//=-- lsan_interceptors.cc ------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a part of LeakSanitizer.
// Interceptors for standalone LSan.
//
//===----------------------------------------------------------------------===//

#include "interception/interception.h"
#include "sanitizer_common/sanitizer_allocator.h"
#include "sanitizer_common/sanitizer_atomic.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_flags.h"
#include "sanitizer_common/sanitizer_internal_defs.h"
#include "sanitizer_common/sanitizer_linux.h"
#include "sanitizer_common/sanitizer_platform_limits_posix.h"
#include "lsan.h"
#include "lsan_allocator.h"
#include "lsan_thread.h"

using namespace __lsan;

extern "C" {
int pthread_attr_init(void *attr);
int pthread_attr_destroy(void *attr);
int pthread_attr_getdetachstate(void *attr, int *v);
int pthread_key_create(unsigned *key, void (*destructor)(void* v));
int pthread_setspecific(unsigned key, const void *v);
}

#define GET_STACK_TRACE                                                      \
  StackTrace stack;                                                          \
  {                                                                          \
    uptr stack_top = 0, stack_bottom = 0;                                    \
    ThreadContext *t;                                                        \
    bool fast = common_flags()->fast_unwind_on_malloc;                       \
    if (fast && (t = CurrentThreadContext())) {                              \
      stack_top = t->stack_end();                                            \
      stack_bottom = t->stack_begin();                                       \
    }                                                                        \
    GetStackTrace(&stack, __sanitizer::common_flags()->malloc_context_size,  \
                  StackTrace::GetCurrentPc(),                                \
                  GET_CURRENT_FRAME(), stack_top, stack_bottom, fast);       \
  }

///// Malloc/free interceptors. /////

const bool kAlwaysClearMemory = true;

namespace std {
  struct nothrow_t;
}

INTERCEPTOR(void*, malloc, uptr size) {
  Init();
  GET_STACK_TRACE;
  return Allocate(stack, size, 1, kAlwaysClearMemory);
}

INTERCEPTOR(void, free, void *p) {
  Init();
  Deallocate(p);
}

INTERCEPTOR(void*, calloc, uptr nmemb, uptr size) {
  if (CallocShouldReturnNullDueToOverflow(size, nmemb)) return 0;
  Init();
  GET_STACK_TRACE;
  size *= nmemb;
  return Allocate(stack, size, 1, true);
}

INTERCEPTOR(void*, realloc, void *q, uptr size) {
  Init();
  GET_STACK_TRACE;
  return Reallocate(stack, q, size, 1);
}

INTERCEPTOR(void*, memalign, uptr alignment, uptr size) {
  Init();
  GET_STACK_TRACE;
  return Allocate(stack, size, alignment, kAlwaysClearMemory);
}

INTERCEPTOR(int, posix_memalign, void **memptr, uptr alignment, uptr size) {
  Init();
  GET_STACK_TRACE;
  *memptr = Allocate(stack, size, alignment, kAlwaysClearMemory);
  // FIXME: Return ENOMEM if user requested more than max alloc size.
  return 0;
}

INTERCEPTOR(void*, valloc, uptr size) {
  Init();
  GET_STACK_TRACE;
  if (size == 0)
    size = GetPageSizeCached();
  return Allocate(stack, size, GetPageSizeCached(), kAlwaysClearMemory);
}

INTERCEPTOR(uptr, malloc_usable_size, void *ptr) {
  Init();
  return GetMallocUsableSize(ptr);
}

struct fake_mallinfo {
  int x[10];
};

INTERCEPTOR(struct fake_mallinfo, mallinfo, void) {
  struct fake_mallinfo res;
  internal_memset(&res, 0, sizeof(res));
  return res;
}

INTERCEPTOR(int, mallopt, int cmd, int value) {
  return -1;
}

INTERCEPTOR(void*, pvalloc, uptr size) {
  Init();
  GET_STACK_TRACE;
  uptr PageSize = GetPageSizeCached();
  size = RoundUpTo(size, PageSize);
  if (size == 0) {
    // pvalloc(0) should allocate one page.
    size = PageSize;
  }
  return Allocate(stack, size, GetPageSizeCached(), kAlwaysClearMemory);
}

INTERCEPTOR(void, cfree, void *p) ALIAS("free");

#define OPERATOR_NEW_BODY                              \
  Init();                                              \
  GET_STACK_TRACE;                                     \
  return Allocate(stack, size, 1, kAlwaysClearMemory);

INTERCEPTOR_ATTRIBUTE
void *operator new(uptr size) { OPERATOR_NEW_BODY; }
INTERCEPTOR_ATTRIBUTE
void *operator new[](uptr size) { OPERATOR_NEW_BODY; }
INTERCEPTOR_ATTRIBUTE
void *operator new(uptr size, std::nothrow_t const&) { OPERATOR_NEW_BODY; }
INTERCEPTOR_ATTRIBUTE
void *operator new[](uptr size, std::nothrow_t const&) { OPERATOR_NEW_BODY; }

#define OPERATOR_DELETE_BODY \
  Init();                    \
  Deallocate(ptr);

INTERCEPTOR_ATTRIBUTE
void operator delete(void *ptr) { OPERATOR_DELETE_BODY; }
INTERCEPTOR_ATTRIBUTE
void operator delete[](void *ptr) { OPERATOR_DELETE_BODY; }
INTERCEPTOR_ATTRIBUTE
void operator delete(void *ptr, std::nothrow_t const&) { OPERATOR_DELETE_BODY; }
INTERCEPTOR_ATTRIBUTE
void operator delete[](void *ptr, std::nothrow_t const &) {
  OPERATOR_DELETE_BODY;
}

// We need this to intercept the __libc_memalign calls that are used to
// allocate dynamic TLS space in ld-linux.so.
INTERCEPTOR(void *, __libc_memalign, uptr align, uptr s) ALIAS("memalign");

///// Thread initialization and finalization. /////

static unsigned g_thread_finalize_key;

static void thread_finalize(void *v) {
  uptr iter = (uptr)v;
  if (iter > 1) {
    if (pthread_setspecific(g_thread_finalize_key, (void*)(iter - 1))) {
      Report("LeakSanitizer: failed to set thread key.\n");
      Die();
    }
    return;
  }
  ThreadFinish();
}

struct ThreadParam {
  void *(*callback)(void *arg);
  void *param;
  atomic_uintptr_t tid;
};

// PTHREAD_DESTRUCTOR_ITERATIONS from glibc.
const uptr kPthreadDestructorIterations = 4;

extern "C" void *__lsan_thread_start_func(void *arg) {
  ThreadParam *p = (ThreadParam*)arg;
  void* (*callback)(void *arg) = p->callback;
  void *param = p->param;
  // Wait until the last iteration to maximize the chance that we are the last
  // destructor to run.
  if (pthread_setspecific(g_thread_finalize_key,
                          (void*)kPthreadDestructorIterations)) {
    Report("LeakSanitizer: failed to set thread key.\n");
    Die();
  }
  int tid = 0;
  while ((tid = atomic_load(&p->tid, memory_order_acquire)) == 0)
    internal_sched_yield();
  atomic_store(&p->tid, 0, memory_order_release);
  SetCurrentThread(tid);
  ThreadStart(tid, GetTid());
  return callback(param);
}

INTERCEPTOR(int, pthread_create, void *th, void *attr,
            void *(*callback)(void *), void *param) {
  Init();
  EnsureMainThreadIDIsCorrect();
  __sanitizer_pthread_attr_t myattr;
  if (attr == 0) {
    pthread_attr_init(&myattr);
    attr = &myattr;
  }
  AdjustStackSizeLinux(attr, 0);
  int detached = 0;
  pthread_attr_getdetachstate(attr, &detached);
  ThreadParam p;
  p.callback = callback;
  p.param = param;
  atomic_store(&p.tid, 0, memory_order_relaxed);
  int res = REAL(pthread_create)(th, attr, __lsan_thread_start_func, &p);
  if (res == 0) {
    int tid = ThreadCreate(GetCurrentThread(), *(uptr *)th, detached);
    CHECK_NE(tid, 0);
    atomic_store(&p.tid, tid, memory_order_release);
    while (atomic_load(&p.tid, memory_order_acquire) != 0)
      internal_sched_yield();
  }
  if (attr == &myattr)
    pthread_attr_destroy(&myattr);
  return res;
}

INTERCEPTOR(int, pthread_join, void *th, void **ret) {
  Init();
  int tid = ThreadTid((uptr)th);
  int res = REAL(pthread_join)(th, ret);
  if (res == 0)
    ThreadJoin(tid);
  return res;
}

namespace __lsan {

void InitializeInterceptors() {
  INTERCEPT_FUNCTION(malloc);
  INTERCEPT_FUNCTION(free);
  INTERCEPT_FUNCTION(cfree);
  INTERCEPT_FUNCTION(calloc);
  INTERCEPT_FUNCTION(realloc);
  INTERCEPT_FUNCTION(memalign);
  INTERCEPT_FUNCTION(posix_memalign);
  INTERCEPT_FUNCTION(__libc_memalign);
  INTERCEPT_FUNCTION(valloc);
  INTERCEPT_FUNCTION(pvalloc);
  INTERCEPT_FUNCTION(malloc_usable_size);
  INTERCEPT_FUNCTION(mallinfo);
  INTERCEPT_FUNCTION(mallopt);
  INTERCEPT_FUNCTION(pthread_create);
  INTERCEPT_FUNCTION(pthread_join);

  if (pthread_key_create(&g_thread_finalize_key, &thread_finalize)) {
    Report("LeakSanitizer: failed to create thread key.\n");
    Die();
  }
}

}  // namespace __lsan