diff --git a/libc/private/ScopeGuard.h b/libc/private/ScopeGuard.h new file mode 100644 index 000000000..183e322f7 --- /dev/null +++ b/libc/private/ScopeGuard.h @@ -0,0 +1,53 @@ +/* + * 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. + */ + +#ifndef SCOPE_GUARD_H +#define SCOPE_GUARD_H + +// TODO: include explicit std::move when it becomes available +template +class ScopeGuard { + public: + ScopeGuard(F f) : f_(f), active_(true) {} + + ScopeGuard(ScopeGuard&& that) : f_(that.f_), active_(that.active_) { + that.active_ = false; + } + + ~ScopeGuard() { + if (active_) { + f_(); + } + } + + void disable() { + active_ = false; + } + private: + F f_; + bool active_; + + ScopeGuard() = delete; + ScopeGuard(const ScopeGuard&) = delete; + ScopeGuard& operator=(const ScopeGuard&) = delete; +}; + +template +ScopeGuard create_scope_guard(T f) { + return ScopeGuard(f); +} + +#endif // SCOPE_GUARD_H diff --git a/libc/private/UniquePtr.h b/libc/private/UniquePtr.h new file mode 100644 index 000000000..5ac7599a0 --- /dev/null +++ b/libc/private/UniquePtr.h @@ -0,0 +1,140 @@ +/* + * Copyright (C) 2010 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 UNIQUE_PTR_H_included +#define UNIQUE_PTR_H_included + +// Default deleter for pointer types. +template +struct DefaultDelete { + enum { type_must_be_complete = sizeof(T) }; + DefaultDelete() {} + void operator()(T* p) const { + delete p; + } +}; + +// Default deleter for array types. +template +struct DefaultDelete { + enum { type_must_be_complete = sizeof(T) }; + void operator()(T* p) const { + delete[] p; + } +}; + +// A smart pointer that deletes the given pointer on destruction. +// Equivalent to C++0x's std::unique_ptr (a combination of boost::scoped_ptr +// and boost::scoped_array). +// Named to be in keeping with Android style but also to avoid +// collision with any other implementation, until we can switch over +// to unique_ptr. +// Use thus: +// UniquePtr c(new C); +template > +class UniquePtr { +public: + // Construct a new UniquePtr, taking ownership of the given raw pointer. + explicit UniquePtr(T* ptr = nullptr) : mPtr(ptr) { } + + UniquePtr(UniquePtr&& that) { + mPtr = that.mPtr; + that.mPtr = nullptr; + } + + ~UniquePtr() { + reset(); + } + + // Accessors. + T& operator*() const { return *mPtr; } + T* operator->() const { return mPtr; } + T* get() const { return mPtr; } + + // Returns the raw pointer and hands over ownership to the caller. + // The pointer will not be deleted by UniquePtr. + T* release() __attribute__((warn_unused_result)) { + T* result = mPtr; + mPtr = nullptr; + return result; + } + + // Takes ownership of the given raw pointer. + // If this smart pointer previously owned a different raw pointer, that + // raw pointer will be freed. + void reset(T* ptr = nullptr) { + if (ptr != mPtr) { + D()(mPtr); + mPtr = ptr; + } + } + +private: + // The raw pointer. + T* mPtr; + + // Comparing unique pointers is probably a mistake, since they're unique. + template bool operator==(const UniquePtr& p) const = delete; + template bool operator!=(const UniquePtr& p) const = delete; + + // Disallow copy and assignment. + UniquePtr(const UniquePtr&) = delete; + void operator=(const UniquePtr&) = delete; +}; + +// Partial specialization for array types. Like std::unique_ptr, this removes +// operator* and operator-> but adds operator[]. +template +class UniquePtr { +public: + explicit UniquePtr(T* ptr = NULL) : mPtr(ptr) { + } + UniquePtr(UniquePtr&& that) { + mPtr = that.mPtr; + that.mPtr = nullptr; + } + + ~UniquePtr() { + reset(); + } + + T& operator[](size_t i) const { + return mPtr[i]; + } + T* get() const { return mPtr; } + + T* release() __attribute__((warn_unused_result)) { + T* result = mPtr; + mPtr = NULL; + return result; + } + + void reset(T* ptr = NULL) { + if (ptr != mPtr) { + D()(mPtr); + mPtr = ptr; + } + } + +private: + T* mPtr; + + // Disallow copy and assignment. + UniquePtr(const UniquePtr&) = delete; + void operator=(const UniquePtr&) = delete; +}; + +#endif // UNIQUE_PTR_H_included diff --git a/linker/dlfcn.cpp b/linker/dlfcn.cpp index 38484d995..3024b3c29 100644 --- a/linker/dlfcn.cpp +++ b/linker/dlfcn.cpp @@ -245,6 +245,7 @@ soinfo* get_libdl_info() { __libdl_info.bucket = g_libdl_buckets; __libdl_info.chain = g_libdl_chains; __libdl_info.has_DT_SYMBOLIC = true; + __libdl_info.ref_count = 1; } return &__libdl_info; diff --git a/linker/linker.cpp b/linker/linker.cpp index 9eb74403c..610489ea5 100644 --- a/linker/linker.cpp +++ b/linker/linker.cpp @@ -44,6 +44,8 @@ #include "private/KernelArgumentBlock.h" #include "private/ScopedPthreadMutexLocker.h" #include "private/ScopedFd.h" +#include "private/ScopeGuard.h" +#include "private/UniquePtr.h" #include "linker.h" #include "linker_debug.h" @@ -170,7 +172,6 @@ DISALLOW_ALLOCATION(void, free, (void* u __unused)); DISALLOW_ALLOCATION(void*, realloc, (void* u1 __unused, size_t u2 __unused)); DISALLOW_ALLOCATION(void*, calloc, (size_t u1 __unused, size_t u2 __unused)); -static char tmp_err_buf[768]; static char __linker_dl_err_buf[768]; char* linker_get_error_buffer() { @@ -512,7 +513,7 @@ static ElfW(Sym)* soinfo_do_lookup(soinfo* si, const char* name, soinfo** lsi) { unsigned elf_hash = elfhash(name); ElfW(Sym)* s = nullptr; - if (si != nullptr && somain != nullptr) { + if (somain != nullptr) { /* * Local scope is executable scope. Just start looking into it right away * for the shortcut. @@ -657,22 +658,47 @@ class TypeBasedAllocator { } }; +class LoadTask { + public: + struct deleter_t { + void operator()(LoadTask* t) { + TypeBasedAllocator::free(t); + } + }; + + typedef UniquePtr unique_ptr; + + static deleter_t deleter; + + static LoadTask* create(const char* name, soinfo* needed_by) { + LoadTask* ptr = TypeBasedAllocator::alloc(); + return new (ptr) LoadTask(name, needed_by); + } + + const char* get_name() { + return name_; + } + + soinfo* get_needed_by() { + return needed_by_; + } + private: + LoadTask(const char* name, soinfo* needed_by) + : name_(name), needed_by_(needed_by) {} + + const char* name_; + soinfo* needed_by_; + + DISALLOW_IMPLICIT_CONSTRUCTORS(LoadTask); +}; + template using linked_list_t = LinkedList>>; typedef linked_list_t SoinfoLinkedList; +typedef linked_list_t StringLinkedList; +typedef linked_list_t LoadTaskList; -static LinkerAllocator> g_soinfo_list_allocator_rw; -class SoinfoListAllocatorRW { - public: - static LinkedListEntry* alloc() { - return g_soinfo_list_allocator_rw.alloc(); - } - - static void free(LinkedListEntry* ptr) { - g_soinfo_list_allocator_rw.free(ptr); - } -}; // This is used by dlsym(3). It performs symbol lookup only within the // specified soinfo object and its dependencies in breadth first order. @@ -798,73 +824,80 @@ static int open_library(const char* name) { return fd; } -static soinfo* load_library(const char* name, int dlflags, const android_dlextinfo* extinfo) { - int fd = -1; - ScopedFd file_guard(-1); - - if (extinfo != nullptr && (extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD) != 0) { - fd = extinfo->library_fd; - } else { - // Open the file. - fd = open_library(name); - if (fd == -1) { - DL_ERR("library \"%s\" not found", name); - return nullptr; - } - - file_guard.reset(fd); +template +static void for_each_dt_needed(const soinfo* si, F action) { + for (ElfW(Dyn)* d = si->dynamic; d->d_tag != DT_NULL; ++d) { + if (d->d_tag == DT_NEEDED) { + action(si->strtab + d->d_un.d_val); } + } +} - ElfReader elf_reader(name, fd); +static soinfo* load_library(LoadTaskList& load_tasks, const char* name, int dlflags, const android_dlextinfo* extinfo) { + int fd = -1; + ScopedFd file_guard(-1); - struct stat file_stat; - if (TEMP_FAILURE_RETRY(fstat(fd, &file_stat)) != 0) { - DL_ERR("unable to stat file for the library %s: %s", name, strerror(errno)); + if (extinfo != nullptr && (extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD) != 0) { + fd = extinfo->library_fd; + } else { + // Open the file. + fd = open_library(name); + if (fd == -1) { + DL_ERR("library \"%s\" not found", name); return nullptr; } - // Check for symlink and other situations where - // file can have different names. - for (soinfo* si = solist; si != nullptr; si = si->next) { - if (si->get_st_dev() != 0 && - si->get_st_ino() != 0 && - si->get_st_dev() == file_stat.st_dev && - si->get_st_ino() == file_stat.st_ino) { - TRACE("library \"%s\" is already loaded under different name/path \"%s\" - will return existing soinfo", name, si->name); - return si; - } + file_guard.reset(fd); + } + + struct stat file_stat; + if (TEMP_FAILURE_RETRY(fstat(fd, &file_stat)) != 0) { + DL_ERR("unable to stat file for the library %s: %s", name, strerror(errno)); + return nullptr; + } + + // Check for symlink and other situations where + // file can have different names. + for (soinfo* si = solist; si != nullptr; si = si->next) { + if (si->get_st_dev() != 0 && + si->get_st_ino() != 0 && + si->get_st_dev() == file_stat.st_dev && + si->get_st_ino() == file_stat.st_ino) { + TRACE("library \"%s\" is already loaded under different name/path \"%s\" - will return existing soinfo", name, si->name); + return si; } + } - if ((dlflags & RTLD_NOLOAD) != 0) { - return nullptr; - } + if ((dlflags & RTLD_NOLOAD) != 0) { + return nullptr; + } - // Read the ELF header and load the segments. - if (!elf_reader.Load(extinfo)) { - return nullptr; - } + // Read the ELF header and load the segments. + ElfReader elf_reader(name, fd); + if (!elf_reader.Load(extinfo)) { + return nullptr; + } - soinfo* si = soinfo_alloc(SEARCH_NAME(name), &file_stat); - if (si == nullptr) { - return nullptr; - } - si->base = elf_reader.load_start(); - si->size = elf_reader.load_size(); - si->load_bias = elf_reader.load_bias(); - si->phnum = elf_reader.phdr_count(); - si->phdr = elf_reader.loaded_phdr(); + soinfo* si = soinfo_alloc(SEARCH_NAME(name), &file_stat); + if (si == nullptr) { + return nullptr; + } + si->base = elf_reader.load_start(); + si->size = elf_reader.load_size(); + si->load_bias = elf_reader.load_bias(); + si->phnum = elf_reader.phdr_count(); + si->phdr = elf_reader.loaded_phdr(); - // At this point we know that whatever is loaded @ base is a valid ELF - // shared library whose segments are properly mapped in. - TRACE("[ load_library base=%p size=%zu name='%s' ]", - reinterpret_cast(si->base), si->size, si->name); + if (!si->PrelinkImage()) { + soinfo_free(si); + return nullptr; + } - if (!si->LinkImage(extinfo)) { - soinfo_free(si); - return nullptr; - } + for_each_dt_needed(si, [&] (const char* name) { + load_tasks.push_back(LoadTask::create(name, si)); + }); - return si; + return si; } static soinfo *find_loaded_library_by_name(const char* name) { @@ -877,33 +910,122 @@ static soinfo *find_loaded_library_by_name(const char* name) { return nullptr; } -static soinfo* find_library_internal(const char* name, int dlflags, const android_dlextinfo* extinfo) { - if (name == nullptr) { - return somain; - } +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); // Library might still be loaded, the accurate detection - // of this fact is done by load_library + // of this fact is done by load_library. if (si == nullptr) { TRACE("[ '%s' has not been found by name. Trying harder...]", name); - si = load_library(name, dlflags, extinfo); - } - - if (si != nullptr && (si->flags & FLAG_LINKED) == 0) { - DL_ERR("recursive link to \"%s\"", si->name); - return nullptr; + si = load_library(load_tasks, name, dlflags, extinfo); } return si; } -static soinfo* find_library(const char* name, int dlflags, const android_dlextinfo* extinfo) { - soinfo* si = find_library_internal(name, dlflags, extinfo); - if (si != nullptr) { - si->ref_count++; +static void soinfo_unload(soinfo* si); + +static bool is_recursive(soinfo* si, soinfo* parent) { + if (parent == nullptr) { + return false; } + + if (si == parent) { + DL_ERR("recursive link to \"%s\"", si->name); + return true; + } + + return !parent->get_parents().visit([&](soinfo* grandparent) { + return !is_recursive(si, grandparent); + }); +} + +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 dlflags, const android_dlextinfo* extinfo) { + // Step 0: prepare. + LoadTaskList load_tasks; + for (size_t i = 0; i < library_names_size; ++i) { + const char* name = library_names[i]; + load_tasks.push_back(LoadTask::create(name, nullptr)); + } + + // Libraries added to this list in reverse order so that we can + // start linking from bottom-up - see step 2. + SoinfoLinkedList found_libs; + size_t soinfos_size = 0; + + auto failure_guard = create_scope_guard([&]() { + // Housekeeping + load_tasks.for_each([] (LoadTask* t) { + LoadTask::deleter(t); + }); + + for (size_t i = 0; iget_name(), dlflags, extinfo); + if (si == nullptr) { + return false; + } + + soinfo* needed_by = task->get_needed_by(); + + if (is_recursive(si, needed_by)) { + soinfo_free(si); + return false; + } + + si->ref_count++; + if (needed_by != nullptr) { + needed_by->add_child(si); + } + found_libs.push_front(si); + + // When ld_preloads is not null first + // ld_preloads_size libs are in fact ld_preloads. + if (ld_preloads != nullptr && soinfos_size < ld_preloads_size) { + ld_preloads[soinfos_size] = si; + } + + if (soinfos_sizeflags & FLAG_LINKED) == 0) { + if (!si->LinkImage(extinfo)) { + return false; + } + si->flags |= FLAG_LINKED; + } + } + + // All is well - found_libs and load_tasks are empty at this point + // and all libs are successfully linked. + failure_guard.disable(); + return true; +} + +static soinfo* find_library(const char* name, int dlflags, const android_dlextinfo* extinfo) { + if (name == nullptr) { + somain->ref_count++; + return somain; + } + + soinfo* si; + + if (!find_libraries(&name, 1, &si, nullptr, 0, dlflags, extinfo)) { + return nullptr; + } + return si; } @@ -925,20 +1047,17 @@ static void soinfo_unload(soinfo* si) { soinfo_unload(children[i]); } } else { - for (ElfW(Dyn)* d = si->dynamic; d->d_tag != DT_NULL; ++d) { - if (d->d_tag == DT_NEEDED) { - const char* library_name = si->strtab + d->d_un.d_val; - TRACE("%s needs to unload %s", si->name, library_name); - soinfo* needed = find_library(library_name, RTLD_NOLOAD, nullptr); - if (needed != nullptr) { - soinfo_unload(needed); - } else { - // 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); - } + for_each_dt_needed(si, [&] (const char* library_name) { + TRACE("deprecated (old format of soinfo): %s needs to unload %s", si->name, library_name); + soinfo* needed = find_library(library_name, RTLD_NOLOAD, nullptr); + if (needed != nullptr) { + soinfo_unload(needed); + } else { + // 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); } - } + }); } notify_gdb_of_unload(si); @@ -1047,9 +1166,6 @@ static void soinfo_ifunc_relocate(soinfo* si, ElfW(Rela)* rela, unsigned count) #if defined(USE_RELA) int soinfo::Relocate(ElfW(Rela)* rela, unsigned count) { - ElfW(Sym)* s; - soinfo* lsi; - for (size_t idx = 0; idx < count; ++idx, ++rela) { unsigned type = ELFW(R_TYPE)(rela->r_info); unsigned sym = ELFW(R_SYM)(rela->r_info); @@ -1061,6 +1177,10 @@ int soinfo::Relocate(ElfW(Rela)* rela, unsigned count) { if (type == 0) { // R_*_NONE continue; } + + ElfW(Sym)* s = nullptr; + soinfo* lsi = nullptr; + if (sym != 0) { sym_name = reinterpret_cast(strtab + symtab[sym].st_name); s = soinfo_do_lookup(this, sym_name, &lsi); @@ -1119,8 +1239,6 @@ int soinfo::Relocate(ElfW(Rela)* rela, unsigned count) { sym_addr = static_cast(s->st_value + lsi->load_bias); } count_relocation(kRelocSymbol); - } else { - s = nullptr; } switch (type) { @@ -1314,9 +1432,6 @@ int soinfo::Relocate(ElfW(Rela)* rela, unsigned count) { #else // REL, not RELA. int soinfo::Relocate(ElfW(Rel)* rel, unsigned count) { - ElfW(Sym)* s; - soinfo* lsi; - for (size_t idx = 0; idx < count; ++idx, ++rel) { unsigned type = ELFW(R_TYPE)(rel->r_info); // TODO: don't use unsigned for 'sym'. Use uint32_t or ElfW(Addr) instead. @@ -1329,6 +1444,10 @@ int soinfo::Relocate(ElfW(Rel)* rel, unsigned count) { if (type == 0) { // R_*_NONE continue; } + + ElfW(Sym)* s = nullptr; + soinfo* lsi = nullptr; + if (sym != 0) { sym_name = reinterpret_cast(strtab + symtab[sym].st_name); s = soinfo_do_lookup(this, sym_name, &lsi); @@ -1390,8 +1509,6 @@ int soinfo::Relocate(ElfW(Rel)* rel, unsigned count) { sym_addr = static_cast(s->st_value + lsi->load_bias); } count_relocation(kRelocSymbol); - } else { - s = nullptr; } switch (type) { @@ -1546,7 +1663,7 @@ static bool mips_relocate_got(soinfo* si) { for (size_t g = gotsym; g < symtabno; g++, sym++, got++) { // This is an undefined reference... try to locate it. const char* sym_name = si->strtab + sym->st_name; - soinfo* lsi; + soinfo* lsi = nullptr; ElfW(Sym)* s = soinfo_do_lookup(si, sym_name, &lsi); if (s == nullptr) { // We only allow an undefined symbol if this is a weak reference. @@ -1643,6 +1760,9 @@ void soinfo::CallConstructors() { } void soinfo::CallDestructors() { + if (!constructors_called) { + return; + } TRACE("\"%s\": calling destructors", name); // DT_FINI_ARRAY must be parsed in reverse order. @@ -1728,7 +1848,7 @@ bool soinfo::get_has_ifuncs() { return false; } -// This is a return on get_children() in case +// This is a return on get_children()/get_parents() if // 'this->flags' does not have FLAG_NEW_SOINFO set. static soinfo::soinfo_list_t g_empty_list; @@ -1740,6 +1860,14 @@ soinfo::soinfo_list_t& soinfo::get_children() { return g_empty_list; } +soinfo::soinfo_list_t& soinfo::get_parents() { + if ((this->flags & FLAG_NEW_SOINFO) == 0) { + return g_empty_list; + } + + return this->parents; +} + /* Force any of the closed stdin, stdout and stderr to be associated with /dev/null. */ static int nullify_closed_stdio() { @@ -1801,20 +1929,18 @@ static int nullify_closed_stdio() { return return_value; } -bool soinfo::LinkImage(const android_dlextinfo* extinfo) { - bool relocating_linker = (flags & FLAG_LINKER) != 0; +bool soinfo::PrelinkImage() { + phdr_table_get_dynamic_section(phdr, phnum, load_bias, &dynamic); - /* We can't debug anything until the linker is relocated */ + /* We can't log anything until the linker is relocated */ + bool relocating_linker = (flags & FLAG_LINKER) != 0; if (!relocating_linker) { INFO("[ linking %s ]", name); DEBUG("si->base = %p si->flags = 0x%08x", reinterpret_cast(base), flags); } /* Extract dynamic section */ - size_t dynamic_count; - ElfW(Word) dynamic_flags; - phdr_table_get_dynamic_section(phdr, phnum, load_bias, &dynamic, - &dynamic_count, &dynamic_flags); + ElfW(Word) dynamic_flags = phdr->p_flags; if (dynamic == nullptr) { if (!relocating_linker) { DL_ERR("missing PT_DYNAMIC in \"%s\"", name); @@ -1882,7 +2008,7 @@ bool soinfo::LinkImage(const android_dlextinfo* extinfo) { // if the dynamic table is writable // FIXME: not working currently for N64 // The flags for the LOAD and DYNAMIC program headers do not agree. -// The LOAD section containng the dynamic table has been mapped as +// The LOAD section containing the dynamic table has been mapped as // read-only, but the DYNAMIC header claims it is writable. #if !(defined(__mips__) && defined(__LP64__)) if ((dynamic_flags & PF_W) != 0) { @@ -2028,38 +2154,10 @@ bool soinfo::LinkImage(const android_dlextinfo* extinfo) { DL_ERR("empty/missing DT_SYMTAB in \"%s\"", name); return false; } + return true; +} - // If this is the main executable, then load all of the libraries from LD_PRELOAD now. - if (flags & FLAG_EXE) { - memset(g_ld_preloads, 0, sizeof(g_ld_preloads)); - size_t preload_count = 0; - for (size_t i = 0; g_ld_preload_names[i] != nullptr; i++) { - soinfo* lsi = find_library(g_ld_preload_names[i], 0, nullptr); - if (lsi != nullptr) { - g_ld_preloads[preload_count++] = lsi; - } else { - // As with glibc, failure to load an LD_PRELOAD library is just a warning. - DL_WARN("could not load library \"%s\" from LD_PRELOAD for \"%s\"; caused by %s", - g_ld_preload_names[i], name, linker_get_error_buffer()); - } - } - } - - for (ElfW(Dyn)* d = dynamic; d->d_tag != DT_NULL; ++d) { - if (d->d_tag == DT_NEEDED) { - const char* library_name = strtab + d->d_un.d_val; - DEBUG("%s needs %s", name, library_name); - soinfo* lsi = find_library(library_name, 0, nullptr); - if (lsi == nullptr) { - strlcpy(tmp_err_buf, linker_get_error_buffer(), sizeof(tmp_err_buf)); - DL_ERR("could not load library \"%s\" needed by \"%s\"; caused by %s", - library_name, name, tmp_err_buf); - return false; - } - - add_child(lsi); - } - } +bool soinfo::LinkImage(const android_dlextinfo* extinfo) { #if !defined(__LP64__) if (has_text_relocations) { @@ -2121,7 +2219,6 @@ bool soinfo::LinkImage(const android_dlextinfo* extinfo) { } #endif - flags |= FLAG_LINKED; DEBUG("[ finished linking %s ]", name); #if !defined(__LP64__) @@ -2183,6 +2280,7 @@ static void add_vdso(KernelArgumentBlock& args __unused) { si->size = phdr_table_get_load_size(si->phdr, si->phnum); si->load_bias = get_elf_exec_load_bias(ehdr_vdso); + si->PrelinkImage(); si->LinkImage(nullptr); #endif } @@ -2216,7 +2314,7 @@ static void init_linker_info_for_gdb(ElfW(Addr) linker_base) { ElfW(Ehdr)* elf_hdr = reinterpret_cast(linker_base); ElfW(Phdr)* phdr = reinterpret_cast(linker_base + elf_hdr->e_phoff); phdr_table_get_dynamic_section(phdr, elf_hdr->e_phnum, linker_base, - &linker_soinfo_for_gdb.dynamic, nullptr, nullptr); + &linker_soinfo_for_gdb.dynamic); insert_soinfo_into_debug_map(&linker_soinfo_for_gdb); } @@ -2312,6 +2410,37 @@ static ElfW(Addr) __linker_init_post_relocation(KernelArgumentBlock& args, ElfW( somain = si; + si->PrelinkImage(); + + // Load ld_preloads and dependencies. + StringLinkedList needed_library_name_list; + size_t needed_libraries_count = 0; + size_t ld_preloads_count = 0; + while (g_ld_preload_names[ld_preloads_count] != nullptr) { + needed_library_name_list.push_back(g_ld_preload_names[ld_preloads_count++]); + ++needed_libraries_count; + } + + for_each_dt_needed(si, [&](const char* name) { + needed_library_name_list.push_back(name); + ++needed_libraries_count; + }); + + const char* needed_library_names[needed_libraries_count]; + soinfo* needed_library_si[needed_libraries_count]; + + memset(needed_library_names, 0, sizeof(needed_library_names)); + 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, 0, nullptr)) { + __libc_format_fd(2, "CANNOT LINK EXECUTABLE DEPENDENCIES: %s\n", linker_get_error_buffer()); + exit(EXIT_FAILURE); + } + + for (size_t i = 0; iadd_child(needed_library_si[i]); + } + if (!si->LinkImage(nullptr)) { __libc_format_fd(2, "CANNOT LINK EXECUTABLE: %s\n", linker_get_error_buffer()); exit(EXIT_FAILURE); @@ -2321,11 +2450,7 @@ static ElfW(Addr) __linker_init_post_relocation(KernelArgumentBlock& args, ElfW( si->CallPreInitConstructors(); - for (size_t i = 0; g_ld_preloads[i] != nullptr; ++i) { - g_ld_preloads[i]->CallConstructors(); - } - - /* After the LinkImage, the si->load_bias is initialized. + /* After the PrelinkImage, the si->load_bias is initialized. * For so lib, the map->l_addr will be updated in notify_gdb_of_load. * We need to update this value for so exe here. So Unwind_Backtrace * for some arch like x86 could work correctly within so exe. @@ -2440,7 +2565,7 @@ extern "C" ElfW(Addr) __linker_init(void* raw_args) { linker_so.phnum = elf_hdr->e_phnum; linker_so.flags |= FLAG_LINKER; - if (!linker_so.LinkImage(nullptr)) { + if (!(linker_so.PrelinkImage() && linker_so.LinkImage(nullptr))) { // 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 // call write() (because it involves a GOT reference). We may as diff --git a/linker/linker.h b/linker/linker.h index 6547d685e..3024d3ab2 100644 --- a/linker/linker.h +++ b/linker/linker.h @@ -204,6 +204,7 @@ struct soinfo { void CallConstructors(); void CallDestructors(); void CallPreInitConstructors(); + bool PrelinkImage(); bool LinkImage(const android_dlextinfo* extinfo); void add_child(soinfo* child); @@ -217,6 +218,7 @@ struct soinfo { bool get_has_ifuncs(); soinfo_list_t& get_children(); + soinfo_list_t& get_parents(); bool inline has_min_version(uint32_t min_version) { return (flags & FLAG_NEW_SOINFO) != 0 && version >= min_version; diff --git a/linker/linker_phdr.cpp b/linker/linker_phdr.cpp index 1bbd57778..436517271 100644 --- a/linker/linker_phdr.cpp +++ b/linker/linker_phdr.cpp @@ -702,34 +702,17 @@ int phdr_table_get_arm_exidx(const ElfW(Phdr)* phdr_table, size_t phdr_count, * load_bias -> load bias * Output: * dynamic -> address of table in memory (null on failure). - * dynamic_count -> number of items in table (0 on failure). - * dynamic_flags -> protection flags for section (unset on failure) * Return: * void */ void phdr_table_get_dynamic_section(const ElfW(Phdr)* phdr_table, size_t phdr_count, - ElfW(Addr) load_bias, - ElfW(Dyn)** dynamic, size_t* dynamic_count, ElfW(Word)* dynamic_flags) { - const ElfW(Phdr)* phdr = phdr_table; - const ElfW(Phdr)* phdr_limit = phdr + phdr_count; - - for (phdr = phdr_table; phdr < phdr_limit; phdr++) { - if (phdr->p_type != PT_DYNAMIC) { - continue; - } - - *dynamic = reinterpret_cast(load_bias + phdr->p_vaddr); - if (dynamic_count) { - *dynamic_count = (unsigned)(phdr->p_memsz / 8); - } - if (dynamic_flags) { - *dynamic_flags = phdr->p_flags; - } - return; - } + ElfW(Addr) load_bias, ElfW(Dyn)** dynamic) { *dynamic = nullptr; - if (dynamic_count) { - *dynamic_count = 0; + for (const ElfW(Phdr)* phdr = phdr_table, *phdr_limit = phdr + phdr_count; phdr < phdr_limit; phdr++) { + if (phdr->p_type == PT_DYNAMIC) { + *dynamic = reinterpret_cast(load_bias + phdr->p_vaddr); + return; + } } } diff --git a/linker/linker_phdr.h b/linker/linker_phdr.h index 50708a0e6..d4c3ce85f 100644 --- a/linker/linker_phdr.h +++ b/linker/linker_phdr.h @@ -101,7 +101,6 @@ int phdr_table_get_arm_exidx(const ElfW(Phdr)* phdr_table, size_t phdr_count, El #endif void phdr_table_get_dynamic_section(const ElfW(Phdr)* phdr_table, size_t phdr_count, - ElfW(Addr) load_bias, - ElfW(Dyn)** dynamic, size_t* dynamic_count, ElfW(Word)* dynamic_flags); + ElfW(Addr) load_bias, ElfW(Dyn)** dynamic); #endif /* LINKER_PHDR_H */ diff --git a/tests/Android.mk b/tests/Android.mk index 26014aca3..cb588d78e 100644 --- a/tests/Android.mk +++ b/tests/Android.mk @@ -114,6 +114,7 @@ libBionicStandardTests_src_files := \ system_properties_test.cpp \ time_test.cpp \ uchar_test.cpp \ + uniqueptr_test.cpp \ unistd_test.cpp \ wchar_test.cpp \ diff --git a/tests/dlfcn_test.cpp b/tests/dlfcn_test.cpp index 6de38c89e..b8c33dd53 100644 --- a/tests/dlfcn_test.cpp +++ b/tests/dlfcn_test.cpp @@ -130,6 +130,55 @@ TEST(dlfcn, ifunc_ctor_call) { } #endif +TEST(dlfcn, dlopen_check_order) { + // Here is how the test library and its dt_needed + // libraries are arranged + // + // libtest_check_order.so + // | + // +-> libtest_check_order_1_left.so + // | | + // | +-> libtest_check_order_a.so + // | | + // | +-> libtest_check_order_b.so + // | + // +-> libtest_check_order_2_right.so + // | | + // | +-> libtest_check_order_d.so + // | | + // | +-> libtest_check_order_b.so + // | + // +-> libtest_check_order_3_c.so + // + // load order should be (1, 2, 3, a, b, d) + // + // get_answer() is defined in (2, 3, a, b, c) + // get_answer2() is defined in (b, d) + void* sym = dlsym(RTLD_DEFAULT, "dlopen_test_get_answer"); + ASSERT_TRUE(sym == nullptr); + void* handle = dlopen("libtest_check_order.so", RTLD_NOW); + ASSERT_TRUE(handle != nullptr); + typedef int (*fn_t) (void); + fn_t fn, fn2; + fn = reinterpret_cast(dlsym(RTLD_DEFAULT, "dlopen_test_get_answer")); + ASSERT_TRUE(fn != NULL); + fn2 = reinterpret_cast(dlsym(RTLD_DEFAULT, "dlopen_test_get_answer2")); + ASSERT_TRUE(fn2 != NULL); + + ASSERT_EQ(42, fn()); + ASSERT_EQ(43, fn2()); + dlclose(handle); +} + +// 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_a.so +TEST(dlfcn, dlopen_check_loop) { + void* handle = dlopen("libtest_with_dependency_loop.so", RTLD_NOW); + ASSERT_TRUE(handle == NULL); + ASSERT_STREQ("dlopen failed: recursive link to \"libtest_with_dependency_loop_a.so\"", dlerror()); +} + TEST(dlfcn, dlopen_failure) { void* self = dlopen("/does/not/exist", RTLD_NOW); ASSERT_TRUE(self == NULL); diff --git a/tests/libs/Android.mk b/tests/libs/Android.mk index b1cc836c6..2ceb15b9e 100644 --- a/tests/libs/Android.mk +++ b/tests/libs/Android.mk @@ -102,6 +102,160 @@ build_type := target build_target := SHARED_LIBRARY include $(TEST_PATH)/Android.build.mk +# ----------------------------------------------------------------------------- +# Libraries used by dlfcn tests to verify correct load order: +# libtest_check_order_2_right.so +# ----------------------------------------------------------------------------- +libtest_check_order_2_right_src_files := \ + dlopen_testlib_answer.cpp + +libtest_check_order_2_right_cflags := -D__ANSWER=42 +module := libtest_check_order_2_right +build_type := target +build_target := SHARED_LIBRARY +include $(TEST_PATH)/Android.build.mk + +# ----------------------------------------------------------------------------- +# libtest_check_order_a.so +# ----------------------------------------------------------------------------- +libtest_check_order_a_src_files := \ + dlopen_testlib_answer.cpp + +libtest_check_order_a_cflags := -D__ANSWER=1 +module := libtest_check_order_a +build_type := target +build_target := SHARED_LIBRARY +include $(TEST_PATH)/Android.build.mk + +# ----------------------------------------------------------------------------- +# libtest_check_order_b.so +# ----------------------------------------------------------------------------- +libtest_check_order_b_src_files := \ + dlopen_testlib_answer.cpp + +libtest_check_order_b_cflags := -D__ANSWER=2 -D__ANSWER2=43 +module := libtest_check_order_b +build_type := target +build_target := SHARED_LIBRARY +include $(TEST_PATH)/Android.build.mk + +# ----------------------------------------------------------------------------- +# libtest_check_order_c.so +# ----------------------------------------------------------------------------- +libtest_check_order_3_c_src_files := \ + dlopen_testlib_answer.cpp + +libtest_check_order_3_c_cflags := -D__ANSWER=3 +module := libtest_check_order_3_c +build_type := target +build_target := SHARED_LIBRARY +include $(TEST_PATH)/Android.build.mk + +# ----------------------------------------------------------------------------- +# libtest_check_order_d.so +# ----------------------------------------------------------------------------- +libtest_check_order_d_src_files := \ + dlopen_testlib_answer.cpp + +libtest_check_order_d_shared_libraries := libtest_check_order_b +libtest_check_order_d_cflags := -D__ANSWER=4 -D__ANSWER2=4 +module := libtest_check_order_d +build_type := target +build_target := SHARED_LIBRARY +include $(TEST_PATH)/Android.build.mk + +# ----------------------------------------------------------------------------- +# libtest_check_order_left.so +# ----------------------------------------------------------------------------- +libtest_check_order_1_left_src_files := \ + empty.cpp + +libtest_check_order_1_left_shared_libraries := libtest_check_order_a libtest_check_order_b + +module := libtest_check_order_1_left +build_type := target +build_target := SHARED_LIBRARY +include $(TEST_PATH)/Android.build.mk + +# ----------------------------------------------------------------------------- +# libtest_check_order.so +# ----------------------------------------------------------------------------- +libtest_check_order_src_files := \ + empty.cpp + +libtest_check_order_shared_libraries := libtest_check_order_1_left \ + libtest_check_order_2_right libtest_check_order_3_c + +module := libtest_check_order +build_type := target +build_target := SHARED_LIBRARY +include $(TEST_PATH)/Android.build.mk + +# ----------------------------------------------------------------------------- +# Library with dependency loop used by dlfcn tests +# +# libtest_with_dependency_loop -> a -> b -> c -> a +# ----------------------------------------------------------------------------- +libtest_with_dependency_loop_src_files := empty.cpp + +libtest_with_dependency_loop_shared_libraries := \ + libtest_with_dependency_loop_a + +module := libtest_with_dependency_loop +build_type := target +build_target := SHARED_LIBRARY +include $(TEST_PATH)/Android.build.mk + +# ----------------------------------------------------------------------------- +# libtest_with_dependency_loop_a.so +# ----------------------------------------------------------------------------- +libtest_with_dependency_loop_a_src_files := empty.cpp + +libtest_with_dependency_loop_a_shared_libraries := \ + libtest_with_dependency_loop_b_tmp + +module := libtest_with_dependency_loop_a +build_type := target +build_target := SHARED_LIBRARY +include $(TEST_PATH)/Android.build.mk + +# ----------------------------------------------------------------------------- +# libtest_with_dependency_loop_b.so +# +# this is temporary placeholder - will be removed +# ----------------------------------------------------------------------------- +libtest_with_dependency_loop_b_tmp_src_files := empty.cpp +libtest_with_dependency_loop_b_tmp_ldflags := -Wl,-soname=libtest_with_dependency_loop_b.so + +module := libtest_with_dependency_loop_b_tmp +build_type := target +build_target := SHARED_LIBRARY +include $(TEST_PATH)/Android.build.mk + +# ----------------------------------------------------------------------------- +# libtest_with_dependency_loop_b.so +# ----------------------------------------------------------------------------- +libtest_with_dependency_loop_b_src_files := empty.cpp +libtest_with_dependency_loop_b_shared_libraries := libtest_with_dependency_loop_c + +module := libtest_with_dependency_loop_b +build_type := target +build_target := SHARED_LIBRARY +include $(TEST_PATH)/Android.build.mk + +# ----------------------------------------------------------------------------- +# libtest_with_dependency_loop_c.so +# ----------------------------------------------------------------------------- +libtest_with_dependency_loop_c_src_files := empty.cpp + +libtest_with_dependency_loop_c_shared_libraries := \ + libtest_with_dependency_loop_a + +module := libtest_with_dependency_loop_c +build_type := target +build_target := SHARED_LIBRARY +include $(TEST_PATH)/Android.build.mk + # ----------------------------------------------------------------------------- # Library with dependency used by dlfcn tests # ----------------------------------------------------------------------------- diff --git a/tests/libs/dlopen_testlib_answer.cpp b/tests/libs/dlopen_testlib_answer.cpp new file mode 100644 index 000000000..a4d75046e --- /dev/null +++ b/tests/libs/dlopen_testlib_answer.cpp @@ -0,0 +1,25 @@ +/* + * 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 dlopen_test_get_answer() { + return __ANSWER; +} + +#ifdef __ANSWER2 +extern "C" int dlopen_test_get_answer2() { + return __ANSWER2; +} +#endif diff --git a/tests/uniqueptr_test.cpp b/tests/uniqueptr_test.cpp new file mode 100644 index 000000000..4b6608af2 --- /dev/null +++ b/tests/uniqueptr_test.cpp @@ -0,0 +1,101 @@ +/* + * 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. + */ + +#include + +#include + +static int cCount = 0; +struct C { + C() { ++cCount; } + ~C() { --cCount; } +}; + +static bool freed = false; +struct Freer { + void operator() (int* p) { + ASSERT_EQ(123, *p); + free(p); + freed = true; + } +}; + +TEST(UniquePtr, smoke) { + // + // UniquePtr tests... + // + + // Can we free a single object? + { + UniquePtr c(new C); + ASSERT_TRUE(cCount == 1); + } + ASSERT_TRUE(cCount == 0); + // Does release work? + C* rawC; + { + UniquePtr c(new C); + ASSERT_TRUE(cCount == 1); + rawC = c.release(); + } + ASSERT_TRUE(cCount == 1); + delete rawC; + // Does reset work? + { + UniquePtr c(new C); + ASSERT_TRUE(cCount == 1); + c.reset(new C); + ASSERT_TRUE(cCount == 1); + } + ASSERT_TRUE(cCount == 0); + + // + // UniquePtr tests... + // + + // Can we free an array? + { + UniquePtr cs(new C[4]); + ASSERT_TRUE(cCount == 4); + } + ASSERT_TRUE(cCount == 0); + // Does release work? + { + UniquePtr c(new C[4]); + ASSERT_TRUE(cCount == 4); + rawC = c.release(); + } + ASSERT_TRUE(cCount == 4); + delete[] rawC; + // Does reset work? + { + UniquePtr c(new C[4]); + ASSERT_TRUE(cCount == 4); + c.reset(new C[2]); + ASSERT_TRUE(cCount == 2); + } + ASSERT_TRUE(cCount == 0); + + // + // Custom deleter tests... + // + ASSERT_TRUE(!freed); + { + UniquePtr i(reinterpret_cast(malloc(sizeof(int)))); + *i = 123; + } + ASSERT_TRUE(freed); +}