libsanitizer/asan/asan_fuchsia.cc

   1 //===-- asan_fuchsia.cc --------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===---------------------------------------------------------------------===//
   7 //
   8 // This file is a part of AddressSanitizer, an address sanity checker.
   9 //
  10 // Fuchsia-specific details.
  11 //===---------------------------------------------------------------------===//
  12
  13 #include "sanitizer_common/sanitizer_fuchsia.h"
  14 #if SANITIZER_FUCHSIA
  15
  16 #include "asan_interceptors.h"
  17 #include "asan_internal.h"
  18 #include "asan_stack.h"
  19 #include "asan_thread.h"
  20
  21 #include <limits.h>
  22 #include <zircon/sanitizer.h>
  23 #include <zircon/syscalls.h>
  24 #include <zircon/threads.h>
  25
  26 namespace __asan {
  27
  28 // The system already set up the shadow memory for us.
  29 // __sanitizer::GetMaxUserVirtualAddress has already been called by
  30 // AsanInitInternal->InitializeHighMemEnd (asan_rtl.cc).
  31 // Just do some additional sanity checks here.
  32 void InitializeShadowMemory() {
  33   if (Verbosity()) PrintAddressSpaceLayout();
  34
  35   // Make sure SHADOW_OFFSET doesn't use __asan_shadow_memory_dynamic_address.
  36   __asan_shadow_memory_dynamic_address = kDefaultShadowSentinel;
  37   DCHECK(kLowShadowBeg != kDefaultShadowSentinel);
  38   __asan_shadow_memory_dynamic_address = kLowShadowBeg;
  39
  40   CHECK_EQ(kShadowGapEnd, kHighShadowBeg - 1);
  41   CHECK_EQ(kHighMemEnd, __sanitizer::ShadowBounds.memory_limit - 1);
  42   CHECK_EQ(kHighMemBeg, __sanitizer::ShadowBounds.shadow_limit);
  43   CHECK_EQ(kHighShadowBeg, __sanitizer::ShadowBounds.shadow_base);
  44   CHECK_EQ(kShadowGapEnd, __sanitizer::ShadowBounds.shadow_base - 1);
  45   CHECK_EQ(kLowShadowEnd, 0);
  46   CHECK_EQ(kLowShadowBeg, 0);
  47 }
  48
  49 void AsanApplyToGlobals(globals_op_fptr op, const void *needle) {
  50   UNIMPLEMENTED();
  51 }
  52
  53 void AsanCheckDynamicRTPrereqs() {}
  54 void AsanCheckIncompatibleRT() {}
  55 void InitializeAsanInterceptors() {}
  56
  57 void *AsanDoesNotSupportStaticLinkage() { return nullptr; }
  58
  59 void InitializePlatformExceptionHandlers() {}
  60 void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
  61   UNIMPLEMENTED();
  62 }
  63
  64 // We can use a plain thread_local variable for TSD.
  65 static thread_local void *per_thread;
  66
  67 void *AsanTSDGet() { return per_thread; }
  68
  69 void AsanTSDSet(void *tsd) { per_thread = tsd; }
  70
  71 // There's no initialization needed, and the passed-in destructor
  72 // will never be called.  Instead, our own thread destruction hook
  73 // (below) will call AsanThread::TSDDtor directly.
  74 void AsanTSDInit(void (*destructor)(void *tsd)) {
  75   DCHECK(destructor == &PlatformTSDDtor);
  76 }
  77
  78 void PlatformTSDDtor(void *tsd) { UNREACHABLE(__func__); }
  79
  80 static inline size_t AsanThreadMmapSize() {
  81   return RoundUpTo(sizeof(AsanThread), PAGE_SIZE);
  82 }
  83
  84 struct AsanThread::InitOptions {
  85   uptr stack_bottom, stack_size;
  86 };
  87
  88 // Shared setup between thread creation and startup for the initial thread.
  89 static AsanThread *CreateAsanThread(StackTrace *stack, u32 parent_tid,
  90                                     uptr user_id, bool detached,
  91                                     const char *name, uptr stack_bottom,
  92                                     uptr stack_size) {
  93   // In lieu of AsanThread::Create.
  94   AsanThread *thread = (AsanThread *)MmapOrDie(AsanThreadMmapSize(), __func__);
  95
  96   AsanThreadContext::CreateThreadContextArgs args = {thread, stack};
  97   u32 tid =
  98       asanThreadRegistry().CreateThread(user_id, detached, parent_tid, &args);
  99   asanThreadRegistry().SetThreadName(tid, name);
 100
 101   // On other systems, AsanThread::Init() is called from the new
 102   // thread itself.  But on Fuchsia we already know the stack address
 103   // range beforehand, so we can do most of the setup right now.
 104   const AsanThread::InitOptions options = {stack_bottom, stack_size};
 105   thread->Init(&options);
 106
 107   return thread;
 108 }
 109
 110 // This gets the same arguments passed to Init by CreateAsanThread, above.
 111 // We're in the creator thread before the new thread is actually started,
 112 // but its stack address range is already known.  We don't bother tracking
 113 // the static TLS address range because the system itself already uses an
 114 // ASan-aware allocator for that.
 115 void AsanThread::SetThreadStackAndTls(const AsanThread::InitOptions *options) {
 116   DCHECK_NE(GetCurrentThread(), this);
 117   DCHECK_NE(GetCurrentThread(), nullptr);
 118   CHECK_NE(options->stack_bottom, 0);
 119   CHECK_NE(options->stack_size, 0);
 120   stack_bottom_ = options->stack_bottom;
 121   stack_top_ = options->stack_bottom + options->stack_size;
 122 }
 123
 124 // Called by __asan::AsanInitInternal (asan_rtl.c).
 125 AsanThread *CreateMainThread() {
 126   thrd_t self = thrd_current();
 127   char name[ZX_MAX_NAME_LEN];
 128   CHECK_NE(__sanitizer::MainThreadStackBase, 0);
 129   CHECK_GT(__sanitizer::MainThreadStackSize, 0);
 130   AsanThread *t = CreateAsanThread(
 131       nullptr, 0, reinterpret_cast<uptr>(self), true,
 132       _zx_object_get_property(thrd_get_zx_handle(self), ZX_PROP_NAME, name,
 133                               sizeof(name)) == ZX_OK
 134           ? name
 135           : nullptr,
 136       __sanitizer::MainThreadStackBase, __sanitizer::MainThreadStackSize);
 137   SetCurrentThread(t);
 138   return t;
 139 }
 140
 141 // This is called before each thread creation is attempted.  So, in
 142 // its first call, the calling thread is the initial and sole thread.
 143 static void *BeforeThreadCreateHook(uptr user_id, bool detached,
 144                                     const char *name, uptr stack_bottom,
 145                                     uptr stack_size) {
 146   EnsureMainThreadIDIsCorrect();
 147   // Strict init-order checking is thread-hostile.
 148   if (flags()->strict_init_order) StopInitOrderChecking();
 149
 150   GET_STACK_TRACE_THREAD;
 151   u32 parent_tid = GetCurrentTidOrInvalid();
 152
 153   return CreateAsanThread(&stack, parent_tid, user_id, detached, name,
 154                           stack_bottom, stack_size);
 155 }
 156
 157 // This is called after creating a new thread (in the creating thread),
 158 // with the pointer returned by BeforeThreadCreateHook (above).
 159 static void ThreadCreateHook(void *hook, bool aborted) {
 160   AsanThread *thread = static_cast<AsanThread *>(hook);
 161   if (!aborted) {
 162     // The thread was created successfully.
 163     // ThreadStartHook is already running in the new thread.
 164   } else {
 165     // The thread wasn't created after all.
 166     // Clean up everything we set up in BeforeThreadCreateHook.
 167     asanThreadRegistry().FinishThread(thread->tid());
 168     UnmapOrDie(thread, AsanThreadMmapSize());
 169   }
 170 }
 171
 172 // This is called in the newly-created thread before it runs anything else,
 173 // with the pointer returned by BeforeThreadCreateHook (above).
 174 // cf. asan_interceptors.cc:asan_thread_start
 175 static void ThreadStartHook(void *hook, uptr os_id) {
 176   AsanThread *thread = static_cast<AsanThread *>(hook);
 177   SetCurrentThread(thread);
 178
 179   // In lieu of AsanThread::ThreadStart.
 180   asanThreadRegistry().StartThread(thread->tid(), os_id, /*workerthread*/ false,
 181                                    nullptr);
 182 }
 183
 184 // Each thread runs this just before it exits,
 185 // with the pointer returned by BeforeThreadCreateHook (above).
 186 // All per-thread destructors have already been called.
 187 static void ThreadExitHook(void *hook, uptr os_id) {
 188   AsanThread::TSDDtor(per_thread);
 189 }
 190
 191 }  // namespace __asan
 192
 193 // These are declared (in extern "C") by <zircon/sanitizer.h>.
 194 // The system runtime will call our definitions directly.
 195
 196 void *__sanitizer_before_thread_create_hook(thrd_t thread, bool detached,
 197                                             const char *name, void *stack_base,
 198                                             size_t stack_size) {
 199   return __asan::BeforeThreadCreateHook(
 200       reinterpret_cast<uptr>(thread), detached, name,
 201       reinterpret_cast<uptr>(stack_base), stack_size);
 202 }
 203
 204 void __sanitizer_thread_create_hook(void *hook, thrd_t thread, int error) {
 205   __asan::ThreadCreateHook(hook, error != thrd_success);
 206 }
 207
 208 void __sanitizer_thread_start_hook(void *hook, thrd_t self) {
 209   __asan::ThreadStartHook(hook, reinterpret_cast<uptr>(self));
 210 }
 211
 212 void __sanitizer_thread_exit_hook(void *hook, thrd_t self) {
 213   __asan::ThreadExitHook(hook, reinterpret_cast<uptr>(self));
 214 }
 215
 216 #endif  // SANITIZER_FUCHSIA