diff --git a/linker/linker.cpp b/linker/linker.cpp
index cf657057ef24e7895a7c17c6b1faf38bc7a25387..34099316fe163eda504e9cd52cb7581012bcdb6c 100644 (file)
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
-#include <sys/stat.h>
+#include <sys/param.h>
#include <unistd.h>
+#include <new>
+
// Private C library headers.
#include "private/bionic_tls.h"
#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"
#define SEARCH_NAME(x) get_base_name(x)
#endif
-static bool soinfo_link_image(soinfo* si, const android_dlextinfo* extinfo);
static ElfW(Addr) get_elf_exec_load_bias(const ElfW(Ehdr)* elf);
static LinkerAllocator<soinfo> g_soinfo_allocator;
static soinfo* solist;
static soinfo* sonext;
-static soinfo* somain; /* main process, always the one after libdl_info */
+static soinfo* somain; // main process, always the one after libdl_info
static const char* const kDefaultLdPaths[] = {
#if defined(__LP64__)
"/vendor/lib",
"/system/lib",
#endif
- NULL
+ nullptr
};
#define LDPATH_BUFSIZE (LDPATH_MAX*64)
__LIBC_HIDDEN__ int g_ld_debug_verbosity;
-__LIBC_HIDDEN__ abort_msg_t* g_abort_message = NULL; // For debuggerd.
+__LIBC_HIDDEN__ abort_msg_t* g_abort_message = nullptr; // For debuggerd.
enum RelocationKind {
- kRelocAbsolute = 0,
- kRelocRelative,
- kRelocCopy,
- kRelocSymbol,
- kRelocMax
+ kRelocAbsolute = 0,
+ kRelocRelative,
+ kRelocCopy,
+ kRelocSymbol,
+ kRelocMax
};
#if STATS
struct linker_stats_t {
- int count[kRelocMax];
+ int count[kRelocMax];
};
static linker_stats_t linker_stats;
static void count_relocation(RelocationKind kind) {
- ++linker_stats.count[kind];
+ ++linker_stats.count[kind];
}
#else
static void count_relocation(RelocationKind) {
#if defined(__LP64__)
#define MARK(offset) \
do { \
- if ((((offset) >> 12) >> 5) < 4096) \
- bitmask[((offset) >> 12) >> 5] |= (1 << (((offset) >> 12) & 31)); \
+ if ((((offset) >> 12) >> 5) < 4096) \
+ bitmask[((offset) >> 12) >> 5] |= (1 << (((offset) >> 12) & 31)); \
} while (0)
#else
#define MARK(offset) \
do { \
- bitmask[((offset) >> 12) >> 3] |= (1 << (((offset) >> 12) & 7)); \
+ bitmask[((offset) >> 12) >> 3] |= (1 << (((offset) >> 12) & 7)); \
} while (0)
#endif
#else
#define DISALLOW_ALLOCATION(return_type, name, ...) \
return_type name __VA_ARGS__ \
{ \
- __libc_fatal("ERROR: " #name " called from the dynamic linker!\n"); \
+ __libc_fatal("ERROR: " #name " called from the dynamic linker!\n"); \
}
DISALLOW_ALLOCATION(void*, malloc, (size_t u __unused));
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() {
return sizeof(__linker_dl_err_buf);
}
-/*
- * This function is an empty stub where GDB locates a breakpoint to get notified
- * about linker activity.
- */
+// This function is an empty stub where GDB locates a breakpoint to get notified
+// about linker activity.
extern "C" void __attribute__((noinline)) __attribute__((visibility("default"))) rtld_db_dlactivity();
static pthread_mutex_t g__r_debug_mutex = PTHREAD_MUTEX_INITIALIZER;
-static r_debug _r_debug = {1, NULL, reinterpret_cast<uintptr_t>(&rtld_db_dlactivity), r_debug::RT_CONSISTENT, 0};
+static r_debug _r_debug = {1, nullptr, reinterpret_cast<uintptr_t>(&rtld_db_dlactivity), r_debug::RT_CONSISTENT, 0};
static link_map* r_debug_tail = 0;
static void insert_soinfo_into_debug_map(soinfo* info) {
- // Copy the necessary fields into the debug structure.
- link_map* map = &(info->link_map_head);
- map->l_addr = info->load_bias;
- map->l_name = reinterpret_cast<char*>(info->name);
- map->l_ld = info->dynamic;
-
- /* Stick the new library at the end of the list.
- * gdb tends to care more about libc than it does
- * about leaf libraries, and ordering it this way
- * reduces the back-and-forth over the wire.
- */
- if (r_debug_tail) {
- r_debug_tail->l_next = map;
- map->l_prev = r_debug_tail;
- map->l_next = 0;
- } else {
- _r_debug.r_map = map;
- map->l_prev = 0;
- map->l_next = 0;
- }
- r_debug_tail = map;
+ // Copy the necessary fields into the debug structure.
+ link_map* map = &(info->link_map_head);
+ map->l_addr = info->load_bias;
+ map->l_name = info->name;
+ map->l_ld = info->dynamic;
+
+ // Stick the new library at the end of the list.
+ // gdb tends to care more about libc than it does
+ // about leaf libraries, and ordering it this way
+ // reduces the back-and-forth over the wire.
+ if (r_debug_tail) {
+ r_debug_tail->l_next = map;
+ map->l_prev = r_debug_tail;
+ map->l_next = 0;
+ } else {
+ _r_debug.r_map = map;
+ map->l_prev = 0;
+ map->l_next = 0;
+ }
+ r_debug_tail = map;
}
static void remove_soinfo_from_debug_map(soinfo* info) {
- link_map* map = &(info->link_map_head);
+ link_map* map = &(info->link_map_head);
- if (r_debug_tail == map) {
- r_debug_tail = map->l_prev;
- }
+ if (r_debug_tail == map) {
+ r_debug_tail = map->l_prev;
+ }
- if (map->l_prev) {
- map->l_prev->l_next = map->l_next;
- }
- if (map->l_next) {
- map->l_next->l_prev = map->l_prev;
- }
+ if (map->l_prev) {
+ map->l_prev->l_next = map->l_next;
+ }
+ if (map->l_next) {
+ map->l_next->l_prev = map->l_prev;
+ }
}
static void notify_gdb_of_load(soinfo* info) {
- if (info->flags & FLAG_EXE) {
- // GDB already knows about the main executable
- return;
- }
+ if (info->is_main_executable()) {
+ // GDB already knows about the main executable
+ return;
+ }
- ScopedPthreadMutexLocker locker(&g__r_debug_mutex);
+ ScopedPthreadMutexLocker locker(&g__r_debug_mutex);
- _r_debug.r_state = r_debug::RT_ADD;
- rtld_db_dlactivity();
+ _r_debug.r_state = r_debug::RT_ADD;
+ rtld_db_dlactivity();
- insert_soinfo_into_debug_map(info);
+ insert_soinfo_into_debug_map(info);
- _r_debug.r_state = r_debug::RT_CONSISTENT;
- rtld_db_dlactivity();
+ _r_debug.r_state = r_debug::RT_CONSISTENT;
+ rtld_db_dlactivity();
}
static void notify_gdb_of_unload(soinfo* info) {
- if (info->flags & FLAG_EXE) {
- // GDB already knows about the main executable
- return;
- }
+ if (info->is_main_executable()) {
+ // GDB already knows about the main executable
+ return;
+ }
- ScopedPthreadMutexLocker locker(&g__r_debug_mutex);
+ ScopedPthreadMutexLocker locker(&g__r_debug_mutex);
- _r_debug.r_state = r_debug::RT_DELETE;
- rtld_db_dlactivity();
+ _r_debug.r_state = r_debug::RT_DELETE;
+ rtld_db_dlactivity();
- remove_soinfo_from_debug_map(info);
+ remove_soinfo_from_debug_map(info);
- _r_debug.r_state = r_debug::RT_CONSISTENT;
- rtld_db_dlactivity();
+ _r_debug.r_state = r_debug::RT_CONSISTENT;
+ rtld_db_dlactivity();
}
void notify_gdb_of_libraries() {
g_soinfo_links_allocator.protect_all(protection);
}
-static soinfo* soinfo_alloc(const char* name, struct stat* file_stat) {
+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) {
DL_ERR("library name \"%s\" too long", name);
- return NULL;
+ return nullptr;
}
- soinfo* si = g_soinfo_allocator.alloc();
-
- // Initialize the new element.
- memset(si, 0, sizeof(soinfo));
- strlcpy(si->name, name, sizeof(si->name));
- si->flags = FLAG_NEW_SOINFO;
-
- if (file_stat != NULL) {
- si->set_st_dev(file_stat->st_dev);
- si->set_st_ino(file_stat->st_ino);
- }
+ soinfo* si = new (g_soinfo_allocator.alloc()) soinfo(name, file_stat, file_offset, rtld_flags);
sonext->next = si;
sonext = si;
}
static void soinfo_free(soinfo* si) {
- if (si == NULL) {
- return;
- }
+ if (si == nullptr) {
+ return;
+ }
- if (si->base != 0 && si->size != 0) {
- munmap(reinterpret_cast<void*>(si->base), si->size);
- }
+ if (si->base != 0 && si->size != 0) {
+ munmap(reinterpret_cast<void*>(si->base), si->size);
+ }
- soinfo *prev = NULL, *trav;
+ soinfo *prev = nullptr, *trav;
- TRACE("name %s: freeing soinfo @ %p", si->name, si);
+ TRACE("name %s: freeing soinfo @ %p", si->name, si);
- for (trav = solist; trav != NULL; trav = trav->next) {
- if (trav == si)
- break;
- prev = trav;
- }
- if (trav == NULL) {
- /* si was not in solist */
- DL_ERR("name \"%s\" is not in solist!", si->name);
- return;
+ for (trav = solist; trav != nullptr; trav = trav->next) {
+ if (trav == si) {
+ break;
}
+ prev = trav;
+ }
+
+ if (trav == nullptr) {
+ // si was not in solist
+ DL_ERR("name \"%s\"@%p is not in solist!", si->name, si);
+ return;
+ }
- // clear links to/from si
- si->remove_all_links();
+ // clear links to/from si
+ si->remove_all_links();
- /* prev will never be NULL, because the first entry in solist is
- always the static libdl_info.
- */
- prev->next = si->next;
- if (si == sonext) {
- sonext = prev;
- }
+ // prev will never be null, because the first entry in solist is
+ // always the static libdl_info.
+ prev->next = si->next;
+ if (si == sonext) {
+ sonext = prev;
+ }
- g_soinfo_allocator.free(si);
+ g_soinfo_allocator.free(si);
}
-
static void parse_path(const char* path, const char* delimiters,
const char** array, char* buf, size_t buf_size, size_t max_count) {
- if (path == NULL) {
+ if (path == nullptr) {
return;
}
// Forget the last path if we had to truncate; this occurs if the 2nd to
// last char isn't '\0' (i.e. wasn't originally a delimiter).
if (i > 0 && len >= buf_size && buf[buf_size - 2] != '\0') {
- array[i - 1] = NULL;
+ array[i - 1] = nullptr;
} else {
- array[i] = NULL;
+ array[i] = nullptr;
}
}
#if defined(__arm__)
-/* For a given PC, find the .so that it belongs to.
- * Returns the base address of the .ARM.exidx section
- * for that .so, and the number of 8-byte entries
- * in that section (via *pcount).
- *
- * Intended to be called by libc's __gnu_Unwind_Find_exidx().
- *
- * This function is exposed via dlfcn.cpp and libdl.so.
- */
+// For a given PC, find the .so that it belongs to.
+// Returns the base address of the .ARM.exidx section
+// for that .so, and the number of 8-byte entries
+// in that section (via *pcount).
+//
+// Intended to be called by libc's __gnu_Unwind_Find_exidx().
+//
+// This function is exposed via dlfcn.cpp and libdl.so.
_Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int* pcount) {
- unsigned addr = (unsigned)pc;
+ unsigned addr = (unsigned)pc;
- for (soinfo* si = solist; si != 0; si = si->next) {
- if ((addr >= si->base) && (addr < (si->base + si->size))) {
- *pcount = si->ARM_exidx_count;
- return (_Unwind_Ptr)si->ARM_exidx;
- }
+ for (soinfo* si = solist; si != 0; si = si->next) {
+ if ((addr >= si->base) && (addr < (si->base + si->size))) {
+ *pcount = si->ARM_exidx_count;
+ return (_Unwind_Ptr)si->ARM_exidx;
}
- *pcount = 0;
- return NULL;
+ }
+ *pcount = 0;
+ return nullptr;
}
#endif
-/* Here, we only have to provide a callback to iterate across all the
- * loaded libraries. gcc_eh does the rest. */
+// Here, we only have to provide a callback to iterate across all the
+// loaded libraries. gcc_eh does the rest.
int dl_iterate_phdr(int (*cb)(dl_phdr_info* info, size_t size, void* data), void* data) {
- int rv = 0;
- for (soinfo* si = solist; si != NULL; si = si->next) {
- dl_phdr_info dl_info;
- dl_info.dlpi_addr = si->link_map_head.l_addr;
- dl_info.dlpi_name = si->link_map_head.l_name;
- dl_info.dlpi_phdr = si->phdr;
- dl_info.dlpi_phnum = si->phnum;
- rv = cb(&dl_info, sizeof(dl_phdr_info), data);
- if (rv != 0) {
- break;
- }
+ int rv = 0;
+ for (soinfo* si = solist; si != nullptr; si = si->next) {
+ dl_phdr_info dl_info;
+ dl_info.dlpi_addr = si->link_map_head.l_addr;
+ dl_info.dlpi_name = si->link_map_head.l_name;
+ dl_info.dlpi_phdr = si->phdr;
+ dl_info.dlpi_phnum = si->phnum;
+ rv = cb(&dl_info, sizeof(dl_phdr_info), data);
+ if (rv != 0) {
+ break;
}
- return rv;
+ }
+ return rv;
+}
+
+ElfW(Sym)* soinfo::find_symbol_by_name(SymbolName& symbol_name) {
+ return is_gnu_hash() ? gnu_lookup(symbol_name) : elf_lookup(symbol_name);
}
-static ElfW(Sym)* soinfo_elf_lookup(soinfo* si, unsigned hash, const char* name) {
- ElfW(Sym)* symtab = si->symtab;
- const char* strtab = si->strtab;
+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->name);
+ }
- TRACE_TYPE(LOOKUP, "SEARCH %s in %s@%p %x %zd",
- name, si->name, reinterpret_cast<void*>(si->base), hash, hash % si->nbucket);
+ return false;
+}
- for (unsigned n = si->bucket[hash % si->nbucket]; n != 0; n = si->chain[n]) {
- ElfW(Sym)* s = symtab + n;
- if (strcmp(strtab + s->st_name, name)) continue;
+ElfW(Sym)* soinfo::gnu_lookup(SymbolName& symbol_name) {
+ uint32_t hash = symbol_name.gnu_hash();
+ uint32_t h2 = hash >> gnu_shift2_;
- /* only concern ourselves with global and weak symbol definitions */
- switch (ELF_ST_BIND(s->st_info)) {
- case STB_GLOBAL:
- case STB_WEAK:
- if (s->st_shndx == SHN_UNDEF) {
- continue;
- }
+ 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];
- TRACE_TYPE(LOOKUP, "FOUND %s in %s (%p) %zd",
- name, si->name, reinterpret_cast<void*>(s->st_value),
- static_cast<size_t>(s->st_size));
- return s;
- case STB_LOCAL:
- continue;
- default:
- __libc_fatal("ERROR: Unexpected ST_BIND value: %d for '%s' in '%s'",
- ELF_ST_BIND(s->st_info), name, si->name);
- }
+ // test against bloom filter
+ if ((1 & (bloom_word >> (hash % bloom_mask_bits)) & (bloom_word >> (h2 % bloom_mask_bits))) == 0) {
+ return nullptr;
}
- TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p %x %zd",
- name, si->name, reinterpret_cast<void*>(si->base), hash, hash % si->nbucket);
+ // bloom test says "probably yes"...
+ uint32_t n = bucket_[hash % nbucket_];
+ if (n == 0) {
+ return nullptr;
+ }
+
+ do {
+ ElfW(Sym)* s = symtab_ + n;
+ if (((chain_[n] ^ hash) >> 1) == 0 &&
+ strcmp(get_string(s->st_name), symbol_name.get_name()) == 0 &&
+ is_symbol_global_and_defined(this, s)) {
+ return s;
+ }
+ } while ((chain_[n++] & 1) == 0);
- return NULL;
+ return nullptr;
}
-static unsigned elfhash(const char* _name) {
- const unsigned char* name = reinterpret_cast<const unsigned char*>(_name);
- unsigned h = 0, g;
+ElfW(Sym)* soinfo::elf_lookup(SymbolName& symbol_name) {
+ uint32_t hash = symbol_name.elf_hash();
- while (*name) {
- h = (h << 4) + *name++;
- g = h & 0xf0000000;
- h ^= g;
- h ^= g >> 24;
+ TRACE_TYPE(LOOKUP, "SEARCH %s in %s@%p h=%x(elf) %zd",
+ symbol_name.get_name(), name, reinterpret_cast<void*>(base), hash, hash % nbucket_);
+
+ for (uint32_t n = bucket_[hash % nbucket_]; n != 0; n = chain_[n]) {
+ ElfW(Sym)* s = symtab_ + n;
+ if (strcmp(get_string(s->st_name), symbol_name.get_name()) == 0 && is_symbol_global_and_defined(this, s)) {
+ TRACE_TYPE(LOOKUP, "FOUND %s in %s (%p) %zd",
+ symbol_name.get_name(), name, reinterpret_cast<void*>(s->st_value),
+ static_cast<size_t>(s->st_size));
+ return s;
}
- return h;
+ }
+
+ TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p %x %zd",
+ symbol_name.get_name(), name, reinterpret_cast<void*>(base), hash, hash % nbucket_);
+
+ return nullptr;
}
-static ElfW(Sym)* soinfo_do_lookup(soinfo* si, const char* name, soinfo** lsi, soinfo* needed[]) {
- unsigned elf_hash = elfhash(name);
- ElfW(Sym)* s = NULL;
+soinfo::soinfo(const char* name, const struct stat* file_stat, off64_t file_offset, int rtld_flags) {
+ memset(this, 0, sizeof(*this));
- if (si != NULL && somain != NULL) {
- /*
- * Local scope is executable scope. Just start looking into it right away
- * for the shortcut.
- */
+ strlcpy(this->name, name, sizeof(this->name));
+ flags_ = FLAG_NEW_SOINFO;
+ version_ = SOINFO_VERSION;
- if (si == somain) {
- s = soinfo_elf_lookup(si, elf_hash, name);
- if (s != NULL) {
- *lsi = si;
- goto done;
- }
-
- /* Next, look for it in the preloads list */
- for (int i = 0; g_ld_preloads[i] != NULL; i++) {
- s = soinfo_elf_lookup(g_ld_preloads[i], elf_hash, name);
- if (s != NULL) {
- *lsi = g_ld_preloads[i];
- goto done;
- }
- }
- } else {
- /* Order of symbol lookup is controlled by DT_SYMBOLIC flag */
+ if (file_stat != nullptr) {
+ this->st_dev_ = file_stat->st_dev;
+ this->st_ino_ = file_stat->st_ino;
+ this->file_offset_ = file_offset;
+ }
- /*
- * If this object was built with symbolic relocations disabled, the
- * first place to look to resolve external references is the main
- * executable.
- */
+ this->rtld_flags_ = rtld_flags;
+}
- if (!si->has_DT_SYMBOLIC) {
- DEBUG("%s: looking up %s in executable %s",
- si->name, name, somain->name);
- s = soinfo_elf_lookup(somain, elf_hash, name);
- if (s != NULL) {
- *lsi = somain;
- goto done;
- }
-
- /* Next, look for it in the preloads list */
- for (int i = 0; g_ld_preloads[i] != NULL; i++) {
- s = soinfo_elf_lookup(g_ld_preloads[i], elf_hash, name);
- if (s != NULL) {
- *lsi = g_ld_preloads[i];
- goto done;
- }
- }
- }
-
- /* Look for symbols in the local scope (the object who is
- * searching). This happens with C++ templates on x86 for some
- * reason.
- *
- * Notes on weak symbols:
- * The ELF specs are ambiguous about treatment of weak definitions in
- * dynamic linking. Some systems return the first definition found
- * and some the first non-weak definition. This is system dependent.
- * Here we return the first definition found for simplicity. */
-
- s = soinfo_elf_lookup(si, elf_hash, name);
- if (s != NULL) {
- *lsi = si;
- goto done;
- }
- /*
- * If this object was built with -Bsymbolic and symbol is not found
- * in the local scope, try to find the symbol in the main executable.
- */
+uint32_t SymbolName::elf_hash() {
+ if (!has_elf_hash_) {
+ const unsigned char* name = reinterpret_cast<const unsigned char*>(name_);
+ uint32_t h = 0, g;
- if (si->has_DT_SYMBOLIC) {
- DEBUG("%s: looking up %s in executable %s after local scope",
- si->name, name, somain->name);
- s = soinfo_elf_lookup(somain, elf_hash, name);
- if (s != NULL) {
- *lsi = somain;
- goto done;
- }
-
- /* Next, look for it in the preloads list */
- for (int i = 0; g_ld_preloads[i] != NULL; i++) {
- s = soinfo_elf_lookup(g_ld_preloads[i], elf_hash, name);
- if (s != NULL) {
- *lsi = g_ld_preloads[i];
- goto done;
- }
- }
- }
- }
+ while (*name) {
+ h = (h << 4) + *name++;
+ g = h & 0xf0000000;
+ h ^= g;
+ h ^= g >> 24;
}
- for (int i = 0; needed[i] != NULL; i++) {
- DEBUG("%s: looking up %s in %s",
- si->name, name, needed[i]->name);
- s = soinfo_elf_lookup(needed[i], elf_hash, name);
- if (s != NULL) {
- *lsi = needed[i];
- goto done;
- }
+ elf_hash_ = h;
+ has_elf_hash_ = true;
+ }
+
+ return elf_hash_;
+}
+
+uint32_t SymbolName::gnu_hash() {
+ if (!has_gnu_hash_) {
+ uint32_t h = 5381;
+ const unsigned char* name = reinterpret_cast<const unsigned char*>(name_);
+ while (*name != 0) {
+ h += (h << 5) + *name++; // h*33 + c = h + h * 32 + c = h + h << 5 + c
}
-done:
- if (s != NULL) {
- TRACE_TYPE(LOOKUP, "si %s sym %s s->st_value = %p, "
- "found in %s, base = %p, load bias = %p",
- si->name, name, reinterpret_cast<void*>(s->st_value),
- (*lsi)->name, reinterpret_cast<void*>((*lsi)->base),
- reinterpret_cast<void*>((*lsi)->load_bias));
- return s;
+ gnu_hash_ = h;
+ has_gnu_hash_ = true;
+ }
+
+ return gnu_hash_;
+}
+
+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) {
+ SymbolName symbol_name(name);
+ ElfW(Sym)* s = nullptr;
+
+ /* "This element's presence in a shared object library alters the dynamic linker's
+ * symbol resolution algorithm for references within the library. Instead of starting
+ * a symbol search with the executable file, the dynamic linker starts from the shared
+ * object itself. If the shared object fails to supply the referenced symbol, the
+ * dynamic linker then searches the executable file and other shared objects as usual."
+ *
+ * http://www.sco.com/developers/gabi/2012-12-31/ch5.dynamic.html
+ *
+ * Note that this is unlikely since static linker avoids generating
+ * relocations for -Bsymbolic linked dynamic executables.
+ */
+ if (si_from->has_DT_SYMBOLIC) {
+ DEBUG("%s: looking up %s in local scope (DT_SYMBOLIC)", si_from->name, name);
+ s = si_from->find_symbol_by_name(symbol_name);
+ if (s != nullptr) {
+ *si_found_in = si_from;
}
+ }
+
+ // 1. Look for it in global_group
+ if (s == nullptr) {
+ global_group.visit([&](soinfo* global_si) {
+ DEBUG("%s: looking up %s in %s (from global group)", si_from->name, name, global_si->name);
+ s = global_si->find_symbol_by_name(symbol_name);
+ if (s != nullptr) {
+ *si_found_in = global_si;
+ return false;
+ }
+
+ return true;
+ });
+ }
+
+ // 2. Look for it in the local group
+ if (s == nullptr) {
+ local_group.visit([&](soinfo* local_si) {
+ if (local_si == si_from && si_from->has_DT_SYMBOLIC) {
+ // we already did this - skip
+ return true;
+ }
+
+ DEBUG("%s: looking up %s in %s (from local group)", si_from->name, name, local_si->name);
+ s = local_si->find_symbol_by_name(symbol_name);
+ if (s != nullptr) {
+ *si_found_in = local_si;
+ return false;
+ }
+
+ return true;
+ });
+ }
- return NULL;
+ if (s != nullptr) {
+ TRACE_TYPE(LOOKUP, "si %s sym %s s->st_value = %p, "
+ "found in %s, base = %p, load bias = %p",
+ si_from->name, name, reinterpret_cast<void*>(s->st_value),
+ (*si_found_in)->name, reinterpret_cast<void*>((*si_found_in)->base),
+ reinterpret_cast<void*>((*si_found_in)->load_bias));
+ }
+
+ return s;
}
-// Another soinfo list allocator to use in dlsym. We don't reuse
-// SoinfoListAllocator because it is write-protected most of the time.
-static LinkerAllocator<LinkedListEntry<soinfo>> g_soinfo_list_allocator_rw;
-class SoinfoListAllocatorRW {
+// Each size has it's own allocator.
+template<size_t size>
+class SizeBasedAllocator {
+ public:
+ static void* alloc() {
+ return allocator_.alloc();
+ }
+
+ static void free(void* ptr) {
+ allocator_.free(ptr);
+ }
+
+ private:
+ static LinkerBlockAllocator allocator_;
+};
+
+template<size_t size>
+LinkerBlockAllocator SizeBasedAllocator<size>::allocator_(size);
+
+template<typename T>
+class TypeBasedAllocator {
+ public:
+ static T* alloc() {
+ return reinterpret_cast<T*>(SizeBasedAllocator<sizeof(T)>::alloc());
+ }
+
+ static void free(T* ptr) {
+ SizeBasedAllocator<sizeof(T)>::free(ptr);
+ }
+};
+
+class LoadTask {
public:
- static LinkedListEntry<soinfo>* alloc() {
- return g_soinfo_list_allocator_rw.alloc();
+ struct deleter_t {
+ void operator()(LoadTask* t) {
+ TypeBasedAllocator<LoadTask>::free(t);
+ }
+ };
+
+ typedef UniquePtr<LoadTask, deleter_t> unique_ptr;
+
+ static deleter_t deleter;
+
+ static LoadTask* create(const char* name, soinfo* needed_by) {
+ LoadTask* ptr = TypeBasedAllocator<LoadTask>::alloc();
+ return new (ptr) LoadTask(name, needed_by);
+ }
+
+ const char* get_name() const {
+ return name_;
}
- static void free(LinkedListEntry<soinfo>* ptr) {
- g_soinfo_list_allocator_rw.free(ptr);
+ soinfo* get_needed_by() const {
+ 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);
};
+LoadTask::deleter_t LoadTask::deleter;
+
+template <typename T>
+using linked_list_t = LinkedList<T, TypeBasedAllocator<LinkedListEntry<T>>>;
+
+typedef linked_list_t<soinfo> SoinfoLinkedList;
+typedef linked_list_t<const char> StringLinkedList;
+typedef linked_list_t<LoadTask> LoadTaskList;
+
+
+// This function walks down the tree of soinfo dependencies
+// in breadth-first order and
+// * calls action(soinfo* si) for each node, and
+// * terminates walk if action returns false.
+//
+// walk_dependencies_tree returns false if walk was terminated
+// by the action and true otherwise.
+template<typename F>
+static bool walk_dependencies_tree(soinfo* root_soinfos[], size_t root_soinfos_size, F action) {
+ SoinfoLinkedList visit_list;
+ SoinfoLinkedList visited;
+
+ for (size_t i = 0; i < root_soinfos_size; ++i) {
+ visit_list.push_back(root_soinfos[i]);
+ }
+
+ soinfo* si;
+ while ((si = visit_list.pop_front()) != nullptr) {
+ if (visited.contains(si)) {
+ continue;
+ }
+
+ if (!action(si)) {
+ return false;
+ }
+
+ visited.push_back(si);
+
+ si->get_children().for_each([&](soinfo* child) {
+ visit_list.push_back(child);
+ });
+ }
+
+ return true;
+}
+
+
// This is used by dlsym(3). It performs symbol lookup only within the
// specified soinfo object and its dependencies in breadth first order.
ElfW(Sym)* dlsym_handle_lookup(soinfo* si, soinfo** found, const char* name) {
- LinkedList<soinfo, SoinfoListAllocatorRW> visit_list;
- LinkedList<soinfo, SoinfoListAllocatorRW> visited;
- visit_list.push_back(si);
- soinfo* current_soinfo;
- while ((current_soinfo = visit_list.pop_front()) != nullptr) {
- if (visited.contains(current_soinfo)) {
- continue;
- }
+ ElfW(Sym)* result = nullptr;
+ SymbolName symbol_name(name);
- ElfW(Sym)* result = soinfo_elf_lookup(current_soinfo, elfhash(name), name);
+ walk_dependencies_tree(&si, 1, [&](soinfo* current_soinfo) {
+ result = current_soinfo->find_symbol_by_name(symbol_name);
if (result != nullptr) {
*found = current_soinfo;
- visit_list.clear();
- visited.clear();
- return result;
+ return false;
}
- visited.push_back(current_soinfo);
- current_soinfo->get_children().for_each([&](soinfo* child) {
- visit_list.push_back(child);
- });
- }
+ return true;
+ });
- visit_list.clear();
- visited.clear();
- return nullptr;
+ return result;
}
/* This is used by dlsym(3) to performs a global symbol lookup. If the
@@ -649,22 +743,26 @@ ElfW(Sym)* dlsym_handle_lookup(soinfo* si, soinfo** found, const char* name) {
specified soinfo (for RTLD_NEXT).
*/
ElfW(Sym)* dlsym_linear_lookup(const char* name, soinfo** found, soinfo* start) {
- unsigned elf_hash = elfhash(name);
+ SymbolName symbol_name(name);
- if (start == NULL) {
+ if (start == nullptr) {
start = solist;
}
- ElfW(Sym)* s = NULL;
- for (soinfo* si = start; (s == NULL) && (si != NULL); si = si->next) {
- s = soinfo_elf_lookup(si, elf_hash, name);
- if (s != NULL) {
+ ElfW(Sym)* s = nullptr;
+ for (soinfo* si = start; (s == nullptr) && (si != nullptr); si = si->next) {
+ if ((si->get_rtld_flags() & RTLD_GLOBAL) == 0) {
+ continue;
+ }
+
+ s = si->find_symbol_by_name(symbol_name);
+ if (s != nullptr) {
*found = si;
break;
}
}
- if (s != NULL) {
+ if (s != nullptr) {
TRACE_TYPE(LOOKUP, "%s s->st_value = %p, found->base = %p",
name, reinterpret_cast<void*>(s->st_value), reinterpret_cast<void*>((*found)->base));
}
@@ -674,34 +772,63 @@ ElfW(Sym)* dlsym_linear_lookup(const char* name, soinfo** found, soinfo* start)
soinfo* find_containing_library(const void* p) {
ElfW(Addr) address = reinterpret_cast<ElfW(Addr)>(p);
- for (soinfo* si = solist; si != NULL; si = si->next) {
+ for (soinfo* si = solist; si != nullptr; si = si->next) {
if (address >= si->base && address - si->base < si->size) {
return si;
}
}
- return NULL;
+ 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) - base;
+
+ for (size_t i = 0; i < nbucket_; ++i) {
+ uint32_t n = bucket_[i];
+
+ if (n == 0) {
+ continue;
+ }
+
+ do {
+ ElfW(Sym)* sym = symtab_ + n;
+ if (symbol_matches_soaddr(sym, soaddr)) {
+ return sym;
+ }
+ } while ((chain_[n++] & 1) == 0);
+ }
+
+ return nullptr;
}
-ElfW(Sym)* dladdr_find_symbol(soinfo* si, const void* addr) {
- ElfW(Addr) soaddr = reinterpret_cast<ElfW(Addr)>(addr) - si->base;
+ElfW(Sym)* soinfo::elf_addr_lookup(const void* addr) {
+ ElfW(Addr) soaddr = reinterpret_cast<ElfW(Addr)>(addr) - base;
// Search the library's symbol table for any defined symbol which
// contains this address.
- for (size_t i = 0; i < si->nchain; ++i) {
- ElfW(Sym)* sym = &si->symtab[i];
- if (sym->st_shndx != SHN_UNDEF &&
- soaddr >= sym->st_value &&
- soaddr < sym->st_value + sym->st_size) {
+ for (size_t i = 0; i < nchain_; ++i) {
+ ElfW(Sym)* sym = symtab_ + i;
+ if (symbol_matches_soaddr(sym, soaddr)) {
return sym;
}
}
- return NULL;
+ return nullptr;
}
static int open_library_on_path(const char* name, const char* const paths[]) {
char buf[512];
- for (size_t i = 0; paths[i] != NULL; ++i) {
+ for (size_t i = 0; paths[i] != nullptr; ++i) {
int n = __libc_format_buffer(buf, sizeof(buf), "%s/%s", paths[i], name);
if (n < 0 || n >= static_cast<int>(sizeof(buf))) {
PRINT("Warning: ignoring very long library path: %s/%s", paths[i], name);
TRACE("[ opening %s ]", name);
// If the name contains a slash, we should attempt to open it directly and not search the paths.
- if (strchr(name, '/') != NULL) {
+ if (strchr(name, '/') != nullptr) {
int fd = TEMP_FAILURE_RETRY(open(name, O_RDONLY | O_CLOEXEC));
if (fd != -1) {
return fd;
return fd;
}
-static soinfo* load_library(const char* name, int dlflags, const android_dlextinfo* extinfo) {
- int fd = -1;
- ScopedFd file_guard(-1);
+template<typename F>
+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->get_string(d->d_un.d_val));
+ }
+ }
+}
- if (extinfo != NULL && (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 NULL;
- }
+static soinfo* load_library(LoadTaskList& load_tasks, const char* name, int rtld_flags, const android_dlextinfo* extinfo) {
+ int fd = -1;
+ off64_t file_offset = 0;
+ ScopedFd file_guard(-1);
- file_guard.reset(fd);
+ if (extinfo != nullptr && (extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD) != 0) {
+ fd = extinfo->library_fd;
+ if ((extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET) != 0) {
+ file_offset = extinfo->library_fd_offset;
+ }
+ } else {
+ // Open the file.
+ fd = open_library(name);
+ if (fd == -1) {
+ DL_ERR("library \"%s\" not found", name);
+ return nullptr;
}
- ElfReader elf_reader(name, fd);
+ 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 NULL;
- }
+ if ((file_offset % PAGE_SIZE) != 0) {
+ DL_ERR("file offset for the library \"%s\" is not page-aligned: %" PRId64, name, file_offset);
+ return nullptr;
+ }
+ if (file_offset < 0) {
+ DL_ERR("file offset for the library \"%s\" is negative: %" PRId64, name, file_offset);
+ return nullptr;
+ }
- // Check for symlink and other situations where
- // file can have different names.
- for (soinfo* si = solist; si != NULL; 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;
- }
- }
+ 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;
+ }
+ if (file_offset >= file_stat.st_size) {
+ DL_ERR("file offset for the library \"%s\" >= file size: %" PRId64 " >= %" PRId64, name, file_offset, file_stat.st_size);
+ return nullptr;
+ }
- if ((dlflags & RTLD_NOLOAD) != 0) {
- return NULL;
+ // 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 &&
+ si->get_file_offset() == file_offset) {
+ TRACE("library \"%s\" is already loaded under different name/path \"%s\" - will return existing soinfo", name, si->name);
+ return si;
}
+ }
- // Read the ELF header and load the segments.
- if (!elf_reader.Load(extinfo)) {
- return NULL;
- }
+ if ((rtld_flags & RTLD_NOLOAD) != 0) {
+ DL_ERR("library \"%s\" wasn't loaded and RTLD_NOLOAD prevented it", name);
+ return nullptr;
+ }
- soinfo* si = soinfo_alloc(SEARCH_NAME(name), &file_stat);
- if (si == NULL) {
- return NULL;
- }
- 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();
+ // Read the ELF header and load the segments.
+ ElfReader elf_reader(name, fd, file_offset);
+ if (!elf_reader.Load(extinfo)) {
+ return nullptr;
+ }
- // 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<void*>(si->base), si->size, si->name);
+ soinfo* si = soinfo_alloc(SEARCH_NAME(name), &file_stat, file_offset, rtld_flags);
+ 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();
- if (!soinfo_link_image(si, extinfo)) {
- soinfo_free(si);
- return NULL;
- }
+ if (!si->prelink_image()) {
+ 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) {
const char* search_name = SEARCH_NAME(name);
- for (soinfo* si = solist; si != NULL; si = si->next) {
+ for (soinfo* si = solist; si != nullptr; si = si->next) {
if (!strcmp(search_name, si->name)) {
return si;
}
}
- return NULL;
+ return nullptr;
}
-static soinfo* find_library_internal(const char* name, int dlflags, const android_dlextinfo* extinfo) {
- if (name == NULL) {
- return somain;
- }
+static soinfo* find_library_internal(LoadTaskList& load_tasks, const char* name, int rtld_flags, 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
- if (si == NULL) {
+ // 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 != NULL && (si->flags & FLAG_LINKED) == 0) {
- DL_ERR("recursive link to \"%s\"", si->name);
- return NULL;
+ si = load_library(load_tasks, name, rtld_flags, 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 != NULL) {
- si->ref_count++;
+static void soinfo_unload(soinfo* si);
+
+// 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 si;
+
+ return global_group;
}
-static void soinfo_unload(soinfo* si) {
- if (si->ref_count == 1) {
- TRACE("unloading '%s'", si->name);
- si->CallDestructors();
+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) {
+ // Step 0: prepare.
+ LoadTaskList load_tasks;
+ for (size_t i = 0; i < library_names_count; ++i) {
+ const char* name = library_names[i];
+ load_tasks.push_back(LoadTask::create(name, start_with));
+ }
- if ((si->flags | FLAG_NEW_SOINFO) != 0) {
- si->get_children().for_each([&] (soinfo* child) {
- TRACE("%s needs to unload %s", si->name, child->name);
- soinfo_unload(child);
- });
- } 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, NULL);
- if (needed != NULL) {
- 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);
- }
- }
- }
- }
+ // Construct global_group.
+ soinfo::soinfo_list_t global_group = make_global_group();
- notify_gdb_of_unload(si);
- si->ref_count = 0;
- soinfo_free(si);
- } else {
- si->ref_count--;
- TRACE("not unloading '%s', decrementing ref_count to %zd", si->name, si->ref_count);
- }
-}
+ // If soinfos array is null allocate one on stack.
+ // The array is needed in case of failure; for example
+ // when library_names[] = {libone.so, libtwo.so} and libone.so
+ // is loaded correctly but libtwo.so failed for some reason.
+ // In this case libone.so should be unloaded on return.
+ // See also implementation of failure_guard below.
-void do_android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size) {
- // Use basic string manipulation calls to avoid snprintf.
- // snprintf indirectly calls pthread_getspecific to get the size of a buffer.
- // When debug malloc is enabled, this call returns 0. This in turn causes
- // snprintf to do nothing, which causes libraries to fail to load.
- // See b/17302493 for further details.
- // Once the above bug is fixed, this code can be modified to use
- // snprintf again.
- size_t required_len = strlen(kDefaultLdPaths[0]) + strlen(kDefaultLdPaths[1]) + 2;
- if (buffer_size < required_len) {
- __libc_fatal("android_get_LD_LIBRARY_PATH failed, buffer too small: buffer len %zu, required len %zu",
- buffer_size, required_len);
+ if (soinfos == nullptr) {
+ size_t soinfos_size = sizeof(soinfo*)*library_names_count;
+ soinfos = reinterpret_cast<soinfo**>(alloca(soinfos_size));
+ memset(soinfos, 0, soinfos_size);
}
- char* end = stpcpy(buffer, kDefaultLdPaths[0]);
- *end = ':';
- strcpy(end + 1, kDefaultLdPaths[1]);
-}
-void do_android_update_LD_LIBRARY_PATH(const char* ld_library_path) {
- if (!get_AT_SECURE()) {
- parse_LD_LIBRARY_PATH(ld_library_path);
- }
-}
+ // list of libraries to link - see step 2.
+ size_t soinfos_count = 0;
+
+ auto failure_guard = make_scope_guard([&]() {
+ // Housekeeping
+ load_tasks.for_each([] (LoadTask* t) {
+ LoadTask::deleter(t);
+ });
+
+ for (size_t i = 0; i<soinfos_count; ++i) {
+ soinfo_unload(soinfos[i]);
+ }
+ });
+
+ // 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())) {
+ soinfo* si = find_library_internal(load_tasks, task->get_name(), rtld_flags, extinfo);
+ if (si == nullptr) {
+ return false;
+ }
+
+ soinfo* needed_by = task->get_needed_by();
+
+ if (needed_by != nullptr) {
+ needed_by->add_child(si);
+ }
+
+ if (si->is_linked()) {
+ si->increment_ref_count();
+ }
+
+ // When ld_preloads is not null, the first
+ // ld_preloads_count libs are in fact ld_preloads.
+ 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;
+ }
+
+ if (soinfos_count < library_names_count) {
+ soinfos[soinfos_count++] = si;
+ }
+ }
+
+ // Step 2: link libraries.
+ soinfo::soinfo_list_t local_group;
+ walk_dependencies_tree(
+ start_with == nullptr ? soinfos : &start_with,
+ start_with == nullptr ? soinfos_count : 1,
+ [&] (soinfo* si) {
+ local_group.push_back(si);
+ return true;
+ });
+
+ // We need to increment ref_count in case
+ // the root of the local group was not linked.
+ bool was_local_group_root_linked = local_group.front()->is_linked();
+
+ bool linked = local_group.visit([&](soinfo* si) {
+ if (!si->is_linked()) {
+ if (!si->link_image(global_group, local_group, extinfo)) {
+ return false;
+ }
+ si->set_linked();
+ }
+
+ return true;
+ });
+
+ if (linked) {
+ failure_guard.disable();
+ }
+
+ if (!was_local_group_root_linked) {
+ local_group.front()->increment_ref_count();
+ }
+
+ return linked;
+}
+
+static soinfo* find_library(const char* name, int rtld_flags, const android_dlextinfo* extinfo) {
+ soinfo* si;
+
+ if (name == nullptr) {
+ si = somain;
+ } else if (!find_libraries(nullptr, &name, 1, &si, nullptr, 0, rtld_flags, extinfo)) {
+ return nullptr;
+ }
+
+ return si;
+}
+
+static void soinfo_unload(soinfo* root) {
+ // Note that the library can be loaded but not linked;
+ // in which case there is no root but we still need
+ // to walk the tree and unload soinfos involved.
+ //
+ // This happens on unsuccessful dlopen, when one of
+ // the DT_NEEDED libraries could not be linked/found.
+ if (root->is_linked()) {
+ root = root->get_local_group_root();
+ }
+
+ if (!root->can_unload()) {
+ TRACE("not unloading '%s' - the binary is flagged with NODELETE", root->name);
+ return;
+ }
+
+ size_t ref_count = root->is_linked() ? root->decrement_ref_count() : 0;
+
+ if (ref_count == 0) {
+ soinfo::soinfo_list_t local_unload_list;
+ soinfo::soinfo_list_t external_unload_list;
+ soinfo::soinfo_list_t depth_first_list;
+ depth_first_list.push_back(root);
+ soinfo* si = nullptr;
+
+ while ((si = depth_first_list.pop_front()) != nullptr) {
+ if (local_unload_list.contains(si)) {
+ continue;
+ }
+
+ local_unload_list.push_back(si);
+
+ if (si->has_min_version(0)) {
+ soinfo* child = nullptr;
+ while ((child = si->get_children().pop_front()) != nullptr) {
+ TRACE("%s@%p needs to unload %s@%p", si->name, si, child->name, child);
+ if (local_unload_list.contains(child)) {
+ continue;
+ } else if (child->is_linked() && child->get_local_group_root() != root) {
+ external_unload_list.push_back(child);
+ } else {
+ depth_first_list.push_front(child);
+ }
+ }
+ } else {
+#ifdef __LP64__
+ __libc_fatal("soinfo for \"%s\"@%p has no version", si->name, si);
+#else
+ PRINT("warning: soinfo for \"%s\"@%p has no version", si->name, si);
+ for_each_dt_needed(si, [&] (const char* library_name) {
+ TRACE("deprecated (old format of soinfo): %s needs to unload %s", si->name, library_name);
+ soinfo* needed = find_library(library_name, RTLD_NOLOAD, nullptr);
+ if (needed != nullptr) {
+ // Not found: for example if symlink was deleted between dlopen and dlclose
+ // Since we cannot really handle errors at this point - print and continue.
+ PRINT("warning: couldn't find %s needed by %s on unload.", library_name, si->name);
+ return;
+ } else if (local_unload_list.contains(needed)) {
+ // already visited
+ return;
+ } else if (needed->is_linked() && needed->get_local_group_root() != root) {
+ // external group
+ external_unload_list.push_back(needed);
+ } else {
+ // local group
+ depth_first_list.push_front(needed);
+ }
+ });
+#endif
+ }
+ }
+
+ local_unload_list.for_each([](soinfo* si) {
+ si->call_destructors();
+ });
+
+ while ((si = local_unload_list.pop_front()) != nullptr) {
+ notify_gdb_of_unload(si);
+ soinfo_free(si);
+ }
+
+ while ((si = external_unload_list.pop_front()) != nullptr) {
+ soinfo_unload(si);
+ }
+ } else {
+ TRACE("not unloading '%s' group, decrementing ref_count to %zd", root->name, ref_count);
+ }
+}
+
+void do_android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size) {
+ // Use basic string manipulation calls to avoid snprintf.
+ // snprintf indirectly calls pthread_getspecific to get the size of a buffer.
+ // When debug malloc is enabled, this call returns 0. This in turn causes
+ // snprintf to do nothing, which causes libraries to fail to load.
+ // See b/17302493 for further details.
+ // Once the above bug is fixed, this code can be modified to use
+ // snprintf again.
+ size_t required_len = strlen(kDefaultLdPaths[0]) + strlen(kDefaultLdPaths[1]) + 2;
+ if (buffer_size < required_len) {
+ __libc_fatal("android_get_LD_LIBRARY_PATH failed, buffer too small: buffer len %zu, required len %zu",
+ buffer_size, required_len);
+ }
+ char* end = stpcpy(buffer, kDefaultLdPaths[0]);
+ *end = ':';
+ strcpy(end + 1, kDefaultLdPaths[1]);
+}
+
+void do_android_update_LD_LIBRARY_PATH(const char* ld_library_path) {
+ if (!get_AT_SECURE()) {
+ parse_LD_LIBRARY_PATH(ld_library_path);
+ }
+}
soinfo* do_dlopen(const char* name, int flags, const android_dlextinfo* extinfo) {
- if ((flags & ~(RTLD_NOW|RTLD_LAZY|RTLD_LOCAL|RTLD_GLOBAL|RTLD_NOLOAD)) != 0) {
+ if ((flags & ~(RTLD_NOW|RTLD_LAZY|RTLD_LOCAL|RTLD_GLOBAL|RTLD_NODELETE|RTLD_NOLOAD)) != 0) {
DL_ERR("invalid flags to dlopen: %x", flags);
- return NULL;
+ return nullptr;
}
- if (extinfo != NULL && ((extinfo->flags & ~(ANDROID_DLEXT_VALID_FLAG_BITS)) != 0)) {
- DL_ERR("invalid extended flags to android_dlopen_ext: %" PRIx64, extinfo->flags);
- return NULL;
+ if (extinfo != nullptr) {
+ if ((extinfo->flags & ~(ANDROID_DLEXT_VALID_FLAG_BITS)) != 0) {
+ DL_ERR("invalid extended flags to android_dlopen_ext: 0x%" PRIx64, extinfo->flags);
+ return nullptr;
+ }
+ if ((extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD) == 0 &&
+ (extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET) != 0) {
+ DL_ERR("invalid extended flag combination (ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET without ANDROID_DLEXT_USE_LIBRARY_FD): 0x%" PRIx64, extinfo->flags);
+ return nullptr;
+ }
}
protect_data(PROT_READ | PROT_WRITE);
soinfo* si = find_library(name, flags, extinfo);
- if (si != NULL) {
- si->CallConstructors();
+ if (si != nullptr) {
+ si->call_constructors();
}
protect_data(PROT_READ);
return si;
protect_data(PROT_READ);
}
-#if defined(USE_RELA)
-static int soinfo_relocate(soinfo* si, ElfW(Rela)* rela, unsigned count, soinfo* needed[]) {
- ElfW(Sym)* s;
- soinfo* lsi;
+static 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();
+ TRACE_TYPE(RELO, "Called ifunc_resolver@%p. The result is %p", ifunc_resolver, reinterpret_cast<void*>(ifunc_addr));
+
+ return ifunc_addr;
+}
+#if defined(USE_RELA)
+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) {
unsigned type = ELFW(R_TYPE)(rela->r_info);
unsigned sym = ELFW(R_SYM)(rela->r_info);
- ElfW(Addr) reloc = static_cast<ElfW(Addr)>(rela->r_offset + si->load_bias);
+ ElfW(Addr) reloc = static_cast<ElfW(Addr)>(rela->r_offset + load_bias);
ElfW(Addr) sym_addr = 0;
- const char* sym_name = NULL;
+ const char* sym_name = nullptr;
- DEBUG("Processing '%s' relocation at index %zd", si->name, idx);
+ DEBUG("Processing '%s' relocation at index %zd", name, idx);
if (type == 0) { // R_*_NONE
continue;
}
+
+ ElfW(Sym)* s = nullptr;
+ soinfo* lsi = nullptr;
+
if (sym != 0) {
- sym_name = reinterpret_cast<const char*>(si->strtab + si->symtab[sym].st_name);
- s = soinfo_do_lookup(si, sym_name, &lsi, needed);
- if (s == NULL) {
+ sym_name = get_string(symtab_[sym].st_name);
+ s = soinfo_do_lookup(this, sym_name, &lsi, global_group,local_group);
+ if (s == nullptr) {
// We only allow an undefined symbol if this is a weak reference...
- s = &si->symtab[sym];
+ s = &symtab_[sym];
if (ELF_ST_BIND(s->st_info) != STB_WEAK) {
- DL_ERR("cannot locate symbol \"%s\" referenced by \"%s\"...", sym_name, si->name);
+ DL_ERR("cannot locate symbol \"%s\" referenced by \"%s\"...", sym_name, name);
return -1;
}
@@ -972,151 +1319,158 @@ static int soinfo_relocate(soinfo* si, ElfW(Rela)* rela, unsigned count, soinfo*
switch (type) {
#if defined(__aarch64__)
- case R_AARCH64_JUMP_SLOT:
- case R_AARCH64_GLOB_DAT:
- case R_AARCH64_ABS64:
- case R_AARCH64_ABS32:
- case R_AARCH64_ABS16:
- case R_AARCH64_RELATIVE:
- /*
- * The sym_addr was initialized to be zero above, or the relocation
- * code below does not care about value of sym_addr.
- * No need to do anything.
- */
- break;
+ case R_AARCH64_JUMP_SLOT:
+ case R_AARCH64_GLOB_DAT:
+ case R_AARCH64_ABS64:
+ case R_AARCH64_ABS32:
+ case R_AARCH64_ABS16:
+ case R_AARCH64_RELATIVE:
+ case R_AARCH64_IRELATIVE:
+ /*
+ * The sym_addr was initialized to be zero above, or the relocation
+ * code below does not care about value of sym_addr.
+ * No need to do anything.
+ */
+ break;
#elif defined(__x86_64__)
- case R_X86_64_JUMP_SLOT:
- case R_X86_64_GLOB_DAT:
- case R_X86_64_32:
- case R_X86_64_64:
- case R_X86_64_RELATIVE:
- // No need to do anything.
- break;
- case R_X86_64_PC32:
- sym_addr = reloc;
- break;
+ case R_X86_64_JUMP_SLOT:
+ case R_X86_64_GLOB_DAT:
+ case R_X86_64_32:
+ case R_X86_64_64:
+ case R_X86_64_RELATIVE:
+ case R_X86_64_IRELATIVE:
+ // No need to do anything.
+ break;
+ case R_X86_64_PC32:
+ sym_addr = reloc;
+ break;
#endif
- default:
- DL_ERR("unknown weak reloc type %d @ %p (%zu)", type, rela, idx);
- return -1;
+ default:
+ DL_ERR("unknown weak reloc type %d @ %p (%zu)", type, rela, idx);
+ return -1;
}
} else {
// We got a definition.
- sym_addr = static_cast<ElfW(Addr)>(s->st_value + lsi->load_bias);
+ sym_addr = lsi->resolve_symbol_address(s);
}
count_relocation(kRelocSymbol);
- } else {
- s = NULL;
}
switch (type) {
#if defined(__aarch64__)
- case R_AARCH64_JUMP_SLOT:
+ case R_AARCH64_JUMP_SLOT:
count_relocation(kRelocAbsolute);
MARK(rela->r_offset);
TRACE_TYPE(RELO, "RELO JMP_SLOT %16llx <- %16llx %s\n",
reloc, (sym_addr + rela->r_addend), sym_name);
*reinterpret_cast<ElfW(Addr)*>(reloc) = (sym_addr + rela->r_addend);
break;
- case R_AARCH64_GLOB_DAT:
+ case R_AARCH64_GLOB_DAT:
count_relocation(kRelocAbsolute);
MARK(rela->r_offset);
TRACE_TYPE(RELO, "RELO GLOB_DAT %16llx <- %16llx %s\n",
reloc, (sym_addr + rela->r_addend), sym_name);
*reinterpret_cast<ElfW(Addr)*>(reloc) = (sym_addr + rela->r_addend);
break;
- case R_AARCH64_ABS64:
+ case R_AARCH64_ABS64:
count_relocation(kRelocAbsolute);
MARK(rela->r_offset);
TRACE_TYPE(RELO, "RELO ABS64 %16llx <- %16llx %s\n",
reloc, (sym_addr + rela->r_addend), sym_name);
*reinterpret_cast<ElfW(Addr)*>(reloc) += (sym_addr + rela->r_addend);
break;
- case R_AARCH64_ABS32:
+ case R_AARCH64_ABS32:
count_relocation(kRelocAbsolute);
MARK(rela->r_offset);
TRACE_TYPE(RELO, "RELO ABS32 %16llx <- %16llx %s\n",
reloc, (sym_addr + rela->r_addend), sym_name);
if ((static_cast<ElfW(Addr)>(INT32_MIN) <= (*reinterpret_cast<ElfW(Addr)*>(reloc) + (sym_addr + rela->r_addend))) &&
((*reinterpret_cast<ElfW(Addr)*>(reloc) + (sym_addr + rela->r_addend)) <= static_cast<ElfW(Addr)>(UINT32_MAX))) {
- *reinterpret_cast<ElfW(Addr)*>(reloc) += (sym_addr + rela->r_addend);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) += (sym_addr + rela->r_addend);
} else {
- DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
- (*reinterpret_cast<ElfW(Addr)*>(reloc) + (sym_addr + rela->r_addend)),
- static_cast<ElfW(Addr)>(INT32_MIN),
- static_cast<ElfW(Addr)>(UINT32_MAX));
- return -1;
+ DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
+ (*reinterpret_cast<ElfW(Addr)*>(reloc) + (sym_addr + rela->r_addend)),
+ static_cast<ElfW(Addr)>(INT32_MIN),
+ static_cast<ElfW(Addr)>(UINT32_MAX));
+ return -1;
}
break;
- case R_AARCH64_ABS16:
+ case R_AARCH64_ABS16:
count_relocation(kRelocAbsolute);
MARK(rela->r_offset);
TRACE_TYPE(RELO, "RELO ABS16 %16llx <- %16llx %s\n",
reloc, (sym_addr + rela->r_addend), sym_name);
if ((static_cast<ElfW(Addr)>(INT16_MIN) <= (*reinterpret_cast<ElfW(Addr)*>(reloc) + (sym_addr + rela->r_addend))) &&
((*reinterpret_cast<ElfW(Addr)*>(reloc) + (sym_addr + rela->r_addend)) <= static_cast<ElfW(Addr)>(UINT16_MAX))) {
- *reinterpret_cast<ElfW(Addr)*>(reloc) += (sym_addr + rela->r_addend);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) += (sym_addr + rela->r_addend);
} else {
- DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
- (*reinterpret_cast<ElfW(Addr)*>(reloc) + (sym_addr + rela->r_addend)),
- static_cast<ElfW(Addr)>(INT16_MIN),
- static_cast<ElfW(Addr)>(UINT16_MAX));
- return -1;
+ DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
+ (*reinterpret_cast<ElfW(Addr)*>(reloc) + (sym_addr + rela->r_addend)),
+ static_cast<ElfW(Addr)>(INT16_MIN),
+ static_cast<ElfW(Addr)>(UINT16_MAX));
+ return -1;
}
break;
- case R_AARCH64_PREL64:
+ case R_AARCH64_PREL64:
count_relocation(kRelocRelative);
MARK(rela->r_offset);
TRACE_TYPE(RELO, "RELO REL64 %16llx <- %16llx - %16llx %s\n",
reloc, (sym_addr + rela->r_addend), rela->r_offset, sym_name);
*reinterpret_cast<ElfW(Addr)*>(reloc) += (sym_addr + rela->r_addend) - rela->r_offset;
break;
- case R_AARCH64_PREL32:
+ case R_AARCH64_PREL32:
count_relocation(kRelocRelative);
MARK(rela->r_offset);
TRACE_TYPE(RELO, "RELO REL32 %16llx <- %16llx - %16llx %s\n",
reloc, (sym_addr + rela->r_addend), rela->r_offset, sym_name);
if ((static_cast<ElfW(Addr)>(INT32_MIN) <= (*reinterpret_cast<ElfW(Addr)*>(reloc) + ((sym_addr + rela->r_addend) - rela->r_offset))) &&
((*reinterpret_cast<ElfW(Addr)*>(reloc) + ((sym_addr + rela->r_addend) - rela->r_offset)) <= static_cast<ElfW(Addr)>(UINT32_MAX))) {
- *reinterpret_cast<ElfW(Addr)*>(reloc) += ((sym_addr + rela->r_addend) - rela->r_offset);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) += ((sym_addr + rela->r_addend) - rela->r_offset);
} else {
- DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
- (*reinterpret_cast<ElfW(Addr)*>(reloc) + ((sym_addr + rela->r_addend) - rela->r_offset)),
- static_cast<ElfW(Addr)>(INT32_MIN),
- static_cast<ElfW(Addr)>(UINT32_MAX));
- return -1;
+ DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
+ (*reinterpret_cast<ElfW(Addr)*>(reloc) + ((sym_addr + rela->r_addend) - rela->r_offset)),
+ static_cast<ElfW(Addr)>(INT32_MIN),
+ static_cast<ElfW(Addr)>(UINT32_MAX));
+ return -1;
}
break;
- case R_AARCH64_PREL16:
+ case R_AARCH64_PREL16:
count_relocation(kRelocRelative);
MARK(rela->r_offset);
TRACE_TYPE(RELO, "RELO REL16 %16llx <- %16llx - %16llx %s\n",
reloc, (sym_addr + rela->r_addend), rela->r_offset, sym_name);
if ((static_cast<ElfW(Addr)>(INT16_MIN) <= (*reinterpret_cast<ElfW(Addr)*>(reloc) + ((sym_addr + rela->r_addend) - rela->r_offset))) &&
((*reinterpret_cast<ElfW(Addr)*>(reloc) + ((sym_addr + rela->r_addend) - rela->r_offset)) <= static_cast<ElfW(Addr)>(UINT16_MAX))) {
- *reinterpret_cast<ElfW(Addr)*>(reloc) += ((sym_addr + rela->r_addend) - rela->r_offset);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) += ((sym_addr + rela->r_addend) - rela->r_offset);
} else {
- DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
- (*reinterpret_cast<ElfW(Addr)*>(reloc) + ((sym_addr + rela->r_addend) - rela->r_offset)),
- static_cast<ElfW(Addr)>(INT16_MIN),
- static_cast<ElfW(Addr)>(UINT16_MAX));
- return -1;
+ DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
+ (*reinterpret_cast<ElfW(Addr)*>(reloc) + ((sym_addr + rela->r_addend) - rela->r_offset)),
+ static_cast<ElfW(Addr)>(INT16_MIN),
+ static_cast<ElfW(Addr)>(UINT16_MAX));
+ return -1;
}
break;
- case R_AARCH64_RELATIVE:
+ case R_AARCH64_RELATIVE:
count_relocation(kRelocRelative);
MARK(rela->r_offset);
if (sym) {
- DL_ERR("odd RELATIVE form...");
- return -1;
+ DL_ERR("odd RELATIVE form...");
+ return -1;
}
TRACE_TYPE(RELO, "RELO RELATIVE %16llx <- %16llx\n",
- reloc, (si->base + rela->r_addend));
- *reinterpret_cast<ElfW(Addr)*>(reloc) = (si->base + rela->r_addend);
+ reloc, (base + rela->r_addend));
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = (base + rela->r_addend);
break;
- case R_AARCH64_COPY:
+ case R_AARCH64_IRELATIVE:
+ count_relocation(kRelocRelative);
+ MARK(rela->r_offset);
+ TRACE_TYPE(RELO, "RELO IRELATIVE %16llx <- %16llx\n", reloc, (base + rela->r_addend));
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = call_ifunc_resolver(base + rela->r_addend);
+ break;
+
+ case R_AARCH64_COPY:
/*
* ET_EXEC is not supported so this should not happen.
*
@@ -1126,328 +1480,337 @@ static int soinfo_relocate(soinfo* si, ElfW(Rela)* rela, unsigned count, soinfo*
* R_AARCH64_COPY may only appear in executable objects where e_type is
* set to ET_EXEC.
*/
- DL_ERR("%s R_AARCH64_COPY relocations are not supported", si->name);
+ DL_ERR("%s R_AARCH64_COPY relocations are not supported", name);
return -1;
- case R_AARCH64_TLS_TPREL64:
+ case R_AARCH64_TLS_TPREL64:
TRACE_TYPE(RELO, "RELO TLS_TPREL64 *** %16llx <- %16llx - %16llx\n",
reloc, (sym_addr + rela->r_addend), rela->r_offset);
break;
- case R_AARCH64_TLS_DTPREL32:
+ case R_AARCH64_TLS_DTPREL32:
TRACE_TYPE(RELO, "RELO TLS_DTPREL32 *** %16llx <- %16llx - %16llx\n",
reloc, (sym_addr + rela->r_addend), rela->r_offset);
break;
#elif defined(__x86_64__)
- case R_X86_64_JUMP_SLOT:
- count_relocation(kRelocAbsolute);
- MARK(rela->r_offset);
- TRACE_TYPE(RELO, "RELO JMP_SLOT %08zx <- %08zx %s", static_cast<size_t>(reloc),
- static_cast<size_t>(sym_addr + rela->r_addend), sym_name);
- *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + rela->r_addend;
- break;
- case R_X86_64_GLOB_DAT:
- count_relocation(kRelocAbsolute);
- MARK(rela->r_offset);
- TRACE_TYPE(RELO, "RELO GLOB_DAT %08zx <- %08zx %s", static_cast<size_t>(reloc),
- static_cast<size_t>(sym_addr + rela->r_addend), sym_name);
- *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + rela->r_addend;
- break;
- case R_X86_64_RELATIVE:
- count_relocation(kRelocRelative);
- MARK(rela->r_offset);
- if (sym) {
- DL_ERR("odd RELATIVE form...");
- return -1;
- }
- TRACE_TYPE(RELO, "RELO RELATIVE %08zx <- +%08zx", static_cast<size_t>(reloc),
- static_cast<size_t>(si->base));
- *reinterpret_cast<ElfW(Addr)*>(reloc) = si->base + rela->r_addend;
- break;
- case R_X86_64_32:
- count_relocation(kRelocRelative);
- MARK(rela->r_offset);
- TRACE_TYPE(RELO, "RELO R_X86_64_32 %08zx <- +%08zx %s", static_cast<size_t>(reloc),
- static_cast<size_t>(sym_addr), sym_name);
- *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + rela->r_addend;
- break;
- case R_X86_64_64:
- count_relocation(kRelocRelative);
- MARK(rela->r_offset);
- TRACE_TYPE(RELO, "RELO R_X86_64_64 %08zx <- +%08zx %s", static_cast<size_t>(reloc),
- static_cast<size_t>(sym_addr), sym_name);
- *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + rela->r_addend;
- break;
- case R_X86_64_PC32:
- count_relocation(kRelocRelative);
- MARK(rela->r_offset);
- TRACE_TYPE(RELO, "RELO R_X86_64_PC32 %08zx <- +%08zx (%08zx - %08zx) %s",
- static_cast<size_t>(reloc), static_cast<size_t>(sym_addr - reloc),
- static_cast<size_t>(sym_addr), static_cast<size_t>(reloc), sym_name);
- *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + rela->r_addend - reloc;
- break;
+ case R_X86_64_JUMP_SLOT:
+ count_relocation(kRelocAbsolute);
+ MARK(rela->r_offset);
+ TRACE_TYPE(RELO, "RELO JMP_SLOT %08zx <- %08zx %s", static_cast<size_t>(reloc),
+ static_cast<size_t>(sym_addr + rela->r_addend), sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + rela->r_addend;
+ break;
+ case R_X86_64_GLOB_DAT:
+ count_relocation(kRelocAbsolute);
+ MARK(rela->r_offset);
+ TRACE_TYPE(RELO, "RELO GLOB_DAT %08zx <- %08zx %s", static_cast<size_t>(reloc),
+ static_cast<size_t>(sym_addr + rela->r_addend), sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + rela->r_addend;
+ break;
+ case R_X86_64_RELATIVE:
+ count_relocation(kRelocRelative);
+ MARK(rela->r_offset);
+ if (sym) {
+ DL_ERR("odd RELATIVE form...");
+ return -1;
+ }
+ TRACE_TYPE(RELO, "RELO RELATIVE %08zx <- +%08zx", static_cast<size_t>(reloc),
+ static_cast<size_t>(base));
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = base + rela->r_addend;
+ break;
+ case R_X86_64_IRELATIVE:
+ count_relocation(kRelocRelative);
+ MARK(rela->r_offset);
+ TRACE_TYPE(RELO, "RELO IRELATIVE %16llx <- %16llx\n", reloc, (base + rela->r_addend));
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = call_ifunc_resolver(base + rela->r_addend);
+ break;
+ case R_X86_64_32:
+ count_relocation(kRelocRelative);
+ MARK(rela->r_offset);
+ TRACE_TYPE(RELO, "RELO R_X86_64_32 %08zx <- +%08zx %s", static_cast<size_t>(reloc),
+ static_cast<size_t>(sym_addr), sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + rela->r_addend;
+ break;
+ case R_X86_64_64:
+ count_relocation(kRelocRelative);
+ MARK(rela->r_offset);
+ TRACE_TYPE(RELO, "RELO R_X86_64_64 %08zx <- +%08zx %s", static_cast<size_t>(reloc),
+ static_cast<size_t>(sym_addr), sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + rela->r_addend;
+ break;
+ case R_X86_64_PC32:
+ count_relocation(kRelocRelative);
+ MARK(rela->r_offset);
+ TRACE_TYPE(RELO, "RELO R_X86_64_PC32 %08zx <- +%08zx (%08zx - %08zx) %s",
+ static_cast<size_t>(reloc), static_cast<size_t>(sym_addr - reloc),
+ static_cast<size_t>(sym_addr), static_cast<size_t>(reloc), sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + rela->r_addend - reloc;
+ break;
#endif
- default:
- DL_ERR("unknown reloc type %d @ %p (%zu)", type, rela, idx);
- return -1;
+ default:
+ DL_ERR("unknown reloc type %d @ %p (%zu)", type, rela, idx);
+ return -1;
}
}
return 0;
}
#else // REL, not RELA.
+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) {
+ unsigned type = ELFW(R_TYPE)(rel->r_info);
+ // TODO: don't use unsigned for 'sym'. Use uint32_t or ElfW(Addr) instead.
+ unsigned sym = ELFW(R_SYM)(rel->r_info);
+ ElfW(Addr) reloc = static_cast<ElfW(Addr)>(rel->r_offset + load_bias);
+ ElfW(Addr) sym_addr = 0;
+ const char* sym_name = nullptr;
-static int soinfo_relocate(soinfo* si, ElfW(Rel)* rel, unsigned count, soinfo* needed[]) {
- ElfW(Sym)* s;
- soinfo* lsi;
+ DEBUG("Processing '%s' relocation at index %zd", name, idx);
+ if (type == 0) { // R_*_NONE
+ continue;
+ }
- 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.
- unsigned sym = ELFW(R_SYM)(rel->r_info);
- ElfW(Addr) reloc = static_cast<ElfW(Addr)>(rel->r_offset + si->load_bias);
- ElfW(Addr) sym_addr = 0;
- const char* sym_name = NULL;
+ ElfW(Sym)* s = nullptr;
+ soinfo* lsi = nullptr;
- DEBUG("Processing '%s' relocation at index %zd", si->name, idx);
- if (type == 0) { // R_*_NONE
- continue;
+ if (sym != 0) {
+ sym_name = get_string(symtab_[sym].st_name);
+ s = soinfo_do_lookup(this, sym_name, &lsi, global_group, local_group);
+ if (s == nullptr) {
+ // We only allow an undefined symbol if this is a weak reference...
+ s = &symtab_[sym];
+ if (ELF_ST_BIND(s->st_info) != STB_WEAK) {
+ DL_ERR("cannot locate symbol \"%s\" referenced by \"%s\"...", sym_name, name);
+ return -1;
}
- if (sym != 0) {
- sym_name = reinterpret_cast<const char*>(si->strtab + si->symtab[sym].st_name);
- s = soinfo_do_lookup(si, sym_name, &lsi, needed);
- if (s == NULL) {
- // We only allow an undefined symbol if this is a weak reference...
- s = &si->symtab[sym];
- if (ELF_ST_BIND(s->st_info) != STB_WEAK) {
- DL_ERR("cannot locate symbol \"%s\" referenced by \"%s\"...", sym_name, si->name);
- return -1;
- }
-
- /* IHI0044C AAELF 4.5.1.1:
-
- Libraries are not searched to resolve weak references.
- It is not an error for a weak reference to remain
- unsatisfied.
-
- During linking, the value of an undefined weak reference is:
- - Zero if the relocation type is absolute
- - The address of the place if the relocation is pc-relative
- - The address of nominal base address if the relocation
- type is base-relative.
- */
-
- switch (type) {
+
+ /* IHI0044C AAELF 4.5.1.1:
+
+ Libraries are not searched to resolve weak references.
+ It is not an error for a weak reference to remain
+ unsatisfied.
+
+ During linking, the value of an undefined weak reference is:
+ - Zero if the relocation type is absolute
+ - The address of the place if the relocation is pc-relative
+ - The address of nominal base address if the relocation
+ type is base-relative.
+ */
+
+ switch (type) {
#if defined(__arm__)
- case R_ARM_JUMP_SLOT:
- case R_ARM_GLOB_DAT:
- case R_ARM_ABS32:
- case R_ARM_RELATIVE: /* Don't care. */
- // sym_addr was initialized to be zero above or relocation
- // code below does not care about value of sym_addr.
- // No need to do anything.
- break;
+ case R_ARM_JUMP_SLOT:
+ case R_ARM_GLOB_DAT:
+ case R_ARM_ABS32:
+ case R_ARM_RELATIVE: /* Don't care. */
+ // sym_addr was initialized to be zero above or relocation
+ // code below does not care about value of sym_addr.
+ // No need to do anything.
+ break;
#elif defined(__i386__)
- case R_386_JMP_SLOT:
- case R_386_GLOB_DAT:
- case R_386_32:
- case R_386_RELATIVE: /* Don't care. */
- // sym_addr was initialized to be zero above or relocation
- // code below does not care about value of sym_addr.
- // No need to do anything.
- break;
- case R_386_PC32:
- sym_addr = reloc;
- break;
+ case R_386_JMP_SLOT:
+ case R_386_GLOB_DAT:
+ case R_386_32:
+ case R_386_RELATIVE: /* Don't care. */
+ case R_386_IRELATIVE:
+ // sym_addr was initialized to be zero above or relocation
+ // code below does not care about value of sym_addr.
+ // No need to do anything.
+ break;
+ case R_386_PC32:
+ sym_addr = reloc;
+ break;
#endif
#if defined(__arm__)
- case R_ARM_COPY:
- // Fall through. Can't really copy if weak symbol is not found at run-time.
+ case R_ARM_COPY:
+ // Fall through. Can't really copy if weak symbol is not found at run-time.
#endif
- default:
- DL_ERR("unknown weak reloc type %d @ %p (%zu)", type, rel, idx);
- return -1;
- }
- } else {
- // We got a definition.
- sym_addr = static_cast<ElfW(Addr)>(s->st_value + lsi->load_bias);
- }
- count_relocation(kRelocSymbol);
- } else {
- s = NULL;
+ default:
+ DL_ERR("unknown weak reloc type %d @ %p (%zu)", type, rel, idx);
+ return -1;
}
+ } else {
+ // We got a definition.
+ sym_addr = lsi->resolve_symbol_address(s);
+ }
+ count_relocation(kRelocSymbol);
+ }
- switch (type) {
+ switch (type) {
#if defined(__arm__)
- case R_ARM_JUMP_SLOT:
- count_relocation(kRelocAbsolute);
- MARK(rel->r_offset);
- TRACE_TYPE(RELO, "RELO JMP_SLOT %08x <- %08x %s", reloc, sym_addr, sym_name);
- *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr;
- break;
- case R_ARM_GLOB_DAT:
- count_relocation(kRelocAbsolute);
- MARK(rel->r_offset);
- TRACE_TYPE(RELO, "RELO GLOB_DAT %08x <- %08x %s", reloc, sym_addr, sym_name);
- *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr;
- break;
- case R_ARM_ABS32:
- count_relocation(kRelocAbsolute);
- MARK(rel->r_offset);
- TRACE_TYPE(RELO, "RELO ABS %08x <- %08x %s", reloc, sym_addr, sym_name);
- *reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
- break;
- case R_ARM_REL32:
- count_relocation(kRelocRelative);
- MARK(rel->r_offset);
- TRACE_TYPE(RELO, "RELO REL32 %08x <- %08x - %08x %s",
- reloc, sym_addr, rel->r_offset, sym_name);
- *reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr - rel->r_offset;
- break;
- case R_ARM_COPY:
- /*
- * ET_EXEC is not supported so this should not happen.
- *
- * http://infocenter.arm.com/help/topic/com.arm.doc.ihi0044d/IHI0044D_aaelf.pdf
- *
- * Section 4.7.1.10 "Dynamic relocations"
- * R_ARM_COPY may only appear in executable objects where e_type is
- * set to ET_EXEC.
- */
- DL_ERR("%s R_ARM_COPY relocations are not supported", si->name);
- return -1;
+ case R_ARM_JUMP_SLOT:
+ count_relocation(kRelocAbsolute);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "RELO JMP_SLOT %08x <- %08x %s", reloc, sym_addr, sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr;
+ break;
+ case R_ARM_GLOB_DAT:
+ count_relocation(kRelocAbsolute);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "RELO GLOB_DAT %08x <- %08x %s", reloc, sym_addr, sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr;
+ break;
+ case R_ARM_ABS32:
+ count_relocation(kRelocAbsolute);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "RELO ABS %08x <- %08x %s", reloc, sym_addr, sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
+ break;
+ case R_ARM_REL32:
+ count_relocation(kRelocRelative);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "RELO REL32 %08x <- %08x - %08x %s",
+ reloc, sym_addr, rel->r_offset, sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr - rel->r_offset;
+ break;
+ case R_ARM_COPY:
+ /*
+ * ET_EXEC is not supported so this should not happen.
+ *
+ * http://infocenter.arm.com/help/topic/com.arm.doc.ihi0044d/IHI0044D_aaelf.pdf
+ *
+ * Section 4.7.1.10 "Dynamic relocations"
+ * R_ARM_COPY may only appear in executable objects where e_type is
+ * set to ET_EXEC.
+ */
+ DL_ERR("%s R_ARM_COPY relocations are not supported", name);
+ return -1;
#elif defined(__i386__)
- case R_386_JMP_SLOT:
- count_relocation(kRelocAbsolute);
- MARK(rel->r_offset);
- TRACE_TYPE(RELO, "RELO JMP_SLOT %08x <- %08x %s", reloc, sym_addr, sym_name);
- *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr;
- break;
- case R_386_GLOB_DAT:
- count_relocation(kRelocAbsolute);
- MARK(rel->r_offset);
- TRACE_TYPE(RELO, "RELO GLOB_DAT %08x <- %08x %s", reloc, sym_addr, sym_name);
- *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr;
- break;
- case R_386_32:
- count_relocation(kRelocRelative);
- MARK(rel->r_offset);
- TRACE_TYPE(RELO, "RELO R_386_32 %08x <- +%08x %s", reloc, sym_addr, sym_name);
- *reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
- break;
- case R_386_PC32:
- count_relocation(kRelocRelative);
- MARK(rel->r_offset);
- TRACE_TYPE(RELO, "RELO R_386_PC32 %08x <- +%08x (%08x - %08x) %s",
- reloc, (sym_addr - reloc), sym_addr, reloc, sym_name);
- *reinterpret_cast<ElfW(Addr)*>(reloc) += (sym_addr - reloc);
- break;
+ case R_386_JMP_SLOT:
+ count_relocation(kRelocAbsolute);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "RELO JMP_SLOT %08x <- %08x %s", reloc, sym_addr, sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr;
+ break;
+ case R_386_GLOB_DAT:
+ count_relocation(kRelocAbsolute);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "RELO GLOB_DAT %08x <- %08x %s", reloc, sym_addr, sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr;
+ break;
+ case R_386_32:
+ count_relocation(kRelocRelative);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "RELO R_386_32 %08x <- +%08x %s", reloc, sym_addr, sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
+ break;
+ case R_386_PC32:
+ count_relocation(kRelocRelative);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "RELO R_386_PC32 %08x <- +%08x (%08x - %08x) %s",
+ reloc, (sym_addr - reloc), sym_addr, reloc, sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) += (sym_addr - reloc);
+ break;
#elif defined(__mips__)
- case R_MIPS_REL32:
+ case R_MIPS_REL32:
#if defined(__LP64__)
- // MIPS Elf64_Rel entries contain compound relocations
- // We only handle the R_MIPS_NONE|R_MIPS_64|R_MIPS_REL32 case
- if (ELF64_R_TYPE2(rel->r_info) != R_MIPS_64 ||
- ELF64_R_TYPE3(rel->r_info) != R_MIPS_NONE) {
- DL_ERR("Unexpected compound relocation type:%d type2:%d type3:%d @ %p (%zu)",
- type, (unsigned)ELF64_R_TYPE2(rel->r_info),
- (unsigned)ELF64_R_TYPE3(rel->r_info), rel, idx);
- return -1;
- }
+ // MIPS Elf64_Rel entries contain compound relocations
+ // We only handle the R_MIPS_NONE|R_MIPS_64|R_MIPS_REL32 case
+ if (ELF64_R_TYPE2(rel->r_info) != R_MIPS_64 ||
+ ELF64_R_TYPE3(rel->r_info) != R_MIPS_NONE) {
+ DL_ERR("Unexpected compound relocation type:%d type2:%d type3:%d @ %p (%zu)",
+ type, (unsigned)ELF64_R_TYPE2(rel->r_info),
+ (unsigned)ELF64_R_TYPE3(rel->r_info), rel, idx);
+ return -1;
+ }
#endif
- count_relocation(kRelocAbsolute);
- MARK(rel->r_offset);
- TRACE_TYPE(RELO, "RELO REL32 %08zx <- %08zx %s", static_cast<size_t>(reloc),
- static_cast<size_t>(sym_addr), sym_name ? sym_name : "*SECTIONHDR*");
- if (s) {
- *reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
- } else {
- *reinterpret_cast<ElfW(Addr)*>(reloc) += si->base;
- }
- break;
+ count_relocation(kRelocAbsolute);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "RELO REL32 %08zx <- %08zx %s", static_cast<size_t>(reloc),
+ static_cast<size_t>(sym_addr), sym_name ? sym_name : "*SECTIONHDR*");
+ if (s) {
+ *reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
+ } else {
+ *reinterpret_cast<ElfW(Addr)*>(reloc) += base;
+ }
+ break;
#endif
#if defined(__arm__)
- case R_ARM_RELATIVE:
+ case R_ARM_RELATIVE:
#elif defined(__i386__)
- case R_386_RELATIVE:
+ case R_386_RELATIVE:
#endif
- count_relocation(kRelocRelative);
- MARK(rel->r_offset);
- if (sym) {
- DL_ERR("odd RELATIVE form...");
- return -1;
- }
- TRACE_TYPE(RELO, "RELO RELATIVE %p <- +%p",
- reinterpret_cast<void*>(reloc), reinterpret_cast<void*>(si->base));
- *reinterpret_cast<ElfW(Addr)*>(reloc) += si->base;
- break;
-
- default:
- DL_ERR("unknown reloc type %d @ %p (%zu)", type, rel, idx);
- return -1;
+ count_relocation(kRelocRelative);
+ MARK(rel->r_offset);
+ if (sym) {
+ DL_ERR("odd RELATIVE form...");
+ return -1;
}
+ TRACE_TYPE(RELO, "RELO RELATIVE %p <- +%p",
+ reinterpret_cast<void*>(reloc), reinterpret_cast<void*>(base));
+ *reinterpret_cast<ElfW(Addr)*>(reloc) += base;
+ break;
+#if defined(__i386__)
+ case R_386_IRELATIVE:
+ count_relocation(kRelocRelative);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "RELO IRELATIVE %p <- %p", reinterpret_cast<void*>(reloc), reinterpret_cast<void*>(base));
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = call_ifunc_resolver(base + *reinterpret_cast<ElfW(Addr)*>(reloc));
+ break;
+#endif
+
+ default:
+ DL_ERR("unknown reloc type %d @ %p (%zu)", type, rel, idx);
+ return -1;
}
- return 0;
+ }
+ return 0;
}
#endif
#if defined(__mips__)
-static bool mips_relocate_got(soinfo* si, soinfo* needed[]) {
- ElfW(Addr)** got = si->plt_got;
- if (got == NULL) {
- return true;
+bool soinfo::mips_relocate_got(const soinfo_list_t& global_group, const soinfo_list_t& local_group) {
+ ElfW(Addr)** got = plt_got_;
+ if (got == nullptr) {
+ return true;
+ }
+
+ // got[0] is the address of the lazy resolver function.
+ // got[1] may be used for a GNU extension.
+ // Set it to a recognizable address in case someone calls it (should be _rtld_bind_start).
+ // FIXME: maybe this should be in a separate routine?
+ if ((flags_ & FLAG_LINKER) == 0) {
+ size_t g = 0;
+ got[g++] = reinterpret_cast<ElfW(Addr)*>(0xdeadbeef);
+ if (reinterpret_cast<intptr_t>(got[g]) < 0) {
+ got[g++] = reinterpret_cast<ElfW(Addr)*>(0xdeadfeed);
}
- unsigned local_gotno = si->mips_local_gotno;
- unsigned gotsym = si->mips_gotsym;
- unsigned symtabno = si->mips_symtabno;
- ElfW(Sym)* symtab = si->symtab;
-
- // got[0] is the address of the lazy resolver function.
- // got[1] may be used for a GNU extension.
- // Set it to a recognizable address in case someone calls it (should be _rtld_bind_start).
- // FIXME: maybe this should be in a separate routine?
- if ((si->flags & FLAG_LINKER) == 0) {
- size_t g = 0;
- got[g++] = reinterpret_cast<ElfW(Addr)*>(0xdeadbeef);
- if (reinterpret_cast<intptr_t>(got[g]) < 0) {
- got[g++] = reinterpret_cast<ElfW(Addr)*>(0xdeadfeed);
- }
- // Relocate the local GOT entries.
- for (; g < local_gotno; g++) {
- got[g] = reinterpret_cast<ElfW(Addr)*>(reinterpret_cast<uintptr_t>(got[g]) + si->load_bias);
- }
+ // Relocate the local GOT entries.
+ for (; g < mips_local_gotno_; g++) {
+ got[g] = reinterpret_cast<ElfW(Addr)*>(reinterpret_cast<uintptr_t>(got[g]) + load_bias);
}
+ }
- // Now for the global GOT entries...
- ElfW(Sym)* sym = symtab + gotsym;
- got = si->plt_got + local_gotno;
- 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;
- ElfW(Sym)* s = soinfo_do_lookup(si, sym_name, &lsi, needed);
- if (s == NULL) {
- // We only allow an undefined symbol if this is a weak reference.
- s = &symtab[g];
- if (ELF_ST_BIND(s->st_info) != STB_WEAK) {
- DL_ERR("cannot locate \"%s\"...", sym_name);
- return false;
- }
- *got = 0;
- } else {
- // FIXME: is this sufficient?
- // For reference see NetBSD link loader
- // http://cvsweb.netbsd.org/bsdweb.cgi/src/libexec/ld.elf_so/arch/mips/mips_reloc.c?rev=1.53&content-type=text/x-cvsweb-markup
- *got = reinterpret_cast<ElfW(Addr)*>(lsi->load_bias + s->st_value);
- }
+ // Now for the global GOT entries...
+ ElfW(Sym)* sym = symtab_ + mips_gotsym_;
+ got = plt_got_ + mips_local_gotno_;
+ for (size_t g = mips_gotsym_; g < mips_symtabno_; g++, sym++, got++) {
+ // This is an undefined reference... try to locate it.
+ const char* sym_name = get_string(sym->st_name);
+ soinfo* lsi = nullptr;
+ ElfW(Sym)* s = soinfo_do_lookup(this, sym_name, &lsi, global_group, local_group);
+ if (s == nullptr) {
+ // We only allow an undefined symbol if this is a weak reference.
+ s = &symtab_[g];
+ if (ELF_ST_BIND(s->st_info) != STB_WEAK) {
+ DL_ERR("cannot locate \"%s\"...", sym_name);
+ return false;
+ }
+ *got = 0;
+ } else {
+ // FIXME: is this sufficient?
+ // For reference see NetBSD link loader
+ // http://cvsweb.netbsd.org/bsdweb.cgi/src/libexec/ld.elf_so/arch/mips/mips_reloc.c?rev=1.53&content-type=text/x-cvsweb-markup
+ *got = reinterpret_cast<ElfW(Addr)*>(lsi->resolve_symbol_address(s));
}
- return true;
+ }
+ return true;
}
#endif
-void soinfo::CallArray(const char* array_name __unused, linker_function_t* functions, size_t count, bool reverse) {
- if (functions == NULL) {
+void soinfo::call_array(const char* array_name __unused, linker_function_t* functions, size_t count, bool reverse) {
+ if (functions == nullptr) {
return;
}
@@ -1459,14 +1822,14 @@ void soinfo::CallArray(const char* array_name __unused, linker_function_t* funct
for (int i = begin; i != end; i += step) {
TRACE("[ %s[%d] == %p ]", array_name, i, functions[i]);
- CallFunction("function", functions[i]);
+ call_function("function", functions[i]);
}
TRACE("[ Done calling %s for '%s' ]", array_name, name);
}
-void soinfo::CallFunction(const char* function_name __unused, linker_function_t function) {
- if (function == NULL || reinterpret_cast<uintptr_t>(function) == static_cast<uintptr_t>(-1)) {
+void soinfo::call_function(const char* function_name __unused, linker_function_t function) {
+ if (function == nullptr || reinterpret_cast<uintptr_t>(function) == static_cast<uintptr_t>(-1)) {
return;
}
@@ -1479,13 +1842,13 @@ void soinfo::CallFunction(const char* function_name __unused, linker_function_t
protect_data(PROT_READ | PROT_WRITE);
}
-void soinfo::CallPreInitConstructors() {
+void soinfo::call_pre_init_constructors() {
// DT_PREINIT_ARRAY functions are called before any other constructors for executables,
// but ignored in a shared library.
- CallArray("DT_PREINIT_ARRAY", preinit_array, preinit_array_count, false);
+ call_array("DT_PREINIT_ARRAY", preinit_array_, preinit_array_count_, false);
}
-void soinfo::CallConstructors() {
+void soinfo::call_constructors() {
if (constructors_called) {
return;
}
// out above, the libc constructor will be called again (recursively!).
constructors_called = true;
- if ((flags & FLAG_EXE) == 0 && preinit_array != NULL) {
+ if (!is_main_executable() && preinit_array_ != nullptr) {
// The GNU dynamic linker silently ignores these, but we warn the developer.
PRINT("\"%s\": ignoring %zd-entry DT_PREINIT_ARRAY in shared library!",
- name, preinit_array_count);
+ name, preinit_array_count_);
}
get_children().for_each([] (soinfo* si) {
- si->CallConstructors();
+ si->call_constructors();
});
TRACE("\"%s\": calling constructors", name);
// DT_INIT should be called before DT_INIT_ARRAY if both are present.
- CallFunction("DT_INIT", init_func);
- CallArray("DT_INIT_ARRAY", init_array, init_array_count, false);
+ call_function("DT_INIT", init_func_);
+ call_array("DT_INIT_ARRAY", init_array_, init_array_count_, false);
}
-void soinfo::CallDestructors() {
+void soinfo::call_destructors() {
+ if (!constructors_called) {
+ return;
+ }
TRACE("\"%s\": calling destructors", name);
// DT_FINI_ARRAY must be parsed in reverse order.
- CallArray("DT_FINI_ARRAY", fini_array, fini_array_count, true);
+ call_array("DT_FINI_ARRAY", fini_array_, fini_array_count_, true);
// DT_FINI should be called after DT_FINI_ARRAY if both are present.
- CallFunction("DT_FINI", fini_func);
+ call_function("DT_FINI", fini_func_);
// This is needed on second call to dlopen
// after library has been unloaded with RTLD_NODELETE
}
void soinfo::add_child(soinfo* child) {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
- return;
+ if (has_min_version(0)) {
+ child->parents_.push_back(this);
+ this->children_.push_back(child);
}
-
- this->children.push_front(child);
- child->parents.push_front(this);
}
void soinfo::remove_all_links() {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
+ if (!has_min_version(0)) {
return;
}
// 1. Untie connected soinfos from 'this'.
- children.for_each([&] (soinfo* child) {
- child->parents.remove_if([&] (const soinfo* parent) {
+ children_.for_each([&] (soinfo* child) {
+ child->parents_.remove_if([&] (const soinfo* parent) {
return parent == this;
});
});
- parents.for_each([&] (soinfo* parent) {
- parent->children.for_each([&] (const soinfo* child) {
+ parents_.for_each([&] (soinfo* parent) {
+ parent->children_.remove_if([&] (const soinfo* child) {
return child == this;
});
});
// 2. Once everything untied - clear local lists.
- parents.clear();
- children.clear();
+ parents_.clear();
+ children_.clear();
}
-void soinfo::set_st_dev(dev_t dev) {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
- return;
+dev_t soinfo::get_st_dev() const {
+ if (has_min_version(0)) {
+ return st_dev_;
}
- st_dev = dev;
+ return 0;
+};
+
+ino_t soinfo::get_st_ino() const {
+ if (has_min_version(0)) {
+ return st_ino_;
+ }
+
+ return 0;
}
-void soinfo::set_st_ino(ino_t ino) {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
- return;
+off64_t soinfo::get_file_offset() const {
+ if (has_min_version(1)) {
+ return file_offset_;
}
- st_ino = ino;
+ return 0;
+}
+
+uint32_t soinfo::get_rtld_flags() const {
+ if (has_min_version(1)) {
+ return rtld_flags_;
+ }
+
+ return 0;
}
-dev_t soinfo::get_st_dev() {
- if ((this->flags & FLAG_NEW_SOINFO) == 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;
+ }
+
+ dt_flags_1_ = dt_flags_1;
+ }
+}
+
+// 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;
+
+soinfo::soinfo_list_t& soinfo::get_children() {
+ if (has_min_version(0)) {
+ return children_;
+ }
+
+ return g_empty_list;
+}
+
+soinfo::soinfo_list_t& soinfo::get_parents() {
+ if (has_min_version(0)) {
+ return parents_;
+ }
+
+ return g_empty_list;
+}
+
+ElfW(Addr) soinfo::resolve_symbol_address(ElfW(Sym)* s) {
+ 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", name, strtab_size_, index);
+ }
+
+ return strtab_ + index;
+}
+
+bool soinfo::is_gnu_hash() const {
+ return (flags_ & FLAG_GNU_HASH) != 0;
+}
+
+bool soinfo::can_unload() const {
+ return (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;
+}
+
+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_;
+}
+
+/* Force any of the closed stdin, stdout and stderr to be associated with
+ /dev/null. */
+static int nullify_closed_stdio() {
+ int dev_null, i, status;
+ int return_value = 0;
+
+ dev_null = TEMP_FAILURE_RETRY(open("/dev/null", O_RDWR));
+ if (dev_null < 0) {
+ DL_ERR("cannot open /dev/null: %s", strerror(errno));
+ return -1;
+ }
+ TRACE("[ Opened /dev/null file-descriptor=%d]", dev_null);
+
+ /* If any of the stdio file descriptors is valid and not associated
+ with /dev/null, dup /dev/null to it. */
+ for (i = 0; i < 3; i++) {
+ /* If it is /dev/null already, we are done. */
+ if (i == dev_null) {
+ continue;
+ }
+
+ TRACE("[ Nullifying stdio file descriptor %d]", i);
+ status = TEMP_FAILURE_RETRY(fcntl(i, F_GETFL));
+
+ /* If file is opened, we are good. */
+ if (status != -1) {
+ continue;
+ }
+
+ /* The only error we allow is that the file descriptor does not
+ exist, in which case we dup /dev/null to it. */
+ if (errno != EBADF) {
+ DL_ERR("fcntl failed: %s", strerror(errno));
+ return_value = -1;
+ continue;
+ }
+
+ /* Try dupping /dev/null to this stdio file descriptor and
+ repeat if there is a signal. Note that any errors in closing
+ the stdio descriptor are lost. */
+ status = TEMP_FAILURE_RETRY(dup2(dev_null, i));
+ if (status < 0) {
+ DL_ERR("dup2 failed: %s", strerror(errno));
+ return_value = -1;
+ continue;
+ }
}
- return st_dev;
-};
-
-ino_t soinfo::get_st_ino() {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
- return 0;
+ /* If /dev/null is not one of the stdio file descriptors, close it. */
+ if (dev_null > 2) {
+ TRACE("[ Closing /dev/null file-descriptor=%d]", dev_null);
+ status = TEMP_FAILURE_RETRY(close(dev_null));
+ if (status == -1) {
+ DL_ERR("close failed: %s", strerror(errno));
+ return_value = -1;
+ }
}
- return st_ino;
+ return return_value;
}
-// This is a return on get_children() in case
-// 'this->flags' does not have FLAG_NEW_SOINFO set.
-static soinfo::soinfo_list_t g_empty_list;
+bool soinfo::prelink_image() {
+ /* Extract dynamic section */
+ ElfW(Word) dynamic_flags = 0;
+ phdr_table_get_dynamic_section(phdr, phnum, load_bias, &dynamic, &dynamic_flags);
-soinfo::soinfo_list_t& soinfo::get_children() {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
- return g_empty_list;
+ /* 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<void*>(base), flags_);
}
- return this->children;
-}
+ if (dynamic == nullptr) {
+ if (!relocating_linker) {
+ DL_ERR("missing PT_DYNAMIC in \"%s\"", name);
+ }
+ return false;
+ } else {
+ if (!relocating_linker) {
+ DEBUG("dynamic = %p", dynamic);
+ }
+ }
-/* Force any of the closed stdin, stdout and stderr to be associated with
- /dev/null. */
-static int nullify_closed_stdio() {
- int dev_null, i, status;
- int return_value = 0;
+#if defined(__arm__)
+ (void) phdr_table_get_arm_exidx(phdr, phnum, load_bias,
+ &ARM_exidx, &ARM_exidx_count);
+#endif
- dev_null = TEMP_FAILURE_RETRY(open("/dev/null", O_RDWR));
- if (dev_null < 0) {
- DL_ERR("cannot open /dev/null: %s", strerror(errno));
- return -1;
- }
- TRACE("[ Opened /dev/null file-descriptor=%d]", dev_null);
+ // Extract useful information from dynamic section.
+ uint32_t needed_count = 0;
+ for (ElfW(Dyn)* d = dynamic; d->d_tag != DT_NULL; ++d) {
+ DEBUG("d = %p, d[0](tag) = %p d[1](val) = %p",
+ d, reinterpret_cast<void*>(d->d_tag), reinterpret_cast<void*>(d->d_un.d_val));
+ switch (d->d_tag) {
+ case DT_SONAME:
+ // TODO: glibc dynamic linker uses this name for
+ // initial library lookup; consider doing the same here.
+ break;
- /* If any of the stdio file descriptors is valid and not associated
- with /dev/null, dup /dev/null to it. */
- for (i = 0; i < 3; i++) {
- /* If it is /dev/null already, we are done. */
- if (i == dev_null) {
- continue;
+ case DT_HASH:
+ if (nbucket_ != 0) {
+ // in case of --hash-style=both, we prefer gnu
+ break;
}
- TRACE("[ Nullifying stdio file descriptor %d]", i);
- status = TEMP_FAILURE_RETRY(fcntl(i, F_GETFL));
+ nbucket_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[0];
+ nchain_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[1];
+ bucket_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr + 8);
+ chain_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr + 8 + nbucket_ * 4);
+ break;
- /* If file is opened, we are good. */
- if (status != -1) {
- continue;
+ case DT_GNU_HASH:
+ if (nbucket_ != 0) {
+ // in case of --hash-style=both, we prefer gnu
+ nchain_ = 0;
}
- /* The only error we allow is that the file descriptor does not
- exist, in which case we dup /dev/null to it. */
- if (errno != EBADF) {
- DL_ERR("fcntl failed: %s", strerror(errno));
- return_value = -1;
- continue;
- }
+ nbucket_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[0];
+ // skip symndx
+ gnu_maskwords_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[2];
+ gnu_shift2_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[3];
- /* Try dupping /dev/null to this stdio file descriptor and
- repeat if there is a signal. Note that any errors in closing
- the stdio descriptor are lost. */
- status = TEMP_FAILURE_RETRY(dup2(dev_null, i));
- if (status < 0) {
- DL_ERR("dup2 failed: %s", strerror(errno));
- return_value = -1;
- continue;
- }
- }
+ gnu_bloom_filter_ = reinterpret_cast<ElfW(Addr)*>(load_bias + d->d_un.d_ptr + 16);
+ bucket_ = reinterpret_cast<uint32_t*>(gnu_bloom_filter_ + gnu_maskwords_);
+ // amend chain for symndx = header[1]
+ chain_ = bucket_ + nbucket_ - reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[1];
- /* If /dev/null is not one of the stdio file descriptors, close it. */
- if (dev_null > 2) {
- TRACE("[ Closing /dev/null file-descriptor=%d]", dev_null);
- status = TEMP_FAILURE_RETRY(close(dev_null));
- if (status == -1) {
- DL_ERR("close failed: %s", strerror(errno));
- return_value = -1;
+ if (!powerof2(gnu_maskwords_)) {
+ DL_ERR("invalid maskwords for gnu_hash = 0x%x, in \"%s\" expecting power to two", gnu_maskwords_, name);
+ return false;
}
- }
+ --gnu_maskwords_;
- return return_value;
-}
+ flags_ |= FLAG_GNU_HASH;
+ break;
-static bool soinfo_link_image(soinfo* si, const android_dlextinfo* extinfo) {
- /* "base" might wrap around UINT32_MAX. */
- ElfW(Addr) base = si->load_bias;
- const ElfW(Phdr)* phdr = si->phdr;
- int phnum = si->phnum;
- bool relocating_linker = (si->flags & FLAG_LINKER) != 0;
+ case DT_STRTAB:
+ strtab_ = reinterpret_cast<const char*>(load_bias + d->d_un.d_ptr);
+ break;
- /* We can't debug anything until the linker is relocated */
- if (!relocating_linker) {
- INFO("[ linking %s ]", si->name);
- DEBUG("si->base = %p si->flags = 0x%08x", reinterpret_cast<void*>(si->base), si->flags);
- }
+ case DT_STRSZ:
+ strtab_size_ = d->d_un.d_val;
+ break;
- /* Extract dynamic section */
- size_t dynamic_count;
- ElfW(Word) dynamic_flags;
- phdr_table_get_dynamic_section(phdr, phnum, base, &si->dynamic,
- &dynamic_count, &dynamic_flags);
- if (si->dynamic == NULL) {
- if (!relocating_linker) {
- DL_ERR("missing PT_DYNAMIC in \"%s\"", si->name);
- }
- return false;
- } else {
- if (!relocating_linker) {
- DEBUG("dynamic = %p", si->dynamic);
+ case DT_SYMTAB:
+ symtab_ = reinterpret_cast<ElfW(Sym)*>(load_bias + d->d_un.d_ptr);
+ break;
+
+ case DT_SYMENT:
+ if (d->d_un.d_val != sizeof(ElfW(Sym))) {
+ DL_ERR("invalid DT_SYMENT: %zd in \"%s\"", static_cast<size_t>(d->d_un.d_val), name);
+ return false;
}
- }
+ break;
-#if defined(__arm__)
- (void) phdr_table_get_arm_exidx(phdr, phnum, base,
- &si->ARM_exidx, &si->ARM_exidx_count);
+ case DT_PLTREL:
+#if defined(USE_RELA)
+ if (d->d_un.d_val != DT_RELA) {
+ DL_ERR("unsupported DT_PLTREL in \"%s\"; expected DT_RELA", name);
+ return false;
+ }
+#else
+ if (d->d_un.d_val != DT_REL) {
+ DL_ERR("unsupported DT_PLTREL in \"%s\"; expected DT_REL", name);
+ return false;
+ }
#endif
+ break;
- // Extract useful information from dynamic section.
- uint32_t needed_count = 0;
- for (ElfW(Dyn)* d = si->dynamic; d->d_tag != DT_NULL; ++d) {
- DEBUG("d = %p, d[0](tag) = %p d[1](val) = %p",
- d, reinterpret_cast<void*>(d->d_tag), reinterpret_cast<void*>(d->d_un.d_val));
- switch (d->d_tag) {
- case DT_HASH:
- si->nbucket = reinterpret_cast<uint32_t*>(base + d->d_un.d_ptr)[0];
- si->nchain = reinterpret_cast<uint32_t*>(base + d->d_un.d_ptr)[1];
- si->bucket = reinterpret_cast<uint32_t*>(base + d->d_un.d_ptr + 8);
- si->chain = reinterpret_cast<uint32_t*>(base + d->d_un.d_ptr + 8 + si->nbucket * 4);
- break;
- case DT_STRTAB:
- si->strtab = reinterpret_cast<const char*>(base + d->d_un.d_ptr);
- break;
- case DT_SYMTAB:
- si->symtab = reinterpret_cast<ElfW(Sym)*>(base + d->d_un.d_ptr);
- break;
-#if !defined(__LP64__)
- case DT_PLTREL:
- if (d->d_un.d_val != DT_REL) {
- DL_ERR("unsupported DT_RELA in \"%s\"", si->name);
- return false;
- }
- break;
-#endif
- case DT_JMPREL:
+ case DT_JMPREL:
#if defined(USE_RELA)
- si->plt_rela = reinterpret_cast<ElfW(Rela)*>(base + d->d_un.d_ptr);
+ plt_rela_ = reinterpret_cast<ElfW(Rela)*>(load_bias + d->d_un.d_ptr);
#else
- si->plt_rel = reinterpret_cast<ElfW(Rel)*>(base + d->d_un.d_ptr);
+ plt_rel_ = reinterpret_cast<ElfW(Rel)*>(load_bias + d->d_un.d_ptr);
#endif
- break;
- case DT_PLTRELSZ:
+ break;
+
+ case DT_PLTRELSZ:
#if defined(USE_RELA)
- si->plt_rela_count = d->d_un.d_val / sizeof(ElfW(Rela));
+ plt_rela_count_ = d->d_un.d_val / sizeof(ElfW(Rela));
#else
- si->plt_rel_count = d->d_un.d_val / sizeof(ElfW(Rel));
+ plt_rel_count_ = d->d_un.d_val / sizeof(ElfW(Rel));
#endif
- break;
+ break;
+
+ case DT_PLTGOT:
#if defined(__mips__)
- case DT_PLTGOT:
- // Used by mips and mips64.
- si->plt_got = reinterpret_cast<ElfW(Addr)**>(base + d->d_un.d_ptr);
- break;
+ // Used by mips and mips64.
+ plt_got_ = reinterpret_cast<ElfW(Addr)**>(load_bias + d->d_un.d_ptr);
#endif
- case DT_DEBUG:
- // Set the DT_DEBUG entry to the address of _r_debug for GDB
- // if the dynamic table is writable
+ // Ignore for other platforms... (because RTLD_LAZY is not supported)
+ break;
+
+ case DT_DEBUG:
+ // Set the DT_DEBUG entry to the address of _r_debug for GDB
+ // 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) {
- d->d_un.d_val = reinterpret_cast<uintptr_t>(&_r_debug);
- }
- break;
+ if ((dynamic_flags & PF_W) != 0) {
+ d->d_un.d_val = reinterpret_cast<uintptr_t>(&_r_debug);
+ }
+ break;
#endif
#if defined(USE_RELA)
- case DT_RELA:
- si->rela = reinterpret_cast<ElfW(Rela)*>(base + d->d_un.d_ptr);
- break;
- case DT_RELASZ:
- si->rela_count = d->d_un.d_val / sizeof(ElfW(Rela));
- break;
- case DT_REL:
- DL_ERR("unsupported DT_REL in \"%s\"", si->name);
- return false;
- case DT_RELSZ:
- DL_ERR("unsupported DT_RELSZ in \"%s\"", si->name);
- return false;
+ case DT_RELA:
+ rela_ = reinterpret_cast<ElfW(Rela)*>(load_bias + d->d_un.d_ptr);
+ break;
+
+ case DT_RELASZ:
+ rela_count_ = d->d_un.d_val / sizeof(ElfW(Rela));
+ break;
+
+ case DT_RELAENT:
+ if (d->d_un.d_val != sizeof(ElfW(Rela))) {
+ DL_ERR("invalid DT_RELAENT: %zd", static_cast<size_t>(d->d_un.d_val));
+ return false;
+ }
+ break;
+
+ // ignored (see DT_RELCOUNT comments for details)
+ case DT_RELACOUNT:
+ break;
+
+ case DT_REL:
+ DL_ERR("unsupported DT_REL in \"%s\"", name);
+ return false;
+
+ case DT_RELSZ:
+ DL_ERR("unsupported DT_RELSZ in \"%s\"", name);
+ return false;
#else
- case DT_REL:
- si->rel = reinterpret_cast<ElfW(Rel)*>(base + d->d_un.d_ptr);
- break;
- case DT_RELSZ:
- si->rel_count = d->d_un.d_val / sizeof(ElfW(Rel));
- break;
- case DT_RELA:
- DL_ERR("unsupported DT_RELA in \"%s\"", si->name);
- return false;
+ case DT_REL:
+ rel_ = reinterpret_cast<ElfW(Rel)*>(load_bias + d->d_un.d_ptr);
+ break;
+
+ case DT_RELSZ:
+ rel_count_ = d->d_un.d_val / sizeof(ElfW(Rel));
+ break;
+
+ case DT_RELENT:
+ if (d->d_un.d_val != sizeof(ElfW(Rel))) {
+ DL_ERR("invalid DT_RELENT: %zd", static_cast<size_t>(d->d_un.d_val));
+ return false;
+ }
+ break;
+
+ // "Indicates that all RELATIVE relocations have been concatenated together,
+ // and specifies the RELATIVE relocation count."
+ //
+ // TODO: Spec also mentions that this can be used to optimize relocation process;
+ // Not currently used by bionic linker - ignored.
+ case DT_RELCOUNT:
+ break;
+ case DT_RELA:
+ DL_ERR("unsupported DT_RELA in \"%s\"", name);
+ return false;
#endif
- case DT_INIT:
- si->init_func = reinterpret_cast<linker_function_t>(base + d->d_un.d_ptr);
- DEBUG("%s constructors (DT_INIT) found at %p", si->name, si->init_func);
- break;
- case DT_FINI:
- si->fini_func = reinterpret_cast<linker_function_t>(base + d->d_un.d_ptr);
- DEBUG("%s destructors (DT_FINI) found at %p", si->name, si->fini_func);
- break;
- case DT_INIT_ARRAY:
- si->init_array = reinterpret_cast<linker_function_t*>(base + d->d_un.d_ptr);
- DEBUG("%s constructors (DT_INIT_ARRAY) found at %p", si->name, si->init_array);
- break;
- case DT_INIT_ARRAYSZ:
- si->init_array_count = ((unsigned)d->d_un.d_val) / sizeof(ElfW(Addr));
- break;
- case DT_FINI_ARRAY:
- si->fini_array = reinterpret_cast<linker_function_t*>(base + d->d_un.d_ptr);
- DEBUG("%s destructors (DT_FINI_ARRAY) found at %p", si->name, si->fini_array);
- break;
- case DT_FINI_ARRAYSZ:
- si->fini_array_count = ((unsigned)d->d_un.d_val) / sizeof(ElfW(Addr));
- break;
- case DT_PREINIT_ARRAY:
- si->preinit_array = reinterpret_cast<linker_function_t*>(base + d->d_un.d_ptr);
- DEBUG("%s constructors (DT_PREINIT_ARRAY) found at %p", si->name, si->preinit_array);
- break;
- case DT_PREINIT_ARRAYSZ:
- si->preinit_array_count = ((unsigned)d->d_un.d_val) / sizeof(ElfW(Addr));
- break;
- case DT_TEXTREL:
+ case DT_INIT:
+ init_func_ = reinterpret_cast<linker_function_t>(load_bias + d->d_un.d_ptr);
+ DEBUG("%s constructors (DT_INIT) found at %p", name, init_func_);
+ break;
+
+ case DT_FINI:
+ fini_func_ = reinterpret_cast<linker_function_t>(load_bias + d->d_un.d_ptr);
+ DEBUG("%s destructors (DT_FINI) found at %p", name, fini_func_);
+ break;
+
+ case DT_INIT_ARRAY:
+ init_array_ = reinterpret_cast<linker_function_t*>(load_bias + d->d_un.d_ptr);
+ DEBUG("%s constructors (DT_INIT_ARRAY) found at %p", name, init_array_);
+ break;
+
+ case DT_INIT_ARRAYSZ:
+ init_array_count_ = ((unsigned)d->d_un.d_val) / sizeof(ElfW(Addr));
+ break;
+
+ case DT_FINI_ARRAY:
+ fini_array_ = reinterpret_cast<linker_function_t*>(load_bias + d->d_un.d_ptr);
+ DEBUG("%s destructors (DT_FINI_ARRAY) found at %p", name, fini_array_);
+ break;
+
+ case DT_FINI_ARRAYSZ:
+ fini_array_count_ = ((unsigned)d->d_un.d_val) / sizeof(ElfW(Addr));
+ break;
+
+ case DT_PREINIT_ARRAY:
+ preinit_array_ = reinterpret_cast<linker_function_t*>(load_bias + d->d_un.d_ptr);
+ DEBUG("%s constructors (DT_PREINIT_ARRAY) found at %p", name, preinit_array_);
+ break;
+
+ case DT_PREINIT_ARRAYSZ:
+ preinit_array_count_ = ((unsigned)d->d_un.d_val) / sizeof(ElfW(Addr));
+ break;
+
+ case DT_TEXTREL:
#if defined(__LP64__)
- DL_ERR("text relocations (DT_TEXTREL) found in 64-bit ELF file \"%s\"", si->name);
- return false;
+ DL_ERR("text relocations (DT_TEXTREL) found in 64-bit ELF file \"%s\"", name);
+ return false;
#else
- si->has_text_relocations = true;
- break;
+ has_text_relocations = true;
+ break;
#endif
- case DT_SYMBOLIC:
- si->has_DT_SYMBOLIC = true;
- break;
- case DT_NEEDED:
- ++needed_count;
- break;
- case DT_FLAGS:
- if (d->d_un.d_val & DF_TEXTREL) {
+
+ case DT_SYMBOLIC:
+ has_DT_SYMBOLIC = true;
+ break;
+
+ case DT_NEEDED:
+ ++needed_count;
+ break;
+
+ case DT_FLAGS:
+ if (d->d_un.d_val & DF_TEXTREL) {
#if defined(__LP64__)
- DL_ERR("text relocations (DF_TEXTREL) found in 64-bit ELF file \"%s\"", si->name);
- return false;
+ DL_ERR("text relocations (DF_TEXTREL) found in 64-bit ELF file \"%s\"", name);
+ return false;
#else
- si->has_text_relocations = true;
+ has_text_relocations = true;
#endif
- }
- if (d->d_un.d_val & DF_SYMBOLIC) {
- si->has_DT_SYMBOLIC = true;
- }
- break;
-#if defined(__mips__)
- case DT_STRSZ:
- case DT_SYMENT:
- case DT_RELENT:
- break;
- case DT_MIPS_RLD_MAP:
- // Set the DT_MIPS_RLD_MAP entry to the address of _r_debug for GDB.
- {
- r_debug** dp = reinterpret_cast<r_debug**>(base + d->d_un.d_ptr);
- *dp = &_r_debug;
- }
- break;
- case DT_MIPS_RLD_VERSION:
- case DT_MIPS_FLAGS:
- case DT_MIPS_BASE_ADDRESS:
- case DT_MIPS_UNREFEXTNO:
- break;
+ }
+ if (d->d_un.d_val & DF_SYMBOLIC) {
+ has_DT_SYMBOLIC = true;
+ }
+ break;
- case DT_MIPS_SYMTABNO:
- si->mips_symtabno = d->d_un.d_val;
- break;
+ case DT_FLAGS_1:
+ set_dt_flags_1(d->d_un.d_val);
- case DT_MIPS_LOCAL_GOTNO:
- si->mips_local_gotno = d->d_un.d_val;
- break;
+ if ((d->d_un.d_val & ~SUPPORTED_DT_FLAGS_1) != 0) {
+ DL_WARN("Unsupported flags DT_FLAGS_1=%p", reinterpret_cast<void*>(d->d_un.d_val));
+ }
+ break;
+#if defined(__mips__)
+ case DT_MIPS_RLD_MAP:
+ // Set the DT_MIPS_RLD_MAP entry to the address of _r_debug for GDB.
+ {
+ r_debug** dp = reinterpret_cast<r_debug**>(load_bias + d->d_un.d_ptr);
+ *dp = &_r_debug;
+ }
+ break;
- case DT_MIPS_GOTSYM:
- si->mips_gotsym = d->d_un.d_val;
- break;
-#endif
+ case DT_MIPS_RLD_VERSION:
+ case DT_MIPS_FLAGS:
+ case DT_MIPS_BASE_ADDRESS:
+ case DT_MIPS_UNREFEXTNO:
+ break;
- default:
- DEBUG("Unused DT entry: type %p arg %p",
- reinterpret_cast<void*>(d->d_tag), reinterpret_cast<void*>(d->d_un.d_val));
- break;
- }
- }
+ case DT_MIPS_SYMTABNO:
+ mips_symtabno_ = d->d_un.d_val;
+ break;
- DEBUG("si->base = %p, si->strtab = %p, si->symtab = %p",
- reinterpret_cast<void*>(si->base), si->strtab, si->symtab);
+ case DT_MIPS_LOCAL_GOTNO:
+ mips_local_gotno_ = d->d_un.d_val;
+ break;
- // Sanity checks.
- if (relocating_linker && needed_count != 0) {
- DL_ERR("linker cannot have DT_NEEDED dependencies on other libraries");
- return false;
- }
- if (si->nbucket == 0) {
- DL_ERR("empty/missing DT_HASH in \"%s\" (built with --hash-style=gnu?)", si->name);
- return false;
- }
- if (si->strtab == 0) {
- DL_ERR("empty/missing DT_STRTAB in \"%s\"", si->name);
- return false;
- }
- if (si->symtab == 0) {
- DL_ERR("empty/missing DT_SYMTAB in \"%s\"", si->name);
- return false;
- }
+ case DT_MIPS_GOTSYM:
+ mips_gotsym_ = d->d_un.d_val;
+ break;
+#endif
+ // Ignored: "Its use has been superseded by the DF_BIND_NOW flag"
+ case DT_BIND_NOW:
+ break;
+
+ // Ignore: bionic does not support symbol versioning...
+ case DT_VERSYM:
+ case DT_VERDEF:
+ case DT_VERDEFNUM:
+ case DT_VERNEED:
+ case DT_VERNEEDNUM:
+ break;
- // If this is the main executable, then load all of the libraries from LD_PRELOAD now.
- if (si->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] != NULL; i++) {
- soinfo* lsi = find_library(g_ld_preload_names[i], 0, NULL);
- if (lsi != NULL) {
- 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], si->name, linker_get_error_buffer());
- }
+ default:
+ if (!relocating_linker) {
+ DL_WARN("%s: unused DT entry: type %p arg %p", name,
+ reinterpret_cast<void*>(d->d_tag), reinterpret_cast<void*>(d->d_un.d_val));
}
+ break;
}
+ }
- soinfo** needed = reinterpret_cast<soinfo**>(alloca((1 + needed_count) * sizeof(soinfo*)));
- soinfo** pneeded = needed;
+ DEBUG("si->base = %p, si->strtab = %p, si->symtab = %p",
+ reinterpret_cast<void*>(base), strtab_, symtab_);
+
+ // Sanity checks.
+ if (relocating_linker && needed_count != 0) {
+ DL_ERR("linker cannot have DT_NEEDED dependencies on other libraries");
+ return false;
+ }
+ if (nbucket_ == 0) {
+ DL_ERR("empty/missing DT_HASH/DT_GNU_HASH in \"%s\" (new hash type from the future?)", name);
+ return false;
+ }
+ if (strtab_ == 0) {
+ DL_ERR("empty/missing DT_STRTAB in \"%s\"", name);
+ return false;
+ }
+ if (symtab_ == 0) {
+ DL_ERR("empty/missing DT_SYMTAB in \"%s\"", name);
+ return false;
+ }
+ return true;
+}
- 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;
- DEBUG("%s needs %s", si->name, library_name);
- soinfo* lsi = find_library(library_name, 0, NULL);
- if (lsi == NULL) {
- 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, si->name, tmp_err_buf);
- return false;
- }
+bool soinfo::link_image(const soinfo_list_t& global_group, const soinfo_list_t& local_group, const android_dlextinfo* extinfo) {
- si->add_child(lsi);
- *pneeded++ = lsi;
- }
- }
- *pneeded = NULL;
+ local_group_root_ = local_group.front();
+ if (local_group_root_ == nullptr) {
+ local_group_root_ = this;
+ }
#if !defined(__LP64__)
- if (si->has_text_relocations) {
- // Make segments writable to allow text relocations to work properly. We will later call
- // phdr_table_protect_segments() after all of them are applied and all constructors are run.
- DL_WARN("%s has text relocations. This is wasting memory and prevents "
- "security hardening. Please fix.", si->name);
- if (phdr_table_unprotect_segments(si->phdr, si->phnum, si->load_bias) < 0) {
- DL_ERR("can't unprotect loadable segments for \"%s\": %s",
- si->name, strerror(errno));
- return false;
- }
+ if (has_text_relocations) {
+ // Make segments writable to allow text relocations to work properly. We will later call
+ // phdr_table_protect_segments() after all of them are applied and all constructors are run.
+ DL_WARN("%s has text relocations. This is wasting memory and prevents "
+ "security hardening. Please fix.", name);
+ if (phdr_table_unprotect_segments(phdr, phnum, load_bias) < 0) {
+ DL_ERR("can't unprotect loadable segments for \"%s\": %s",
+ name, strerror(errno));
+ return false;
}
+ }
#endif
#if defined(USE_RELA)
- if (si->plt_rela != NULL) {
- DEBUG("[ relocating %s plt ]\n", si->name);
- if (soinfo_relocate(si, si->plt_rela, si->plt_rela_count, needed)) {
- return false;
- }
+ if (rela_ != nullptr) {
+ DEBUG("[ relocating %s ]", name);
+ if (relocate(rela_, rela_count_, global_group, local_group)) {
+ return false;
}
- if (si->rela != NULL) {
- DEBUG("[ relocating %s ]\n", si->name);
- if (soinfo_relocate(si, si->rela, si->rela_count, needed)) {
- return false;
- }
+ }
+ if (plt_rela_ != nullptr) {
+ DEBUG("[ relocating %s plt ]", name);
+ if (relocate(plt_rela_, plt_rela_count_, global_group, local_group)) {
+ return false;
}
+ }
#else
- if (si->plt_rel != NULL) {
- DEBUG("[ relocating %s plt ]", si->name);
- if (soinfo_relocate(si, si->plt_rel, si->plt_rel_count, needed)) {
- return false;
- }
+ if (rel_ != nullptr) {
+ DEBUG("[ relocating %s ]", name);
+ if (relocate(rel_, rel_count_, global_group, local_group)) {
+ return false;
}
- if (si->rel != NULL) {
- DEBUG("[ relocating %s ]", si->name);
- if (soinfo_relocate(si, si->rel, si->rel_count, needed)) {
- return false;
- }
+ }
+ if (plt_rel_ != nullptr) {
+ DEBUG("[ relocating %s plt ]", name);
+ if (relocate(plt_rel_, plt_rel_count_, global_group, local_group)) {
+ return false;
}
+ }
#endif
#if defined(__mips__)
- if (!mips_relocate_got(si, needed)) {
- return false;
- }
+ if (!mips_relocate_got(global_group, local_group)) {
+ return false;
+ }
#endif
- si->flags |= FLAG_LINKED;
- DEBUG("[ finished linking %s ]", si->name);
+ DEBUG("[ finished linking %s ]", name);
#if !defined(__LP64__)
- if (si->has_text_relocations) {
- // All relocations are done, we can protect our segments back to read-only.
- if (phdr_table_protect_segments(si->phdr, si->phnum, si->load_bias) < 0) {
- DL_ERR("can't protect segments for \"%s\": %s",
- si->name, strerror(errno));
- return false;
- }
+ if (has_text_relocations) {
+ // All relocations are done, we can protect our segments back to read-only.
+ if (phdr_table_protect_segments(phdr, phnum, load_bias) < 0) {
+ DL_ERR("can't protect segments for \"%s\": %s",
+ name, strerror(errno));
+ return false;
}
+ }
#endif
- /* We can also turn on GNU RELRO protection */
- if (phdr_table_protect_gnu_relro(si->phdr, si->phnum, si->load_bias) < 0) {
- DL_ERR("can't enable GNU RELRO protection for \"%s\": %s",
- si->name, strerror(errno));
- return false;
- }
+ /* We can also turn on GNU RELRO protection */
+ if (phdr_table_protect_gnu_relro(phdr, phnum, load_bias) < 0) {
+ DL_ERR("can't enable GNU RELRO protection for \"%s\": %s",
+ name, strerror(errno));
+ return false;
+ }
- /* Handle serializing/sharing the RELRO segment */
- if (extinfo && (extinfo->flags & ANDROID_DLEXT_WRITE_RELRO)) {
- if (phdr_table_serialize_gnu_relro(si->phdr, si->phnum, si->load_bias,
- extinfo->relro_fd) < 0) {
- DL_ERR("failed serializing GNU RELRO section for \"%s\": %s",
- si->name, strerror(errno));
- return false;
- }
- } else if (extinfo && (extinfo->flags & ANDROID_DLEXT_USE_RELRO)) {
- if (phdr_table_map_gnu_relro(si->phdr, si->phnum, si->load_bias,
- extinfo->relro_fd) < 0) {
- DL_ERR("failed mapping GNU RELRO section for \"%s\": %s",
- si->name, strerror(errno));
- return false;
- }
+ /* Handle serializing/sharing the RELRO segment */
+ if (extinfo && (extinfo->flags & ANDROID_DLEXT_WRITE_RELRO)) {
+ if (phdr_table_serialize_gnu_relro(phdr, phnum, load_bias,
+ extinfo->relro_fd) < 0) {
+ DL_ERR("failed serializing GNU RELRO section for \"%s\": %s",
+ name, strerror(errno));
+ return false;
+ }
+ } else if (extinfo && (extinfo->flags & ANDROID_DLEXT_USE_RELRO)) {
+ if (phdr_table_map_gnu_relro(phdr, phnum, load_bias,
+ extinfo->relro_fd) < 0) {
+ DL_ERR("failed mapping GNU RELRO section for \"%s\": %s",
+ name, strerror(errno));
+ return false;
}
+ }
- notify_gdb_of_load(si);
- return true;
+ notify_gdb_of_load(this);
+ return true;
}
/*
@@ -2037,11 +2569,11 @@ static bool soinfo_link_image(soinfo* si, const android_dlextinfo* extinfo) {
static void add_vdso(KernelArgumentBlock& args __unused) {
#if defined(AT_SYSINFO_EHDR)
ElfW(Ehdr)* ehdr_vdso = reinterpret_cast<ElfW(Ehdr)*>(args.getauxval(AT_SYSINFO_EHDR));
- if (ehdr_vdso == NULL) {
+ if (ehdr_vdso == nullptr) {
return;
}
- soinfo* si = soinfo_alloc("[vdso]", NULL);
+ soinfo* si = soinfo_alloc("[vdso]", nullptr, 0, 0);
si->phdr = reinterpret_cast<ElfW(Phdr)*>(reinterpret_cast<char*>(ehdr_vdso) + ehdr_vdso->e_phoff);
si->phnum = ehdr_vdso->e_phnum;
si->size = phdr_table_get_load_size(si->phdr, si->phnum);
si->load_bias = get_elf_exec_load_bias(ehdr_vdso);
- soinfo_link_image(si, NULL);
+ si->prelink_image();
+ si->link_image(g_empty_list, soinfo::soinfo_list_t::make_list(si), nullptr);
#endif
}
/*
* This is linker soinfo for GDB. See details below.
*/
-static soinfo linker_soinfo_for_gdb;
+#if defined(__LP64__)
+#define LINKER_PATH "/system/bin/linker64"
+#else
+#define LINKER_PATH "/system/bin/linker"
+#endif
+static soinfo linker_soinfo_for_gdb(LINKER_PATH, nullptr, 0, 0);
/* gdb expects the linker to be in the debug shared object list.
* Without this, gdb has trouble locating the linker's ".text"
* be on the soinfo list.
*/
static void init_linker_info_for_gdb(ElfW(Addr) linker_base) {
-#if defined(__LP64__)
- strlcpy(linker_soinfo_for_gdb.name, "/system/bin/linker64", sizeof(linker_soinfo_for_gdb.name));
-#else
- strlcpy(linker_soinfo_for_gdb.name, "/system/bin/linker", sizeof(linker_soinfo_for_gdb.name));
-#endif
- linker_soinfo_for_gdb.flags = FLAG_NEW_SOINFO;
linker_soinfo_for_gdb.base = linker_base;
/*
ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(linker_base);
ElfW(Phdr)* phdr = reinterpret_cast<ElfW(Phdr)*>(linker_base + elf_hdr->e_phoff);
phdr_table_get_dynamic_section(phdr, elf_hdr->e_phnum, linker_base,
- &linker_soinfo_for_gdb.dynamic, NULL, NULL);
+ &linker_soinfo_for_gdb.dynamic, nullptr);
insert_soinfo_into_debug_map(&linker_soinfo_for_gdb);
}
* and other non-local data at this point.
*/
static ElfW(Addr) __linker_init_post_relocation(KernelArgumentBlock& args, ElfW(Addr) linker_base) {
- /* NOTE: we store the args pointer on a special location
- * of the temporary TLS area in order to pass it to
- * the C Library's runtime initializer.
- *
- * The initializer must clear the slot and reset the TLS
- * to point to a different location to ensure that no other
- * shared library constructor can access it.
- */
- __libc_init_tls(args);
-
#if TIMING
- struct timeval t0, t1;
- gettimeofday(&t0, 0);
+ struct timeval t0, t1;
+ gettimeofday(&t0, 0);
#endif
- // Initialize environment functions, and get to the ELF aux vectors table.
- linker_env_init(args);
+ // Initialize environment functions, and get to the ELF aux vectors table.
+ linker_env_init(args);
- // If this is a setuid/setgid program, close the security hole described in
- // ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-02:23.stdio.asc
- if (get_AT_SECURE()) {
- nullify_closed_stdio();
- }
+ // If this is a setuid/setgid program, close the security hole described in
+ // ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-02:23.stdio.asc
+ if (get_AT_SECURE()) {
+ nullify_closed_stdio();
+ }
- debuggerd_init();
+ debuggerd_init();
- // Get a few environment variables.
- const char* LD_DEBUG = linker_env_get("LD_DEBUG");
- if (LD_DEBUG != NULL) {
- g_ld_debug_verbosity = atoi(LD_DEBUG);
- }
+ // Get a few environment variables.
+ const char* LD_DEBUG = linker_env_get("LD_DEBUG");
+ if (LD_DEBUG != nullptr) {
+ g_ld_debug_verbosity = atoi(LD_DEBUG);
+ }
- // Normally, these are cleaned by linker_env_init, but the test
- // doesn't cost us anything.
- const char* ldpath_env = NULL;
- const char* ldpreload_env = NULL;
- if (!get_AT_SECURE()) {
- ldpath_env = linker_env_get("LD_LIBRARY_PATH");
- ldpreload_env = linker_env_get("LD_PRELOAD");
- }
+ // Normally, these are cleaned by linker_env_init, but the test
+ // doesn't cost us anything.
+ const char* ldpath_env = nullptr;
+ const char* ldpreload_env = nullptr;
+ if (!get_AT_SECURE()) {
+ ldpath_env = linker_env_get("LD_LIBRARY_PATH");
+ ldpreload_env = linker_env_get("LD_PRELOAD");
+ }
- INFO("[ android linker & debugger ]");
+ INFO("[ android linker & debugger ]");
- soinfo* si = soinfo_alloc(args.argv[0], NULL);
- if (si == NULL) {
- exit(EXIT_FAILURE);
- }
+ soinfo* si = soinfo_alloc(args.argv[0], nullptr, 0, RTLD_GLOBAL);
+ if (si == nullptr) {
+ exit(EXIT_FAILURE);
+ }
- /* bootstrap the link map, the main exe always needs to be first */
- si->flags |= FLAG_EXE;
- link_map* map = &(si->link_map_head);
+ /* bootstrap the link map, the main exe always needs to be first */
+ si->set_main_executable();
+ link_map* map = &(si->link_map_head);
- map->l_addr = 0;
- map->l_name = args.argv[0];
- map->l_prev = NULL;
- map->l_next = NULL;
+ map->l_addr = 0;
+ map->l_name = args.argv[0];
+ map->l_prev = nullptr;
+ map->l_next = nullptr;
- _r_debug.r_map = map;
- r_debug_tail = map;
-
- init_linker_info_for_gdb(linker_base);
-
- // Extract information passed from the kernel.
- si->phdr = reinterpret_cast<ElfW(Phdr)*>(args.getauxval(AT_PHDR));
- si->phnum = args.getauxval(AT_PHNUM);
- si->entry = args.getauxval(AT_ENTRY);
-
- /* Compute the value of si->base. We can't rely on the fact that
- * the first entry is the PHDR because this will not be true
- * for certain executables (e.g. some in the NDK unit test suite)
- */
- si->base = 0;
- si->size = phdr_table_get_load_size(si->phdr, si->phnum);
- si->load_bias = 0;
- for (size_t i = 0; i < si->phnum; ++i) {
- if (si->phdr[i].p_type == PT_PHDR) {
- si->load_bias = reinterpret_cast<ElfW(Addr)>(si->phdr) - si->phdr[i].p_vaddr;
- si->base = reinterpret_cast<ElfW(Addr)>(si->phdr) - si->phdr[i].p_offset;
- break;
- }
- }
- si->dynamic = NULL;
- si->ref_count = 1;
+ _r_debug.r_map = map;
+ r_debug_tail = map;
+
+ init_linker_info_for_gdb(linker_base);
+
+ // Extract information passed from the kernel.
+ si->phdr = reinterpret_cast<ElfW(Phdr)*>(args.getauxval(AT_PHDR));
+ si->phnum = args.getauxval(AT_PHNUM);
+ si->entry = args.getauxval(AT_ENTRY);
- ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(si->base);
- if (elf_hdr->e_type != ET_DYN) {
- __libc_format_fd(2, "error: only position independent executables (PIE) are supported.\n");
- exit(EXIT_FAILURE);
+ /* Compute the value of si->base. We can't rely on the fact that
+ * the first entry is the PHDR because this will not be true
+ * for certain executables (e.g. some in the NDK unit test suite)
+ */
+ si->base = 0;
+ si->size = phdr_table_get_load_size(si->phdr, si->phnum);
+ si->load_bias = 0;
+ for (size_t i = 0; i < si->phnum; ++i) {
+ if (si->phdr[i].p_type == PT_PHDR) {
+ si->load_bias = reinterpret_cast<ElfW(Addr)>(si->phdr) - si->phdr[i].p_vaddr;
+ si->base = reinterpret_cast<ElfW(Addr)>(si->phdr) - si->phdr[i].p_offset;
+ break;
}
+ }
+ si->dynamic = nullptr;
- // Use LD_LIBRARY_PATH and LD_PRELOAD (but only if we aren't setuid/setgid).
- parse_LD_LIBRARY_PATH(ldpath_env);
- parse_LD_PRELOAD(ldpreload_env);
+ ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(si->base);
+ if (elf_hdr->e_type != ET_DYN) {
+ __libc_format_fd(2, "error: only position independent executables (PIE) are supported.\n");
+ exit(EXIT_FAILURE);
+ }
- somain = si;
+ // Use LD_LIBRARY_PATH and LD_PRELOAD (but only if we aren't setuid/setgid).
+ parse_LD_LIBRARY_PATH(ldpath_env);
+ parse_LD_PRELOAD(ldpreload_env);
- if (!soinfo_link_image(si, NULL)) {
- __libc_format_fd(2, "CANNOT LINK EXECUTABLE: %s\n", linker_get_error_buffer());
- exit(EXIT_FAILURE);
- }
+ somain = si;
+
+ si->prelink_image();
+
+ // add somain to global group
+ si->set_dt_flags_1(si->get_dt_flags_1() | DF_1_GLOBAL);
+
+ // 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;
+ });
- add_vdso(args);
+ const char* needed_library_names[needed_libraries_count];
- si->CallPreInitConstructors();
+ memset(needed_library_names, 0, sizeof(needed_library_names));
+ needed_library_name_list.copy_to_array(needed_library_names, needed_libraries_count);
- for (size_t i = 0; g_ld_preloads[i] != NULL; ++i) {
- g_ld_preloads[i]->CallConstructors();
+ if (needed_libraries_count > 0 && !find_libraries(si, needed_library_names, needed_libraries_count, nullptr, g_ld_preloads, ld_preloads_count, RTLD_GLOBAL, nullptr)) {
+ __libc_format_fd(2, "CANNOT LINK EXECUTABLE: %s\n", linker_get_error_buffer());
+ exit(EXIT_FAILURE);
+ } else if (needed_libraries_count == 0) {
+ if (!si->link_image(g_empty_list, soinfo::soinfo_list_t::make_list(si), nullptr)) {
+ __libc_format_fd(2, "CANNOT LINK EXECUTABLE: %s\n", linker_get_error_buffer());
+ exit(EXIT_FAILURE);
}
+ si->increment_ref_count();
+ }
+
+ add_vdso(args);
- /* After the link_image, 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.
- */
- map->l_addr = si->load_bias;
- si->CallConstructors();
+ si->call_pre_init_constructors();
+
+ /* After the prelink_image, 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.
+ */
+ map->l_addr = si->load_bias;
+ si->call_constructors();
#if TIMING
- gettimeofday(&t1, NULL);
- PRINT("LINKER TIME: %s: %d microseconds", args.argv[0], (int) (
- (((long long)t1.tv_sec * 1000000LL) + (long long)t1.tv_usec) -
- (((long long)t0.tv_sec * 1000000LL) + (long long)t0.tv_usec)));
+ gettimeofday(&t1, nullptr);
+ PRINT("LINKER TIME: %s: %d microseconds", args.argv[0], (int) (
+ (((long long)t1.tv_sec * 1000000LL) + (long long)t1.tv_usec) -
+ (((long long)t0.tv_sec * 1000000LL) + (long long)t0.tv_usec)));
#endif
#if STATS
- PRINT("RELO STATS: %s: %d abs, %d rel, %d copy, %d symbol", args.argv[0],
- linker_stats.count[kRelocAbsolute],
- linker_stats.count[kRelocRelative],
- linker_stats.count[kRelocCopy],
- linker_stats.count[kRelocSymbol]);
+ PRINT("RELO STATS: %s: %d abs, %d rel, %d copy, %d symbol", args.argv[0],
+ linker_stats.count[kRelocAbsolute],
+ linker_stats.count[kRelocRelative],
+ linker_stats.count[kRelocCopy],
+ linker_stats.count[kRelocSymbol]);
#endif
#if COUNT_PAGES
- {
- unsigned n;
- unsigned i;
- unsigned count = 0;
- for (n = 0; n < 4096; n++) {
- if (bitmask[n]) {
- unsigned x = bitmask[n];
+ {
+ unsigned n;
+ unsigned i;
+ unsigned count = 0;
+ for (n = 0; n < 4096; n++) {
+ if (bitmask[n]) {
+ unsigned x = bitmask[n];
#if defined(__LP64__)
- for (i = 0; i < 32; i++) {
+ for (i = 0; i < 32; i++) {
#else
- for (i = 0; i < 8; i++) {
+ for (i = 0; i < 8; i++) {
#endif
- if (x & 1) {
- count++;
- }
- x >>= 1;
- }
- }
+ if (x & 1) {
+ count++;
+ }
+ x >>= 1;
}
- PRINT("PAGES MODIFIED: %s: %d (%dKB)", args.argv[0], count, count * 4);
+ }
}
+ PRINT("PAGES MODIFIED: %s: %d (%dKB)", args.argv[0], count, count * 4);
+ }
#endif
#if TIMING || STATS || COUNT_PAGES
- fflush(stdout);
+ fflush(stdout);
#endif
- TRACE("[ Ready to execute '%s' @ %p ]", si->name, reinterpret_cast<void*>(si->entry));
- return si->entry;
+ TRACE("[ Ready to execute '%s' @ %p ]", si->name, reinterpret_cast<void*>(si->entry));
+ return si->entry;
}
/* Compute the load-bias of an existing executable. This shall only
* function, or other GOT reference will generate a segfault.
*/
extern "C" ElfW(Addr) __linker_init(void* raw_args) {
- // Initialize static variables.
- solist = get_libdl_info();
- sonext = get_libdl_info();
-
KernelArgumentBlock args(raw_args);
ElfW(Addr) linker_addr = args.getauxval(AT_BASE);
ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(linker_addr);
ElfW(Phdr)* phdr = reinterpret_cast<ElfW(Phdr)*>(linker_addr + elf_hdr->e_phoff);
- soinfo linker_so;
- memset(&linker_so, 0, sizeof(soinfo));
+ soinfo linker_so("[dynamic linker]", nullptr, 0, 0);
// If the linker is not acting as PT_INTERP entry_point is equal to
// _start. Which means that the linker is running as an executable and
__libc_fatal("This is %s, the helper program for shared library executables.\n", args.argv[0]);
}
- strcpy(linker_so.name, "[dynamic linker]");
linker_so.base = linker_addr;
linker_so.size = phdr_table_get_load_size(phdr, elf_hdr->e_phnum);
linker_so.load_bias = get_elf_exec_load_bias(elf_hdr);
- linker_so.dynamic = NULL;
+ linker_so.dynamic = nullptr;
linker_so.phdr = phdr;
linker_so.phnum = elf_hdr->e_phnum;
- linker_so.flags |= FLAG_LINKER;
-
- if (!soinfo_link_image(&linker_so, NULL)) {
+ linker_so.set_linker_flag();
+
+ // 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.prelink_image() && linker_so.link_image(g_empty_list, g_empty_list, 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
_exit(EXIT_FAILURE);
}
+ __libc_init_tls(args);
+
// Initialize the linker's own global variables
- linker_so.CallConstructors();
+ linker_so.call_constructors();
+
+ // Initialize static variables. Note that in order to
+ // get correct libdl_info we need to call constructors
+ // before get_libdl_info().
+ solist = get_libdl_info();
+ sonext = get_libdl_info();
// We have successfully fixed our own relocations. It's safe to run
// the main part of the linker now.