Extract soinfo and globals to separate files.
Move soinfo and globals out of linker.cpp to
separate files.
Breaking up huge linker.cpp into smaller peaces
in order to make it easier to extract part of the
code that belongs to libdl.so and remove parts of
the code that do not belong to linker
(refactoring part 2 of many)
Change-Id: I868417f4b8d2b84d0e8265e354bc7977161497e2
diff --git a/linker/linker.cpp b/linker/linker.cpp
index b57ba27..ca8ffbc 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -53,6 +53,7 @@
#include "linker.h"
#include "linker_block_allocator.h"
#include "linker_gdb_support.h"
+#include "linker_globals.h"
#include "linker_debug.h"
#include "linker_dlwarning.h"
#include "linker_namespaces.h"
@@ -76,9 +77,6 @@
#undef ELF_ST_TYPE
#define ELF_ST_TYPE(x) (static_cast<uint32_t>(x) & 0xf)
-android_namespace_t g_default_namespace;
-
-static std::unordered_map<uintptr_t, soinfo*> g_soinfo_handles_map;
static android_namespace_t* g_anonymous_namespace = &g_default_namespace;
static ElfW(Addr) get_elf_exec_load_bias(const ElfW(Ehdr)* elf);
@@ -134,8 +132,6 @@
static const char* const kSystemLibDir = "/system/lib";
#endif
-static std::string dirname(const char *path);
-
// TODO(dimitry): The grey-list is a workaround for http://b/26394120 ---
// gradually remove libraries from this list until it is gone.
static bool is_greylisted(const char* name, const soinfo* needed_by) {
@@ -186,9 +182,6 @@
}
// END OF WORKAROUND
-static const ElfW(Versym) kVersymNotNeeded = 0;
-static const ElfW(Versym) kVersymGlobal = 1;
-
static const char* const* g_default_ld_paths;
static std::vector<std::string> g_ld_preload_names;
@@ -200,19 +193,6 @@
int g_ld_debug_verbosity;
abort_msg_t* g_abort_message = nullptr; // For debuggerd.
-// These values are used to call constructors for .init_array && .preinit_array
-int g_argc = 0;
-char** g_argv = nullptr;
-char** g_envp = nullptr;
-
-static std::string dirname(const char *path) {
- const char* last_slash = strrchr(path, '/');
- if (last_slash == path) return "/";
- else if (last_slash == nullptr) return ".";
- else
- return std::string(path, last_slash - path);
-}
-
#if STATS
struct linker_stats_t {
int count[kRelocMax];
@@ -232,16 +212,6 @@
uint32_t bitmask[4096];
#endif
-static char __linker_dl_err_buf[768];
-
-char* linker_get_error_buffer() {
- return &__linker_dl_err_buf[0];
-}
-
-size_t linker_get_error_buffer_size() {
- return sizeof(__linker_dl_err_buf);
-}
-
static void notify_gdb_of_load(soinfo* info) {
if (info->is_linker() || info->is_main_executable()) {
// gdb already knows about the linker and the main executable.
@@ -348,60 +318,6 @@
g_soinfo_allocator.free(si);
}
-// For every path element this function checks of it exists, and is a directory,
-// and normalizes it:
-// 1. For regular path it converts it to realpath()
-// 2. For path in a zip file it uses realpath on the zipfile
-// normalizes entry name by calling normalize_path function.
-static void resolve_paths(std::vector<std::string>& paths,
- std::vector<std::string>* resolved_paths) {
- resolved_paths->clear();
- for (const auto& path : paths) {
- char resolved_path[PATH_MAX];
- const char* original_path = path.c_str();
- if (realpath(original_path, resolved_path) != nullptr) {
- struct stat s;
- if (stat(resolved_path, &s) == 0) {
- if (S_ISDIR(s.st_mode)) {
- resolved_paths->push_back(resolved_path);
- } else {
- DL_WARN("Warning: \"%s\" is not a directory (excluding from path)", resolved_path);
- continue;
- }
- } else {
- DL_WARN("Warning: cannot stat file \"%s\": %s", resolved_path, strerror(errno));
- continue;
- }
- } else {
- std::string zip_path;
- std::string entry_path;
-
- std::string normalized_path;
-
- if (!normalize_path(original_path, &normalized_path)) {
- DL_WARN("Warning: unable to normalize \"%s\"", original_path);
- continue;
- }
-
- if (parse_zip_path(normalized_path.c_str(), &zip_path, &entry_path)) {
- if (realpath(zip_path.c_str(), resolved_path) == nullptr) {
- DL_WARN("Warning: unable to resolve \"%s\": %s", zip_path.c_str(), strerror(errno));
- continue;
- }
-
- resolved_paths->push_back(std::string(resolved_path) + kZipFileSeparator + entry_path);
- }
- }
- }
-}
-
-static void split_path(const char* path, const char* delimiters,
- std::vector<std::string>* paths) {
- if (path != nullptr && path[0] != 0) {
- *paths = android::base::Split(path, delimiters);
- }
-}
-
static void parse_path(const char* path, const char* delimiters,
std::vector<std::string>* resolved_paths) {
std::vector<std::string> paths;
@@ -415,45 +331,6 @@
g_default_namespace.set_ld_library_paths(std::move(ld_libary_paths));
}
-void soinfo::set_dt_runpath(const char* path) {
- if (!has_min_version(3)) {
- return;
- }
-
- std::vector<std::string> runpaths;
-
- split_path(path, ":", &runpaths);
-
- std::string origin = dirname(get_realpath());
- // FIXME: add $LIB and $PLATFORM.
- std::pair<std::string, std::string> substs[] = {{"ORIGIN", origin}};
- for (auto&& s : runpaths) {
- size_t pos = 0;
- while (pos < s.size()) {
- pos = s.find("$", pos);
- if (pos == std::string::npos) break;
- for (const auto& subst : substs) {
- const std::string& token = subst.first;
- const std::string& replacement = subst.second;
- if (s.substr(pos + 1, token.size()) == token) {
- s.replace(pos, token.size() + 1, replacement);
- // -1 to compensate for the ++pos below.
- pos += replacement.size() - 1;
- break;
- } else if (s.substr(pos + 1, token.size() + 2) == "{" + token + "}") {
- s.replace(pos, token.size() + 3, replacement);
- pos += replacement.size() - 1;
- break;
- }
- }
- // Skip $ in case it did not match any of the known substitutions.
- ++pos;
- }
- }
-
- resolve_paths(runpaths, &dt_runpath_);
-}
-
static void parse_LD_PRELOAD(const char* path) {
g_ld_preload_names.clear();
if (path != nullptr) {
@@ -520,332 +397,6 @@
return rv;
}
-const ElfW(Versym)* soinfo::get_versym(size_t n) const {
- if (has_min_version(2) && versym_ != nullptr) {
- return versym_ + n;
- }
-
- return nullptr;
-}
-
-ElfW(Addr) soinfo::get_verneed_ptr() const {
- if (has_min_version(2)) {
- return verneed_ptr_;
- }
-
- return 0;
-}
-
-size_t soinfo::get_verneed_cnt() const {
- if (has_min_version(2)) {
- return verneed_cnt_;
- }
-
- return 0;
-}
-
-ElfW(Addr) soinfo::get_verdef_ptr() const {
- if (has_min_version(2)) {
- return verdef_ptr_;
- }
-
- return 0;
-}
-
-size_t soinfo::get_verdef_cnt() const {
- if (has_min_version(2)) {
- return verdef_cnt_;
- }
-
- return 0;
-}
-
-template<typename F>
-static bool for_each_verdef(const soinfo* si, F functor) {
- if (!si->has_min_version(2)) {
- return true;
- }
-
- uintptr_t verdef_ptr = si->get_verdef_ptr();
- if (verdef_ptr == 0) {
- return true;
- }
-
- size_t offset = 0;
-
- size_t verdef_cnt = si->get_verdef_cnt();
- for (size_t i = 0; i<verdef_cnt; ++i) {
- const ElfW(Verdef)* verdef = reinterpret_cast<ElfW(Verdef)*>(verdef_ptr + offset);
- size_t verdaux_offset = offset + verdef->vd_aux;
- offset += verdef->vd_next;
-
- if (verdef->vd_version != 1) {
- DL_ERR("unsupported verdef[%zd] vd_version: %d (expected 1) library: %s",
- i, verdef->vd_version, si->get_realpath());
- return false;
- }
-
- if ((verdef->vd_flags & VER_FLG_BASE) != 0) {
- // "this is the version of the file itself. It must not be used for
- // matching a symbol. It can be used to match references."
- //
- // http://www.akkadia.org/drepper/symbol-versioning
- continue;
- }
-
- if (verdef->vd_cnt == 0) {
- DL_ERR("invalid verdef[%zd] vd_cnt == 0 (version without a name)", i);
- return false;
- }
-
- const ElfW(Verdaux)* verdaux = reinterpret_cast<ElfW(Verdaux)*>(verdef_ptr + verdaux_offset);
-
- if (functor(i, verdef, verdaux) == true) {
- break;
- }
- }
-
- return true;
-}
-
-bool soinfo::find_verdef_version_index(const version_info* vi, ElfW(Versym)* versym) const {
- if (vi == nullptr) {
- *versym = kVersymNotNeeded;
- return true;
- }
-
- *versym = kVersymGlobal;
-
- return for_each_verdef(this,
- [&](size_t, const ElfW(Verdef)* verdef, const ElfW(Verdaux)* verdaux) {
- if (verdef->vd_hash == vi->elf_hash &&
- strcmp(vi->name, get_string(verdaux->vda_name)) == 0) {
- *versym = verdef->vd_ndx;
- return true;
- }
-
- return false;
- }
- );
-}
-
-bool soinfo::find_symbol_by_name(SymbolName& symbol_name,
- const version_info* vi,
- const ElfW(Sym)** symbol) const {
- uint32_t symbol_index;
- bool success =
- is_gnu_hash() ?
- gnu_lookup(symbol_name, vi, &symbol_index) :
- elf_lookup(symbol_name, vi, &symbol_index);
-
- if (success) {
- *symbol = symbol_index == 0 ? nullptr : symtab_ + symbol_index;
- }
-
- return success;
-}
-
-static bool is_symbol_global_and_defined(const soinfo* si, const ElfW(Sym)* s) {
- if (ELF_ST_BIND(s->st_info) == STB_GLOBAL ||
- ELF_ST_BIND(s->st_info) == STB_WEAK) {
- 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->get_realpath());
- }
-
- return false;
-}
-
-static const ElfW(Versym) kVersymHiddenBit = 0x8000;
-
-static inline bool is_versym_hidden(const ElfW(Versym)* versym) {
- // the symbol is hidden if bit 15 of versym is set.
- return versym != nullptr && (*versym & kVersymHiddenBit) != 0;
-}
-
-static inline bool check_symbol_version(const ElfW(Versym) verneed,
- const ElfW(Versym)* verdef) {
- return verneed == kVersymNotNeeded ||
- verdef == nullptr ||
- verneed == (*verdef & ~kVersymHiddenBit);
-}
-
-bool soinfo::gnu_lookup(SymbolName& symbol_name,
- const version_info* vi,
- uint32_t* symbol_index) const {
- uint32_t hash = symbol_name.gnu_hash();
- uint32_t h2 = hash >> gnu_shift2_;
-
- uint32_t bloom_mask_bits = sizeof(ElfW(Addr))*8;
- uint32_t word_num = (hash / bloom_mask_bits) & gnu_maskwords_;
- ElfW(Addr) bloom_word = gnu_bloom_filter_[word_num];
-
- *symbol_index = 0;
-
- TRACE_TYPE(LOOKUP, "SEARCH %s in %s@%p (gnu)",
- symbol_name.get_name(), get_realpath(), 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(), get_realpath(), reinterpret_cast<void*>(base));
-
- return true;
- }
-
- // bloom test says "probably yes"...
- uint32_t n = gnu_bucket_[hash % gnu_nbucket_];
-
- if (n == 0) {
- TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p",
- symbol_name.get_name(), get_realpath(), reinterpret_cast<void*>(base));
-
- return true;
- }
-
- // lookup versym for the version definition in this library
- // note the difference between "version is not requested" (vi == nullptr)
- // and "version not found". In the first case verneed is kVersymNotNeeded
- // which implies that the default version can be accepted; the second case results in
- // verneed = 1 (kVersymGlobal) and implies that we should ignore versioned symbols
- // for this library and consider only *global* ones.
- ElfW(Versym) verneed = 0;
- if (!find_verdef_version_index(vi, &verneed)) {
- return false;
- }
-
- do {
- ElfW(Sym)* s = symtab_ + n;
- const ElfW(Versym)* verdef = get_versym(n);
- // skip hidden versions when verneed == kVersymNotNeeded (0)
- if (verneed == kVersymNotNeeded && is_versym_hidden(verdef)) {
- continue;
- }
- if (((gnu_chain_[n] ^ hash) >> 1) == 0 &&
- check_symbol_version(verneed, verdef) &&
- 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(), get_realpath(), reinterpret_cast<void*>(s->st_value),
- static_cast<size_t>(s->st_size));
- *symbol_index = n;
- return true;
- }
- } while ((gnu_chain_[n++] & 1) == 0);
-
- TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p",
- symbol_name.get_name(), get_realpath(), reinterpret_cast<void*>(base));
-
- return true;
-}
-
-bool soinfo::elf_lookup(SymbolName& symbol_name,
- const version_info* vi,
- uint32_t* symbol_index) const {
- uint32_t hash = symbol_name.elf_hash();
-
- TRACE_TYPE(LOOKUP, "SEARCH %s in %s@%p h=%x(elf) %zd",
- symbol_name.get_name(), get_realpath(),
- reinterpret_cast<void*>(base), hash, hash % nbucket_);
-
- ElfW(Versym) verneed = 0;
- if (!find_verdef_version_index(vi, &verneed)) {
- return false;
- }
-
- for (uint32_t n = bucket_[hash % nbucket_]; n != 0; n = chain_[n]) {
- ElfW(Sym)* s = symtab_ + n;
- const ElfW(Versym)* verdef = get_versym(n);
-
- // skip hidden versions when verneed == 0
- if (verneed == kVersymNotNeeded && is_versym_hidden(verdef)) {
- continue;
- }
-
- if (check_symbol_version(verneed, verdef) &&
- 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(), get_realpath(),
- reinterpret_cast<void*>(s->st_value),
- static_cast<size_t>(s->st_size));
- *symbol_index = n;
- return true;
- }
- }
-
- TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p %x %zd",
- symbol_name.get_name(), get_realpath(),
- reinterpret_cast<void*>(base), hash, hash % nbucket_);
-
- *symbol_index = 0;
- return true;
-}
-
-soinfo::soinfo(android_namespace_t* ns, const char* realpath,
- const struct stat* file_stat, off64_t file_offset,
- int rtld_flags) {
- memset(this, 0, sizeof(*this));
-
- if (realpath != nullptr) {
- realpath_ = realpath;
- }
-
- flags_ = FLAG_NEW_SOINFO;
- version_ = SOINFO_VERSION;
-
- if (file_stat != nullptr) {
- this->st_dev_ = file_stat->st_dev;
- this->st_ino_ = file_stat->st_ino;
- this->file_offset_ = file_offset;
- }
-
- this->rtld_flags_ = rtld_flags;
- this->primary_namespace_ = ns;
-}
-
-soinfo::~soinfo() {
- g_soinfo_handles_map.erase(handle_);
-}
-
-static uint32_t calculate_elf_hash(const char* name) {
- const uint8_t* name_bytes = reinterpret_cast<const uint8_t*>(name);
- uint32_t h = 0, g;
-
- while (*name_bytes) {
- h = (h << 4) + *name_bytes++;
- g = h & 0xf0000000;
- h ^= g;
- h ^= g >> 24;
- }
-
- return h;
-}
-
-uint32_t SymbolName::elf_hash() {
- if (!has_elf_hash_) {
- elf_hash_ = calculate_elf_hash(name_);
- has_elf_hash_ = true;
- }
-
- return elf_hash_;
-}
-
-uint32_t SymbolName::gnu_hash() {
- if (!has_gnu_hash_) {
- uint32_t h = 5381;
- 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
- }
-
- gnu_hash_ = h;
- has_gnu_hash_ = true;
- }
-
- return gnu_hash_;
-}
bool soinfo_do_lookup(soinfo* si_from, const char* name, const version_info* vi,
soinfo** si_found_in, const soinfo_list_t& global_group,
@@ -1304,52 +855,6 @@
return nullptr;
}
-ElfW(Sym)* soinfo::find_symbol_by_address(const void* addr) {
- return is_gnu_hash() ? gnu_addr_lookup(addr) : elf_addr_lookup(addr);
-}
-
-static bool symbol_matches_soaddr(const ElfW(Sym)* sym, ElfW(Addr) soaddr) {
- return sym->st_shndx != SHN_UNDEF &&
- soaddr >= sym->st_value &&
- soaddr < sym->st_value + sym->st_size;
-}
-
-ElfW(Sym)* soinfo::gnu_addr_lookup(const void* addr) {
- ElfW(Addr) soaddr = reinterpret_cast<ElfW(Addr)>(addr) - load_bias;
-
- for (size_t i = 0; i < gnu_nbucket_; ++i) {
- uint32_t n = gnu_bucket_[i];
-
- if (n == 0) {
- continue;
- }
-
- do {
- ElfW(Sym)* sym = symtab_ + n;
- if (symbol_matches_soaddr(sym, soaddr)) {
- return sym;
- }
- } while ((gnu_chain_[n++] & 1) == 0);
- }
-
- return nullptr;
-}
-
-ElfW(Sym)* soinfo::elf_addr_lookup(const void* addr) {
- ElfW(Addr) soaddr = reinterpret_cast<ElfW(Addr)>(addr) - load_bias;
-
- // Search the library's symbol table for any defined symbol which
- // contains this address.
- for (size_t i = 0; i < nchain_; ++i) {
- ElfW(Sym)* sym = symtab_ + i;
- if (symbol_matches_soaddr(sym, soaddr)) {
- return sym;
- }
- }
-
- return nullptr;
-}
-
class ZipArchiveCache {
public:
ZipArchiveCache() {}
@@ -2549,7 +2054,7 @@
return ns;
}
-static ElfW(Addr) call_ifunc_resolver(ElfW(Addr) resolver_addr) {
+ElfW(Addr) call_ifunc_resolver(ElfW(Addr) resolver_addr) {
typedef ElfW(Addr) (*ifunc_resolver_t)(void);
ifunc_resolver_t ifunc_resolver = reinterpret_cast<ifunc_resolver_t>(resolver_addr);
ElfW(Addr) ifunc_addr = ifunc_resolver();
@@ -2628,6 +2133,75 @@
return true;
}
+template <typename F>
+static bool for_each_verdef(const soinfo* si, F functor) {
+ if (!si->has_min_version(2)) {
+ return true;
+ }
+
+ uintptr_t verdef_ptr = si->get_verdef_ptr();
+ if (verdef_ptr == 0) {
+ return true;
+ }
+
+ size_t offset = 0;
+
+ size_t verdef_cnt = si->get_verdef_cnt();
+ for (size_t i = 0; i<verdef_cnt; ++i) {
+ const ElfW(Verdef)* verdef = reinterpret_cast<ElfW(Verdef)*>(verdef_ptr + offset);
+ size_t verdaux_offset = offset + verdef->vd_aux;
+ offset += verdef->vd_next;
+
+ if (verdef->vd_version != 1) {
+ DL_ERR("unsupported verdef[%zd] vd_version: %d (expected 1) library: %s",
+ i, verdef->vd_version, si->get_realpath());
+ return false;
+ }
+
+ if ((verdef->vd_flags & VER_FLG_BASE) != 0) {
+ // "this is the version of the file itself. It must not be used for
+ // matching a symbol. It can be used to match references."
+ //
+ // http://www.akkadia.org/drepper/symbol-versioning
+ continue;
+ }
+
+ if (verdef->vd_cnt == 0) {
+ DL_ERR("invalid verdef[%zd] vd_cnt == 0 (version without a name)", i);
+ return false;
+ }
+
+ const ElfW(Verdaux)* verdaux = reinterpret_cast<ElfW(Verdaux)*>(verdef_ptr + verdaux_offset);
+
+ if (functor(i, verdef, verdaux) == true) {
+ break;
+ }
+ }
+
+ return true;
+}
+
+bool find_verdef_version_index(const soinfo* si, const version_info* vi, ElfW(Versym)* versym) {
+ if (vi == nullptr) {
+ *versym = kVersymNotNeeded;
+ return true;
+ }
+
+ *versym = kVersymGlobal;
+
+ return for_each_verdef(si,
+ [&](size_t, const ElfW(Verdef)* verdef, const ElfW(Verdaux)* verdaux) {
+ if (verdef->vd_hash == vi->elf_hash &&
+ strcmp(vi->name, si->get_string(verdaux->vda_name)) == 0) {
+ *versym = verdef->vd_ndx;
+ return true;
+ }
+
+ return false;
+ }
+ );
+}
+
bool VersionTracker::init_verdef(const soinfo* si_from) {
return for_each_verdef(si_from,
[&](size_t, const ElfW(Verdef)* verdef, const ElfW(Verdaux)* verdaux) {
@@ -2646,6 +2220,25 @@
return init_verneed(si_from) && init_verdef(si_from);
}
+#if !defined(__mips__)
+#if defined(USE_RELA)
+static ElfW(Addr) get_addend(ElfW(Rela)* rela, ElfW(Addr) reloc_addr __unused) {
+ return rela->r_addend;
+}
+#else
+static ElfW(Addr) get_addend(ElfW(Rel)* rel, ElfW(Addr) reloc_addr) {
+ if (ELFW(R_TYPE)(rel->r_info) == R_GENERIC_RELATIVE ||
+ ELFW(R_TYPE)(rel->r_info) == R_GENERIC_IRELATIVE) {
+ return *reinterpret_cast<ElfW(Addr)*>(reloc_addr);
+ }
+ return 0;
+}
+#endif
+
+// TODO (dimitry): Methods below need to be moved out of soinfo
+// and in more isolated file in order minimize dependencies on
+// unnecessary object in the linker binary. Consider making them
+// independent from soinfo (?).
bool soinfo::lookup_version_info(const VersionTracker& version_tracker, ElfW(Word) sym,
const char* sym_name, const version_info** vi) {
const ElfW(Versym)* sym_ver_ptr = get_versym(sym);
@@ -2667,21 +2260,6 @@
return true;
}
-#if !defined(__mips__)
-#if defined(USE_RELA)
-static ElfW(Addr) get_addend(ElfW(Rela)* rela, ElfW(Addr) reloc_addr __unused) {
- return rela->r_addend;
-}
-#else
-static ElfW(Addr) get_addend(ElfW(Rel)* rel, ElfW(Addr) reloc_addr) {
- if (ELFW(R_TYPE)(rel->r_info) == R_GENERIC_RELATIVE ||
- ELFW(R_TYPE)(rel->r_info) == R_GENERIC_IRELATIVE) {
- return *reinterpret_cast<ElfW(Addr)*>(reloc_addr);
- }
- return 0;
-}
-#endif
-
template<typename ElfRelIteratorT>
bool soinfo::relocate(const VersionTracker& version_tracker, ElfRelIteratorT&& rel_iterator,
const soinfo_list_t& global_group, const soinfo_list_t& local_group) {
@@ -3046,409 +2624,9 @@
}
#endif // !defined(__mips__)
-static void call_function(const char* function_name __unused,
- linker_ctor_function_t function,
- const char* realpath __unused) {
- if (function == nullptr || reinterpret_cast<uintptr_t>(function) == static_cast<uintptr_t>(-1)) {
- return;
- }
-
- TRACE("[ Calling c-tor %s @ %p for '%s' ]", function_name, function, realpath);
- function(g_argc, g_argv, g_envp);
- TRACE("[ Done calling c-tor %s @ %p for '%s' ]", function_name, function, realpath);
-}
-
-static void call_function(const char* function_name __unused,
- linker_dtor_function_t function,
- const char* realpath __unused) {
- if (function == nullptr || reinterpret_cast<uintptr_t>(function) == static_cast<uintptr_t>(-1)) {
- return;
- }
-
- TRACE("[ Calling d-tor %s @ %p for '%s' ]", function_name, function, realpath);
- function();
- TRACE("[ Done calling d-tor %s @ %p for '%s' ]", function_name, function, realpath);
-}
-
-template <typename F>
-static void call_array(const char* array_name __unused,
- F* functions,
- size_t count,
- bool reverse,
- const char* realpath) {
- if (functions == nullptr) {
- return;
- }
-
- TRACE("[ Calling %s (size %zd) @ %p for '%s' ]", array_name, count, functions, realpath);
-
- int begin = reverse ? (count - 1) : 0;
- int end = reverse ? -1 : count;
- int step = reverse ? -1 : 1;
-
- for (int i = begin; i != end; i += step) {
- TRACE("[ %s[%d] == %p ]", array_name, i, functions[i]);
- call_function("function", functions[i], realpath);
- }
-
- TRACE("[ Done calling %s for '%s' ]", array_name, realpath);
-}
-
-void soinfo::call_pre_init_constructors() {
- // DT_PREINIT_ARRAY functions are called before any other constructors for executables,
- // but ignored in a shared library.
- call_array("DT_PREINIT_ARRAY", preinit_array_, preinit_array_count_, false, get_realpath());
-}
-
-void soinfo::call_constructors() {
- if (constructors_called) {
- return;
- }
-
- // We set constructors_called before actually calling the constructors, otherwise it doesn't
- // protect against recursive constructor calls. One simple example of constructor recursion
- // is the libc debug malloc, which is implemented in libc_malloc_debug_leak.so:
- // 1. The program depends on libc, so libc's constructor is called here.
- // 2. The libc constructor calls dlopen() to load libc_malloc_debug_leak.so.
- // 3. dlopen() calls the constructors on the newly created
- // soinfo for libc_malloc_debug_leak.so.
- // 4. The debug .so depends on libc, so CallConstructors is
- // called again with the libc soinfo. If it doesn't trigger the early-
- // out above, the libc constructor will be called again (recursively!).
- constructors_called = true;
-
- if (!is_main_executable() && preinit_array_ != nullptr) {
- // The GNU dynamic linker silently ignores these, but we warn the developer.
- PRINT("\"%s\": ignoring DT_PREINIT_ARRAY in shared library!", get_realpath());
- }
-
- get_children().for_each([] (soinfo* si) {
- si->call_constructors();
- });
-
- TRACE("\"%s\": calling constructors", get_realpath());
-
- // DT_INIT should be called before DT_INIT_ARRAY if both are present.
- call_function("DT_INIT", init_func_, get_realpath());
- call_array("DT_INIT_ARRAY", init_array_, init_array_count_, false, get_realpath());
-}
-
-void soinfo::call_destructors() {
- if (!constructors_called) {
- return;
- }
- TRACE("\"%s\": calling destructors", get_realpath());
-
- // DT_FINI_ARRAY must be parsed in reverse order.
- call_array("DT_FINI_ARRAY", fini_array_, fini_array_count_, true, get_realpath());
-
- // DT_FINI should be called after DT_FINI_ARRAY if both are present.
- call_function("DT_FINI", fini_func_, get_realpath());
-}
-
-void soinfo::add_child(soinfo* child) {
- if (has_min_version(0)) {
- child->parents_.push_back(this);
- this->children_.push_back(child);
- }
-}
-
-void soinfo::remove_all_links() {
- if (!has_min_version(0)) {
- return;
- }
-
- // 1. Untie connected soinfos from 'this'.
- children_.for_each([&] (soinfo* child) {
- child->parents_.remove_if([&] (const soinfo* parent) {
- return parent == this;
- });
- });
-
- parents_.for_each([&] (soinfo* parent) {
- parent->children_.remove_if([&] (const soinfo* child) {
- return child == this;
- });
- });
-
- // 2. Remove from the primary namespace
- primary_namespace_->remove_soinfo(this);
- primary_namespace_ = nullptr;
-
- // 3. Remove from secondary namespaces
- secondary_namespaces_.for_each([&](android_namespace_t* ns) {
- ns->remove_soinfo(this);
- });
-
-
- // 4. Once everything untied - clear local lists.
- parents_.clear();
- children_.clear();
- secondary_namespaces_.clear();
-}
-
-dev_t soinfo::get_st_dev() const {
- if (has_min_version(0)) {
- return st_dev_;
- }
-
- return 0;
-};
-
-ino_t soinfo::get_st_ino() const {
- if (has_min_version(0)) {
- return st_ino_;
- }
-
- return 0;
-}
-
-off64_t soinfo::get_file_offset() const {
- if (has_min_version(1)) {
- return file_offset_;
- }
-
- return 0;
-}
-
-uint32_t soinfo::get_rtld_flags() const {
- if (has_min_version(1)) {
- return rtld_flags_;
- }
-
- return 0;
-}
-
-uint32_t soinfo::get_dt_flags_1() const {
- if (has_min_version(1)) {
- return dt_flags_1_;
- }
-
- return 0;
-}
-
-void soinfo::set_dt_flags_1(uint32_t dt_flags_1) {
- if (has_min_version(1)) {
- if ((dt_flags_1 & DF_1_GLOBAL) != 0) {
- rtld_flags_ |= RTLD_GLOBAL;
- }
-
- if ((dt_flags_1 & DF_1_NODELETE) != 0) {
- rtld_flags_ |= RTLD_NODELETE;
- }
-
- dt_flags_1_ = dt_flags_1;
- }
-}
-
-void soinfo::set_nodelete() {
- rtld_flags_ |= RTLD_NODELETE;
-}
-
-const char* soinfo::get_realpath() const {
-#if defined(__work_around_b_24465209__)
- if (has_min_version(2)) {
- return realpath_.c_str();
- } else {
- return old_name_;
- }
-#else
- return realpath_.c_str();
-#endif
-}
-
-void soinfo::set_soname(const char* soname) {
-#if defined(__work_around_b_24465209__)
- if (has_min_version(2)) {
- soname_ = soname;
- }
- strlcpy(old_name_, soname_, sizeof(old_name_));
-#else
- soname_ = soname;
-#endif
-}
-
-const char* soinfo::get_soname() const {
-#if defined(__work_around_b_24465209__)
- if (has_min_version(2)) {
- return soname_;
- } else {
- return old_name_;
- }
-#else
- return soname_;
-#endif
-}
-
-// This is a return on get_children()/get_parents() if
-// 'this->flags' does not have FLAG_NEW_SOINFO set.
+// An empty list of soinfos
static soinfo_list_t g_empty_list;
-soinfo_list_t& soinfo::get_children() {
- if (has_min_version(0)) {
- return children_;
- }
-
- return g_empty_list;
-}
-
-const soinfo_list_t& soinfo::get_children() const {
- if (has_min_version(0)) {
- return children_;
- }
-
- return g_empty_list;
-}
-
-soinfo_list_t& soinfo::get_parents() {
- if (has_min_version(0)) {
- return parents_;
- }
-
- return g_empty_list;
-}
-
-static std::vector<std::string> g_empty_runpath;
-
-const std::vector<std::string>& soinfo::get_dt_runpath() const {
- if (has_min_version(3)) {
- return dt_runpath_;
- }
-
- return g_empty_runpath;
-}
-
-android_namespace_t* soinfo::get_primary_namespace() {
- if (has_min_version(3)) {
- return primary_namespace_;
- }
-
- return &g_default_namespace;
-}
-
-void soinfo::add_secondary_namespace(android_namespace_t* secondary_ns) {
- CHECK(has_min_version(3));
- secondary_namespaces_.push_back(secondary_ns);
-}
-
-ElfW(Addr) soinfo::resolve_symbol_address(const ElfW(Sym)* s) const {
- if (ELF_ST_TYPE(s->st_info) == STT_GNU_IFUNC) {
- return call_ifunc_resolver(s->st_value + load_bias);
- }
-
- return static_cast<ElfW(Addr)>(s->st_value + load_bias);
-}
-
-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",
- get_realpath(), strtab_size_, index);
- }
-
- return strtab_ + index;
-}
-
-bool soinfo::is_gnu_hash() const {
- return (flags_ & FLAG_GNU_HASH) != 0;
-}
-
-bool soinfo::can_unload() const {
- return !is_linked() || ((get_rtld_flags() & (RTLD_NODELETE | RTLD_GLOBAL)) == 0);
-}
-
-bool soinfo::is_linked() const {
- return (flags_ & FLAG_LINKED) != 0;
-}
-
-bool soinfo::is_main_executable() const {
- return (flags_ & FLAG_EXE) != 0;
-}
-
-bool soinfo::is_linker() const {
- return (flags_ & FLAG_LINKER) != 0;
-}
-
-void soinfo::set_linked() {
- flags_ |= FLAG_LINKED;
-}
-
-void soinfo::set_linker_flag() {
- flags_ |= FLAG_LINKER;
-}
-
-void soinfo::set_main_executable() {
- flags_ |= FLAG_EXE;
-}
-
-void soinfo::increment_ref_count() {
- local_group_root_->ref_count_++;
-}
-
-size_t soinfo::decrement_ref_count() {
- return --local_group_root_->ref_count_;
-}
-
-soinfo* soinfo::get_local_group_root() const {
- return local_group_root_;
-}
-
-
-void soinfo::set_mapped_by_caller(bool mapped_by_caller) {
- if (mapped_by_caller) {
- flags_ |= FLAG_MAPPED_BY_CALLER;
- } else {
- flags_ &= ~FLAG_MAPPED_BY_CALLER;
- }
-}
-
-bool soinfo::is_mapped_by_caller() const {
- return (flags_ & FLAG_MAPPED_BY_CALLER) != 0;
-}
-
-// This function returns api-level at the time of
-// dlopen/load. Note that libraries opened by system
-// will always have 'current' api level.
-uint32_t soinfo::get_target_sdk_version() const {
- if (!has_min_version(2)) {
- return __ANDROID_API__;
- }
-
- return local_group_root_->target_sdk_version_;
-}
-
-uintptr_t soinfo::get_handle() const {
- CHECK(has_min_version(3));
- CHECK(handle_ != 0);
- return handle_;
-}
-
-void* soinfo::to_handle() {
- if (get_application_target_sdk_version() <= 23 || !has_min_version(3)) {
- return this;
- }
-
- return reinterpret_cast<void*>(get_handle());
-}
-
-void soinfo::generate_handle() {
- CHECK(has_min_version(3));
- CHECK(handle_ == 0); // Make sure this is the first call
-
- // Make sure the handle is unique and does not collide
- // with special values which are RTLD_DEFAULT and RTLD_NEXT.
- do {
- arc4random_buf(&handle_, sizeof(handle_));
- // the least significant bit for the handle is always 1
- // making it easy to test the type of handle passed to
- // dl* functions.
- handle_ = handle_ | 1;
- } while (handle_ == reinterpret_cast<uintptr_t>(RTLD_DEFAULT) ||
- handle_ == reinterpret_cast<uintptr_t>(RTLD_NEXT) ||
- g_soinfo_handles_map.find(handle_) != g_soinfo_handles_map.end());
-
- g_soinfo_handles_map[handle_] = this;
-}
-
bool soinfo::prelink_image() {
/* Extract dynamic section */
ElfW(Word) dynamic_flags = 0;
@@ -4371,8 +3549,8 @@
return 0;
}
-static void __linker_cannot_link() {
- __libc_fatal("CANNOT LINK EXECUTABLE \"%s\": %s", g_argv[0], linker_get_error_buffer());
+static void __linker_cannot_link(const char* argv0) {
+ __libc_fatal("CANNOT LINK EXECUTABLE \"%s\": %s", argv0, linker_get_error_buffer());
}
/*
@@ -4387,10 +3565,6 @@
extern "C" ElfW(Addr) __linker_init(void* raw_args) {
KernelArgumentBlock args(raw_args);
- g_argc = args.argc;
- g_argv = args.argv;
- g_envp = args.envp;
-
ElfW(Addr) linker_addr = args.getauxval(AT_BASE);
ElfW(Addr) entry_point = args.getauxval(AT_ENTRY);
ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(linker_addr);
@@ -4407,7 +3581,7 @@
if (reinterpret_cast<ElfW(Addr)>(&_start) == entry_point) {
__libc_format_fd(STDOUT_FILENO,
"This is %s, the helper program for shared library executables.\n",
- g_argv[0]);
+ args.argv[0]);
exit(0);
}
@@ -4420,7 +3594,7 @@
linker_so.set_linker_flag();
// Prelink the linker so we can access linker globals.
- if (!linker_so.prelink_image()) __linker_cannot_link();
+ if (!linker_so.prelink_image()) __linker_cannot_link(args.argv[0]);
// This might not be obvious... The reasons why we pass g_empty_list
// in place of local_group here are (1) we do not really need it, because
@@ -4428,7 +3602,7 @@
// itself without having to look into local_group and (2) allocators
// are not yet initialized, and therefore we cannot use linked_list.push_*
// functions at this point.
- if (!linker_so.link_image(g_empty_list, g_empty_list, nullptr)) __linker_cannot_link();
+ if (!linker_so.link_image(g_empty_list, g_empty_list, nullptr)) __linker_cannot_link(args.argv[0]);
#if defined(__i386__)
// On x86, we can't make system calls before this point.
@@ -4444,11 +3618,16 @@
// We didn't protect the linker's RELRO pages in link_image because we
// couldn't make system calls on x86 at that point, but we can now...
- if (!linker_so.protect_relro()) __linker_cannot_link();
+ if (!linker_so.protect_relro()) __linker_cannot_link(args.argv[0]);
// Initialize the linker's static libc's globals
__libc_init_globals(args);
+ // store argc/argv/envp to use them for calling constructors
+ g_argc = args.argc;
+ g_argv = args.argv;
+ g_envp = args.envp;
+
// Initialize the linker's own global variables
linker_so.call_constructors();