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      1 //=-- lsan_thread.cc ------------------------------------------------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file is a part of LeakSanitizer.
     11 // See lsan_thread.h for details.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #include "lsan_thread.h"
     16 
     17 #include "sanitizer_common/sanitizer_common.h"
     18 #include "sanitizer_common/sanitizer_placement_new.h"
     19 #include "sanitizer_common/sanitizer_thread_registry.h"
     20 #include "sanitizer_common/sanitizer_tls_get_addr.h"
     21 #include "lsan_allocator.h"
     22 
     23 namespace __lsan {
     24 
     25 const u32 kInvalidTid = (u32) -1;
     26 
     27 static ThreadRegistry *thread_registry;
     28 static THREADLOCAL u32 current_thread_tid = kInvalidTid;
     29 
     30 static ThreadContextBase *CreateThreadContext(u32 tid) {
     31   void *mem = MmapOrDie(sizeof(ThreadContext), "ThreadContext");
     32   return new(mem) ThreadContext(tid);
     33 }
     34 
     35 static const uptr kMaxThreads = 1 << 13;
     36 static const uptr kThreadQuarantineSize = 64;
     37 
     38 void InitializeThreadRegistry() {
     39   static char thread_registry_placeholder[sizeof(ThreadRegistry)] ALIGNED(64);
     40   thread_registry = new(thread_registry_placeholder)
     41     ThreadRegistry(CreateThreadContext, kMaxThreads, kThreadQuarantineSize);
     42 }
     43 
     44 u32 GetCurrentThread() {
     45   return current_thread_tid;
     46 }
     47 
     48 void SetCurrentThread(u32 tid) {
     49   current_thread_tid = tid;
     50 }
     51 
     52 ThreadContext::ThreadContext(int tid)
     53     : ThreadContextBase(tid),
     54       stack_begin_(0),
     55       stack_end_(0),
     56       cache_begin_(0),
     57       cache_end_(0),
     58       tls_begin_(0),
     59       tls_end_(0),
     60       dtls_(nullptr) {}
     61 
     62 struct OnStartedArgs {
     63   uptr stack_begin, stack_end,
     64        cache_begin, cache_end,
     65        tls_begin, tls_end;
     66   DTLS *dtls;
     67 };
     68 
     69 void ThreadContext::OnStarted(void *arg) {
     70   OnStartedArgs *args = reinterpret_cast<OnStartedArgs *>(arg);
     71   stack_begin_ = args->stack_begin;
     72   stack_end_ = args->stack_end;
     73   tls_begin_ = args->tls_begin;
     74   tls_end_ = args->tls_end;
     75   cache_begin_ = args->cache_begin;
     76   cache_end_ = args->cache_end;
     77   dtls_ = args->dtls;
     78 }
     79 
     80 void ThreadContext::OnFinished() {
     81   AllocatorThreadFinish();
     82   DTLS_Destroy();
     83 }
     84 
     85 u32 ThreadCreate(u32 parent_tid, uptr user_id, bool detached) {
     86   return thread_registry->CreateThread(user_id, detached, parent_tid,
     87                                        /* arg */ nullptr);
     88 }
     89 
     90 void ThreadStart(u32 tid, uptr os_id) {
     91   OnStartedArgs args;
     92   uptr stack_size = 0;
     93   uptr tls_size = 0;
     94   GetThreadStackAndTls(tid == 0, &args.stack_begin, &stack_size,
     95                        &args.tls_begin, &tls_size);
     96   args.stack_end = args.stack_begin + stack_size;
     97   args.tls_end = args.tls_begin + tls_size;
     98   GetAllocatorCacheRange(&args.cache_begin, &args.cache_end);
     99   args.dtls = DTLS_Get();
    100   thread_registry->StartThread(tid, os_id, &args);
    101 }
    102 
    103 void ThreadFinish() {
    104   thread_registry->FinishThread(GetCurrentThread());
    105 }
    106 
    107 ThreadContext *CurrentThreadContext() {
    108   if (!thread_registry) return nullptr;
    109   if (GetCurrentThread() == kInvalidTid)
    110     return nullptr;
    111   // No lock needed when getting current thread.
    112   return (ThreadContext *)thread_registry->GetThreadLocked(GetCurrentThread());
    113 }
    114 
    115 static bool FindThreadByUid(ThreadContextBase *tctx, void *arg) {
    116   uptr uid = (uptr)arg;
    117   if (tctx->user_id == uid && tctx->status != ThreadStatusInvalid) {
    118     return true;
    119   }
    120   return false;
    121 }
    122 
    123 u32 ThreadTid(uptr uid) {
    124   return thread_registry->FindThread(FindThreadByUid, (void*)uid);
    125 }
    126 
    127 void ThreadJoin(u32 tid) {
    128   CHECK_NE(tid, kInvalidTid);
    129   thread_registry->JoinThread(tid, /* arg */nullptr);
    130 }
    131 
    132 void EnsureMainThreadIDIsCorrect() {
    133   if (GetCurrentThread() == 0)
    134     CurrentThreadContext()->os_id = GetTid();
    135 }
    136 
    137 ///// Interface to the common LSan module. /////
    138 
    139 bool GetThreadRangesLocked(uptr os_id, uptr *stack_begin, uptr *stack_end,
    140                            uptr *tls_begin, uptr *tls_end, uptr *cache_begin,
    141                            uptr *cache_end, DTLS **dtls) {
    142   ThreadContext *context = static_cast<ThreadContext *>(
    143       thread_registry->FindThreadContextByOsIDLocked(os_id));
    144   if (!context) return false;
    145   *stack_begin = context->stack_begin();
    146   *stack_end = context->stack_end();
    147   *tls_begin = context->tls_begin();
    148   *tls_end = context->tls_end();
    149   *cache_begin = context->cache_begin();
    150   *cache_end = context->cache_end();
    151   *dtls = context->dtls();
    152   return true;
    153 }
    154 
    155 void ForEachExtraStackRange(uptr os_id, RangeIteratorCallback callback,
    156                             void *arg) {
    157 }
    158 
    159 void LockThreadRegistry() {
    160   thread_registry->Lock();
    161 }
    162 
    163 void UnlockThreadRegistry() {
    164   thread_registry->Unlock();
    165 }
    166 
    167 } // namespace __lsan
    168