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 
CreateThreadContext(u32 tid)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 
InitializeThreadRegistry()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 
GetCurrentThread()44 u32 GetCurrentThread() {
45   return current_thread_tid;
46 }
47 
SetCurrentThread(u32 tid)48 void SetCurrentThread(u32 tid) {
49   current_thread_tid = tid;
50 }
51 
ThreadContext(int tid)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 
OnStarted(void * arg)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 
OnFinished()80 void ThreadContext::OnFinished() {
81   AllocatorThreadFinish();
82   DTLS_Destroy();
83 }
84 
ThreadCreate(u32 parent_tid,uptr user_id,bool detached)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 
ThreadStart(u32 tid,uptr os_id)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 
ThreadFinish()103 void ThreadFinish() {
104   thread_registry->FinishThread(GetCurrentThread());
105 }
106 
CurrentThreadContext()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 
FindThreadByUid(ThreadContextBase * tctx,void * arg)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 
ThreadTid(uptr uid)123 u32 ThreadTid(uptr uid) {
124   return thread_registry->FindThread(FindThreadByUid, (void*)uid);
125 }
126 
ThreadJoin(u32 tid)127 void ThreadJoin(u32 tid) {
128   CHECK_NE(tid, kInvalidTid);
129   thread_registry->JoinThread(tid, /* arg */nullptr);
130 }
131 
EnsureMainThreadIDIsCorrect()132 void EnsureMainThreadIDIsCorrect() {
133   if (GetCurrentThread() == 0)
134     CurrentThreadContext()->os_id = GetTid();
135 }
136 
137 ///// Interface to the common LSan module. /////
138 
GetThreadRangesLocked(uptr os_id,uptr * stack_begin,uptr * stack_end,uptr * tls_begin,uptr * tls_end,uptr * cache_begin,uptr * cache_end,DTLS ** dtls)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 
ForEachExtraStackRange(uptr os_id,RangeIteratorCallback callback,void * arg)155 void ForEachExtraStackRange(uptr os_id, RangeIteratorCallback callback,
156                             void *arg) {
157 }
158 
LockThreadRegistry()159 void LockThreadRegistry() {
160   thread_registry->Lock();
161 }
162 
UnlockThreadRegistry()163 void UnlockThreadRegistry() {
164   thread_registry->Unlock();
165 }
166 
167 } // namespace __lsan
168