soinfo_alloc(realpath.c_str(), &file_stat, file_offset, rtld_flags);
if (si == nullptr) {
return nullptr;
}
@ -1275,7 +1301,7 @@ static void soinfo_unload(soinfo* root) {
}
if (!root->can_unload()) {
TRACE("not unloading '%s' - the binary is flagged with NODELETE", root->name);
TRACE("not unloading '%s' - the binary is flagged with NODELETE", root->get_soname());
return;
}
@ -1298,7 +1324,7 @@ static void soinfo_unload(soinfo* root) {
if (si->has_min_version(0)) {
soinfo* child = nullptr;
while ((child = si->get_children().pop_front()) != nullptr) {
TRACE("%s@%p needs to unload %s@%p", si->name, si, child->name, child);
TRACE("%s@%p needs to unload %s@%p", si->get_soname(), si, child->get_soname(), child);
if (local_unload_list.contains(child)) {
continue;
} else if (child->is_linked() && child->get_local_group_root() != root) {
@ -1308,17 +1334,20 @@ static void soinfo_unload(soinfo* root) {
}
}
} else {
#ifdef __LP64__
__libc_fatal("soinfo for \"%s\"@%p has no version", si->name, si);
#if !defined(__arm__)
__libc_fatal("soinfo for \"%s\"@%p has no version", si->get_soname(), si);
#else
PRINT("warning: soinfo for \"%s\"@%p has no version", si->name, si);
PRINT("warning: soinfo for \"%s\"@%p has no version", si->get_soname(), si);
for_each_dt_needed(si, [&] (const char* library_name) {
TRACE("deprecated (old format of soinfo): %s needs to unload %s", si->name, library_name);
TRACE("deprecated (old format of soinfo): %s needs to unload %s",
si->get_soname(), library_name);
soinfo* needed = find_library(library_name, RTLD_NOLOAD, nullptr);
if (needed != nullptr) {
// Not found: for example if symlink was deleted between dlopen and dlclose
// Since we cannot really handle errors at this point - print and continue.
PRINT("warning: couldn't find %s needed by %s on unload.", library_name, si->name);
PRINT("warning: couldn't find %s needed by %s on unload.",
library_name, si->get_soname());
return;
} else if (local_unload_list.contains(needed)) {
// already visited
@ -1348,7 +1377,7 @@ static void soinfo_unload(soinfo* root) {
soinfo_unload(si);
}
} else {
TRACE("not unloading '%s' group, decrementing ref_count to %zd", root->name, ref_count);
TRACE("not unloading '%s' group, decrementing ref_count to %zd", root->get_soname(), ref_count);
}
}
@ -1447,7 +1476,7 @@ bool soinfo::relocate(ElfRelIteratorT&& rel_iterator, const soinfo_list_t& globa
const char* sym_name = nullptr;
ElfW(Addr) addend = get_addend(rel, reloc);
DEBUG("Processing '%s' relocation at index %zd", this->name, idx);
DEBUG("Processing '%s' relocation at index %zd", get_soname(), idx);
if (type == R_GENERIC_NONE) {
continue;
}
@ -1462,7 +1491,7 @@ bool soinfo::relocate(ElfRelIteratorT&& rel_iterator, const soinfo_list_t& globa
// We only allow an undefined symbol if this is a weak reference...
s = &symtab_[sym];
if (ELF_ST_BIND(s->st_info) != STB_WEAK) {
DL_ERR("cannot locate symbol \"%s\" referenced by \"%s\"...", sym_name, name);
DL_ERR("cannot locate symbol \"%s\" referenced by \"%s\"...", sym_name, get_soname());
return false;
}
@ -1652,13 +1681,13 @@ bool soinfo::relocate(ElfRelIteratorT&& rel_iterator, const soinfo_list_t& globa
/*
* ET_EXEC is not supported so this should not happen.
*
* http://infocenter.arm.com/help/topic/com.arm.doc.ihi0044d/IHI0044D_aaelf.pdf
* http://infocenter.arm.com/help/topic/com.arm.doc.ihi0056b/IHI0056B_aaelf64.pdf
*
* Section 4.7.1.10 "Dynamic relocations"
* Section 4.6.11 "Dynamic relocations"
* R_AARCH64_COPY may only appear in executable objects where e_type is
* set to ET_EXEC.
*/
DL_ERR("%s R_AARCH64_COPY relocations are not supported", name);
DL_ERR("%s R_AARCH64_COPY relocations are not supported", get_soname());
return false;
case R_AARCH64_TLS_TPREL64:
TRACE_TYPE(RELO, "RELO TLS_TPREL64 *** %16llx <- %16llx - %16llx\n",
@ -1711,11 +1740,11 @@ bool soinfo::relocate(ElfRelIteratorT&& rel_iterator, const soinfo_list_t& globa
*
* http://infocenter.arm.com/help/topic/com.arm.doc.ihi0044d/IHI0044D_aaelf.pdf
*
* Section 4.7.1.10 "Dynamic relocations"
* Section 4.6.1.10 "Dynamic relocations"
* R_ARM_COPY may only appear in executable objects where e_type is
* set to ET_EXEC.
*/
DL_ERR("%s R_ARM_COPY relocations are not supported", name);
DL_ERR("%s R_ARM_COPY relocations are not supported", get_soname());
return false;
#elif defined(__i386__)
case R_386_32:
@ -1747,7 +1776,7 @@ void soinfo::call_array(const char* array_name __unused, linker_function_t* func
return;
}
TRACE("[ Calling %s (size %zd) @ %p for '%s' ]", array_name, count, functions, name);
TRACE("[ Calling %s (size %zd) @ %p for '%s' ]", array_name, count, functions, get_soname());
int begin = reverse ? (count - 1) : 0;
int end = reverse ? -1 : count;
@ -1758,7 +1787,7 @@ void soinfo::call_array(const char* array_name __unused, linker_function_t* func
call_function("function", functions[i]);
}
TRACE("[ Done calling %s for '%s' ]", array_name, name);
TRACE("[ Done calling %s for '%s' ]", array_name, get_soname());
}
void soinfo::call_function(const char* function_name __unused, linker_function_t function) {
@ -1766,9 +1795,9 @@ void soinfo::call_function(const char* function_name __unused, linker_function_t
return;
}
TRACE("[ Calling %s @ %p for '%s' ]", function_name, function, name);
TRACE("[ Calling %s @ %p for '%s' ]", function_name, function, get_soname());
function();
TRACE("[ Done calling %s @ %p for '%s' ]", function_name, function, name);
TRACE("[ Done calling %s @ %p for '%s' ]", function_name, function, get_soname());
}
void soinfo::call_pre_init_constructors() {
@ -1797,14 +1826,14 @@ void soinfo::call_constructors() {
if (!is_main_executable() && preinit_array_ != nullptr) {
// The GNU dynamic linker silently ignores these, but we warn the developer.
PRINT("\"%s\": ignoring %zd-entry DT_PREINIT_ARRAY in shared library!",
name, preinit_array_count_);
get_soname(), preinit_array_count_);
}
get_children().for_each([] (soinfo* si) {
si->call_constructors();
});
TRACE("\"%s\": calling constructors", name);
TRACE("\"%s\": calling constructors", get_soname());
// DT_INIT should be called before DT_INIT_ARRAY if both are present.
call_function("DT_INIT", init_func_);
@ -1815,7 +1844,7 @@ void soinfo::call_destructors() {
if (!constructors_called) {
return;
}
TRACE("\"%s\": calling destructors", name);
TRACE("\"%s\": calling destructors", get_soname());
// DT_FINI_ARRAY must be parsed in reverse order.
call_array("DT_FINI_ARRAY", fini_array_, fini_array_count_, true);
@ -1912,12 +1941,28 @@ void soinfo::set_dt_flags_1(uint32_t dt_flags_1) {
}
}
const char* soinfo::get_soname() {
const char* soinfo::get_realpath() const {
#if defined(__arm__)
if (has_min_version(2)) {
return realpath_.c_str();
} else {
return old_name_;
}
#else
return realpath_.c_str();
#endif
}
const char* soinfo::get_soname() const {
#if defined(__arm__)
if (has_min_version(2)) {
return soname_;
} else {
return name;
return old_name_;
}
#else
return soname_;
#endif
}
// This is a return on get_children()/get_parents() if
@ -1950,7 +1995,8 @@ ElfW(Addr) soinfo::resolve_symbol_address(ElfW(Sym)* s) {
const char* soinfo::get_string(ElfW(Word) index) const {
if (has_min_version(1) && (index >= strtab_size_)) {
__libc_fatal("%s: strtab out of bounds error; STRSZ=%zd, name=%d", name, strtab_size_, index);
__libc_fatal("%s: strtab out of bounds error; STRSZ=%zd, name=%d",
get_soname(), strtab_size_, index);
}
return strtab_ + index;
@ -2065,13 +2111,13 @@ bool soinfo::prelink_image() {
/* We can't log anything until the linker is relocated */
bool relocating_linker = (flags_ & FLAG_LINKER) != 0;
if (!relocating_linker) {
INFO("[ linking %s ]", name);
INFO("[ linking %s ]", get_soname());
DEBUG("si->base = %p si->flags = 0x%08x", reinterpret_cast<void*>(base), flags_);
}
if (dynamic == nullptr) {
if (!relocating_linker) {
DL_ERR("missing PT_DYNAMIC in \"%s\"", name);
DL_ERR("missing PT_DYNAMIC in \"%s\"", get_soname());
}
return false;
} else {
@ -2120,7 +2166,7 @@ bool soinfo::prelink_image() {
if (!powerof2(gnu_maskwords_)) {
DL_ERR("invalid maskwords for gnu_hash = 0x%x, in \"%s\" expecting power to two",
gnu_maskwords_, name);
gnu_maskwords_, get_realpath());
return false;
}
--gnu_maskwords_;
@ -2142,7 +2188,8 @@ bool soinfo::prelink_image() {
case DT_SYMENT:
if (d->d_un.d_val != sizeof(ElfW(Sym))) {
DL_ERR("invalid DT_SYMENT: %zd in \"%s\"", static_cast<size_t>(d->d_un.d_val), name);
DL_ERR("invalid DT_SYMENT: %zd in \"%s\"",
static_cast<size_t>(d->d_un.d_val), get_realpath());
return false;
}
break;
@ -2150,12 +2197,12 @@ bool soinfo::prelink_image() {
case DT_PLTREL:
#if defined(USE_RELA)
if (d->d_un.d_val != DT_RELA) {
DL_ERR("unsupported DT_PLTREL in \"%s\"; expected DT_RELA", name);
DL_ERR("unsupported DT_PLTREL in \"%s\"; expected DT_RELA", get_realpath());
return false;
}
#else
if (d->d_un.d_val != DT_REL) {
DL_ERR("unsupported DT_PLTREL in \"%s\"; expected DT_REL", name);
DL_ERR("unsupported DT_PLTREL in \"%s\"; expected DT_REL", get_realpath());
return false;
}
#endif
@ -2216,11 +2263,11 @@ bool soinfo::prelink_image() {
break;
case DT_ANDROID_REL:
DL_ERR("unsupported DT_ANDROID_REL in \"%s\"", name);
DL_ERR("unsupported DT_ANDROID_REL in \"%s\"", get_realpath());
return false;
case DT_ANDROID_RELSZ:
DL_ERR("unsupported DT_ANDROID_RELSZ in \"%s\"", name);
DL_ERR("unsupported DT_ANDROID_RELSZ in \"%s\"", get_realpath());
return false;
case DT_RELAENT:
@ -2235,11 +2282,11 @@ bool soinfo::prelink_image() {
break;
case DT_REL:
DL_ERR("unsupported DT_REL in \"%s\"", name);
DL_ERR("unsupported DT_REL in \"%s\"", get_realpath());
return false;
case DT_RELSZ:
DL_ERR("unsupported DT_RELSZ in \"%s\"", name);
DL_ERR("unsupported DT_RELSZ in \"%s\"", get_realpath());
return false;
#else
@ -2267,11 +2314,11 @@ bool soinfo::prelink_image() {
break;
case DT_ANDROID_RELA:
DL_ERR("unsupported DT_ANDROID_RELA in \"%s\"", name);
DL_ERR("unsupported DT_ANDROID_RELA in \"%s\"", get_realpath());
return false;
case DT_ANDROID_RELASZ:
DL_ERR("unsupported DT_ANDROID_RELASZ in \"%s\"", name);
DL_ERR("unsupported DT_ANDROID_RELASZ in \"%s\"", get_realpath());
return false;
// "Indicates that all RELATIVE relocations have been concatenated together,
@ -2283,27 +2330,27 @@ bool soinfo::prelink_image() {
break;
case DT_RELA:
DL_ERR("unsupported DT_RELA in \"%s\"", name);
DL_ERR("unsupported DT_RELA in \"%s\"", get_realpath());
return false;
case DT_RELASZ:
DL_ERR("unsupported DT_RELASZ in \"%s\"", name);
DL_ERR("unsupported DT_RELASZ in \"%s\"", get_realpath());
return false;
#endif
case DT_INIT:
init_func_ = reinterpret_cast<linker_function_t>(load_bias + d->d_un.d_ptr);
DEBUG("%s constructors (DT_INIT) found at %p", name, init_func_);
DEBUG("%s constructors (DT_INIT) found at %p", get_realpath(), init_func_);
break;
case DT_FINI:
fini_func_ = reinterpret_cast<linker_function_t>(load_bias + d->d_un.d_ptr);
DEBUG("%s destructors (DT_FINI) found at %p", name, fini_func_);
DEBUG("%s destructors (DT_FINI) found at %p", get_realpath(), fini_func_);
break;
case DT_INIT_ARRAY:
init_array_ = reinterpret_cast<linker_function_t*>(load_bias + d->d_un.d_ptr);
DEBUG("%s constructors (DT_INIT_ARRAY) found at %p", name, init_array_);
DEBUG("%s constructors (DT_INIT_ARRAY) found at %p", get_realpath(), init_array_);
break;
case DT_INIT_ARRAYSZ:
@ -2312,7 +2359,7 @@ bool soinfo::prelink_image() {
case DT_FINI_ARRAY:
fini_array_ = reinterpret_cast<linker_function_t*>(load_bias + d->d_un.d_ptr);
DEBUG("%s destructors (DT_FINI_ARRAY) found at %p", name, fini_array_);
DEBUG("%s destructors (DT_FINI_ARRAY) found at %p", get_realpath(), fini_array_);
break;
case DT_FINI_ARRAYSZ:
@ -2321,7 +2368,7 @@ bool soinfo::prelink_image() {
case DT_PREINIT_ARRAY:
preinit_array_ = reinterpret_cast<linker_function_t*>(load_bias + d->d_un.d_ptr);
DEBUG("%s constructors (DT_PREINIT_ARRAY) found at %p", name, preinit_array_);
DEBUG("%s constructors (DT_PREINIT_ARRAY) found at %p", get_realpath(), preinit_array_);
break;
case DT_PREINIT_ARRAYSZ:
@ -2330,7 +2377,7 @@ bool soinfo::prelink_image() {
case DT_TEXTREL:
#if defined(__LP64__)
DL_ERR("text relocations (DT_TEXTREL) found in 64-bit ELF file \"%s\"", name);
DL_ERR("text relocations (DT_TEXTREL) found in 64-bit ELF file \"%s\"", get_realpath());
return false;
#else
has_text_relocations = true;
@ -2348,7 +2395,7 @@ bool soinfo::prelink_image() {
case DT_FLAGS:
if (d->d_un.d_val & DF_TEXTREL) {
#if defined(__LP64__)
DL_ERR("text relocations (DF_TEXTREL) found in 64-bit ELF file \"%s\"", name);
DL_ERR("text relocations (DF_TEXTREL) found in 64-bit ELF file \"%s\"", get_realpath());
return false;
#else
has_text_relocations = true;
@ -2415,7 +2462,7 @@ bool soinfo::prelink_image() {
default:
if (!relocating_linker) {
DL_WARN("%s: unused DT entry: type %p arg %p", name,
DL_WARN("%s: unused DT entry: type %p arg %p", get_realpath(),
reinterpret_cast<void*>(d->d_tag), reinterpret_cast<void*>(d->d_un.d_val));
}
break;
@ -2426,6 +2473,9 @@ bool soinfo::prelink_image() {
for (ElfW(Dyn)* d = dynamic; d->d_tag != DT_NULL; ++d) {
if (d->d_tag == DT_SONAME) {
soname_ = get_string(d->d_un.d_val);
#if defined(__arm__)
strlcpy(old_name_, soname_, sizeof(old_name_));
#endif
break;
}
}
@ -2439,15 +2489,16 @@ bool soinfo::prelink_image() {
return false;
}
if (nbucket_ == 0 && gnu_nbucket_ == 0) {
DL_ERR("empty/missing DT_HASH/DT_GNU_HASH in \"%s\" (new hash type from the future?)", name);
DL_ERR("empty/missing DT_HASH/DT_GNU_HASH in \"%s\" "
"(new hash type from the future?)", get_soname());
return false;
}
if (strtab_ == 0) {
DL_ERR("empty/missing DT_STRTAB in \"%s\"", name);
DL_ERR("empty/missing DT_STRTAB in \"%s\"", get_soname());
return false;
}
if (symtab_ == 0) {
DL_ERR("empty/missing DT_SYMTAB in \"%s\"", name);
DL_ERR("empty/missing DT_SYMTAB in \"%s\"", get_soname());
return false;
}
return true;
@ -2466,10 +2517,10 @@ bool soinfo::link_image(const soinfo_list_t& global_group, const soinfo_list_t&
// Make segments writable to allow text relocations to work properly. We will later call
// phdr_table_protect_segments() after all of them are applied and all constructors are run.
DL_WARN("%s has text relocations. This is wasting memory and prevents "
"security hardening. Please fix.", name);
"security hardening. Please fix.", get_soname());
if (phdr_table_unprotect_segments(phdr, phnum, load_bias) < 0) {
DL_ERR("can't unprotect loadable segments for \"%s\": %s",
name, strerror(errno));
get_soname(), strerror(errno));
return false;
}
}
@ -2482,7 +2533,7 @@ bool soinfo::link_image(const soinfo_list_t& global_group, const soinfo_list_t&
android_relocs_[1] == 'P' &&
(android_relocs_[2] == 'U' || android_relocs_[2] == 'S') &&
android_relocs_[3] == '2') {
DEBUG("[ android relocating %s ]", name);
DEBUG("[ android relocating %s ]", get_soname());
bool relocated = false;
const uint8_t* packed_relocs = android_relocs_ + 4;
@ -2511,26 +2562,26 @@ bool soinfo::link_image(const soinfo_list_t& global_group, const soinfo_list_t&
#if defined(USE_RELA)
if (rela_ != nullptr) {
DEBUG("[ relocating %s ]", name);
DEBUG("[ relocating %s ]", get_soname());
if (!relocate(plain_reloc_iterator(rela_, rela_count_), global_group, local_group)) {
return false;
}
}
if (plt_rela_ != nullptr) {
DEBUG("[ relocating %s plt ]", name);
DEBUG("[ relocating %s plt ]", get_soname());
if (!relocate(plain_reloc_iterator(plt_rela_, plt_rela_count_), global_group, local_group)) {
return false;
}
}
#else
if (rel_ != nullptr) {
DEBUG("[ relocating %s ]", name);
DEBUG("[ relocating %s ]", get_soname());
if (!relocate(plain_reloc_iterator(rel_, rel_count_), global_group, local_group)) {
return false;
}
}
if (plt_rel_ != nullptr) {
DEBUG("[ relocating %s plt ]", name);
DEBUG("[ relocating %s plt ]", get_soname());
if (!relocate(plain_reloc_iterator(plt_rel_, plt_rel_count_), global_group, local_group)) {
return false;
}
@ -2543,14 +2594,14 @@ bool soinfo::link_image(const soinfo_list_t& global_group, const soinfo_list_t&
}
#endif
DEBUG("[ finished linking %s ]", name);
DEBUG("[ finished linking %s ]", get_soname());
#if !defined(__LP64__)
if (has_text_relocations) {
// All relocations are done, we can protect our segments back to read-only.
if (phdr_table_protect_segments(phdr, phnum, load_bias) < 0) {
DL_ERR("can't protect segments for \"%s\": %s",
name, strerror(errno));
get_soname(), strerror(errno));
return false;
}
}
@ -2559,7 +2610,7 @@ bool soinfo::link_image(const soinfo_list_t& global_group, const soinfo_list_t&
/* We can also turn on GNU RELRO protection */
if (phdr_table_protect_gnu_relro(phdr, phnum, load_bias) < 0) {
DL_ERR("can't enable GNU RELRO protection for \"%s\": %s",
name, strerror(errno));
get_soname(), strerror(errno));
return false;
}
@ -2568,14 +2619,14 @@ bool soinfo::link_image(const soinfo_list_t& global_group, const soinfo_list_t&
if (phdr_table_serialize_gnu_relro(phdr, phnum, load_bias,
extinfo->relro_fd) < 0) {
DL_ERR("failed serializing GNU RELRO section for \"%s\": %s",
name, strerror(errno));
get_soname(), strerror(errno));
return false;
}
} else if (extinfo && (extinfo->flags & ANDROID_DLEXT_USE_RELRO)) {
if (phdr_table_map_gnu_relro(phdr, phnum, load_bias,
extinfo->relro_fd) < 0) {
DL_ERR("failed mapping GNU RELRO section for \"%s\": %s",
name, strerror(errno));
get_soname(), strerror(errno));
return false;
}
}
@ -2617,7 +2668,12 @@ static void add_vdso(KernelArgumentBlock& args __unused) {
#else
#define LINKER_PATH "/system/bin/linker"
#endif
static soinfo linker_soinfo_for_gdb(LINKER_PATH, nullptr, 0, 0);
// This is done to avoid calling c-tor prematurely
// because soinfo c-tor needs memory allocator
// which might be initialized after global variables.
static uint8_t linker_soinfo_for_gdb_buf[sizeof(soinfo)] __attribute__((aligned(8)));
static soinfo* linker_soinfo_for_gdb = nullptr;
/* gdb expects the linker to be in the debug shared object list.
* Without this, gdb has trouble locating the linker's ".text"
@ -2627,7 +2683,9 @@ static soinfo linker_soinfo_for_gdb(LINKER_PATH, nullptr, 0, 0);
* be on the soinfo list.
*/
static void init_linker_info_for_gdb(ElfW(Addr) linker_base) {
linker_soinfo_for_gdb.base = linker_base;
linker_soinfo_for_gdb = new (linker_soinfo_for_gdb_buf) soinfo(LINKER_PATH, nullptr, 0, 0);
linker_soinfo_for_gdb->base = linker_base;
/*
* Set the dynamic field in the link map otherwise gdb will complain with
@ -2638,8 +2696,8 @@ static void init_linker_info_for_gdb(ElfW(Addr) linker_base) {
ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(linker_base);
ElfW(Phdr)* phdr = reinterpret_cast<ElfW(Phdr)*>(linker_base + elf_hdr->e_phoff);
phdr_table_get_dynamic_section(phdr, elf_hdr->e_phnum, linker_base,
&linker_soinfo_for_gdb.dynamic, nullptr);
insert_soinfo_into_debug_map(&linker_soinfo_for_gdb);
&linker_soinfo_for_gdb->dynamic, nullptr);
insert_soinfo_into_debug_map(linker_soinfo_for_gdb);
}
/*
@ -2837,7 +2895,7 @@ static ElfW(Addr) __linker_init_post_relocation(KernelArgumentBlock& args, ElfW(
fflush(stdout);
#endif
TRACE("[ Ready to execute '%s' @ %p ]", si->name, reinterpret_cast<void*>(si->entry));
TRACE("[ Ready to execute '%s' @ %p ]", si->get_soname(), reinterpret_cast<void*>(si->entry));
return si->entry;
}
@ -2883,7 +2941,7 @@ extern "C" ElfW(Addr) __linker_init(void* raw_args) {
ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(linker_addr);
ElfW(Phdr)* phdr = reinterpret_cast<ElfW(Phdr)*>(linker_addr + elf_hdr->e_phoff);
soinfo linker_so("[dynamic linker]", nullptr, 0, 0);
soinfo linker_so(nullptr, nullptr, 0, 0);
// If the linker is not acting as PT_INTERP entry_point is equal to
// _start. Which means that the linker is running as an executable and

19
linker/linker.h
View File

@ -39,6 +39,8 @@
#include "private/libc_logging.h"
#include "linked_list.h"
#include <string>
#define DL_ERR(fmt, x...) \
do { \
__libc_format_buffer(linker_get_error_buffer(), linker_get_error_buffer_size(), fmt, ##x); \
@ -94,7 +96,9 @@
#define SOINFO_VERSION 2
#if defined(__arm__)
#define SOINFO_NAME_LEN 128
#endif
typedef void (*linker_function_t)();
@ -141,8 +145,11 @@ class SymbolName {
struct soinfo {
public:
typedef LinkedList<soinfo, SoinfoListAllocator> soinfo_list_t;
#if defined(__arm__)
private:
char old_name_[SOINFO_NAME_LEN];
#endif
public:
char name[SOINFO_NAME_LEN];
const ElfW(Phdr)* phdr;
size_t phnum;
ElfW(Addr) entry;
@ -263,8 +270,12 @@ struct soinfo {
bool can_unload() const;
bool is_gnu_hash() const;
bool inline has_min_version(uint32_t min_version) const {
bool inline has_min_version(uint32_t min_version __unused) const {
#if defined(__arm__)
return (flags_ & FLAG_NEW_SOINFO) != 0 && version_ >= min_version;
#else
return true;
#endif
}
bool is_linked() const;
@ -279,7 +290,8 @@ struct soinfo {
soinfo* get_local_group_root() const;
const char* get_soname();
const char* get_soname() const;
const char* get_realpath() const;
private:
ElfW(Sym)* elf_lookup(SymbolName& symbol_name);
@ -327,6 +339,7 @@ struct soinfo {
size_t android_relocs_size_;
const char* soname_;
std::string realpath_;
friend soinfo* get_libdl_info();
};

4
linker/linker_mips.cpp
View File

@ -64,7 +64,7 @@ bool soinfo::relocate(ElfRelIteratorT&& rel_iterator,
ElfW(Addr) sym_addr = 0;
const char* sym_name = nullptr;
DEBUG("Processing '%s' relocation at index %zd", this->name, idx);
DEBUG("Processing '%s' relocation at index %zd", get_soname(), idx);
if (type == R_GENERIC_NONE) {
continue;
}
@ -77,7 +77,7 @@ bool soinfo::relocate(ElfRelIteratorT&& rel_iterator,
s = soinfo_do_lookup(this, sym_name, &lsi, global_group,local_group);
if (s == nullptr) {
// mips does not support relocation with weak-undefined symbols
DL_ERR("cannot locate symbol \"%s\" referenced by \"%s\"...", sym_name, name);
DL_ERR("cannot locate symbol \"%s\" referenced by \"%s\"...", sym_name, get_soname());
return false;
} else {
// We got a definition.

4
tests/dlext_test.cpp
View File

@ -156,9 +156,9 @@ TEST_F(DlExtTest, ExtInfoUseFdWithInvalidOffset) {
ASSERT_SUBSTR("dlopen failed: file offset for the library \"libname_placeholder\" is negative", dlerror());
extinfo.library_fd_offset = PAGE_SIZE;
handle_ = android_dlopen_ext("libname_placeholder", RTLD_NOW, &extinfo);
handle_ = android_dlopen_ext("libname_ignored", RTLD_NOW, &extinfo);
ASSERT_TRUE(handle_ == nullptr);
ASSERT_STREQ("dlopen failed: \"libname_placeholder\" has bad ELF magic", dlerror());
ASSERT_EQ("dlopen failed: \"" + lib_path + "\" has bad ELF magic", dlerror());
close(extinfo.library_fd);
}

55
tests/dlfcn_test.cpp
View File

@ -26,9 +26,12 @@
#include <string>
#include "utils.h"
#define ASSERT_SUBSTR(needle, haystack) \
ASSERT_PRED_FORMAT2(::testing::IsSubstring, needle, haystack)
static bool g_called = false;
extern "C" void DlSymTestFunction() {
g_called = true;
@ -699,7 +702,7 @@ TEST(dlfcn, dlsym_failures) {
ASSERT_EQ(0, dlclose(self));
}
TEST(dlfcn, dladdr) {
TEST(dlfcn, dladdr_executable) {
dlerror(); // Clear any pending errors.
void* self = dlopen(NULL, RTLD_NOW);
ASSERT_TRUE(self != NULL);
@ -720,13 +723,11 @@ TEST(dlfcn, dladdr) {
rc = readlink("/proc/self/exe", executable_path, sizeof(executable_path));
ASSERT_NE(rc, -1);
executable_path[rc] = '\0';
std::string executable_name(basename(executable_path));
// The filename should be that of this executable.
// Note that we don't know whether or not we have the full path, so we want an "ends_with" test.
std::string dli_fname(info.dli_fname);
dli_fname = basename(&dli_fname[0]);
ASSERT_EQ(dli_fname, executable_name);
char dli_realpath[PATH_MAX];
ASSERT_TRUE(realpath(info.dli_fname, dli_realpath) != nullptr);
ASSERT_STREQ(executable_path, dli_realpath);
// The symbol name should be the symbol we looked up.
ASSERT_STREQ(info.dli_sname, "DlSymTestFunction");
@ -734,22 +735,16 @@ TEST(dlfcn, dladdr) {
// The address should be the exact address of the symbol.
ASSERT_EQ(info.dli_saddr, sym);
// Look in /proc/pid/maps to find out what address we were loaded at.
// TODO: factor /proc/pid/maps parsing out into a class and reuse all over bionic.
void* base_address = NULL;
char line[BUFSIZ];
FILE* fp = fopen("/proc/self/maps", "r");
ASSERT_TRUE(fp != NULL);
while (fgets(line, sizeof(line), fp) != NULL) {
uintptr_t start = strtoul(line, 0, 16);
line[strlen(line) - 1] = '\0'; // Chomp the '\n'.
char* path = strchr(line, '/');
if (path != NULL && strcmp(executable_path, path) == 0) {
base_address = reinterpret_cast<void*>(start);
std::vector<map_record> maps;
ASSERT_TRUE(Maps::parse_maps(&maps));
void* base_address = nullptr;
for (const map_record& rec : maps) {
if (executable_path == rec.pathname) {
base_address = reinterpret_cast<void*>(rec.addr_start);
break;
}
}
fclose(fp);
// The base address should be the address we were loaded at.
ASSERT_EQ(info.dli_fbase, base_address);
@ -757,6 +752,28 @@ TEST(dlfcn, dladdr) {
ASSERT_EQ(0, dlclose(self));
}
#if defined(__LP64__)
#define BIONIC_PATH_TO_LIBC "/system/lib64/libc.so"
#else
#define BIONIC_PATH_TO_LIBC "/system/lib/libc.so"
#endif
TEST(dlfcn, dladdr_libc) {
#if defined(__BIONIC__)
Dl_info info;
void* addr = reinterpret_cast<void*>(puts); // well-known libc function
ASSERT_TRUE(dladdr(addr, &info) != 0);
ASSERT_STREQ(BIONIC_PATH_TO_LIBC, info.dli_fname);
// TODO: add check for dfi_fbase
ASSERT_STREQ("puts", info.dli_sname);
ASSERT_EQ(addr, info.dli_saddr);
#else
GTEST_LOG_(INFO) << "This test does nothing for glibc. Glibc returns path from ldconfig "
"for libc.so, which is symlink itself (not a realpath).\n";
#endif
}
TEST(dlfcn, dladdr_invalid) {
Dl_info info;

84
tests/utils.h Normal file
View File

@ -0,0 +1,84 @@
/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __TEST_UTILS_H
#define __TEST_UTILS_H
#include <inttypes.h>
#include <sys/mman.h>
#include "private/ScopeGuard.h"
struct map_record {
uintptr_t addr_start;
uintptr_t addr_end;
int perms;
size_t offset;
dev_t device;
ino_t inode;
std::string pathname;
};
class Maps {
public:
static bool parse_maps(std::vector<map_record>* maps) {
char path[64];
snprintf(path, sizeof(path), "/proc/self/task/%d/maps", getpid());
FILE* fp = fopen(path, "re");
if (fp == nullptr) {
return false;
}
auto fp_guard = make_scope_guard([&]() {
fclose(fp);
});
char line[BUFSIZ];
while (fgets(line, sizeof(line), fp) != nullptr) {
map_record record;
dev_t dev_major, dev_minor;
char pathstr[BUFSIZ];
char prot[5]; // sizeof("rwxp")
if (sscanf(line, "%" SCNxPTR "-%" SCNxPTR " %4s %" SCNxPTR " %x:%x %lu %s",
&record.addr_start, &record.addr_end, prot, &record.offset,
&dev_major, &dev_minor, &record.inode, pathstr) == 8) {
record.perms = 0;
if (prot[0] == 'r') {
record.perms |= PROT_READ;
}
if (prot[1] == 'w') {
record.perms |= PROT_WRITE;
}
if (prot[2] == 'x') {
record.perms |= PROT_EXEC;
}
// TODO: parse shared/private?
record.device = makedev(dev_major, dev_minor);
record.pathname = pathstr;
maps->push_back(record);
}
}
return true;
}
};
#endif