1//===-- sanitizer_stoptheworld_mac.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// See sanitizer_stoptheworld.h for details.
10//
11//===----------------------------------------------------------------------===//
12
13#include "sanitizer_platform.h"
14
15#if SANITIZER_APPLE && (defined(__x86_64__) || defined(__aarch64__) || \
16 defined(__i386))
17
18#include <mach/mach.h>
19#include <mach/thread_info.h>
20#include <pthread.h>
21
22#include "sanitizer_stoptheworld.h"
23
24namespace __sanitizer {
25typedef struct {
26 tid_t tid;
27 thread_t thread;
28} SuspendedThreadInfo;
29
30class SuspendedThreadsListMac final : public SuspendedThreadsList {
31 public:
32 SuspendedThreadsListMac() = default;
33
34 tid_t GetThreadID(uptr index) const override;
35 thread_t GetThread(uptr index) const;
36 uptr ThreadCount() const override;
37 bool ContainsThread(thread_t thread) const;
38 void Append(thread_t thread);
39
40 PtraceRegistersStatus GetRegistersAndSP(uptr index,
41 InternalMmapVector<uptr> *buffer,
42 uptr *sp) const override;
43
44 private:
45 InternalMmapVector<SuspendedThreadInfo> threads_;
46};
47
48struct RunThreadArgs {
49 StopTheWorldCallback callback;
50 void *argument;
51};
52
53void *RunThread(void *arg) {
54 struct RunThreadArgs *run_args = (struct RunThreadArgs *)arg;
55 SuspendedThreadsListMac suspended_threads_list;
56
57 thread_array_t threads;
58 mach_msg_type_number_t num_threads;
59 kern_return_t err = task_threads(mach_task_self(), &threads, &num_threads);
60 if (err != KERN_SUCCESS) {
61 VReport(1, "Failed to get threads for task (errno %d).\n", err);
62 return nullptr;
63 }
64
65 thread_t thread_self = mach_thread_self();
66 for (unsigned int i = 0; i < num_threads; ++i) {
67 if (threads[i] == thread_self) continue;
68
69 thread_suspend(threads[i]);
70 suspended_threads_list.Append(threads[i]);
71 }
72
73 run_args->callback(suspended_threads_list, run_args->argument);
74
75 uptr num_suspended = suspended_threads_list.ThreadCount();
76 for (unsigned int i = 0; i < num_suspended; ++i) {
77 thread_resume(suspended_threads_list.GetThread(i));
78 }
79 return nullptr;
80}
81
82void StopTheWorld(StopTheWorldCallback callback, void *argument) {
83 struct RunThreadArgs arg = {callback, argument};
84 pthread_t run_thread = (pthread_t)internal_start_thread(RunThread, &arg);
85 internal_join_thread(run_thread);
86}
87
88#if defined(__x86_64__)
89typedef x86_thread_state64_t regs_struct;
90#define regs_flavor x86_THREAD_STATE64
91
92#define SP_REG __rsp
93
94#elif defined(__aarch64__)
95typedef arm_thread_state64_t regs_struct;
96#define regs_flavor ARM_THREAD_STATE64
97
98# if __DARWIN_UNIX03
99# define SP_REG __sp
100# else
101# define SP_REG sp
102# endif
103
104#elif defined(__i386)
105typedef x86_thread_state32_t regs_struct;
106#define regs_flavor x86_THREAD_STATE32
107
108#define SP_REG __esp
109
110#else
111#error "Unsupported architecture"
112#endif
113
114tid_t SuspendedThreadsListMac::GetThreadID(uptr index) const {
115 CHECK_LT(index, threads_.size());
116 return threads_[index].tid;
117}
118
119thread_t SuspendedThreadsListMac::GetThread(uptr index) const {
120 CHECK_LT(index, threads_.size());
121 return threads_[index].thread;
122}
123
124uptr SuspendedThreadsListMac::ThreadCount() const {
125 return threads_.size();
126}
127
128bool SuspendedThreadsListMac::ContainsThread(thread_t thread) const {
129 for (uptr i = 0; i < threads_.size(); i++) {
130 if (threads_[i].thread == thread) return true;
131 }
132 return false;
133}
134
135void SuspendedThreadsListMac::Append(thread_t thread) {
136 thread_identifier_info_data_t info;
137 mach_msg_type_number_t info_count = THREAD_IDENTIFIER_INFO_COUNT;
138 kern_return_t err = thread_info(thread, THREAD_IDENTIFIER_INFO,
139 (thread_info_t)&info, &info_count);
140 if (err != KERN_SUCCESS) {
141 VReport(1, "Error - unable to get thread ident for a thread\n");
142 return;
143 }
144 threads_.push_back({info.thread_id, thread});
145}
146
147PtraceRegistersStatus SuspendedThreadsListMac::GetRegistersAndSP(
148 uptr index, InternalMmapVector<uptr> *buffer, uptr *sp) const {
149 thread_t thread = GetThread(index);
150 regs_struct regs;
151 int err;
152 mach_msg_type_number_t reg_count = sizeof(regs) / sizeof(natural_t);
153 err = thread_get_state(thread, regs_flavor, (thread_state_t)&regs,
154 &reg_count);
155 if (err != KERN_SUCCESS) {
156 VReport(1, "Error - unable to get registers for a thread\n");
157 // MIG_ARRAY_TOO_LARGE, means that the state is too large, but it's
158 // still safe to proceed.
159 return err == MIG_ARRAY_TOO_LARGE ? REGISTERS_UNAVAILABLE
160 : REGISTERS_UNAVAILABLE_FATAL;
161 }
162
163 buffer->resize(RoundUpTo(sizeof(regs), sizeof(uptr)) / sizeof(uptr));
164 internal_memcpy(buffer->data(), &regs, sizeof(regs));
165#if defined(__aarch64__) && defined(arm_thread_state64_get_sp)
166 *sp = arm_thread_state64_get_sp(regs);
167#else
168 *sp = regs.SP_REG;
169#endif
170
171 // On x86_64 and aarch64, we must account for the stack redzone, which is 128
172 // bytes.
173 if (SANITIZER_WORDSIZE == 64) *sp -= 128;
174
175 return REGISTERS_AVAILABLE;
176}
177
178} // namespace __sanitizer
179
180#endif // SANITIZER_APPLE && (defined(__x86_64__) || defined(__aarch64__)) ||
181 // defined(__i386))
182