1 //=-- lsan_fuchsia.cpp ---------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===---------------------------------------------------------------------===//
8 //
9 // This file is a part of LeakSanitizer.
10 // Standalone LSan RTL code specific to Fuchsia.
11 //
12 //===---------------------------------------------------------------------===//
13 
14 #include "sanitizer_common/sanitizer_platform.h"
15 
16 #if SANITIZER_FUCHSIA
17 #include <zircon/sanitizer.h>
18 
19 #include "lsan.h"
20 #include "lsan_allocator.h"
21 
22 using namespace __lsan;
23 
24 namespace __lsan {
25 
26 void LsanOnDeadlySignal(int signo, void *siginfo, void *context) {}
27 
28 ThreadContext::ThreadContext(int tid) : ThreadContextLsanBase(tid) {}
29 
30 struct OnCreatedArgs {
31   uptr stack_begin, stack_end;
32 };
33 
34 // On Fuchsia, the stack bounds of a new thread are available before
35 // the thread itself has started running.
36 void ThreadContext::OnCreated(void *arg) {
37   // Stack bounds passed through from __sanitizer_before_thread_create_hook
38   // or InitializeMainThread.
39   auto args = reinterpret_cast<const OnCreatedArgs *>(arg);
40   stack_begin_ = args->stack_begin;
41   stack_end_ = args->stack_end;
42 }
43 
44 struct OnStartedArgs {
45   uptr cache_begin, cache_end;
46 };
47 
48 void ThreadContext::OnStarted(void *arg) {
49   ThreadContextLsanBase::OnStarted(arg);
50   auto args = reinterpret_cast<const OnStartedArgs *>(arg);
51   cache_begin_ = args->cache_begin;
52   cache_end_ = args->cache_end;
53 }
54 
55 void ThreadStart(u32 tid) {
56   OnStartedArgs args;
57   GetAllocatorCacheRange(&args.cache_begin, &args.cache_end);
58   CHECK_EQ(args.cache_end - args.cache_begin, sizeof(AllocatorCache));
59   ThreadContextLsanBase::ThreadStart(tid, GetTid(), ThreadType::Regular, &args);
60 }
61 
62 void InitializeMainThread() {
63   OnCreatedArgs args;
64   __sanitizer::GetThreadStackTopAndBottom(true, &args.stack_end,
65                                           &args.stack_begin);
66   u32 tid = ThreadCreate(kMainTid, true, &args);
67   CHECK_EQ(tid, 0);
68   ThreadStart(tid);
69 }
70 
71 void GetAllThreadAllocatorCachesLocked(InternalMmapVector<uptr> *caches) {
72   GetLsanThreadRegistryLocked()->RunCallbackForEachThreadLocked(
73       [](ThreadContextBase *tctx, void *arg) {
74         auto ctx = static_cast<ThreadContext *>(tctx);
75         static_cast<decltype(caches)>(arg)->push_back(ctx->cache_begin());
76       },
77       caches);
78 }
79 
80 // On Fuchsia, leak detection is done by a special hook after atexit hooks.
81 // So this doesn't install any atexit hook like on other platforms.
82 void InstallAtExitCheckLeaks() {}
83 
84 // ASan defines this to check its `halt_on_error` flag.
85 bool UseExitcodeOnLeak() { return true; }
86 
87 }  // namespace __lsan
88 
89 // These are declared (in extern "C") by <zircon/sanitizer.h>.
90 // The system runtime will call our definitions directly.
91 
92 // This is called before each thread creation is attempted.  So, in
93 // its first call, the calling thread is the initial and sole thread.
94 void *__sanitizer_before_thread_create_hook(thrd_t thread, bool detached,
95                                             const char *name, void *stack_base,
96                                             size_t stack_size) {
97   ENSURE_LSAN_INITED;
98   EnsureMainThreadIDIsCorrect();
99   OnCreatedArgs args;
100   args.stack_begin = reinterpret_cast<uptr>(stack_base);
101   args.stack_end = args.stack_begin + stack_size;
102   u32 parent_tid = GetCurrentThreadId();
103   u32 tid = ThreadCreate(parent_tid, detached, &args);
104   return reinterpret_cast<void *>(static_cast<uptr>(tid));
105 }
106 
107 // This is called after creating a new thread (in the creating thread),
108 // with the pointer returned by __sanitizer_before_thread_create_hook (above).
109 void __sanitizer_thread_create_hook(void *hook, thrd_t thread, int error) {
110   u32 tid = static_cast<u32>(reinterpret_cast<uptr>(hook));
111   // On success, there is nothing to do here.
112   if (error != thrd_success) {
113     // Clean up the thread registry for the thread creation that didn't happen.
114     GetLsanThreadRegistryLocked()->FinishThread(tid);
115   }
116 }
117 
118 // This is called in the newly-created thread before it runs anything else,
119 // with the pointer returned by __sanitizer_before_thread_create_hook (above).
120 void __sanitizer_thread_start_hook(void *hook, thrd_t self) {
121   u32 tid = static_cast<u32>(reinterpret_cast<uptr>(hook));
122   ThreadStart(tid);
123 }
124 
125 // Each thread runs this just before it exits,
126 // with the pointer returned by BeforeThreadCreateHook (above).
127 // All per-thread destructors have already been called.
128 void __sanitizer_thread_exit_hook(void *hook, thrd_t self) { ThreadFinish(); }
129 
130 #endif  // SANITIZER_FUCHSIA
131