reference, declarationdefinition
definition → references, declarations, derived classes, virtual overrides
reference to multiple definitions → definitions
unreferenced
    1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
  131
  132
  133
  134
  135
  136
  137
  138
  139
  140
  141
  142
  143
  144
  145
  146
  147
  148
  149
  150
  151
  152
  153
  154
  155
  156
  157
  158
  159
  160
  161
  162
  163
  164
  165
  166
  167
  168
  169
  170
  171
  172
  173
  174
  175
  176
  177
  178
  179
  180
  181
  182
  183
  184
  185
  186
  187
  188
  189
  190
  191
  192
  193
  194
  195
  196
  197
  198
  199
  200
  201
  202
  203
  204
  205
  206
  207
  208
  209
  210
  211
  212
  213
  214
  215
  216
  217
  218
  219
  220
  221
  222
  223
  224
  225
  226
  227
  228
  229
  230
  231
  232
  233
  234
  235
  236
  237
  238
  239
  240
  241
  242
  243
  244
  245
  246
  247
  248
  249
  250
  251
  252
  253
  254
  255
  256
  257
  258
//===-- asan_rtems.cpp ----------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of AddressSanitizer, an address sanity checker.
//
// RTEMS-specific details.
//===----------------------------------------------------------------------===//

#include "sanitizer_common/sanitizer_rtems.h"
#if SANITIZER_RTEMS

#include "asan_internal.h"
#include "asan_interceptors.h"
#include "asan_mapping.h"
#include "asan_poisoning.h"
#include "asan_report.h"
#include "asan_stack.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_libc.h"

#include <pthread.h>
#include <stdlib.h>

namespace __asan {

static void ResetShadowMemory() {
  uptr shadow_start = SHADOW_OFFSET;
  uptr shadow_end = MEM_TO_SHADOW(kMyriadMemoryEnd32);
  uptr gap_start = MEM_TO_SHADOW(shadow_start);
  uptr gap_end = MEM_TO_SHADOW(shadow_end);

  REAL(memset)((void *)shadow_start, 0, shadow_end - shadow_start);
  REAL(memset)((void *)gap_start, kAsanShadowGap, gap_end - gap_start);
}

void InitializeShadowMemory() {
  kHighMemEnd = 0;
  kMidMemBeg =  0;
  kMidMemEnd =  0;

  ResetShadowMemory();
}

void AsanApplyToGlobals(globals_op_fptr op, const void *needle) {
  UNIMPLEMENTED();
}

void AsanCheckDynamicRTPrereqs() {}
void AsanCheckIncompatibleRT() {}
void InitializeAsanInterceptors() {}
void InitializePlatformInterceptors() {}
void InitializePlatformExceptionHandlers() {}

// RTEMS only support static linking; it sufficies to return with no
// error.
void *AsanDoesNotSupportStaticLinkage() { return nullptr; }

void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
  UNIMPLEMENTED();
}

void EarlyInit() {
  // Provide early initialization of shadow memory so that
  // instrumented code running before full initialzation will not
  // report spurious errors.
  ResetShadowMemory();
}

// We can use a plain thread_local variable for TSD.
static thread_local void *per_thread;

void *AsanTSDGet() { return per_thread; }

void AsanTSDSet(void *tsd) { per_thread = tsd; }

// There's no initialization needed, and the passed-in destructor
// will never be called.  Instead, our own thread destruction hook
// (below) will call AsanThread::TSDDtor directly.
void AsanTSDInit(void (*destructor)(void *tsd)) {
  DCHECK(destructor == &PlatformTSDDtor);
}

void PlatformTSDDtor(void *tsd) { UNREACHABLE(__func__); }

//
// Thread registration.  We provide an API similar to the Fushia port.
//

struct AsanThread::InitOptions {
  uptr stack_bottom, stack_size, tls_bottom, tls_size;
};

// Shared setup between thread creation and startup for the initial thread.
static AsanThread *CreateAsanThread(StackTrace *stack, u32 parent_tid,
                                    uptr user_id, bool detached,
                                    uptr stack_bottom, uptr stack_size,
                                    uptr tls_bottom, uptr tls_size) {
  // In lieu of AsanThread::Create.
  AsanThread *thread = (AsanThread *)MmapOrDie(sizeof(AsanThread), __func__);
  AsanThreadContext::CreateThreadContextArgs args = {thread, stack};
  asanThreadRegistry().CreateThread(user_id, detached, parent_tid, &args);

  // On other systems, AsanThread::Init() is called from the new
  // thread itself.  But on RTEMS we already know the stack address
  // range beforehand, so we can do most of the setup right now.
  const AsanThread::InitOptions options = {stack_bottom, stack_size,
                                           tls_bottom, tls_size};
  thread->Init(&options);
  return thread;
}

// This gets the same arguments passed to Init by CreateAsanThread, above.
// We're in the creator thread before the new thread is actually started, but
// its stack and tls address range are already known.
void AsanThread::SetThreadStackAndTls(const AsanThread::InitOptions *options) {
  DCHECK_NE(GetCurrentThread(), this);
  DCHECK_NE(GetCurrentThread(), nullptr);
  CHECK_NE(options->stack_bottom, 0);
  CHECK_NE(options->stack_size, 0);
  stack_bottom_ = options->stack_bottom;
  stack_top_ = options->stack_bottom + options->stack_size;
  tls_begin_ = options->tls_bottom;
  tls_end_ = options->tls_bottom + options->tls_size;
}

// Called by __asan::AsanInitInternal (asan_rtl.c).  Unlike other ports, the
// main thread on RTEMS does not require special treatment; its AsanThread is
// already created by the provided hooks.  This function simply looks up and
// returns the created thread.
AsanThread *CreateMainThread() {
  return GetThreadContextByTidLocked(0)->thread;
}

// This is called before each thread creation is attempted.  So, in
// its first call, the calling thread is the initial and sole thread.
static void *BeforeThreadCreateHook(uptr user_id, bool detached,
                                    uptr stack_bottom, uptr stack_size,
                                    uptr tls_bottom, uptr tls_size) {
  EnsureMainThreadIDIsCorrect();
  // Strict init-order checking is thread-hostile.
  if (flags()->strict_init_order) StopInitOrderChecking();

  GET_STACK_TRACE_THREAD;
  u32 parent_tid = GetCurrentTidOrInvalid();

  return CreateAsanThread(&stack, parent_tid, user_id, detached,
                          stack_bottom, stack_size, tls_bottom, tls_size);
}

// This is called after creating a new thread (in the creating thread),
// with the pointer returned by BeforeThreadCreateHook (above).
static void ThreadCreateHook(void *hook, bool aborted) {
  AsanThread *thread = static_cast<AsanThread *>(hook);
  if (!aborted) {
    // The thread was created successfully.
    // ThreadStartHook is already running in the new thread.
  } else {
    // The thread wasn't created after all.
    // Clean up everything we set up in BeforeThreadCreateHook.
    asanThreadRegistry().FinishThread(thread->tid());
    UnmapOrDie(thread, sizeof(AsanThread));
  }
}

// This is called (1) in the newly-created thread before it runs anything else,
// with the pointer returned by BeforeThreadCreateHook (above).  (2) before a
// thread restart.
static void ThreadStartHook(void *hook, uptr os_id) {
  if (!hook)
    return;

  AsanThread *thread = static_cast<AsanThread *>(hook);
  SetCurrentThread(thread);

  ThreadStatus status =
      asanThreadRegistry().GetThreadLocked(thread->tid())->status;
  DCHECK(status == ThreadStatusCreated || status == ThreadStatusRunning);
  // Determine whether we are starting or restarting the thread.
  if (status == ThreadStatusCreated) {
    // In lieu of AsanThread::ThreadStart.
    asanThreadRegistry().StartThread(thread->tid(), os_id, ThreadType::Regular,
                                     nullptr);
  } else {
    // In a thread restart, a thread may resume execution at an
    // arbitrary function entry point, with its stack and TLS state
    // reset.  We unpoison the stack in that case.
    PoisonShadow(thread->stack_bottom(), thread->stack_size(), 0);
  }
}

// Each thread runs this just before it exits,
// with the pointer returned by BeforeThreadCreateHook (above).
// All per-thread destructors have already been called.
static void ThreadExitHook(void *hook, uptr os_id) {
  AsanThread *thread = static_cast<AsanThread *>(hook);
  if (thread)
    AsanThread::TSDDtor(thread->context());
}

static void HandleExit() {
  // Disable ASan by setting it to uninitialized.  Also reset the
  // shadow memory to avoid reporting errors after the run-time has
  // been desroyed.
  if (asan_inited) {
    asan_inited = false;
    ResetShadowMemory();
  }
}

bool HandleDlopenInit() {
  // Not supported on this platform.
  static_assert(!SANITIZER_SUPPORTS_INIT_FOR_DLOPEN,
                "Expected SANITIZER_SUPPORTS_INIT_FOR_DLOPEN to be false");
  return false;
}
}  // namespace __asan

// These are declared (in extern "C") by <some_path/sanitizer.h>.
// The system runtime will call our definitions directly.

extern "C" {
void __sanitizer_early_init() {
  __asan::EarlyInit();
}

void *__sanitizer_before_thread_create_hook(uptr thread, bool detached,
                                            const char *name,
                                            void *stack_base, size_t stack_size,
                                            void *tls_base, size_t tls_size) {
  return __asan::BeforeThreadCreateHook(
      thread, detached,
      reinterpret_cast<uptr>(stack_base), stack_size,
      reinterpret_cast<uptr>(tls_base), tls_size);
}

void __sanitizer_thread_create_hook(void *handle, uptr thread, int status) {
  __asan::ThreadCreateHook(handle, status != 0);
}

void __sanitizer_thread_start_hook(void *handle, uptr self) {
  __asan::ThreadStartHook(handle, self);
}

void __sanitizer_thread_exit_hook(void *handle, uptr self) {
  __asan::ThreadExitHook(handle, self);
}

void __sanitizer_exit() {
  __asan::HandleExit();
}
}  // "C"

#endif  // SANITIZER_RTEMS