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Merge "Fix symbol lookup order during relocation"

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This commit is contained in:
Dmitriy Ivanov 2014-10-31 23:51:18 +00:00 committed by Gerrit Code Review
commit f33ad40023
11 changed files with 384 additions and 70 deletions
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12
linker/linked_list.h
View File

@ -36,6 +36,12 @@ class LinkedList {
clear(); clear();
} }
LinkedList(LinkedList&& that) {
this->head_ = that.head_;
this->tail_ = that.tail_;
that.head_ = that.tail_ = nullptr;
}
void push_front(T* const element) { void push_front(T* const element) {
LinkedListEntry<T>* new_entry = Allocator::alloc(); LinkedListEntry<T>* new_entry = Allocator::alloc();
new_entry->next = head_; new_entry->next = head_;
@ -140,6 +146,12 @@ class LinkedList {
return false; return false;
} }
static LinkedList make_list(T* const element) {
LinkedList<T, Allocator> one_element_list;
one_element_list.push_back(element);
return one_element_list;
}
private: private:
LinkedListEntry<T>* head_; LinkedListEntry<T>* head_;
LinkedListEntry<T>* tail_; LinkedListEntry<T>* tail_;

162
linker/linker.cpp
View File

@ -284,7 +284,7 @@ static void protect_data(int protection) {
g_soinfo_links_allocator.protect_all(protection); g_soinfo_links_allocator.protect_all(protection);
} }
static soinfo* soinfo_alloc(const char* name, struct stat* file_stat, off64_t file_offset, int rtld_flags) { 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) >= SOINFO_NAME_LEN) {
DL_ERR("library name \"%s\" too long", name); DL_ERR("library name \"%s\" too long", name);
return nullptr; return nullptr;
@ -483,7 +483,8 @@ static unsigned elfhash(const char* _name) {
return h; return h;
} }
static ElfW(Sym)* soinfo_do_lookup(soinfo* si, const char* name, soinfo** lsi, const soinfo::soinfo_list_t& local_group) { static ElfW(Sym)* soinfo_do_lookup(soinfo* si_from, const char* name, soinfo** si_found_in,
const soinfo::soinfo_list_t& global_group, const soinfo::soinfo_list_t& local_group) {
unsigned elf_hash = elfhash(name); unsigned elf_hash = elfhash(name);
ElfW(Sym)* s = nullptr; ElfW(Sym)* s = nullptr;
@ -498,49 +499,40 @@ static ElfW(Sym)* soinfo_do_lookup(soinfo* si, const char* name, soinfo** lsi, c
* Note that this is unlikely since static linker avoids generating * Note that this is unlikely since static linker avoids generating
* relocations for -Bsymbolic linked dynamic executables. * relocations for -Bsymbolic linked dynamic executables.
*/ */
if (si->has_DT_SYMBOLIC) { if (si_from->has_DT_SYMBOLIC) {
DEBUG("%s: looking up %s in local scope (DT_SYMBOLIC)", si->name, name); DEBUG("%s: looking up %s in local scope (DT_SYMBOLIC)", si_from->name, name);
s = soinfo_elf_lookup(si, elf_hash, name); s = soinfo_elf_lookup(si_from, elf_hash, name);
if (s != nullptr) { if (s != nullptr) {
*lsi = si; *si_found_in = si_from;
} }
} }
if (s == nullptr && somain != nullptr) { // 1. Look for it in global_group
// 1. Look for it in the main executable unless we already did. if (s == nullptr) {
if (si != somain || !si->has_DT_SYMBOLIC) { global_group.visit([&](soinfo* global_si) {
DEBUG("%s: looking up %s in executable %s", DEBUG("%s: looking up %s in %s (from global group)", si_from->name, name, global_si->name);
si->name, name, somain->name); s = soinfo_elf_lookup(global_si, elf_hash, name);
s = soinfo_elf_lookup(somain, elf_hash, name);
if (s != nullptr) { if (s != nullptr) {
*lsi = somain; *si_found_in = global_si;
return false;
} }
}
// 2. Look for it in the ld_preloads return true;
if (s == nullptr) { });
for (int i = 0; g_ld_preloads[i] != NULL; i++) {
s = soinfo_elf_lookup(g_ld_preloads[i], elf_hash, name);
if (s != nullptr) {
*lsi = g_ld_preloads[i];
break;
}
}
}
} }
// 3. Look for it in the local group // 2. Look for it in the local group
if (s == nullptr) { if (s == nullptr) {
local_group.visit([&](soinfo* local_si) { local_group.visit([&](soinfo* local_si) {
if (local_si == si && si->has_DT_SYMBOLIC) { if (local_si == si_from && si_from->has_DT_SYMBOLIC) {
// we already did this - skip // we already did this - skip
return true; return true;
} }
DEBUG("%s: looking up %s in %s (from local group)", si->name, name, local_si->name); DEBUG("%s: looking up %s in %s (from local group)", si_from->name, name, local_si->name);
s = soinfo_elf_lookup(local_si, elf_hash, name); s = soinfo_elf_lookup(local_si, elf_hash, name);
if (s != nullptr) { if (s != nullptr) {
*lsi = local_si; *si_found_in = local_si;
return false; return false;
} }
@ -551,9 +543,9 @@ static ElfW(Sym)* soinfo_do_lookup(soinfo* si, const char* name, soinfo** lsi, c
if (s != nullptr) { if (s != nullptr) {
TRACE_TYPE(LOOKUP, "si %s sym %s s->st_value = %p, " TRACE_TYPE(LOOKUP, "si %s sym %s s->st_value = %p, "
"found in %s, base = %p, load bias = %p", "found in %s, base = %p, load bias = %p",
si->name, name, reinterpret_cast<void*>(s->st_value), si_from->name, name, reinterpret_cast<void*>(s->st_value),
(*lsi)->name, reinterpret_cast<void*>((*lsi)->base), (*si_found_in)->name, reinterpret_cast<void*>((*si_found_in)->base),
reinterpret_cast<void*>((*lsi)->load_bias)); reinterpret_cast<void*>((*si_found_in)->load_bias));
} }
return s; return s;
@ -918,6 +910,24 @@ static bool is_recursive(soinfo* si, soinfo* parent) {
}); });
} }
// TODO: this is slightly unusual way to construct
// the global group for relocation. Not every RTLD_GLOBAL
// library is included in this group for backwards-compatibility
// reasons.
//
// This group consists of the main executable, LD_PRELOADs
// and libraries with the DF_1_GLOBAL flag set.
static soinfo::soinfo_list_t make_global_group() {
soinfo::soinfo_list_t global_group;
for (soinfo* si = somain; si != nullptr; si = si->next) {
if ((si->get_dt_flags_1() & DF_1_GLOBAL) != 0) {
global_group.push_back(si);
}
}
return global_group;
}
static bool find_libraries(soinfo* start_with, const char* const library_names[], size_t library_names_count, soinfo* soinfos[], static bool find_libraries(soinfo* start_with, const char* const library_names[], size_t library_names_count, soinfo* soinfos[],
soinfo* ld_preloads[], size_t ld_preloads_count, int rtld_flags, const android_dlextinfo* extinfo) { soinfo* ld_preloads[], size_t ld_preloads_count, int rtld_flags, const android_dlextinfo* extinfo) {
// Step 0: prepare. // Step 0: prepare.
@ -927,6 +937,9 @@ static bool find_libraries(soinfo* start_with, const char* const library_names[]
load_tasks.push_back(LoadTask::create(name, start_with)); load_tasks.push_back(LoadTask::create(name, start_with));
} }
// Construct global_group.
soinfo::soinfo_list_t global_group = make_global_group();
// If soinfos array is null allocate one on stack. // If soinfos array is null allocate one on stack.
// The array is needed in case of failure; for example // The array is needed in case of failure; for example
// when library_names[] = {libone.so, libtwo.so} and libone.so // when library_names[] = {libone.so, libtwo.so} and libone.so
@ -975,6 +988,11 @@ static bool find_libraries(soinfo* start_with, const char* const library_names[]
// When ld_preloads is not null, the first // When ld_preloads is not null, the first
// ld_preloads_count libs are in fact ld_preloads. // ld_preloads_count libs are in fact ld_preloads.
if (ld_preloads != nullptr && soinfos_count < ld_preloads_count) { if (ld_preloads != nullptr && soinfos_count < ld_preloads_count) {
// Add LD_PRELOADed libraries to the global group for future runs.
// There is no need to explicitly add them to the global group
// for this run because they are going to appear in the local
// group in the correct order.
si->set_dt_flags_1(si->get_dt_flags_1() | DF_1_GLOBAL);
ld_preloads[soinfos_count] = si; ld_preloads[soinfos_count] = si;
} }
@ -995,7 +1013,7 @@ static bool find_libraries(soinfo* start_with, const char* const library_names[]
bool linked = local_group.visit([&](soinfo* si) { bool linked = local_group.visit([&](soinfo* si) {
if ((si->flags & FLAG_LINKED) == 0) { if ((si->flags & FLAG_LINKED) == 0) {
if (!si->LinkImage(local_group, extinfo)) { if (!si->LinkImage(global_group, local_group, extinfo)) {
return false; return false;
} }
si->flags |= FLAG_LINKED; si->flags |= FLAG_LINKED;
@ -1140,7 +1158,7 @@ static ElfW(Addr) call_ifunc_resolver(ElfW(Addr) resolver_addr) {
} }
#if defined(USE_RELA) #if defined(USE_RELA)
int soinfo::Relocate(ElfW(Rela)* rela, unsigned count, const soinfo_list_t& local_group) { int soinfo::Relocate(ElfW(Rela)* rela, unsigned count, const soinfo_list_t& global_group, const soinfo_list_t& local_group) {
for (size_t idx = 0; idx < count; ++idx, ++rela) { for (size_t idx = 0; idx < count; ++idx, ++rela) {
unsigned type = ELFW(R_TYPE)(rela->r_info); unsigned type = ELFW(R_TYPE)(rela->r_info);
unsigned sym = ELFW(R_SYM)(rela->r_info); unsigned sym = ELFW(R_SYM)(rela->r_info);
@ -1158,7 +1176,7 @@ int soinfo::Relocate(ElfW(Rela)* rela, unsigned count, const soinfo_list_t& loca
if (sym != 0) { if (sym != 0) {
sym_name = get_string(symtab[sym].st_name); sym_name = get_string(symtab[sym].st_name);
s = soinfo_do_lookup(this, sym_name, &lsi, local_group); s = soinfo_do_lookup(this, sym_name, &lsi, global_group,local_group);
if (s == nullptr) { if (s == nullptr) {
// We only allow an undefined symbol if this is a weak reference... // We only allow an undefined symbol if this is a weak reference...
s = &symtab[sym]; s = &symtab[sym];
@ -1417,7 +1435,7 @@ int soinfo::Relocate(ElfW(Rela)* rela, unsigned count, const soinfo_list_t& loca
} }
#else // REL, not RELA. #else // REL, not RELA.
int soinfo::Relocate(ElfW(Rel)* rel, unsigned count, const soinfo_list_t& local_group) { int soinfo::Relocate(ElfW(Rel)* rel, unsigned count, const soinfo_list_t& global_group, const soinfo_list_t& local_group) {
for (size_t idx = 0; idx < count; ++idx, ++rel) { for (size_t idx = 0; idx < count; ++idx, ++rel) {
unsigned type = ELFW(R_TYPE)(rel->r_info); unsigned type = ELFW(R_TYPE)(rel->r_info);
// TODO: don't use unsigned for 'sym'. Use uint32_t or ElfW(Addr) instead. // TODO: don't use unsigned for 'sym'. Use uint32_t or ElfW(Addr) instead.
@ -1436,7 +1454,7 @@ int soinfo::Relocate(ElfW(Rel)* rel, unsigned count, const soinfo_list_t& local_
if (sym != 0) { if (sym != 0) {
sym_name = get_string(symtab[sym].st_name); sym_name = get_string(symtab[sym].st_name);
s = soinfo_do_lookup(this, sym_name, &lsi, local_group); s = soinfo_do_lookup(this, sym_name, &lsi, global_group, local_group);
if (s == nullptr) { if (s == nullptr) {
// We only allow an undefined symbol if this is a weak reference... // We only allow an undefined symbol if this is a weak reference...
s = &symtab[sym]; s = &symtab[sym];
@ -1622,7 +1640,7 @@ int soinfo::Relocate(ElfW(Rel)* rel, unsigned count, const soinfo_list_t& local_
#endif #endif
#if defined(__mips__) #if defined(__mips__)
static bool mips_relocate_got(soinfo* si, const soinfo::soinfo_list_t& local_group) { static bool mips_relocate_got(soinfo* si, const soinfo::soinfo_list_t& global_group, const soinfo::soinfo_list_t& local_group) {
ElfW(Addr)** got = si->plt_got; ElfW(Addr)** got = si->plt_got;
if (got == nullptr) { if (got == nullptr) {
return true; return true;
@ -1655,7 +1673,7 @@ static bool mips_relocate_got(soinfo* si, const soinfo::soinfo_list_t& local_gro
// This is an undefined reference... try to locate it. // This is an undefined reference... try to locate it.
const char* sym_name = si->get_string(sym->st_name); const char* sym_name = si->get_string(sym->st_name);
soinfo* lsi = nullptr; soinfo* lsi = nullptr;
ElfW(Sym)* s = soinfo_do_lookup(si, sym_name, &lsi, local_group); ElfW(Sym)* s = soinfo_do_lookup(si, sym_name, &lsi, global_group, local_group);
if (s == nullptr) { if (s == nullptr) {
// We only allow an undefined symbol if this is a weak reference. // We only allow an undefined symbol if this is a weak reference.
s = &symtab[g]; s = &symtab[g];
@ -1795,7 +1813,7 @@ void soinfo::remove_all_links() {
children.clear(); children.clear();
} }
dev_t soinfo::get_st_dev() { dev_t soinfo::get_st_dev() const {
if (has_min_version(0)) { if (has_min_version(0)) {
return st_dev; return st_dev;
} }
@ -1803,7 +1821,7 @@ dev_t soinfo::get_st_dev() {
return 0; return 0;
}; };
ino_t soinfo::get_st_ino() { ino_t soinfo::get_st_ino() const {
if (has_min_version(0)) { if (has_min_version(0)) {
return st_ino; return st_ino;
} }
@ -1811,7 +1829,7 @@ ino_t soinfo::get_st_ino() {
return 0; return 0;
} }
off64_t soinfo::get_file_offset() { off64_t soinfo::get_file_offset() const {
if (has_min_version(1)) { if (has_min_version(1)) {
return file_offset; return file_offset;
} }
@ -1819,7 +1837,7 @@ off64_t soinfo::get_file_offset() {
return 0; return 0;
} }
int soinfo::get_rtld_flags() { uint32_t soinfo::get_rtld_flags() const {
if (has_min_version(1)) { if (has_min_version(1)) {
return rtld_flags; return rtld_flags;
} }
@ -1827,6 +1845,27 @@ int soinfo::get_rtld_flags() {
return 0; 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;
}
this->dt_flags_1 = dt_flags_1;
}
}
// This is a return on get_children()/get_parents() if // This is a return on get_children()/get_parents() if
// 'this->flags' does not have FLAG_NEW_SOINFO set. // 'this->flags' does not have FLAG_NEW_SOINFO set.
static soinfo::soinfo_list_t g_empty_list; static soinfo::soinfo_list_t g_empty_list;
@ -1864,8 +1903,9 @@ const char* soinfo::get_string(ElfW(Word) index) const {
} }
bool soinfo::can_unload() const { bool soinfo::can_unload() const {
return (rtld_flags & (RTLD_NODELETE | RTLD_GLOBAL)) == 0; return (get_rtld_flags() & (RTLD_NODELETE | RTLD_GLOBAL)) == 0;
} }
/* Force any of the closed stdin, stdout and stderr to be associated with /* Force any of the closed stdin, stdout and stderr to be associated with
/dev/null. */ /dev/null. */
static int nullify_closed_stdio() { static int nullify_closed_stdio() {
@ -2166,16 +2206,9 @@ bool soinfo::PrelinkImage() {
break; break;
case DT_FLAGS_1: case DT_FLAGS_1:
if ((d->d_un.d_val & DF_1_GLOBAL) != 0) { set_dt_flags_1(d->d_un.d_val);
rtld_flags |= RTLD_GLOBAL;
}
if ((d->d_un.d_val & DF_1_NODELETE) != 0) { if ((d->d_un.d_val & ~SUPPORTED_DT_FLAGS_1) != 0) {
rtld_flags |= RTLD_NODELETE;
}
// TODO: Implement other flags
if ((d->d_un.d_val & ~(DF_1_NOW | DF_1_GLOBAL | DF_1_NODELETE)) != 0) {
DL_WARN("Unsupported flags DT_FLAGS_1=%p", reinterpret_cast<void*>(d->d_un.d_val)); DL_WARN("Unsupported flags DT_FLAGS_1=%p", reinterpret_cast<void*>(d->d_un.d_val));
} }
break; break;
@ -2248,7 +2281,7 @@ bool soinfo::PrelinkImage() {
return true; return true;
} }
bool soinfo::LinkImage(const soinfo_list_t& local_group, const android_dlextinfo* extinfo) { bool soinfo::LinkImage(const soinfo_list_t& global_group, const soinfo_list_t& local_group, const android_dlextinfo* extinfo) {
#if !defined(__LP64__) #if !defined(__LP64__)
if (has_text_relocations) { if (has_text_relocations) {
@ -2267,33 +2300,33 @@ bool soinfo::LinkImage(const soinfo_list_t& local_group, const android_dlextinfo
#if defined(USE_RELA) #if defined(USE_RELA)
if (rela != nullptr) { if (rela != nullptr) {
DEBUG("[ relocating %s ]", name); DEBUG("[ relocating %s ]", name);
if (Relocate(rela, rela_count, local_group)) { if (Relocate(rela, rela_count, global_group, local_group)) {
return false; return false;
} }
} }
if (plt_rela != nullptr) { if (plt_rela != nullptr) {
DEBUG("[ relocating %s plt ]", name); DEBUG("[ relocating %s plt ]", name);
if (Relocate(plt_rela, plt_rela_count, local_group)) { if (Relocate(plt_rela, plt_rela_count, global_group, local_group)) {
return false; return false;
} }
} }
#else #else
if (rel != nullptr) { if (rel != nullptr) {
DEBUG("[ relocating %s ]", name); DEBUG("[ relocating %s ]", name);
if (Relocate(rel, rel_count, local_group)) { if (Relocate(rel, rel_count, global_group, local_group)) {
return false; return false;
} }
} }
if (plt_rel != nullptr) { if (plt_rel != nullptr) {
DEBUG("[ relocating %s plt ]", name); DEBUG("[ relocating %s plt ]", name);
if (Relocate(plt_rel, plt_rel_count, local_group)) { if (Relocate(plt_rel, plt_rel_count, global_group, local_group)) {
return false; return false;
} }
} }
#endif #endif
#if defined(__mips__) #if defined(__mips__)
if (!mips_relocate_got(this, local_group)) { if (!mips_relocate_got(this, global_group, local_group)) {
return false; return false;
} }
#endif #endif
@ -2360,7 +2393,7 @@ static void add_vdso(KernelArgumentBlock& args __unused) {
si->load_bias = get_elf_exec_load_bias(ehdr_vdso); si->load_bias = get_elf_exec_load_bias(ehdr_vdso);
si->PrelinkImage(); si->PrelinkImage();
si->LinkImage(g_empty_list, nullptr); si->LinkImage(g_empty_list, soinfo::soinfo_list_t::make_list(si), nullptr);
#endif #endif
} }
@ -2491,6 +2524,9 @@ static ElfW(Addr) __linker_init_post_relocation(KernelArgumentBlock& args, ElfW(
si->PrelinkImage(); si->PrelinkImage();
// add somain to global group
si->set_dt_flags_1(si->get_dt_flags_1() | DF_1_GLOBAL);
// Load ld_preloads and dependencies. // Load ld_preloads and dependencies.
StringLinkedList needed_library_name_list; StringLinkedList needed_library_name_list;
size_t needed_libraries_count = 0; size_t needed_libraries_count = 0;
@ -2634,7 +2670,13 @@ extern "C" ElfW(Addr) __linker_init(void* raw_args) {
linker_so.phnum = elf_hdr->e_phnum; linker_so.phnum = elf_hdr->e_phnum;
linker_so.flags |= FLAG_LINKER; linker_so.flags |= FLAG_LINKER;
if (!(linker_so.PrelinkImage() && linker_so.LinkImage(g_empty_list, nullptr))) { // 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
// linker is built with DT_SYMBOLIC and therefore relocates its symbols against
// 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.PrelinkImage() && linker_so.LinkImage(g_empty_list, g_empty_list, nullptr))) {
// It would be nice to print an error message, but if the linker // It would be nice to print an error message, but if the linker
// can't link itself, there's no guarantee that we'll be able to // can't link itself, there's no guarantee that we'll be able to
// call write() (because it involves a GOT reference). We may as // call write() (because it involves a GOT reference). We may as

21
linker/linker.h
View File

@ -89,6 +89,8 @@
#define FLAG_LINKER 0x00000010 // The linker itself #define FLAG_LINKER 0x00000010 // The linker itself
#define FLAG_NEW_SOINFO 0x40000000 // new soinfo format #define FLAG_NEW_SOINFO 0x40000000 // new soinfo format
#define SUPPORTED_DT_FLAGS_1 (DF_1_NOW | DF_1_GLOBAL | DF_1_NODELETE)
#define SOINFO_VERSION 1 #define SOINFO_VERSION 1
#define SOINFO_NAME_LEN 128 #define SOINFO_NAME_LEN 128
@ -207,16 +209,18 @@ struct soinfo {
void CallDestructors(); void CallDestructors();
void CallPreInitConstructors(); void CallPreInitConstructors();
bool PrelinkImage(); bool PrelinkImage();
bool LinkImage(const soinfo_list_t& local_group, const android_dlextinfo* extinfo); bool LinkImage(const soinfo_list_t& global_group, const soinfo_list_t& local_group, const android_dlextinfo* extinfo);
void add_child(soinfo* child); void add_child(soinfo* child);
void remove_all_links(); void remove_all_links();
ino_t get_st_ino(); ino_t get_st_ino() const;
dev_t get_st_dev(); dev_t get_st_dev() const;
off64_t get_file_offset(); off64_t get_file_offset() const;
int get_rtld_flags(); uint32_t get_rtld_flags() const;
uint32_t get_dt_flags_1() const;
void set_dt_flags_1(uint32_t dt_flags_1);
soinfo_list_t& get_children(); soinfo_list_t& get_children();
soinfo_list_t& get_parents(); soinfo_list_t& get_parents();
@ -234,9 +238,9 @@ struct soinfo {
void CallArray(const char* array_name, linker_function_t* functions, size_t count, bool reverse); void CallArray(const char* array_name, linker_function_t* functions, size_t count, bool reverse);
void CallFunction(const char* function_name, linker_function_t function); void CallFunction(const char* function_name, linker_function_t function);
#if defined(USE_RELA) #if defined(USE_RELA)
int Relocate(ElfW(Rela)* rela, unsigned count, const soinfo_list_t& local_group); int Relocate(ElfW(Rela)* rela, unsigned count, const soinfo_list_t& global_group, const soinfo_list_t& local_group);
#else #else
int Relocate(ElfW(Rel)* rel, unsigned count, const soinfo_list_t& local_group); int Relocate(ElfW(Rel)* rel, unsigned count, const soinfo_list_t& global_group, const soinfo_list_t& local_group);
#endif #endif
private: private:
@ -254,7 +258,8 @@ struct soinfo {
// version >= 1 // version >= 1
off64_t file_offset; off64_t file_offset;
int rtld_flags; uint32_t rtld_flags;
uint32_t dt_flags_1;
size_t strtab_size; size_t strtab_size;
friend soinfo* get_libdl_info(); friend soinfo* get_libdl_info();

13
tests/Android.mk
View File

@ -233,6 +233,7 @@ bionic-unit-tests_static_libraries := \
bionic-unit-tests_src_files := \ bionic-unit-tests_src_files := \
atexit_test.cpp \ atexit_test.cpp \
dl_test.cpp \
dlext_test.cpp \ dlext_test.cpp \
dlfcn_test.cpp \ dlfcn_test.cpp \
@ -245,8 +246,7 @@ bionic-unit-tests_conlyflags := \
bionic-unit-tests_cppflags := $(test_cppflags) bionic-unit-tests_cppflags := $(test_cppflags)
bionic-unit-tests_ldflags := \ bionic-unit-tests_ldflags := \
-Wl,--export-dynamic \ -Wl,--export-dynamic
-Wl,-u,DlSymTestFunction \
bionic-unit-tests_c_includes := \ bionic-unit-tests_c_includes := \
bionic/libc \ bionic/libc \
@ -255,6 +255,9 @@ bionic-unit-tests_c_includes := \
bionic-unit-tests_shared_libraries_target := \ bionic-unit-tests_shared_libraries_target := \
libdl \ libdl \
libpagemap \ libpagemap \
libdl_preempt_test_1 \
libdl_preempt_test_2 \
libdl_test_df_1_global
module := bionic-unit-tests module := bionic-unit-tests
module_tag := optional module_tag := optional
@ -302,6 +305,12 @@ ifeq ($(HOST_OS)-$(HOST_ARCH),$(filter $(HOST_OS)-$(HOST_ARCH),linux-x86 linux-x
bionic-unit-tests-glibc_src_files := \ bionic-unit-tests-glibc_src_files := \
atexit_test.cpp \ atexit_test.cpp \
dlfcn_test.cpp \ dlfcn_test.cpp \
dl_test.cpp \
bionic-unit-tests-glibc_shared_libraries := \
libdl_preempt_test_1 \
libdl_preempt_test_2 \
libdl_test_df_1_global
bionic-unit-tests-glibc_whole_static_libraries := \ bionic-unit-tests-glibc_whole_static_libraries := \
libBionicStandardTests \ libBionicStandardTests \

72
tests/dl_test.cpp Normal file
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@ -0,0 +1,72 @@
/*
* 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.
*/
#include <gtest/gtest.h>
#include <dlfcn.h>
#include <libgen.h>
#include <limits.h>
#include <stdio.h>
#include <stdint.h>
#include <string>
extern "C" int main_global_default_serial() {
return 3370318;
}
extern "C" int main_global_protected_serial() {
return 2716057;
}
// The following functions are defined in DT_NEEDED
// libdl_preempt_test.so library.
// This one calls main_global_default_serial
extern "C" int main_global_default_get_serial();
// This one calls main_global_protected_serial
extern "C" int main_global_protected_get_serial();
// This one calls lib_global_default_serial
extern "C" int lib_global_default_get_serial();
// This one calls lib_global_protected_serial
extern "C" int lib_global_protected_get_serial();
// This test verifies that the global default function
// main_global_default_serial() is preempted by
// the function defined above.
TEST(dl, main_preempts_global_default) {
ASSERT_EQ(3370318, main_global_default_get_serial());
}
// This one makes sure that the global protected
// symbols do not get preempted
TEST(dl, main_does_not_preempt_global_protected) {
ASSERT_EQ(3370318, main_global_protected_get_serial());
}
// check same things for lib
TEST(dl, lib_preempts_global_default) {
ASSERT_EQ(3370318, lib_global_default_get_serial());
}
TEST(dl, lib_does_not_preempt_global_protected) {
ASSERT_EQ(3370318, lib_global_protected_get_serial());
}
// TODO: Add tests for LD_PRELOADs

14
tests/dlfcn_test.cpp
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@ -499,6 +499,20 @@ TEST(dlfcn, dlopen_nodelete_dt_flags_1) {
ASSERT_TRUE(!is_unloaded); ASSERT_TRUE(!is_unloaded);
} }
TEST(dlfcn, dlsym_df_1_global) {
#if !defined(__arm__)
void* handle = dlopen("libtest_dlsym_df_1_global.so", RTLD_NOW);
ASSERT_TRUE(handle != nullptr) << dlerror();
int (*get_answer)();
get_answer = reinterpret_cast<int (*)()>(dlsym(handle, "dl_df_1_global_get_answer"));
ASSERT_TRUE(get_answer != nullptr) << dlerror();
ASSERT_EQ(42, get_answer());
ASSERT_EQ(0, dlclose(handle));
#else
GTEST_LOG_(INFO) << "This test does nothing on arm (to be reenabled once b/18137520 or b/18130452 are fixed).\n";
#endif
}
TEST(dlfcn, dlopen_failure) { TEST(dlfcn, dlopen_failure) {
void* self = dlopen("/does/not/exist", RTLD_NOW); void* self = dlopen("/does/not/exist", RTLD_NOW);
ASSERT_TRUE(self == NULL); ASSERT_TRUE(self == NULL);

36
tests/libs/Android.mk
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@ -290,6 +290,42 @@ libtest_atexit_src_files := \
module := libtest_atexit module := libtest_atexit
include $(LOCAL_PATH)/Android.build.testlib.mk include $(LOCAL_PATH)/Android.build.testlib.mk
# -----------------------------------------------------------------------------
# This library is used by dl_load test to check symbol preempting
# by main executable
# -----------------------------------------------------------------------------
libdl_preempt_test_1_src_files := dl_preempt_library_1.cpp
module := libdl_preempt_test_1
include $(LOCAL_PATH)/Android.build.testlib.mk
# -----------------------------------------------------------------------------
# This library is used by dl_load test to check symbol preempting
# by libdl_preempt_test_1.so
# -----------------------------------------------------------------------------
libdl_preempt_test_2_src_files := dl_preempt_library_2.cpp
module := libdl_preempt_test_2
include $(LOCAL_PATH)/Android.build.testlib.mk
# -----------------------------------------------------------------------------
# Library with DF_1_GLOBAL
# -----------------------------------------------------------------------------
# TODO: re-enable arm once b/18137520 or b/18130452 are fixed
ifeq ($(filter $(TARGET_ARCH),arm),)
libdl_test_df_1_global_src_files := dl_df_1_global.cpp
libdl_test_df_1_global_ldflags := -fuse-ld=bfd -Wl,-z,global
module := libdl_test_df_1_global
include $(LOCAL_PATH)/Android.build.testlib.mk
endif
# -----------------------------------------------------------------------------
# Library using symbol from libdl_test_df_1_global
# -----------------------------------------------------------------------------
libtest_dlsym_df_1_global_src_files := dl_df_1_use_global.cpp
module := libtest_dlsym_df_1_global
include $(LOCAL_PATH)/Android.build.testlib.mk
# ----------------------------------------------------------------------------- # -----------------------------------------------------------------------------
# Library with weak function # Library with weak function
# ----------------------------------------------------------------------------- # -----------------------------------------------------------------------------

19
tests/libs/dl_df_1_global.cpp Normal file
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@ -0,0 +1,19 @@
/*
* Copyright (C) 2014 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.
*/
extern "C" int dl_df_1_global_get_answer_impl() {
return 42;
}

23
tests/libs/dl_df_1_use_global.cpp Normal file
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@ -0,0 +1,23 @@
/*
* Copyright (C) 2014 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.
*/
extern "C" int __attribute__((weak)) dl_df_1_global_get_answer_impl() {
return 0;
}
extern "C" int dl_df_1_global_get_answer() {
return dl_df_1_global_get_answer_impl();
}

45
tests/libs/dl_preempt_library_1.cpp Normal file
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@ -0,0 +1,45 @@
/*
* Copyright (C) 2014 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.
*/
// This one should be preempted by the function
// defined in the main executable.
extern "C" int __attribute__((weak)) main_global_default_serial() {
return 2716057;
}
// Even though this one is defined by the main
// executable it should not be preempted
// because of protected visibility
extern "C" int __attribute__((weak, visibility("protected"))) main_global_protected_serial() {
return 3370318;
}
extern "C" int main_global_default_get_serial() {
return main_global_default_serial();
}
extern "C" int main_global_protected_get_serial() {
return main_global_protected_serial();
}
// Trying to preempt functions from a DT_NEEDED .so
extern "C" int lib_global_default_serial() {
return 3370318;
}
extern "C" int lib_global_protected_serial() {
return 2716057;
}

37
tests/libs/dl_preempt_library_2.cpp Normal file
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@ -0,0 +1,37 @@
/*
* Copyright (C) 2014 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.
*/
// This one should be preempted by the function
// defined in libdl_preempt_test_1.so
extern "C" int __attribute__((weak)) lib_global_default_serial() {
return 2716057;
}
// Even though this one is defined by
// libdl_preempt_test_1.so it should not be
// preempted because of protected visibility
extern "C" int __attribute__((weak,visibility("protected"))) lib_global_protected_serial() {
return 3370318;
}
extern "C" int lib_global_default_get_serial() {
return lib_global_default_serial();
}
extern "C" int lib_global_protected_get_serial() {
return lib_global_protected_serial();
}