Merge "Do not dlclose after failed reinit."
diff --git a/libc/Android.bp b/libc/Android.bp
index 6f2e347..226a81f 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -1014,6 +1014,7 @@
"bionic/arpa_inet.cpp",
"bionic/assert.cpp",
"bionic/atof.cpp",
+ "bionic/bionic_allocator.cpp",
"bionic/bionic_arc4random.cpp",
"bionic/bionic_futex.cpp",
"bionic/bionic_netlink.cpp",
diff --git a/libc/bionic/__libc_init_main_thread.cpp b/libc/bionic/__libc_init_main_thread.cpp
index 6279e65..4984e38 100644
--- a/libc/bionic/__libc_init_main_thread.cpp
+++ b/libc/bionic/__libc_init_main_thread.cpp
@@ -74,6 +74,7 @@
__libc_init_sysinfo(); // uses AT_SYSINFO auxv entry
#endif
__init_tcb(temp_tcb, &main_thread);
+ __init_tcb_dtv(temp_tcb);
__set_tls(&temp_tcb->tls_slot(0));
main_thread.tid = __getpid();
main_thread.set_cached_pid(main_thread.tid);
diff --git a/linker/linker_allocator.cpp b/libc/bionic/bionic_allocator.cpp
similarity index 77%
rename from linker/linker_allocator.cpp
rename to libc/bionic/bionic_allocator.cpp
index 015768a..d9302ad 100644
--- a/linker/linker_allocator.cpp
+++ b/libc/bionic/bionic_allocator.cpp
@@ -26,21 +26,25 @@
* SUCH DAMAGE.
*/
-#include "linker_allocator.h"
-#include "linker_debug.h"
-#include "linker.h"
+#include "private/bionic_allocator.h"
#include <stdlib.h>
+#include <string.h>
#include <sys/mman.h>
+#include <sys/param.h>
#include <sys/prctl.h>
#include <unistd.h>
+#include <new>
+
#include <async_safe/log.h>
+#include "private/bionic_macros.h"
+#include "private/bionic_page.h"
+
//
-// LinkerMemeoryAllocator is general purpose allocator
-// designed to provide the same functionality as the malloc/free/realloc
-// libc functions.
+// BionicAllocator is a general purpose allocator designed to provide the same
+// functionality as the malloc/free/realloc libc functions.
//
// On alloc:
// If size is >= 1k allocator proxies malloc call directly to mmap
@@ -90,7 +94,7 @@
return result;
}
-LinkerSmallObjectAllocator::LinkerSmallObjectAllocator(uint32_t type,
+BionicSmallObjectAllocator::BionicSmallObjectAllocator(uint32_t type,
size_t block_size)
: type_(type),
block_size_(block_size),
@@ -99,7 +103,7 @@
free_pages_cnt_(0),
page_list_(nullptr) {}
-void* LinkerSmallObjectAllocator::alloc() {
+void* BionicSmallObjectAllocator::alloc() {
CHECK(block_size_ != 0);
if (page_list_ == nullptr) {
@@ -141,7 +145,7 @@
return block_record;
}
-void LinkerSmallObjectAllocator::free_page(small_object_page_info* page) {
+void BionicSmallObjectAllocator::free_page(small_object_page_info* page) {
CHECK(page->free_blocks_cnt == blocks_per_page_);
if (page->prev_page) {
page->prev_page->next_page = page->next_page;
@@ -156,7 +160,7 @@
free_pages_cnt_--;
}
-void LinkerSmallObjectAllocator::free(void* ptr) {
+void BionicSmallObjectAllocator::free(void* ptr) {
small_object_page_info* const page =
reinterpret_cast<small_object_page_info*>(
PAGE_START(reinterpret_cast<uintptr_t>(ptr)));
@@ -186,7 +190,7 @@
}
}
-void LinkerSmallObjectAllocator::alloc_page() {
+void BionicSmallObjectAllocator::alloc_page() {
void* const map_ptr = mmap(nullptr, PAGE_SIZE, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (map_ptr == MAP_FAILED) {
@@ -194,7 +198,7 @@
}
prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, map_ptr, PAGE_SIZE,
- "linker_alloc_small_objects");
+ "bionic_alloc_small_objects");
small_object_page_info* const page =
reinterpret_cast<small_object_page_info*>(map_ptr);
@@ -220,7 +224,7 @@
free_pages_cnt_++;
}
-void LinkerSmallObjectAllocator::add_to_page_list(small_object_page_info* page) {
+void BionicSmallObjectAllocator::add_to_page_list(small_object_page_info* page) {
page->next_page = page_list_;
page->prev_page = nullptr;
if (page_list_) {
@@ -229,7 +233,7 @@
page_list_ = page;
}
-void LinkerSmallObjectAllocator::remove_from_page_list(
+void BionicSmallObjectAllocator::remove_from_page_list(
small_object_page_info* page) {
if (page->prev_page) {
page->prev_page->next_page = page->next_page;
@@ -244,24 +248,30 @@
page->next_page = nullptr;
}
-void LinkerMemoryAllocator::initialize_allocators() {
+void BionicAllocator::initialize_allocators() {
if (allocators_ != nullptr) {
return;
}
- LinkerSmallObjectAllocator* allocators =
- reinterpret_cast<LinkerSmallObjectAllocator*>(allocators_buf_);
+ BionicSmallObjectAllocator* allocators =
+ reinterpret_cast<BionicSmallObjectAllocator*>(allocators_buf_);
for (size_t i = 0; i < kSmallObjectAllocatorsCount; ++i) {
uint32_t type = i + kSmallObjectMinSizeLog2;
- new (allocators + i) LinkerSmallObjectAllocator(type, 1 << type);
+ new (allocators + i) BionicSmallObjectAllocator(type, 1 << type);
}
allocators_ = allocators;
}
-void* LinkerMemoryAllocator::alloc_mmap(size_t size) {
- size_t allocated_size = PAGE_END(size + kPageInfoSize);
+void* BionicAllocator::alloc_mmap(size_t align, size_t size) {
+ size_t header_size = __BIONIC_ALIGN(kPageInfoSize, align);
+ size_t allocated_size;
+ if (__builtin_add_overflow(header_size, size, &allocated_size) ||
+ PAGE_END(allocated_size) < allocated_size) {
+ async_safe_fatal("overflow trying to alloc %zu bytes", size);
+ }
+ allocated_size = PAGE_END(allocated_size);
void* map_ptr = mmap(nullptr, allocated_size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS,
-1, 0);
@@ -269,25 +279,21 @@
async_safe_fatal("mmap failed: %s", strerror(errno));
}
- prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, map_ptr, allocated_size, "linker_alloc_lob");
+ prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, map_ptr, allocated_size, "bionic_alloc_lob");
- page_info* info = reinterpret_cast<page_info*>(map_ptr);
+ void* result = static_cast<char*>(map_ptr) + header_size;
+ page_info* info = get_page_info_unchecked(result);
memcpy(info->signature, kSignature, sizeof(kSignature));
info->type = kLargeObject;
info->allocated_size = allocated_size;
- return reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(info) +
- kPageInfoSize);
+ return result;
}
-void* LinkerMemoryAllocator::alloc(size_t size) {
- // treat alloc(0) as alloc(1)
- if (size == 0) {
- size = 1;
- }
+inline void* BionicAllocator::alloc_impl(size_t align, size_t size) {
if (size > kSmallObjectMaxSize) {
- return alloc_mmap(size);
+ return alloc_mmap(align, size);
}
uint16_t log2_size = log2(size);
@@ -299,8 +305,33 @@
return get_small_object_allocator(log2_size)->alloc();
}
-page_info* LinkerMemoryAllocator::get_page_info(void* ptr) {
- page_info* info = reinterpret_cast<page_info*>(PAGE_START(reinterpret_cast<size_t>(ptr)));
+void* BionicAllocator::alloc(size_t size) {
+ // treat alloc(0) as alloc(1)
+ if (size == 0) {
+ size = 1;
+ }
+ return alloc_impl(16, size);
+}
+
+void* BionicAllocator::memalign(size_t align, size_t size) {
+ // The Bionic allocator only supports alignment up to one page, which is good
+ // enough for ELF TLS.
+ align = MIN(align, PAGE_SIZE);
+ align = MAX(align, 16);
+ if (!powerof2(align)) {
+ align = BIONIC_ROUND_UP_POWER_OF_2(align);
+ }
+ size = MAX(size, align);
+ return alloc_impl(align, size);
+}
+
+inline page_info* BionicAllocator::get_page_info_unchecked(void* ptr) {
+ uintptr_t header_page = PAGE_START(reinterpret_cast<size_t>(ptr) - kPageInfoSize);
+ return reinterpret_cast<page_info*>(header_page);
+}
+
+inline page_info* BionicAllocator::get_page_info(void* ptr) {
+ page_info* info = get_page_info_unchecked(ptr);
if (memcmp(info->signature, kSignature, sizeof(kSignature)) != 0) {
async_safe_fatal("invalid pointer %p (page signature mismatch)", ptr);
}
@@ -308,7 +339,7 @@
return info;
}
-void* LinkerMemoryAllocator::realloc(void* ptr, size_t size) {
+void* BionicAllocator::realloc(void* ptr, size_t size) {
if (ptr == nullptr) {
return alloc(size);
}
@@ -323,9 +354,9 @@
size_t old_size = 0;
if (info->type == kLargeObject) {
- old_size = info->allocated_size - kPageInfoSize;
+ old_size = info->allocated_size - (static_cast<char*>(ptr) - reinterpret_cast<char*>(info));
} else {
- LinkerSmallObjectAllocator* allocator = get_small_object_allocator(info->type);
+ BionicSmallObjectAllocator* allocator = get_small_object_allocator(info->type);
if (allocator != info->allocator_addr) {
async_safe_fatal("invalid pointer %p (page signature mismatch)", ptr);
}
@@ -343,7 +374,7 @@
return ptr;
}
-void LinkerMemoryAllocator::free(void* ptr) {
+void BionicAllocator::free(void* ptr) {
if (ptr == nullptr) {
return;
}
@@ -353,7 +384,7 @@
if (info->type == kLargeObject) {
munmap(info, info->allocated_size);
} else {
- LinkerSmallObjectAllocator* allocator = get_small_object_allocator(info->type);
+ BionicSmallObjectAllocator* allocator = get_small_object_allocator(info->type);
if (allocator != info->allocator_addr) {
async_safe_fatal("invalid pointer %p (invalid allocator address for the page)", ptr);
}
@@ -362,7 +393,7 @@
}
}
-LinkerSmallObjectAllocator* LinkerMemoryAllocator::get_small_object_allocator(uint32_t type) {
+BionicSmallObjectAllocator* BionicAllocator::get_small_object_allocator(uint32_t type) {
if (type < kSmallObjectMinSizeLog2 || type > kSmallObjectMaxSizeLog2) {
async_safe_fatal("invalid type: %u", type);
}
diff --git a/libc/bionic/bionic_elf_tls.cpp b/libc/bionic/bionic_elf_tls.cpp
index 4253b97..3fa5182 100644
--- a/libc/bionic/bionic_elf_tls.cpp
+++ b/libc/bionic/bionic_elf_tls.cpp
@@ -34,9 +34,22 @@
#include <unistd.h>
#include "private/ScopedRWLock.h"
+#include "private/ScopedSignalBlocker.h"
#include "private/bionic_globals.h"
#include "private/bionic_macros.h"
#include "private/bionic_tls.h"
+#include "pthread_internal.h"
+
+// Every call to __tls_get_addr needs to check the generation counter, so
+// accesses to the counter need to be as fast as possible. Keep a copy of it in
+// a hidden variable, which can be accessed without using the GOT. The linker
+// will update this variable when it updates its counter.
+//
+// To allow the linker to update this variable, libc.so's constructor passes its
+// address to the linker. To accommodate a possible __tls_get_addr call before
+// libc.so's constructor, this local copy is initialized to SIZE_MAX, forcing
+// __tls_get_addr to initially use the slow path.
+__LIBC_HIDDEN__ _Atomic(size_t) __libc_tls_generation_copy = SIZE_MAX;
// Search for a TLS segment in the given phdr table. Returns true if it has a
// TLS segment and false otherwise.
@@ -168,6 +181,7 @@
// moving the initial part. If this locking is too slow, we can duplicate the
// static part of the table.
TlsModules& modules = __libc_shared_globals()->tls_modules;
+ ScopedSignalBlocker ssb;
ScopedReadLock locker(&modules.rwlock);
for (size_t i = 0; i < modules.module_count; ++i) {
@@ -187,3 +201,166 @@
module.segment.init_size);
}
}
+
+static inline size_t dtv_size_in_bytes(size_t module_count) {
+ return sizeof(TlsDtv) + module_count * sizeof(void*);
+}
+
+// Calculates the number of module slots to allocate in a new DTV. For small
+// objects (up to 1KiB), the TLS allocator allocates memory in power-of-2 sizes,
+// so for better space usage, ensure that the DTV size (header + slots) is a
+// power of 2.
+//
+// The lock on TlsModules must be held.
+static size_t calculate_new_dtv_count() {
+ size_t loaded_cnt = __libc_shared_globals()->tls_modules.module_count;
+ size_t bytes = dtv_size_in_bytes(MAX(1, loaded_cnt));
+ if (!powerof2(bytes)) {
+ bytes = BIONIC_ROUND_UP_POWER_OF_2(bytes);
+ }
+ return (bytes - sizeof(TlsDtv)) / sizeof(void*);
+}
+
+// This function must be called with signals blocked and a write lock on
+// TlsModules held.
+static void update_tls_dtv(bionic_tcb* tcb) {
+ const TlsModules& modules = __libc_shared_globals()->tls_modules;
+ BionicAllocator& allocator = __libc_shared_globals()->tls_allocator;
+
+ // Use the generation counter from the shared globals instead of the local
+ // copy, which won't be initialized yet if __tls_get_addr is called before
+ // libc.so's constructor.
+ if (__get_tcb_dtv(tcb)->generation == atomic_load(&modules.generation)) {
+ return;
+ }
+
+ const size_t old_cnt = __get_tcb_dtv(tcb)->count;
+
+ // If the DTV isn't large enough, allocate a larger one. Because a signal
+ // handler could interrupt the fast path of __tls_get_addr, we don't free the
+ // old DTV. Instead, we add the old DTV to a list, then free all of a thread's
+ // DTVs at thread-exit. Each time the DTV is reallocated, its size at least
+ // doubles.
+ if (modules.module_count > old_cnt) {
+ size_t new_cnt = calculate_new_dtv_count();
+ TlsDtv* const old_dtv = __get_tcb_dtv(tcb);
+ TlsDtv* const new_dtv = static_cast<TlsDtv*>(allocator.alloc(dtv_size_in_bytes(new_cnt)));
+ memcpy(new_dtv, old_dtv, dtv_size_in_bytes(old_cnt));
+ new_dtv->count = new_cnt;
+ new_dtv->next = old_dtv;
+ __set_tcb_dtv(tcb, new_dtv);
+ }
+
+ TlsDtv* const dtv = __get_tcb_dtv(tcb);
+
+ const StaticTlsLayout& layout = __libc_shared_globals()->static_tls_layout;
+ char* static_tls = reinterpret_cast<char*>(tcb) - layout.offset_bionic_tcb();
+
+ // Initialize static TLS modules and free unloaded modules.
+ for (size_t i = 0; i < dtv->count; ++i) {
+ if (i < modules.module_count) {
+ const TlsModule& mod = modules.module_table[i];
+ if (mod.static_offset != SIZE_MAX) {
+ dtv->modules[i] = static_tls + mod.static_offset;
+ continue;
+ }
+ if (mod.first_generation != kTlsGenerationNone &&
+ mod.first_generation <= dtv->generation) {
+ continue;
+ }
+ }
+ allocator.free(dtv->modules[i]);
+ dtv->modules[i] = nullptr;
+ }
+
+ dtv->generation = atomic_load(&modules.generation);
+}
+
+__attribute__((noinline)) static void* tls_get_addr_slow_path(const TlsIndex* ti) {
+ TlsModules& modules = __libc_shared_globals()->tls_modules;
+ bionic_tcb* tcb = __get_bionic_tcb();
+
+ // Block signals and lock TlsModules. We may need the allocator, so take
+ // a write lock.
+ ScopedSignalBlocker ssb;
+ ScopedWriteLock locker(&modules.rwlock);
+
+ update_tls_dtv(tcb);
+
+ TlsDtv* dtv = __get_tcb_dtv(tcb);
+ const size_t module_idx = __tls_module_id_to_idx(ti->module_id);
+ void* mod_ptr = dtv->modules[module_idx];
+ if (mod_ptr == nullptr) {
+ const TlsSegment& segment = modules.module_table[module_idx].segment;
+ mod_ptr = __libc_shared_globals()->tls_allocator.memalign(segment.alignment, segment.size);
+ if (segment.init_size > 0) {
+ memcpy(mod_ptr, segment.init_ptr, segment.init_size);
+ }
+ dtv->modules[module_idx] = mod_ptr;
+ }
+
+ return static_cast<char*>(mod_ptr) + ti->offset;
+}
+
+// Returns the address of a thread's TLS memory given a module ID and an offset
+// into that module's TLS segment. This function is called on every access to a
+// dynamic TLS variable on targets that don't use TLSDESC. arm64 uses TLSDESC,
+// so it only calls this function on a thread's first access to a module's TLS
+// segment.
+//
+// On most targets, this accessor function is __tls_get_addr and
+// TLS_GET_ADDR_CCONV is unset. 32-bit x86 uses ___tls_get_addr instead and a
+// regparm() calling convention.
+extern "C" void* TLS_GET_ADDR(const TlsIndex* ti) TLS_GET_ADDR_CCONV {
+ TlsDtv* dtv = __get_tcb_dtv(__get_bionic_tcb());
+
+ // TODO: See if we can use a relaxed memory ordering here instead.
+ size_t generation = atomic_load(&__libc_tls_generation_copy);
+ if (__predict_true(generation == dtv->generation)) {
+ void* mod_ptr = dtv->modules[__tls_module_id_to_idx(ti->module_id)];
+ if (__predict_true(mod_ptr != nullptr)) {
+ return static_cast<char*>(mod_ptr) + ti->offset;
+ }
+ }
+
+ return tls_get_addr_slow_path(ti);
+}
+
+// This function frees:
+// - TLS modules referenced by the current DTV.
+// - The list of DTV objects associated with the current thread.
+//
+// The caller must have already blocked signals.
+void __free_dynamic_tls(bionic_tcb* tcb) {
+ TlsModules& modules = __libc_shared_globals()->tls_modules;
+ BionicAllocator& allocator = __libc_shared_globals()->tls_allocator;
+
+ // If we didn't allocate any dynamic memory, skip out early without taking
+ // the lock.
+ TlsDtv* dtv = __get_tcb_dtv(tcb);
+ if (dtv->generation == kTlsGenerationNone) {
+ return;
+ }
+
+ // We need the write lock to use the allocator.
+ ScopedWriteLock locker(&modules.rwlock);
+
+ // First free everything in the current DTV.
+ for (size_t i = 0; i < dtv->count; ++i) {
+ if (i < modules.module_count && modules.module_table[i].static_offset != SIZE_MAX) {
+ // This module's TLS memory is allocated statically, so don't free it here.
+ continue;
+ }
+ allocator.free(dtv->modules[i]);
+ }
+
+ // Now free the thread's list of DTVs.
+ while (dtv->generation != kTlsGenerationNone) {
+ TlsDtv* next = dtv->next;
+ allocator.free(dtv);
+ dtv = next;
+ }
+
+ // Clear the DTV slot. The DTV must not be used again with this thread.
+ tcb->tls_slot(TLS_SLOT_DTV) = nullptr;
+}
diff --git a/libc/bionic/bionic_systrace.cpp b/libc/bionic/bionic_systrace.cpp
index bac3d88..6182ed8 100644
--- a/libc/bionic/bionic_systrace.cpp
+++ b/libc/bionic/bionic_systrace.cpp
@@ -82,7 +82,7 @@
return;
}
- TEMP_FAILURE_RETRY(write(trace_marker_fd, "E", 1));
+ TEMP_FAILURE_RETRY(write(trace_marker_fd, "E|", 2));
}
ScopedTrace::ScopedTrace(const char* message) : called_end_(false) {
diff --git a/libc/bionic/libc_init_dynamic.cpp b/libc/bionic/libc_init_dynamic.cpp
index af1b847..7140776 100644
--- a/libc/bionic/libc_init_dynamic.cpp
+++ b/libc/bionic/libc_init_dynamic.cpp
@@ -51,6 +51,7 @@
#include <elf.h>
#include "libc_init_common.h"
+#include "private/bionic_elf_tls.h"
#include "private/bionic_globals.h"
#include "private/bionic_macros.h"
#include "private/bionic_ssp.h"
@@ -82,6 +83,12 @@
__libc_init_sysinfo();
#endif
+ // Register libc.so's copy of the TLS generation variable so the linker can
+ // update it when it loads or unloads a shared object.
+ TlsModules& tls_modules = __libc_shared_globals()->tls_modules;
+ tls_modules.generation_libc_so = &__libc_tls_generation_copy;
+ __libc_tls_generation_copy = tls_modules.generation;
+
__libc_init_globals();
__libc_init_common();
diff --git a/libc/bionic/libc_init_static.cpp b/libc/bionic/libc_init_static.cpp
index 8fbc20e..514423d 100644
--- a/libc/bionic/libc_init_static.cpp
+++ b/libc/bionic/libc_init_static.cpp
@@ -92,19 +92,22 @@
size_t phdr_ct = getauxval(AT_PHNUM);
static TlsModule mod;
+ TlsModules& modules = __libc_shared_globals()->tls_modules;
if (__bionic_get_tls_segment(phdr_start, phdr_ct, 0, &mod.segment)) {
if (!__bionic_check_tls_alignment(&mod.segment.alignment)) {
async_safe_fatal("error: TLS segment alignment in \"%s\" is not a power of 2: %zu\n",
progname, mod.segment.alignment);
}
mod.static_offset = layout.reserve_exe_segment_and_tcb(&mod.segment, progname);
- mod.first_generation = 1;
- __libc_shared_globals()->tls_modules.generation = 1;
- __libc_shared_globals()->tls_modules.module_count = 1;
- __libc_shared_globals()->tls_modules.module_table = &mod;
+ mod.first_generation = kTlsGenerationFirst;
+
+ modules.module_count = 1;
+ modules.module_table = &mod;
} else {
layout.reserve_exe_segment_and_tcb(nullptr, progname);
}
+ // Enable the fast path in __tls_get_addr.
+ __libc_tls_generation_copy = modules.generation;
layout.finish_layout();
}
diff --git a/libc/bionic/ndk_cruft.cpp b/libc/bionic/ndk_cruft.cpp
index dbacf18..2c3299f 100644
--- a/libc/bionic/ndk_cruft.cpp
+++ b/libc/bionic/ndk_cruft.cpp
@@ -355,9 +355,14 @@
return malloc(size);
}
+} // extern "C"
+
#define __get_thread __real_get_thread
#include "pthread_internal.h"
#undef __get_thread
+
+extern "C" {
+
// Various third-party apps contain a backport of our pthread_rwlock implementation that uses this.
pthread_internal_t* __get_thread() {
return __real_get_thread();
diff --git a/libc/bionic/pthread_create.cpp b/libc/bionic/pthread_create.cpp
index 31e0378..b8784b8 100644
--- a/libc/bionic/pthread_create.cpp
+++ b/libc/bionic/pthread_create.cpp
@@ -44,6 +44,7 @@
#include "private/bionic_globals.h"
#include "private/bionic_macros.h"
#include "private/bionic_ssp.h"
+#include "private/bionic_systrace.h"
#include "private/bionic_tls.h"
#include "private/ErrnoRestorer.h"
@@ -70,6 +71,14 @@
tcb->tls_slot(TLS_SLOT_STACK_GUARD) = reinterpret_cast<void*>(__stack_chk_guard);
}
+__attribute__((no_stack_protector))
+void __init_tcb_dtv(bionic_tcb* tcb) {
+ // Initialize the DTV slot to a statically-allocated empty DTV. The first
+ // access to a dynamic TLS variable allocates a new DTV.
+ static const TlsDtv zero_dtv = {};
+ __set_tcb_dtv(tcb, const_cast<TlsDtv*>(&zero_dtv));
+}
+
void __init_bionic_tls_ptrs(bionic_tcb* tcb, bionic_tls* tls) {
tcb->thread()->bionic_tls = tls;
tcb->tls_slot(TLS_SLOT_BIONIC_TLS) = tls;
@@ -291,6 +300,7 @@
// Initialize TLS memory.
__init_static_tls(mapping.static_tls);
__init_tcb(tcb, thread);
+ __init_tcb_dtv(tcb);
__init_tcb_stack_guard(tcb);
__init_bionic_tls_ptrs(tcb, tls);
@@ -338,6 +348,7 @@
ErrnoRestorer errno_restorer;
pthread_attr_t thread_attr;
+ ScopedTrace trace("pthread_create");
if (attr == nullptr) {
pthread_attr_init(&thread_attr);
} else {
diff --git a/libc/bionic/pthread_exit.cpp b/libc/bionic/pthread_exit.cpp
index 84ea2e6..3b873b3 100644
--- a/libc/bionic/pthread_exit.cpp
+++ b/libc/bionic/pthread_exit.cpp
@@ -98,15 +98,22 @@
thread->alternate_signal_stack = nullptr;
}
+ ThreadJoinState old_state = THREAD_NOT_JOINED;
+ while (old_state == THREAD_NOT_JOINED &&
+ !atomic_compare_exchange_weak(&thread->join_state, &old_state, THREAD_EXITED_NOT_JOINED)) {
+ }
+
+ // We don't want to take a signal after unmapping the stack, the shadow call
+ // stack, or dynamic TLS memory.
+ ScopedSignalBlocker ssb;
+
#ifdef __aarch64__
// Free the shadow call stack and guard pages.
munmap(thread->shadow_call_stack_guard_region, SCS_GUARD_REGION_SIZE);
#endif
- ThreadJoinState old_state = THREAD_NOT_JOINED;
- while (old_state == THREAD_NOT_JOINED &&
- !atomic_compare_exchange_weak(&thread->join_state, &old_state, THREAD_EXITED_NOT_JOINED)) {
- }
+ // Free the ELF TLS DTV and all dynamically-allocated ELF TLS memory.
+ __free_dynamic_tls(__get_bionic_tcb());
if (old_state == THREAD_DETACHED) {
// The thread is detached, no one will use pthread_internal_t after pthread_exit.
@@ -121,10 +128,6 @@
if (thread->mmap_size != 0) {
// We need to free mapped space for detached threads when they exit.
// That's not something we can do in C.
-
- // We don't want to take a signal after we've unmapped the stack.
- // That's one last thing we can do before dropping to assembler.
- ScopedSignalBlocker ssb;
__hwasan_thread_exit();
_exit_with_stack_teardown(thread->mmap_base, thread->mmap_size);
}
diff --git a/libc/bionic/pthread_internal.h b/libc/bionic/pthread_internal.h
index 27ab3df..cbcdadf 100644
--- a/libc/bionic/pthread_internal.h
+++ b/libc/bionic/pthread_internal.h
@@ -38,6 +38,7 @@
#define __hwasan_thread_exit()
#endif
+#include "private/bionic_elf_tls.h"
#include "private/bionic_lock.h"
#include "private/bionic_tls.h"
@@ -154,6 +155,7 @@
__LIBC_HIDDEN__ void __init_tcb(bionic_tcb* tcb, pthread_internal_t* thread);
__LIBC_HIDDEN__ void __init_tcb_stack_guard(bionic_tcb* tcb);
+__LIBC_HIDDEN__ void __init_tcb_dtv(bionic_tcb* tcb);
__LIBC_HIDDEN__ void __init_bionic_tls_ptrs(bionic_tcb* tcb, bionic_tls* tls);
__LIBC_HIDDEN__ bionic_tls* __allocate_temp_bionic_tls();
__LIBC_HIDDEN__ void __free_temp_bionic_tls(bionic_tls* tls);
@@ -179,6 +181,15 @@
return *static_cast<bionic_tls*>(__get_tls()[TLS_SLOT_BIONIC_TLS]);
}
+static inline __always_inline TlsDtv* __get_tcb_dtv(bionic_tcb* tcb) {
+ uintptr_t dtv_slot = reinterpret_cast<uintptr_t>(tcb->tls_slot(TLS_SLOT_DTV));
+ return reinterpret_cast<TlsDtv*>(dtv_slot - offsetof(TlsDtv, generation));
+}
+
+static inline void __set_tcb_dtv(bionic_tcb* tcb, TlsDtv* val) {
+ tcb->tls_slot(TLS_SLOT_DTV) = &val->generation;
+}
+
extern "C" __LIBC_HIDDEN__ int __set_tls(void* ptr);
__LIBC_HIDDEN__ void pthread_key_clean_all(void);
diff --git a/libc/bionic/pthread_join.cpp b/libc/bionic/pthread_join.cpp
index 9aad458..8e4ca59 100644
--- a/libc/bionic/pthread_join.cpp
+++ b/libc/bionic/pthread_join.cpp
@@ -30,10 +30,12 @@
#include "private/bionic_defs.h"
#include "private/bionic_futex.h"
+#include "private/bionic_systrace.h"
#include "pthread_internal.h"
__BIONIC_WEAK_FOR_NATIVE_BRIDGE
int pthread_join(pthread_t t, void** return_value) {
+ ScopedTrace trace("pthread_join");
if (t == pthread_self()) {
return EDEADLK;
}
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index 8d67b9e..6a6ea7d 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -1446,8 +1446,10 @@
LIBC_Q { # introduced=Q
global:
+ ___tls_get_addr; # x86
__aeabi_read_tp; # arm
__res_randomid;
+ __tls_get_addr; # arm x86_64
android_fdsan_close_with_tag;
android_fdsan_create_owner_tag;
android_fdsan_exchange_owner_tag;
diff --git a/linker/linker_allocator.h b/libc/private/bionic_allocator.h
similarity index 80%
rename from linker/linker_allocator.h
rename to libc/private/bionic_allocator.h
index 44a8b0d..c705ce4 100644
--- a/linker/linker_allocator.h
+++ b/libc/private/bionic_allocator.h
@@ -36,13 +36,11 @@
#include <stddef.h>
#include <unistd.h>
-#include <async_safe/log.h>
-
const uint32_t kSmallObjectMaxSizeLog2 = 10;
const uint32_t kSmallObjectMinSizeLog2 = 4;
const uint32_t kSmallObjectAllocatorsCount = kSmallObjectMaxSizeLog2 - kSmallObjectMinSizeLog2 + 1;
-class LinkerSmallObjectAllocator;
+class BionicSmallObjectAllocator;
// This structure is placed at the beginning of each addressable page
// and has all information we need to find the corresponding memory allocator.
@@ -53,7 +51,7 @@
// we use allocated_size for large objects allocator
size_t allocated_size;
// and allocator_addr for small ones.
- LinkerSmallObjectAllocator* allocator_addr;
+ BionicSmallObjectAllocator* allocator_addr;
};
};
@@ -63,14 +61,14 @@
};
// This structure is placed at the beginning of each page managed by
-// LinkerSmallObjectAllocator. Note that a page_info struct is expected at the
+// BionicSmallObjectAllocator. Note that a page_info struct is expected at the
// beginning of each page as well, and therefore this structure contains a
// page_info as its *first* field.
struct small_object_page_info {
page_info info; // Must be the first field.
// Doubly linked list for traversing all pages allocated by a
- // LinkerSmallObjectAllocator.
+ // BionicSmallObjectAllocator.
small_object_page_info* next_page;
small_object_page_info* prev_page;
@@ -81,9 +79,9 @@
size_t free_blocks_cnt;
};
-class LinkerSmallObjectAllocator {
+class BionicSmallObjectAllocator {
public:
- LinkerSmallObjectAllocator(uint32_t type, size_t block_size);
+ BionicSmallObjectAllocator(uint32_t type, size_t block_size);
void* alloc();
void free(void* ptr);
@@ -103,20 +101,23 @@
small_object_page_info* page_list_;
};
-class LinkerMemoryAllocator {
+class BionicAllocator {
public:
- constexpr LinkerMemoryAllocator() : allocators_(nullptr), allocators_buf_() {}
+ constexpr BionicAllocator() : allocators_(nullptr), allocators_buf_() {}
void* alloc(size_t size);
+ void* memalign(size_t align, size_t size);
// Note that this implementation of realloc never shrinks allocation
void* realloc(void* ptr, size_t size);
void free(void* ptr);
private:
- void* alloc_mmap(size_t size);
- page_info* get_page_info(void* ptr);
- LinkerSmallObjectAllocator* get_small_object_allocator(uint32_t type);
+ void* alloc_mmap(size_t align, size_t size);
+ inline void* alloc_impl(size_t align, size_t size);
+ inline page_info* get_page_info_unchecked(void* ptr);
+ inline page_info* get_page_info(void* ptr);
+ BionicSmallObjectAllocator* get_small_object_allocator(uint32_t type);
void initialize_allocators();
- LinkerSmallObjectAllocator* allocators_;
- uint8_t allocators_buf_[sizeof(LinkerSmallObjectAllocator)*kSmallObjectAllocatorsCount];
+ BionicSmallObjectAllocator* allocators_;
+ uint8_t allocators_buf_[sizeof(BionicSmallObjectAllocator)*kSmallObjectAllocatorsCount];
};
diff --git a/libc/private/bionic_elf_tls.h b/libc/private/bionic_elf_tls.h
index 09e1958..fa1af76 100644
--- a/libc/private/bionic_elf_tls.h
+++ b/libc/private/bionic_elf_tls.h
@@ -34,6 +34,8 @@
#include <stdint.h>
#include <sys/cdefs.h>
+__LIBC_HIDDEN__ extern _Atomic(size_t) __libc_tls_generation_copy;
+
struct TlsSegment {
size_t size = 0;
size_t alignment = 1;
@@ -84,6 +86,16 @@
size_t round_up_with_overflow_check(size_t value, size_t alignment);
};
+static constexpr size_t kTlsGenerationNone = 0;
+static constexpr size_t kTlsGenerationFirst = 1;
+
+// The first ELF TLS module has ID 1. Zero is reserved for the first word of
+// the DTV, a generation count. Unresolved weak symbols also use module ID 0.
+static constexpr size_t kTlsUninitializedModuleId = 0;
+
+static inline size_t __tls_module_id_to_idx(size_t id) { return id - 1; }
+static inline size_t __tls_module_idx_to_id(size_t idx) { return idx + 1; }
+
// A descriptor for a single ELF TLS module.
struct TlsModule {
TlsSegment segment;
@@ -93,7 +105,7 @@
// The generation in which this module was loaded. Dynamic TLS lookups use
// this field to detect when a module has been unloaded.
- size_t first_generation = 0;
+ size_t first_generation = kTlsGenerationNone;
// Used by the dynamic linker to track the associated soinfo* object.
void* soinfo_ptr = nullptr;
@@ -105,9 +117,10 @@
struct TlsModules {
constexpr TlsModules() {}
- // A generation counter. The value is incremented each time an solib is loaded
- // or unloaded.
- _Atomic(size_t) generation = 0;
+ // A pointer to the TLS generation counter in libc.so. The counter is
+ // incremented each time an solib is loaded or unloaded.
+ _Atomic(size_t) generation = kTlsGenerationFirst;
+ _Atomic(size_t) *generation_libc_so = nullptr;
// Access to the TlsModule[] table requires taking this lock.
pthread_rwlock_t rwlock = PTHREAD_RWLOCK_INITIALIZER;
@@ -119,3 +132,46 @@
};
void __init_static_tls(void* static_tls);
+
+// Dynamic Thread Vector. Each thread has a different DTV. For each module
+// (executable or solib), the DTV has a pointer to that module's TLS memory. The
+// DTV is initially empty and is allocated on-demand. It grows as more modules
+// are dlopen'ed. See https://www.akkadia.org/drepper/tls.pdf.
+//
+// The layout of the DTV is specified in various documents, but it is not part
+// of Bionic's public ABI. A compiler can't generate code to access it directly,
+// because it can't access libc's global generation counter.
+struct TlsDtv {
+ // Number of elements in this object's modules field.
+ size_t count;
+
+ // A pointer to an older TlsDtv object that should be freed when the thread
+ // exits. The objects aren't immediately freed because a DTV could be
+ // reallocated by a signal handler that interrupted __tls_get_addr's fast
+ // path.
+ TlsDtv* next;
+
+ // The DTV slot points at this field, which allows omitting an add instruction
+ // on the fast path for a TLS lookup. The arm64 tlsdesc_resolver.S depends on
+ // the layout of fields past this point.
+ size_t generation;
+ void* modules[];
+};
+
+struct TlsIndex {
+ size_t module_id;
+ size_t offset;
+};
+
+#if defined(__i386__)
+#define TLS_GET_ADDR_CCONV __attribute__((regparm(1)))
+#define TLS_GET_ADDR ___tls_get_addr
+#else
+#define TLS_GET_ADDR_CCONV
+#define TLS_GET_ADDR __tls_get_addr
+#endif
+
+extern "C" void* TLS_GET_ADDR(const TlsIndex* ti) TLS_GET_ADDR_CCONV;
+
+struct bionic_tcb;
+void __free_dynamic_tls(bionic_tcb* tcb);
diff --git a/libc/private/bionic_globals.h b/libc/private/bionic_globals.h
index 4d40476..21a2a24 100644
--- a/libc/private/bionic_globals.h
+++ b/libc/private/bionic_globals.h
@@ -33,6 +33,7 @@
#include <link.h>
#include <pthread.h>
+#include "private/bionic_allocator.h"
#include "private/bionic_elf_tls.h"
#include "private/bionic_fdsan.h"
#include "private/bionic_malloc_dispatch.h"
@@ -70,6 +71,7 @@
StaticTlsLayout static_tls_layout;
TlsModules tls_modules;
+ BionicAllocator tls_allocator;
// Values passed from the linker to libc.so.
const char* init_progname = nullptr;
diff --git a/linker/Android.bp b/linker/Android.bp
index 4991935..033860a 100644
--- a/linker/Android.bp
+++ b/linker/Android.bp
@@ -4,7 +4,6 @@
recovery_available: true,
srcs: [
- "linker_allocator.cpp",
"linker_memory.cpp",
],
cflags: [
@@ -104,6 +103,7 @@
name: "linker_sources_arm64",
srcs: [
"arch/arm64/begin.S",
+ "arch/arm64/tlsdesc_resolver.S",
],
}
diff --git a/linker/arch/arm64/tlsdesc_resolver.S b/linker/arch/arm64/tlsdesc_resolver.S
new file mode 100644
index 0000000..ef46839
--- /dev/null
+++ b/linker/arch/arm64/tlsdesc_resolver.S
@@ -0,0 +1,203 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <private/bionic_asm.h>
+#include <private/bionic_asm_tls.h>
+
+.globl __tls_get_addr
+
+// These resolver functions must preserve every register except x0. They set x0
+// to the offset of the TLS symbol relative to the thread pointer.
+
+ENTRY_PRIVATE(tlsdesc_resolver_static)
+ ldr x0, [x0, #8]
+ ret
+END(tlsdesc_resolver_static)
+
+ENTRY_PRIVATE(tlsdesc_resolver_dynamic)
+ stp x19, x20, [sp, #-32]!
+ .cfi_def_cfa_offset 32
+ .cfi_rel_offset x19, 0
+ .cfi_rel_offset x20, 8
+ stp x21, x22, [sp, #16]
+ .cfi_rel_offset x21, 16
+ .cfi_rel_offset x22, 24
+
+ mrs x19, tpidr_el0 // __get_tls()
+ ldr x20, [x19, #(TLS_SLOT_DTV * 8)]
+ ldr x21, [x20] // TlsDtv::generation
+
+ ldr x0, [x0, #8] // TlsDynamicResolverArg*
+ ldr x22, [x0] // TlsDynamicResolverArg::generation
+
+ cmp x21, x22
+ b.lo .fallback
+
+ ldr x21, [x0, #8] // TlsIndex::module
+ ldr x22, [x0, #16] // TlsIndex::offset
+ ldr x21, [x20, x21, lsl #3] // TlsDtv::modules[module]
+ cbz x21, .fallback
+ add x0, x21, x22
+ sub x0, x0, x19
+
+ ldp x21, x22, [sp, #16]
+ .cfi_remember_state
+ .cfi_restore x21
+ .cfi_restore x22
+ ldp x19, x20, [sp], #32
+ .cfi_adjust_cfa_offset -32
+ .cfi_restore x19
+ .cfi_restore x20
+ ret
+
+.fallback:
+ .cfi_restore_state
+ ldp x21, x22, [sp, #16]
+ .cfi_restore x21
+ .cfi_restore x22
+ ldp x19, x20, [sp], #32
+ .cfi_adjust_cfa_offset -32
+ .cfi_restore x19
+ .cfi_restore x20
+ b tlsdesc_resolver_dynamic_slow_path
+END(tlsdesc_resolver_dynamic)
+
+#define SAVE_REG(x, slot) \
+ str x, [sp, #((slot) * 8)]; \
+ .cfi_rel_offset x, (slot) * 8; \
+
+#define SAVE_GPR_PAIR(x, y, slot) \
+ stp x, y, [sp, #((slot) * 8)]; \
+ .cfi_rel_offset x, (slot) * 8; \
+ .cfi_rel_offset y, ((slot) + 1) * 8; \
+
+#define SAVE_VEC_PAIR(x, y, slot) \
+ stp x, y, [sp, #((slot) * 8)]; \
+ .cfi_rel_offset x, (slot) * 8; \
+ .cfi_rel_offset y, ((slot) + 2) * 8; \
+
+#define RESTORE_REG(x, slot) \
+ ldr x, [sp, #((slot) * 8)]; \
+ .cfi_restore x; \
+
+#define RESTORE_REG_PAIR(x, y, slot) \
+ ldp x, y, [sp, #((slot) * 8)]; \
+ .cfi_restore x; \
+ .cfi_restore y; \
+
+// On entry, x0 is the address of a TlsDynamicResolverArg object rather than
+// the TlsDescriptor address passed to the original resolver function.
+ENTRY_PRIVATE(tlsdesc_resolver_dynamic_slow_path)
+ sub sp, sp, #(8 * 84)
+ .cfi_def_cfa_offset (8 * 84)
+ SAVE_GPR_PAIR(x29, x30, 0)
+ mov x29, sp
+
+ // Avoid leaking the contents of the shadow call stack register (x18) into
+ // memory. x19 through x29 are callee-save registers, so we do not need to
+ // save them.
+ SAVE_GPR_PAIR(x1, x2, 2)
+ SAVE_GPR_PAIR(x3, x4, 4)
+ SAVE_GPR_PAIR(x5, x6, 6)
+ SAVE_GPR_PAIR(x7, x8, 8)
+ SAVE_GPR_PAIR(x9, x10, 10)
+ SAVE_GPR_PAIR(x11, x12, 12)
+ SAVE_GPR_PAIR(x13, x14, 14)
+ SAVE_GPR_PAIR(x15, x16, 16)
+ SAVE_REG(x17, 18)
+
+ SAVE_VEC_PAIR(q0, q1, 20)
+ SAVE_VEC_PAIR(q2, q3, 24)
+ SAVE_VEC_PAIR(q4, q5, 28)
+ SAVE_VEC_PAIR(q6, q7, 32)
+ SAVE_VEC_PAIR(q8, q9, 36)
+ SAVE_VEC_PAIR(q10, q11, 40)
+ SAVE_VEC_PAIR(q12, q13, 44)
+ SAVE_VEC_PAIR(q14, q15, 48)
+ SAVE_VEC_PAIR(q16, q17, 52)
+ SAVE_VEC_PAIR(q18, q19, 56)
+ SAVE_VEC_PAIR(q20, q21, 60)
+ SAVE_VEC_PAIR(q22, q23, 64)
+ SAVE_VEC_PAIR(q24, q25, 68)
+ SAVE_VEC_PAIR(q26, q27, 72)
+ SAVE_VEC_PAIR(q28, q29, 76)
+ SAVE_VEC_PAIR(q30, q31, 80)
+
+ add x0, x0, #8
+ bl __tls_get_addr
+ mrs x1, tpidr_el0 // __get_tls()
+ sub x0, x0, x1
+
+ RESTORE_REG_PAIR(q30, q31, 80)
+ RESTORE_REG_PAIR(q28, q29, 76)
+ RESTORE_REG_PAIR(q26, q27, 72)
+ RESTORE_REG_PAIR(q24, q25, 68)
+ RESTORE_REG_PAIR(q22, q23, 64)
+ RESTORE_REG_PAIR(q20, q21, 60)
+ RESTORE_REG_PAIR(q18, q19, 56)
+ RESTORE_REG_PAIR(q16, q17, 52)
+ RESTORE_REG_PAIR(q14, q15, 48)
+ RESTORE_REG_PAIR(q12, q13, 44)
+ RESTORE_REG_PAIR(q10, q11, 40)
+ RESTORE_REG_PAIR(q8, q9, 36)
+ RESTORE_REG_PAIR(q6, q7, 32)
+ RESTORE_REG_PAIR(q4, q5, 28)
+ RESTORE_REG_PAIR(q2, q3, 24)
+ RESTORE_REG_PAIR(q0, q1, 20)
+
+ RESTORE_REG(x17, 18)
+ RESTORE_REG_PAIR(x15, x16, 16)
+ RESTORE_REG_PAIR(x13, x14, 14)
+ RESTORE_REG_PAIR(x11, x12, 12)
+ RESTORE_REG_PAIR(x9, x10, 10)
+ RESTORE_REG_PAIR(x7, x8, 8)
+ RESTORE_REG_PAIR(x5, x6, 6)
+ RESTORE_REG_PAIR(x3, x4, 4)
+ RESTORE_REG_PAIR(x1, x2, 2)
+
+ RESTORE_REG_PAIR(x29, x30, 0)
+ add sp, sp, #(8 * 84)
+ .cfi_def_cfa_offset 0
+ ret
+END(tlsdesc_resolver_dynamic_slow_path)
+
+// The address of an unresolved weak TLS symbol evaluates to NULL with TLSDESC.
+// The value returned by this function is added to the thread pointer, so return
+// a negated thread pointer to cancel it out.
+ENTRY_PRIVATE(tlsdesc_resolver_unresolved_weak)
+ str x19, [sp, #-16]!
+ .cfi_def_cfa_offset 16
+ .cfi_rel_offset x19, 0
+ ldr x19, [x0, #8]
+ mrs x0, tpidr_el0 // __get_tls()
+ sub x0, x19, x0
+ ldr x19, [sp], #16
+ .cfi_def_cfa_offset 0
+ .cfi_restore x19
+ ret
+END(tlsdesc_resolver_unresolved_weak)
diff --git a/linker/linker.cpp b/linker/linker.cpp
index 412b8eb..d0c740b 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -2698,6 +2698,7 @@
bool soinfo::relocate(const VersionTracker& version_tracker, ElfRelIteratorT&& rel_iterator,
const soinfo_list_t& global_group, const soinfo_list_t& local_group) {
const size_t tls_tp_base = __libc_shared_globals()->static_tls_layout.offset_thread_pointer();
+ std::vector<std::pair<TlsDescriptor*, size_t>> deferred_tlsdesc_relocs;
for (size_t idx = 0; rel_iterator.has_next(); ++idx) {
const auto rel = rel_iterator.next();
@@ -2722,7 +2723,11 @@
soinfo* lsi = nullptr;
if (sym == 0) {
- // Do nothing.
+ // By convention in ld.bfd and lld, an omitted symbol on a TLS relocation
+ // is a reference to the current module.
+ if (is_tls_reloc(type)) {
+ lsi = this;
+ }
} else if (ELF_ST_BIND(symtab_[sym].st_info) == STB_LOCAL && is_tls_reloc(type)) {
// In certain situations, the Gold linker accesses a TLS symbol using a
// relocation to an STB_LOCAL symbol in .dynsym of either STT_SECTION or
@@ -2830,6 +2835,11 @@
sym_name, get_realpath());
return false;
}
+ if (lsi->get_tls() == nullptr) {
+ DL_ERR("TLS relocation refers to symbol \"%s\" in solib \"%s\" with no TLS segment",
+ sym_name, lsi->get_realpath());
+ return false;
+ }
sym_addr = s->st_value;
} else {
if (ELF_ST_TYPE(s->st_info) == STT_TLS) {
@@ -2916,16 +2926,12 @@
MARK(rel->r_offset);
{
ElfW(Addr) tpoff = 0;
- if (sym == 0) {
- // By convention in ld.bfd and lld, an omitted symbol
- // (ELFW(R_SYM) == 0) refers to the local module.
- lsi = this;
- }
if (lsi == nullptr) {
// Unresolved weak relocation. Leave tpoff at 0 to resolve
// &weak_tls_symbol to __get_tls().
- } else if (soinfo_tls* lsi_tls = lsi->get_tls()) {
- const TlsModule& mod = get_tls_module(lsi_tls->module_id);
+ } else {
+ CHECK(lsi->get_tls() != nullptr); // We rejected a missing TLS segment above.
+ const TlsModule& mod = get_tls_module(lsi->get_tls()->module_id);
if (mod.static_offset != SIZE_MAX) {
tpoff += mod.static_offset - tls_tp_base;
} else {
@@ -2933,10 +2939,6 @@
sym_name, lsi->get_realpath(), get_realpath());
return false;
}
- } else {
- DL_ERR("TLS relocation refers to symbol \"%s\" in solib \"%s\" with no TLS segment",
- sym_name, lsi->get_realpath());
- return false;
}
tpoff += sym_addr + addend;
TRACE_TYPE(RELO, "RELO TLS_TPREL %16p <- %16p %s\n",
@@ -2946,6 +2948,78 @@
}
break;
+#if !defined(__aarch64__)
+ // Omit support for DTPMOD/DTPREL on arm64, at least until
+ // http://b/123385182 is fixed. arm64 uses TLSDESC instead.
+ case R_GENERIC_TLS_DTPMOD:
+ count_relocation(kRelocRelative);
+ MARK(rel->r_offset);
+ {
+ size_t module_id = 0;
+ if (lsi == nullptr) {
+ // Unresolved weak relocation. Evaluate the module ID to 0.
+ } else {
+ CHECK(lsi->get_tls() != nullptr); // We rejected a missing TLS segment above.
+ module_id = lsi->get_tls()->module_id;
+ }
+ TRACE_TYPE(RELO, "RELO TLS_DTPMOD %16p <- %zu %s\n",
+ reinterpret_cast<void*>(reloc), module_id, sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = module_id;
+ }
+ break;
+ case R_GENERIC_TLS_DTPREL:
+ count_relocation(kRelocRelative);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "RELO TLS_DTPREL %16p <- %16p %s\n",
+ reinterpret_cast<void*>(reloc),
+ reinterpret_cast<void*>(sym_addr + addend), sym_name);
+ *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + addend;
+ break;
+#endif // !defined(__aarch64__)
+
+#if defined(__aarch64__)
+ // Bionic currently only implements TLSDESC for arm64. This implementation should work with
+ // other architectures, as long as the resolver functions are implemented.
+ case R_GENERIC_TLSDESC:
+ count_relocation(kRelocRelative);
+ MARK(rel->r_offset);
+ {
+ TlsDescriptor* desc = reinterpret_cast<TlsDescriptor*>(reloc);
+ if (lsi == nullptr) {
+ // Unresolved weak relocation.
+ desc->func = tlsdesc_resolver_unresolved_weak;
+ desc->arg = addend;
+ TRACE_TYPE(RELO, "RELO TLSDESC %16p <- unresolved weak 0x%zx %s\n",
+ reinterpret_cast<void*>(reloc), static_cast<size_t>(addend), sym_name);
+ } else {
+ CHECK(lsi->get_tls() != nullptr); // We rejected a missing TLS segment above.
+ size_t module_id = lsi->get_tls()->module_id;
+ const TlsModule& mod = get_tls_module(module_id);
+ if (mod.static_offset != SIZE_MAX) {
+ desc->func = tlsdesc_resolver_static;
+ desc->arg = mod.static_offset - tls_tp_base + sym_addr + addend;
+ TRACE_TYPE(RELO, "RELO TLSDESC %16p <- static (0x%zx - 0x%zx + 0x%zx + 0x%zx) %s\n",
+ reinterpret_cast<void*>(reloc), mod.static_offset, tls_tp_base,
+ static_cast<size_t>(sym_addr), static_cast<size_t>(addend), sym_name);
+ } else {
+ tlsdesc_args_.push_back({
+ .generation = mod.first_generation,
+ .index.module_id = module_id,
+ .index.offset = sym_addr + addend,
+ });
+ // Defer the TLSDESC relocation until the address of the TlsDynamicResolverArg object
+ // is finalized.
+ deferred_tlsdesc_relocs.push_back({ desc, tlsdesc_args_.size() - 1 });
+ const TlsDynamicResolverArg& desc_arg = tlsdesc_args_.back();
+ TRACE_TYPE(RELO, "RELO TLSDESC %16p <- dynamic (gen %zu, mod %zu, off %zu) %s",
+ reinterpret_cast<void*>(reloc), desc_arg.generation,
+ desc_arg.index.module_id, desc_arg.index.offset, sym_name);
+ }
+ }
+ }
+ break;
+#endif // defined(R_GENERIC_TLSDESC)
+
#if defined(__aarch64__)
case R_AARCH64_ABS64:
count_relocation(kRelocAbsolute);
@@ -3115,6 +3189,13 @@
return false;
}
}
+
+ for (const std::pair<TlsDescriptor*, size_t>& pair : deferred_tlsdesc_relocs) {
+ TlsDescriptor* desc = pair.first;
+ desc->func = tlsdesc_resolver_dynamic;
+ desc->arg = reinterpret_cast<size_t>(&tlsdesc_args_[pair.second]);
+ }
+
return true;
}
#endif // !defined(__mips__)
@@ -3528,13 +3609,14 @@
// this is parsed after we have strtab initialized (see below).
break;
+ case DT_TLSDESC_GOT:
+ case DT_TLSDESC_PLT:
+ // These DT entries are used for lazy TLSDESC relocations. Bionic
+ // resolves everything eagerly, so these can be ignored.
+ break;
+
default:
if (!relocating_linker) {
- if (d->d_tag == DT_TLSDESC_GOT || d->d_tag == DT_TLSDESC_PLT) {
- DL_ERR("unsupported ELF TLS DT entry in \"%s\"", get_realpath());
- return false;
- }
-
const char* tag_name;
if (d->d_tag == DT_RPATH) {
tag_name = "DT_RPATH";
diff --git a/linker/linker_block_allocator.h b/linker/linker_block_allocator.h
index 85e6bd9..458d092 100644
--- a/linker/linker_block_allocator.h
+++ b/linker/linker_block_allocator.h
@@ -68,18 +68,18 @@
* of a single fixed-size type. Allocations are backed by page-sized private
* anonymous mmaps.
*
- * The differences between this allocator and LinkerMemoryAllocator are:
- * 1. This allocator manages space more efficiently. LinkerMemoryAllocator
- * operates in power-of-two sized blocks up to 1k, when this implementation
- * splits the page to aligned size of structure; For example for structures
- * with size 513 this allocator will use 516 (520 for lp64) bytes of data
- * where generalized implementation is going to use 1024 sized blocks.
+ * The differences between this allocator and BionicAllocator are:
+ * 1. This allocator manages space more efficiently. BionicAllocator operates in
+ * power-of-two sized blocks up to 1k, when this implementation splits the
+ * page to aligned size of structure; For example for structures with size
+ * 513 this allocator will use 516 (520 for lp64) bytes of data where
+ * generalized implementation is going to use 1024 sized blocks.
*
* 2. Unless all allocated memory is freed, this allocator does not munmap
- * allocated memory, where LinkerMemoryAllocator does.
+ * allocated memory, where BionicAllocator does.
*
- * 3. This allocator provides mprotect services to the user, where LinkerMemoryAllocator
- * always treats it's memory as READ|WRITE.
+ * 3. This allocator provides mprotect services to the user, where BionicAllocator
+ * always treats its memory as READ|WRITE.
*/
template<typename T>
class LinkerTypeAllocator {
diff --git a/linker/linker_memory.cpp b/linker/linker_memory.cpp
index f2cce01..ce29997 100644
--- a/linker/linker_memory.cpp
+++ b/linker/linker_memory.cpp
@@ -26,7 +26,7 @@
* SUCH DAMAGE.
*/
-#include "linker_allocator.h"
+#include "private/bionic_allocator.h"
#include <stdlib.h>
#include <sys/cdefs.h>
@@ -36,7 +36,7 @@
#include <async_safe/log.h>
-static LinkerMemoryAllocator g_linker_allocator;
+static BionicAllocator g_bionic_allocator;
static std::atomic<pid_t> fallback_tid(0);
// Used by libdebuggerd_handler to switch allocators during a crash dump, in
@@ -56,16 +56,16 @@
}
}
-static LinkerMemoryAllocator& get_fallback_allocator() {
- static LinkerMemoryAllocator fallback_allocator;
+static BionicAllocator& get_fallback_allocator() {
+ static BionicAllocator fallback_allocator;
return fallback_allocator;
}
-static LinkerMemoryAllocator& get_allocator() {
+static BionicAllocator& get_allocator() {
if (__predict_false(fallback_tid) && __predict_false(gettid() == fallback_tid)) {
return get_fallback_allocator();
}
- return g_linker_allocator;
+ return g_bionic_allocator;
}
void* malloc(size_t byte_count) {
diff --git a/linker/linker_soinfo.h b/linker/linker_soinfo.h
index 14571de..dd9c6aa 100644
--- a/linker/linker_soinfo.h
+++ b/linker/linker_soinfo.h
@@ -32,9 +32,11 @@
#include <memory>
#include <string>
+#include <vector>
#include "private/bionic_elf_tls.h"
#include "linker_namespaces.h"
+#include "linker_tls.h"
#define FLAG_LINKED 0x00000001
#define FLAG_EXE 0x00000004 // The main executable
@@ -102,14 +104,9 @@
// TODO(dimitry): remove reference from soinfo member functions to this class.
class VersionTracker;
-// The first ELF TLS module has ID 1. Zero is reserved for the first word of
-// the DTV, a generation count, and unresolved weak symbols also use module
-// ID 0.
-static constexpr size_t kUninitializedModuleId = 0;
-
struct soinfo_tls {
TlsSegment segment;
- size_t module_id = kUninitializedModuleId;
+ size_t module_id = kTlsUninitializedModuleId;
};
#if defined(__work_around_b_24465209__)
@@ -383,6 +380,7 @@
// version >= 5
std::unique_ptr<soinfo_tls> tls_;
+ std::vector<TlsDynamicResolverArg> tlsdesc_args_;
};
// This function is used by dlvsym() to calculate hash of sym_ver
diff --git a/linker/linker_tls.cpp b/linker/linker_tls.cpp
index 0d1796b..a3aa9bf 100644
--- a/linker/linker_tls.cpp
+++ b/linker/linker_tls.cpp
@@ -31,6 +31,7 @@
#include <vector>
#include "private/ScopedRWLock.h"
+#include "private/ScopedSignalBlocker.h"
#include "private/bionic_defs.h"
#include "private/bionic_elf_tls.h"
#include "private/bionic_globals.h"
@@ -41,9 +42,6 @@
static bool g_static_tls_finished;
static std::vector<TlsModule> g_tls_modules;
-static inline size_t module_id_to_idx(size_t id) { return id - 1; }
-static inline size_t module_idx_to_id(size_t idx) { return idx + 1; }
-
static size_t get_unused_module_index() {
for (size_t i = 0; i < g_tls_modules.size(); ++i) {
if (g_tls_modules[i].soinfo_ptr == nullptr) {
@@ -57,37 +55,47 @@
}
static void register_tls_module(soinfo* si, size_t static_offset) {
+ TlsModules& libc_modules = __libc_shared_globals()->tls_modules;
+
// The global TLS module table points at the std::vector of modules declared
// in this file, so acquire a write lock before modifying the std::vector.
- ScopedWriteLock locker(&__libc_shared_globals()->tls_modules.rwlock);
+ ScopedSignalBlocker ssb;
+ ScopedWriteLock locker(&libc_modules.rwlock);
size_t module_idx = get_unused_module_index();
soinfo_tls* si_tls = si->get_tls();
- si_tls->module_id = module_idx_to_id(module_idx);
+ si_tls->module_id = __tls_module_idx_to_id(module_idx);
+
+ const size_t new_generation = ++libc_modules.generation;
+ __libc_tls_generation_copy = new_generation;
+ if (libc_modules.generation_libc_so != nullptr) {
+ *libc_modules.generation_libc_so = new_generation;
+ }
g_tls_modules[module_idx] = {
.segment = si_tls->segment,
.static_offset = static_offset,
- .first_generation = ++__libc_shared_globals()->tls_modules.generation,
+ .first_generation = new_generation,
.soinfo_ptr = si,
};
}
static void unregister_tls_module(soinfo* si) {
+ ScopedSignalBlocker ssb;
ScopedWriteLock locker(&__libc_shared_globals()->tls_modules.rwlock);
soinfo_tls* si_tls = si->get_tls();
- TlsModule& mod = g_tls_modules[module_id_to_idx(si_tls->module_id)];
+ TlsModule& mod = g_tls_modules[__tls_module_id_to_idx(si_tls->module_id)];
CHECK(mod.static_offset == SIZE_MAX);
CHECK(mod.soinfo_ptr == si);
mod = {};
- si_tls->module_id = kUninitializedModuleId;
+ si_tls->module_id = kTlsUninitializedModuleId;
}
// The reference is valid until a TLS module is registered or unregistered.
const TlsModule& get_tls_module(size_t module_id) {
- size_t module_idx = module_id_to_idx(module_id);
+ size_t module_idx = __tls_module_id_to_idx(module_id);
CHECK(module_idx < g_tls_modules.size());
return g_tls_modules[module_idx];
}
@@ -123,7 +131,7 @@
void register_soinfo_tls(soinfo* si) {
soinfo_tls* si_tls = si->get_tls();
- if (si_tls == nullptr || si_tls->module_id != kUninitializedModuleId) {
+ if (si_tls == nullptr || si_tls->module_id != kTlsUninitializedModuleId) {
return;
}
size_t static_offset = SIZE_MAX;
@@ -136,7 +144,7 @@
void unregister_soinfo_tls(soinfo* si) {
soinfo_tls* si_tls = si->get_tls();
- if (si_tls == nullptr || si_tls->module_id == kUninitializedModuleId) {
+ if (si_tls == nullptr || si_tls->module_id == kTlsUninitializedModuleId) {
return;
}
return unregister_tls_module(si);
diff --git a/linker/linker_tls.h b/linker/linker_tls.h
index fbb1dcf..87e1f0d 100644
--- a/linker/linker_tls.h
+++ b/linker/linker_tls.h
@@ -30,6 +30,8 @@
#include <stdlib.h>
+#include "private/bionic_elf_tls.h"
+
struct TlsModule;
struct soinfo;
@@ -40,3 +42,24 @@
void unregister_soinfo_tls(soinfo* si);
const TlsModule& get_tls_module(size_t module_id);
+
+typedef size_t TlsDescResolverFunc(size_t);
+
+struct TlsDescriptor {
+#if defined(__arm__)
+ size_t arg;
+ TlsDescResolverFunc* func;
+#else
+ TlsDescResolverFunc* func;
+ size_t arg;
+#endif
+};
+
+struct TlsDynamicResolverArg {
+ size_t generation;
+ TlsIndex index;
+};
+
+__LIBC_HIDDEN__ extern "C" size_t tlsdesc_resolver_static(size_t);
+__LIBC_HIDDEN__ extern "C" size_t tlsdesc_resolver_dynamic(size_t);
+__LIBC_HIDDEN__ extern "C" size_t tlsdesc_resolver_unresolved_weak(size_t);
diff --git a/linker/tests/Android.mk b/linker/tests/Android.mk
index 9268e31..63e0555 100644
--- a/linker/tests/Android.mk
+++ b/linker/tests/Android.mk
@@ -43,10 +43,8 @@
linker_config_test.cpp \
linker_globals.cpp \
linked_list_test.cpp \
- linker_memory_allocator_test.cpp \
linker_sleb128_test.cpp \
linker_utils_test.cpp \
- ../linker_allocator.cpp \
../linker_block_allocator.cpp \
../linker_config.cpp \
../linker_utils.cpp \
diff --git a/tests/Android.bp b/tests/Android.bp
index 0a45a8e..b374c27 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -533,7 +533,6 @@
"libdl_preempt_test_1",
"libdl_preempt_test_2",
"libdl_test_df_1_global",
- "libelf-tls-library",
"libgnu-hash-table-library",
"libsysv-hash-table-library",
"libtestshared",
@@ -571,6 +570,10 @@
"libtest_dlsym_from_this",
"libtest_dlsym_weak_func",
"libtest_dt_runpath_d",
+ "libtest_elftls_dynamic",
+ "libtest_elftls_dynamic_filler_1",
+ "libtest_elftls_dynamic_filler_2",
+ "libtest_elftls_dynamic_filler_3",
"libtest_elftls_shared_var",
"libtest_elftls_shared_var_ie",
"libtest_elftls_tprel",
@@ -661,6 +664,13 @@
"gtest_preinit_debuggerd.cpp",
"gtest_globals.cpp",
"gtest_main.cpp",
+
+ // The Bionic allocator has its own C++ API. It isn't packaged into its
+ // own library, so it can only be tested when it's part of libc.a.
+ "bionic_allocator_test.cpp",
+ ],
+ include_dirs: [
+ "bionic/libc",
],
whole_static_libs: [
"libBionicTests",
diff --git a/linker/tests/linker_memory_allocator_test.cpp b/tests/bionic_allocator_test.cpp
similarity index 75%
rename from linker/tests/linker_memory_allocator_test.cpp
rename to tests/bionic_allocator_test.cpp
index c284eaa..f710907 100644
--- a/linker/tests/linker_memory_allocator_test.cpp
+++ b/tests/bionic_allocator_test.cpp
@@ -32,7 +32,7 @@
#include <gtest/gtest.h>
-#include "../linker_allocator.h"
+#include "private/bionic_allocator.h"
#include <unistd.h>
@@ -61,20 +61,20 @@
static size_t kPageSize = sysconf(_SC_PAGE_SIZE);
-TEST(linker_memory, test_alloc_0) {
- LinkerMemoryAllocator allocator;
+TEST(bionic_allocator, test_alloc_0) {
+ BionicAllocator allocator;
void* ptr = allocator.alloc(0);
ASSERT_TRUE(ptr != nullptr);
allocator.free(ptr);
}
-TEST(linker_memory, test_free_nullptr) {
- LinkerMemoryAllocator allocator;
+TEST(bionic_allocator, test_free_nullptr) {
+ BionicAllocator allocator;
allocator.free(nullptr);
}
-TEST(linker_memory, test_realloc) {
- LinkerMemoryAllocator allocator;
+TEST(bionic_allocator, test_realloc) {
+ BionicAllocator allocator;
uint32_t* array = reinterpret_cast<uint32_t*>(allocator.alloc(512));
const size_t array_size = 512 / sizeof(uint32_t);
@@ -127,8 +127,8 @@
ASSERT_EQ(nullptr, allocator.realloc(reallocated_ptr, 0));
}
-TEST(linker_memory, test_small_smoke) {
- LinkerMemoryAllocator allocator;
+TEST(bionic_allocator, test_small_smoke) {
+ BionicAllocator allocator;
uint8_t zeros[16];
memset(zeros, 0, sizeof(zeros));
@@ -150,8 +150,8 @@
allocator.free(ptr2);
}
-TEST(linker_memory, test_huge_smoke) {
- LinkerMemoryAllocator allocator;
+TEST(bionic_allocator, test_huge_smoke) {
+ BionicAllocator allocator;
// this should trigger proxy-to-mmap
test_struct_huge* ptr1 =
@@ -170,8 +170,8 @@
allocator.free(ptr1);
}
-TEST(linker_memory, test_large) {
- LinkerMemoryAllocator allocator;
+TEST(bionic_allocator, test_large) {
+ BionicAllocator allocator;
test_struct_large* ptr1 =
reinterpret_cast<test_struct_large*>(allocator.alloc(sizeof(test_struct_large)));
@@ -212,4 +212,49 @@
allocator.free(ptr_to_free);
}
+TEST(bionic_allocator, test_memalign_small) {
+ BionicAllocator allocator;
+ void* ptr;
+ // simple case
+ ptr = allocator.memalign(0x100, 0x100);
+ ASSERT_TRUE(ptr != nullptr);
+ ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr) % 0x100);
+ allocator.free(ptr);
+
+ // small objects are automatically aligned to their size.
+ ptr = allocator.alloc(0x200);
+ ASSERT_TRUE(ptr != nullptr);
+ ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr) % 0x200);
+ allocator.free(ptr);
+
+ // the size (0x10) is bumped up to the alignment (0x100)
+ ptr = allocator.memalign(0x100, 0x10);
+ ASSERT_TRUE(ptr != nullptr);
+ ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr) % 0x100);
+ allocator.free(ptr);
+}
+
+TEST(bionic_allocator, test_memalign_large) {
+ BionicAllocator allocator;
+ void* ptr;
+
+ // a large object with alignment < PAGE_SIZE
+ ptr = allocator.memalign(0x100, 0x2000);
+ ASSERT_TRUE(ptr != nullptr);
+ ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr) % 0x100);
+ allocator.free(ptr);
+
+ // a large object with alignment == PAGE_SIZE
+ ptr = allocator.memalign(0x1000, 0x2000);
+ ASSERT_TRUE(ptr != nullptr);
+ ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr) % 0x1000);
+ allocator.free(ptr);
+
+ // A large object with alignment > PAGE_SIZE is only guaranteed to have page
+ // alignment.
+ ptr = allocator.memalign(0x2000, 0x4000);
+ ASSERT_TRUE(ptr != nullptr);
+ ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr) % 0x1000);
+ allocator.free(ptr);
+}
diff --git a/tests/dlfcn_test.cpp b/tests/dlfcn_test.cpp
index 176a6f8..8a3b6f3 100644
--- a/tests/dlfcn_test.cpp
+++ b/tests/dlfcn_test.cpp
@@ -1082,13 +1082,6 @@
ASSERT_SUBSTR("libsysv-hash-table-library.so", dlinfo.dli_fname);
}
-TEST(dlfcn, dlopen_library_with_ELF_TLS) {
- dlerror(); // Clear any pending errors.
- void* handle = dlopen("libelf-tls-library.so", RTLD_NOW);
- ASSERT_TRUE(handle == nullptr);
- ASSERT_SUBSTR("unknown reloc type ", dlerror());
-}
-
TEST(dlfcn, dlopen_bad_flags) {
dlerror(); // Clear any pending errors.
void* handle;
diff --git a/tests/elftls_dl_test.cpp b/tests/elftls_dl_test.cpp
index 0a97c28..e908fb9 100644
--- a/tests/elftls_dl_test.cpp
+++ b/tests/elftls_dl_test.cpp
@@ -34,6 +34,10 @@
#include "gtest_globals.h"
#include "utils.h"
+#if defined(__BIONIC__)
+#include "bionic/pthread_internal.h"
+#endif
+
// Access libtest_elftls_shared_var.so's TLS variable using an IE access.
__attribute__((tls_model("initial-exec"))) extern "C" __thread int elftls_shared_var;
@@ -78,3 +82,175 @@
eth.SetArgs({ helper.c_str(), nullptr });
eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, 0, error.c_str());
}
+
+// Use a GD access (__tls_get_addr or TLSDESC) to modify a variable in static
+// TLS memory.
+TEST(elftls_dl, access_static_tls) {
+ void* lib = dlopen("libtest_elftls_dynamic.so", RTLD_LOCAL | RTLD_NOW);
+ ASSERT_NE(nullptr, lib);
+
+ auto bump_shared_var = reinterpret_cast<int(*)()>(dlsym(lib, "bump_shared_var"));
+ ASSERT_NE(nullptr, bump_shared_var);
+
+ ASSERT_EQ(21, ++elftls_shared_var);
+ ASSERT_EQ(22, bump_shared_var());
+
+ std::thread([bump_shared_var] {
+ ASSERT_EQ(21, ++elftls_shared_var);
+ ASSERT_EQ(22, bump_shared_var());
+ }).join();
+}
+
+TEST(elftls_dl, bump_local_vars) {
+ void* lib = dlopen("libtest_elftls_dynamic.so", RTLD_LOCAL | RTLD_NOW);
+ ASSERT_NE(nullptr, lib);
+
+ auto bump_local_vars = reinterpret_cast<int(*)()>(dlsym(lib, "bump_local_vars"));
+ ASSERT_NE(nullptr, bump_local_vars);
+
+ ASSERT_EQ(42, bump_local_vars());
+ std::thread([bump_local_vars] {
+ ASSERT_EQ(42, bump_local_vars());
+ }).join();
+}
+
+// The behavior of accessing an unresolved weak TLS symbol using a dynamic TLS
+// relocation depends on which kind of implementation the target uses. With
+// TLSDESC, the result is NULL. With __tls_get_addr, the result is the
+// generation count (or maybe undefined behavior)? This test only tests TLSDESC.
+TEST(elftls_dl, missing_weak) {
+#if defined(__aarch64__)
+ void* lib = dlopen("libtest_elftls_dynamic.so", RTLD_LOCAL | RTLD_NOW);
+ ASSERT_NE(nullptr, lib);
+
+ auto missing_weak_dyn_tls_addr = reinterpret_cast<int*(*)()>(dlsym(lib, "missing_weak_dyn_tls_addr"));
+ ASSERT_NE(nullptr, missing_weak_dyn_tls_addr);
+
+ ASSERT_EQ(nullptr, missing_weak_dyn_tls_addr());
+ std::thread([missing_weak_dyn_tls_addr] {
+ ASSERT_EQ(nullptr, missing_weak_dyn_tls_addr());
+ }).join();
+#else
+ GTEST_LOG_(INFO) << "This test is only run on TLSDESC-based targets.\n";
+#endif
+}
+
+TEST(elftls_dl, dtv_resize) {
+#if defined(__BIONIC__)
+#define LOAD_LIB(soname) ({ \
+ auto lib = dlopen(soname, RTLD_LOCAL | RTLD_NOW); \
+ ASSERT_NE(nullptr, lib); \
+ reinterpret_cast<int(*)()>(dlsym(lib, "bump")); \
+ })
+
+ auto dtv = []() -> TlsDtv* { return __get_tcb_dtv(__get_bionic_tcb()); };
+
+ static_assert(sizeof(TlsDtv) == 3 * sizeof(void*),
+ "This test assumes that the Dtv has a 3-word header");
+
+ // Initially there are 3 modules:
+ // - the main test executable
+ // - libtest_elftls_shared_var
+ // - libtest_elftls_tprel
+
+ // The initial DTV is an empty DTV with no generation and a size of 0.
+ TlsDtv* zero_dtv = dtv();
+ ASSERT_EQ(0u, zero_dtv->count);
+ ASSERT_EQ(nullptr, zero_dtv->next);
+ ASSERT_EQ(kTlsGenerationNone, zero_dtv->generation);
+
+ // Load the fourth module.
+ auto func1 = LOAD_LIB("libtest_elftls_dynamic_filler_1.so");
+ ASSERT_EQ(101, func1());
+
+ // After loading one module, the DTV should be initialized to the next
+ // power-of-2 size (including the header).
+ TlsDtv* initial_dtv = dtv();
+ ASSERT_EQ(5u, initial_dtv->count);
+ ASSERT_EQ(zero_dtv, initial_dtv->next);
+ ASSERT_LT(0u, initial_dtv->generation);
+
+ // Load module 5.
+ auto func2 = LOAD_LIB("libtest_elftls_dynamic_filler_2.so");
+ ASSERT_EQ(102, func1());
+ ASSERT_EQ(201, func2());
+ ASSERT_EQ(initial_dtv, dtv());
+ ASSERT_EQ(5u, initial_dtv->count);
+
+ // Load module 6.
+ auto func3 = LOAD_LIB("libtest_elftls_dynamic_filler_3.so");
+ ASSERT_EQ(103, func1());
+ ASSERT_EQ(202, func2());
+
+#if defined(__aarch64__)
+ // The arm64 TLSDESC resolver doesn't update the DTV if it is new enough for
+ // the given access.
+ ASSERT_EQ(5u, dtv()->count);
+#else
+ // __tls_get_addr updates the DTV anytime the generation counter changes.
+ ASSERT_EQ(13u, dtv()->count);
+#endif
+
+ ASSERT_EQ(301, func3());
+
+ TlsDtv* new_dtv = dtv();
+ ASSERT_EQ(13u, new_dtv->count);
+ ASSERT_NE(initial_dtv, new_dtv);
+ ASSERT_EQ(initial_dtv, new_dtv->next);
+
+#undef LOAD_LIB
+#else
+ GTEST_LOG_(INFO) << "This test is skipped for glibc because it tests Bionic internals.";
+#endif
+}
+
+// Verify that variables are reset to their initial values after the library
+// containing them is closed.
+TEST(elftls_dl, dlclose_resets_values) {
+ for (int round = 0; round < 2; ++round) {
+ void* lib = dlopen("libtest_elftls_dynamic.so", RTLD_LOCAL | RTLD_NOW);
+ ASSERT_NE(nullptr, lib);
+
+ auto bump_local_vars = reinterpret_cast<int(*)()>(dlsym(lib, "bump_local_vars"));
+ ASSERT_NE(nullptr, bump_local_vars);
+
+ ASSERT_EQ(42, bump_local_vars());
+ ASSERT_EQ(44, bump_local_vars());
+
+ ASSERT_EQ(0, dlclose(lib));
+ }
+}
+
+// Calling dlclose should remove the entry for the solib from the global list of
+// ELF TLS modules. Test that repeatedly loading and unloading a library doesn't
+// increase the DTV size.
+TEST(elftls_dl, dlclose_removes_entry) {
+#if defined(__BIONIC__)
+ auto dtv = []() -> TlsDtv* { return __get_tcb_dtv(__get_bionic_tcb()); };
+
+ bool first = true;
+ size_t count = 0;
+
+ // Use a large number of rounds in case the DTV is initially larger than
+ // expected.
+ for (int round = 0; round < 32; ++round) {
+ void* lib = dlopen("libtest_elftls_dynamic.so", RTLD_LOCAL | RTLD_NOW);
+ ASSERT_NE(nullptr, lib);
+
+ auto bump_local_vars = reinterpret_cast<int(*)()>(dlsym(lib, "bump_local_vars"));
+ ASSERT_NE(nullptr, bump_local_vars);
+
+ ASSERT_EQ(42, bump_local_vars());
+ if (first) {
+ first = false;
+ count = dtv()->count;
+ } else {
+ ASSERT_EQ(count, dtv()->count);
+ }
+
+ dlclose(lib);
+ }
+#else
+ GTEST_LOG_(INFO) << "This test is skipped for glibc because it tests Bionic internals.";
+#endif
+}
diff --git a/tests/elftls_test.cpp b/tests/elftls_test.cpp
index 11d41ce..2d83d70 100644
--- a/tests/elftls_test.cpp
+++ b/tests/elftls_test.cpp
@@ -83,3 +83,17 @@
ASSERT_EQ(8, bump_static_tls_var_2());
}).join();
}
+
+// Because this C++ source file is built with -fpic, the compiler will access
+// this variable using a GD model. Typically, the static linker will relax the
+// GD to LE, but the arm32 linker doesn't do TLS relaxations, so we can test
+// calling __tls_get_addr in a static executable. The static linker knows that
+// the main executable's TlsIndex::module_id is 1 and writes that into the GOT.
+__thread int tlsvar_general = 30;
+
+TEST(elftls, general) {
+ ASSERT_EQ(31, ++tlsvar_general);
+ std::thread([] {
+ ASSERT_EQ(31, ++tlsvar_general);
+ }).join();
+}
diff --git a/tests/headers/posix/signal_h.c b/tests/headers/posix/signal_h.c
index 661b55e..c2e544e 100644
--- a/tests/headers/posix/signal_h.c
+++ b/tests/headers/posix/signal_h.c
@@ -53,7 +53,7 @@
STRUCT_MEMBER(struct sigevent, int, sigev_signo);
STRUCT_MEMBER(struct sigevent, union sigval, sigev_value);
STRUCT_MEMBER_FUNCTION_POINTER(struct sigevent, void (*f)(union sigval), sigev_notify_function);
-#if defined(__BIONIC__) || defined(__GLIBC__)
+#if defined(__BIONIC__)
STRUCT_MEMBER(struct sigevent, void*, sigev_notify_attributes);
#else
STRUCT_MEMBER(struct sigevent, pthread_attr_t*, sigev_notify_attributes);
diff --git a/tests/libs/Android.bp b/tests/libs/Android.bp
index 05d1ed2..d58b6b8 100644
--- a/tests/libs/Android.bp
+++ b/tests/libs/Android.bp
@@ -43,14 +43,6 @@
// Libraries and helper binaries for ELF TLS
// -----------------------------------------------------------------------------
cc_test_library {
- name: "libelf-tls-library",
- defaults: ["bionic_testlib_defaults"],
- srcs: ["elf_tls_test_library.cpp"],
- cflags: ["-fno-emulated-tls"],
- allow_undefined_symbols: true, // __tls_get_addr is undefined.
-}
-
-cc_test_library {
name: "libtest_elftls_shared_var",
defaults: ["bionic_testlib_defaults"],
srcs: ["elftls_shared_var.cpp"],
@@ -79,6 +71,35 @@
ldflags: ["-Wl,--rpath,${ORIGIN}/.."],
}
+cc_test_library {
+ name: "libtest_elftls_dynamic",
+ defaults: ["bionic_testlib_defaults"],
+ srcs: ["elftls_dynamic.cpp"],
+ cflags: ["-fno-emulated-tls"],
+ shared_libs: ["libtest_elftls_shared_var"],
+}
+
+cc_test_library {
+ name: "libtest_elftls_dynamic_filler_1",
+ defaults: ["bionic_testlib_defaults"],
+ srcs: ["elftls_dynamic_filler.cpp"],
+ cflags: ["-fno-emulated-tls", "-DTLS_FILLER=100"],
+}
+
+cc_test_library {
+ name: "libtest_elftls_dynamic_filler_2",
+ defaults: ["bionic_testlib_defaults"],
+ srcs: ["elftls_dynamic_filler.cpp"],
+ cflags: ["-fno-emulated-tls", "-DTLS_FILLER=200"],
+}
+
+cc_test_library {
+ name: "libtest_elftls_dynamic_filler_3",
+ defaults: ["bionic_testlib_defaults"],
+ srcs: ["elftls_dynamic_filler.cpp"],
+ cflags: ["-fno-emulated-tls", "-DTLS_FILLER=300"],
+}
+
// -----------------------------------------------------------------------------
// Library to test gnu-styled hash
// -----------------------------------------------------------------------------
diff --git a/tests/libs/elf_tls_test_library.cpp b/tests/libs/elf_tls_test_library.cpp
deleted file mode 100644
index 56d0171..0000000
--- a/tests/libs/elf_tls_test_library.cpp
+++ /dev/null
@@ -1,19 +0,0 @@
-/*
- * Copyright (C) 2018 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-thread_local int elf_tls_variable;
-
-extern "C" int* get() { return &elf_tls_variable; }
diff --git a/tests/libs/elftls_dynamic.cpp b/tests/libs/elftls_dynamic.cpp
new file mode 100644
index 0000000..7fa239c
--- /dev/null
+++ b/tests/libs/elftls_dynamic.cpp
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+// This shared object test library is dlopen'ed by the main test executable.
+// This variable comes from libtest_elftls_shared_var.so, which is part of
+// static TLS. Verify that a GD-model access can access the variable.
+//
+// Accessing the static TLS variable from an solib prevents the static linker
+// from relaxing the GD access to IE and lets us test that __tls_get_addr and
+// the tlsdesc resolver handle a static TLS variable.
+extern "C" __thread int elftls_shared_var;
+
+extern "C" int bump_shared_var() {
+ return ++elftls_shared_var;
+}
+
+// The static linker denotes the current module by omitting the symbol from
+// the DTPMOD/TLSDESC relocations.
+static __thread int local_var_1 = 15;
+static __thread int local_var_2 = 25;
+
+extern "C" int bump_local_vars() {
+ return ++local_var_1 + ++local_var_2;
+}
+
+__attribute__((weak)) extern "C" __thread int missing_weak_dyn_tls;
+
+extern "C" int* missing_weak_dyn_tls_addr() {
+ return &missing_weak_dyn_tls;
+}
diff --git a/tests/libs/elftls_dynamic_filler.cpp b/tests/libs/elftls_dynamic_filler.cpp
new file mode 100644
index 0000000..9c00ab0
--- /dev/null
+++ b/tests/libs/elftls_dynamic_filler.cpp
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+__thread int var = TLS_FILLER;
+
+extern "C" int bump() {
+ return ++var;
+}
diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp
index 1c57264..9c6b975 100644
--- a/tests/pthread_test.cpp
+++ b/tests/pthread_test.cpp
@@ -25,6 +25,7 @@
#include <stdio.h>
#include <sys/mman.h>
#include <sys/prctl.h>
+#include <sys/resource.h>
#include <sys/syscall.h>
#include <time.h>
#include <unistd.h>