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am 9d3382d9: Revert "Fix dlsym() to take into account RTLD_GLOBAL/LOCAL"

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* commit '9d3382d97a2cdc8c8f78c7825ece16f09292fc36':
  Revert "Fix dlsym() to take into account RTLD_GLOBAL/LOCAL"
This commit is contained in:
Dmitriy Ivanov
2014-11-04 17:17:58 +00:00
committed by Android Git Automerger
parent e1d9881a8d 9d3382d97a
commit 39af759260
5 changed files with 20 additions and 72 deletions
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2
linker/dlfcn.cpp
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@@ -232,7 +232,7 @@ 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 }; static unsigned g_libdl_chains[] = { 0, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
#endif #endif
static soinfo __libdl_info("libdl.so", nullptr, 0, RTLD_GLOBAL); static soinfo __libdl_info("libdl.so", nullptr, 0);
// This is used by the dynamic linker. Every process gets these symbols for free. // This is used by the dynamic linker. Every process gets these symbols for free.
soinfo* get_libdl_info() { soinfo* get_libdl_info() {

48
linker/linker.cpp
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@@ -282,13 +282,13 @@ 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) {
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;
} }
soinfo* si = new (g_soinfo_allocator.alloc()) soinfo(name, file_stat, file_offset, rtld_flags); soinfo* si = new (g_soinfo_allocator.alloc()) soinfo(name, file_stat, file_offset);
sonext->next = si; sonext->next = si;
sonext = si; sonext = si;
@@ -452,7 +452,7 @@ static ElfW(Sym)* soinfo_elf_lookup(soinfo* si, unsigned hash, const char* name)
return nullptr; return nullptr;
} }
soinfo::soinfo(const char* name, const struct stat* file_stat, off64_t file_offset, int rtld_flags) { soinfo::soinfo(const char* name, const struct stat* file_stat, off64_t file_offset) {
memset(this, 0, sizeof(*this)); memset(this, 0, sizeof(*this));
strlcpy(this->name, name, sizeof(this->name)); strlcpy(this->name, name, sizeof(this->name));
@@ -464,8 +464,6 @@ soinfo::soinfo(const char* name, const struct stat* file_stat, off64_t file_offs
this->st_ino = file_stat->st_ino; this->st_ino = file_stat->st_ino;
this->file_offset = file_offset; this->file_offset = file_offset;
} }
this->rtld_flags = rtld_flags;
} }
static unsigned elfhash(const char* _name) { static unsigned elfhash(const char* _name) {
@@ -686,10 +684,6 @@ ElfW(Sym)* dlsym_linear_lookup(const char* name, soinfo** found, soinfo* start)
ElfW(Sym)* s = nullptr; ElfW(Sym)* s = nullptr;
for (soinfo* si = start; (s == nullptr) && (si != nullptr); si = si->next) { for (soinfo* si = start; (s == nullptr) && (si != nullptr); si = si->next) {
if ((si->get_rtld_flags() & RTLD_GLOBAL) == 0) {
continue;
}
s = soinfo_elf_lookup(si, elf_hash, name); s = soinfo_elf_lookup(si, elf_hash, name);
if (s != nullptr) { if (s != nullptr) {
*found = si; *found = si;
@@ -780,7 +774,7 @@ static void for_each_dt_needed(const soinfo* si, F action) {
} }
} }
static soinfo* load_library(LoadTaskList& load_tasks, const char* name, int rtld_flags, const android_dlextinfo* extinfo) { static soinfo* load_library(LoadTaskList& load_tasks, const char* name, int dlflags, const android_dlextinfo* extinfo) {
int fd = -1; int fd = -1;
off64_t file_offset = 0; off64_t file_offset = 0;
ScopedFd file_guard(-1); ScopedFd file_guard(-1);
@@ -825,7 +819,7 @@ static soinfo* load_library(LoadTaskList& load_tasks, const char* name, int rtld
} }
} }
if ((rtld_flags & RTLD_NOLOAD) != 0) { if ((dlflags & RTLD_NOLOAD) != 0) {
DL_ERR("library \"%s\" wasn't loaded and RTLD_NOLOAD prevented it", name); DL_ERR("library \"%s\" wasn't loaded and RTLD_NOLOAD prevented it", name);
return nullptr; return nullptr;
} }
@@ -836,7 +830,7 @@ static soinfo* load_library(LoadTaskList& load_tasks, const char* name, int rtld
return nullptr; return nullptr;
} }
soinfo* si = soinfo_alloc(SEARCH_NAME(name), &file_stat, file_offset, rtld_flags); soinfo* si = soinfo_alloc(SEARCH_NAME(name), &file_stat, file_offset);
if (si == nullptr) { if (si == nullptr) {
return nullptr; return nullptr;
} }
@@ -868,7 +862,7 @@ static soinfo *find_loaded_library_by_name(const char* name) {
return nullptr; return nullptr;
} }
static soinfo* find_library_internal(LoadTaskList& load_tasks, const char* name, int rtld_flags, const android_dlextinfo* extinfo) { static soinfo* find_library_internal(LoadTaskList& load_tasks, const char* name, int dlflags, const android_dlextinfo* extinfo) {
soinfo* si = find_loaded_library_by_name(name); soinfo* si = find_loaded_library_by_name(name);
@@ -876,7 +870,7 @@ static soinfo* find_library_internal(LoadTaskList& load_tasks, const char* name,
// of this fact is done by load_library. // of this fact is done by load_library.
if (si == nullptr) { if (si == nullptr) {
TRACE("[ '%s' has not been found by name. Trying harder...]", name); TRACE("[ '%s' has not been found by name. Trying harder...]", name);
si = load_library(load_tasks, name, rtld_flags, extinfo); si = load_library(load_tasks, name, dlflags, extinfo);
} }
return si; return si;
@@ -900,7 +894,7 @@ static bool is_recursive(soinfo* si, soinfo* parent) {
} }
static bool find_libraries(const char* const library_names[], size_t library_names_size, soinfo* soinfos[], static bool find_libraries(const char* const library_names[], size_t library_names_size, soinfo* soinfos[],
soinfo* ld_preloads[], size_t ld_preloads_size, int rtld_flags, const android_dlextinfo* extinfo) { soinfo* ld_preloads[], size_t ld_preloads_size, int dlflags, const android_dlextinfo* extinfo) {
// Step 0: prepare. // Step 0: prepare.
LoadTaskList load_tasks; LoadTaskList load_tasks;
for (size_t i = 0; i < library_names_size; ++i) { for (size_t i = 0; i < library_names_size; ++i) {
@@ -926,7 +920,7 @@ static bool find_libraries(const char* const library_names[], size_t library_nam
// Step 1: load and pre-link all DT_NEEDED libraries in breadth first order. // Step 1: load and pre-link all DT_NEEDED libraries in breadth first order.
for (LoadTask::unique_ptr task(load_tasks.pop_front()); task.get() != nullptr; task.reset(load_tasks.pop_front())) { for (LoadTask::unique_ptr task(load_tasks.pop_front()); task.get() != nullptr; task.reset(load_tasks.pop_front())) {
soinfo* si = find_library_internal(load_tasks, task->get_name(), rtld_flags, extinfo); soinfo* si = find_library_internal(load_tasks, task->get_name(), dlflags, extinfo);
if (si == nullptr) { if (si == nullptr) {
return false; return false;
} }
@@ -971,7 +965,7 @@ static bool find_libraries(const char* const library_names[], size_t library_nam
return true; return true;
} }
static soinfo* find_library(const char* name, int rtld_flags, const android_dlextinfo* extinfo) { static soinfo* find_library(const char* name, int dlflags, const android_dlextinfo* extinfo) {
if (name == nullptr) { if (name == nullptr) {
somain->ref_count++; somain->ref_count++;
return somain; return somain;
@@ -979,7 +973,7 @@ static soinfo* find_library(const char* name, int rtld_flags, const android_dlex
soinfo* si; soinfo* si;
if (!find_libraries(&name, 1, &si, nullptr, 0, rtld_flags, extinfo)) { if (!find_libraries(&name, 1, &si, nullptr, 0, dlflags, extinfo)) {
return nullptr; return nullptr;
} }
@@ -1764,14 +1758,6 @@ off64_t soinfo::get_file_offset() {
return 0; return 0;
} }
int soinfo::get_rtld_flags() {
if (has_min_version(1)) {
return rtld_flags;
}
return 0;
}
// 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;
@@ -2289,7 +2275,7 @@ static void add_vdso(KernelArgumentBlock& args __unused) {
return; return;
} }
soinfo* si = soinfo_alloc("[vdso]", nullptr, 0, 0); soinfo* si = soinfo_alloc("[vdso]", nullptr, 0);
si->phdr = reinterpret_cast<ElfW(Phdr)*>(reinterpret_cast<char*>(ehdr_vdso) + ehdr_vdso->e_phoff); si->phdr = reinterpret_cast<ElfW(Phdr)*>(reinterpret_cast<char*>(ehdr_vdso) + ehdr_vdso->e_phoff);
si->phnum = ehdr_vdso->e_phnum; si->phnum = ehdr_vdso->e_phnum;
@@ -2310,7 +2296,7 @@ static void add_vdso(KernelArgumentBlock& args __unused) {
#else #else
#define LINKER_PATH "/system/bin/linker" #define LINKER_PATH "/system/bin/linker"
#endif #endif
static soinfo linker_soinfo_for_gdb(LINKER_PATH, nullptr, 0, 0); static soinfo linker_soinfo_for_gdb(LINKER_PATH, nullptr, 0);
/* gdb expects the linker to be in the debug shared object list. /* gdb expects the linker to be in the debug shared object list.
* Without this, gdb has trouble locating the linker's ".text" * Without this, gdb has trouble locating the linker's ".text"
@@ -2374,7 +2360,7 @@ static ElfW(Addr) __linker_init_post_relocation(KernelArgumentBlock& args, ElfW(
INFO("[ android linker & debugger ]"); INFO("[ android linker & debugger ]");
soinfo* si = soinfo_alloc(args.argv[0], nullptr, 0, RTLD_GLOBAL); soinfo* si = soinfo_alloc(args.argv[0], nullptr, 0);
if (si == nullptr) { if (si == nullptr) {
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
} }
@@ -2449,7 +2435,7 @@ static ElfW(Addr) __linker_init_post_relocation(KernelArgumentBlock& args, ElfW(
memset(needed_library_names, 0, sizeof(needed_library_names)); memset(needed_library_names, 0, sizeof(needed_library_names));
needed_library_name_list.copy_to_array(needed_library_names, needed_libraries_count); needed_library_name_list.copy_to_array(needed_library_names, needed_libraries_count);
if (needed_libraries_count > 0 && !find_libraries(needed_library_names, needed_libraries_count, needed_library_si, g_ld_preloads, ld_preloads_count, RTLD_GLOBAL, nullptr)) { if (needed_libraries_count > 0 && !find_libraries(needed_library_names, needed_libraries_count, needed_library_si, g_ld_preloads, ld_preloads_count, 0, nullptr)) {
__libc_format_fd(2, "CANNOT LINK EXECUTABLE DEPENDENCIES: %s\n", linker_get_error_buffer()); __libc_format_fd(2, "CANNOT LINK EXECUTABLE DEPENDENCIES: %s\n", linker_get_error_buffer());
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
} }
@@ -2562,7 +2548,7 @@ extern "C" ElfW(Addr) __linker_init(void* raw_args) {
ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(linker_addr); ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(linker_addr);
ElfW(Phdr)* phdr = reinterpret_cast<ElfW(Phdr)*>(linker_addr + elf_hdr->e_phoff); ElfW(Phdr)* phdr = reinterpret_cast<ElfW(Phdr)*>(linker_addr + elf_hdr->e_phoff);
soinfo linker_so("[dynamic linker]", nullptr, 0, 0); soinfo linker_so("[dynamic linker]", nullptr, 0);
// If the linker is not acting as PT_INTERP entry_point is equal to // 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 // _start. Which means that the linker is running as an executable and

4
linker/linker.h
View File

@@ -201,7 +201,7 @@ struct soinfo {
#endif #endif
bool has_DT_SYMBOLIC; bool has_DT_SYMBOLIC;
soinfo(const char* name, const struct stat* file_stat, off64_t file_offset, int rtld_flags); soinfo(const char* name, const struct stat* file_stat, off64_t file_offset);
void CallConstructors(); void CallConstructors();
void CallDestructors(); void CallDestructors();
@@ -216,8 +216,6 @@ struct soinfo {
dev_t get_st_dev(); dev_t get_st_dev();
off64_t get_file_offset(); off64_t get_file_offset();
int get_rtld_flags();
soinfo_list_t& get_children(); soinfo_list_t& get_children();
soinfo_list_t& get_parents(); soinfo_list_t& get_parents();

36
tests/dlfcn_test.cpp
View File

@@ -202,42 +202,6 @@ TEST(dlfcn, dlopen_check_order) {
dlclose(handle); dlclose(handle);
} }
TEST(dlfcn, dlopen_check_rtld_local) {
void* sym = dlsym(RTLD_DEFAULT, "dlopen_testlib_simple_func");
ASSERT_TRUE(sym == nullptr);
// implicit RTLD_LOCAL
void* handle = dlopen("libtest_simple.so", RTLD_NOW);
sym = dlsym(RTLD_DEFAULT, "dlopen_testlib_simple_func");
ASSERT_TRUE(sym == nullptr);
ASSERT_SUBSTR("undefined symbol: dlopen_testlib_simple_func", dlerror());
sym = dlsym(handle, "dlopen_testlib_simple_func");
ASSERT_TRUE(sym != nullptr);
ASSERT_TRUE(reinterpret_cast<bool (*)(void)>(sym)());
dlclose(handle);
// explicit RTLD_LOCAL
handle = dlopen("libtest_simple.so", RTLD_NOW | RTLD_LOCAL);
sym = dlsym(RTLD_DEFAULT, "dlopen_testlib_simple_func");
ASSERT_TRUE(sym == nullptr);
ASSERT_SUBSTR("undefined symbol: dlopen_testlib_simple_func", dlerror());
sym = dlsym(handle, "dlopen_testlib_simple_func");
ASSERT_TRUE(sym != nullptr);
ASSERT_TRUE(reinterpret_cast<bool (*)(void)>(sym)());
dlclose(handle);
}
TEST(dlfcn, dlopen_check_rtld_global) {
void* sym = dlsym(RTLD_DEFAULT, "dlopen_testlib_simple_func");
ASSERT_TRUE(sym == nullptr);
void* handle = dlopen("libtest_simple.so", RTLD_NOW | RTLD_GLOBAL);
sym = dlsym(RTLD_DEFAULT, "dlopen_testlib_simple_func");
ASSERT_TRUE(sym != nullptr) << dlerror();
ASSERT_TRUE(reinterpret_cast<bool (*)(void)>(sym)());
dlclose(handle);
}
// libtest_with_dependency_loop.so -> libtest_with_dependency_loop_a.so -> // libtest_with_dependency_loop.so -> libtest_with_dependency_loop_a.so ->
// libtest_with_dependency_loop_b.so -> libtest_with_dependency_loop_c.so -> // libtest_with_dependency_loop_b.so -> libtest_with_dependency_loop_c.so ->
// libtest_with_dependency_loop_a.so // libtest_with_dependency_loop_a.so

2
tests/libs/dlopen_testlib_simple.cpp
View File

@@ -19,6 +19,6 @@
uint32_t dlopen_testlib_taxicab_number = 1729; uint32_t dlopen_testlib_taxicab_number = 1729;
extern "C" bool dlopen_testlib_simple_func() { bool dlopen_testlib_simple_func() {
return true; return true;
} }