PerformanceEventBuffer.cpp 8.8 KB

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  1. /*
  2. * Copyright (c) 2020-2021, Andreas Kling <kling@serenityos.org>
  3. *
  4. * SPDX-License-Identifier: BSD-2-Clause
  5. */
  6. #include <AK/JsonArraySerializer.h>
  7. #include <AK/JsonObject.h>
  8. #include <AK/JsonObjectSerializer.h>
  9. #include <Kernel/Arch/x86/SmapDisabler.h>
  10. #include <Kernel/FileSystem/Custody.h>
  11. #include <Kernel/KBufferBuilder.h>
  12. #include <Kernel/PerformanceEventBuffer.h>
  13. #include <Kernel/Process.h>
  14. namespace Kernel {
  15. PerformanceEventBuffer::PerformanceEventBuffer(NonnullOwnPtr<KBuffer> buffer)
  16. : m_buffer(move(buffer))
  17. {
  18. }
  19. NEVER_INLINE KResult PerformanceEventBuffer::append(int type, FlatPtr arg1, FlatPtr arg2, const StringView& arg3, Thread* current_thread)
  20. {
  21. FlatPtr ebp;
  22. asm volatile("movl %%ebp, %%eax"
  23. : "=a"(ebp));
  24. return append_with_eip_and_ebp(current_thread->pid(), current_thread->tid(), 0, ebp, type, 0, arg1, arg2, arg3);
  25. }
  26. static Vector<FlatPtr, PerformanceEvent::max_stack_frame_count> raw_backtrace(FlatPtr ebp, FlatPtr eip)
  27. {
  28. Vector<FlatPtr, PerformanceEvent::max_stack_frame_count> backtrace;
  29. if (eip != 0)
  30. backtrace.append(eip);
  31. FlatPtr stack_ptr_copy;
  32. FlatPtr stack_ptr = (FlatPtr)ebp;
  33. // FIXME: Figure out how to remove this SmapDisabler without breaking profile stacks.
  34. SmapDisabler disabler;
  35. while (stack_ptr) {
  36. void* fault_at;
  37. if (!safe_memcpy(&stack_ptr_copy, (void*)stack_ptr, sizeof(FlatPtr), fault_at))
  38. break;
  39. FlatPtr retaddr;
  40. if (!safe_memcpy(&retaddr, (void*)(stack_ptr + sizeof(FlatPtr)), sizeof(FlatPtr), fault_at))
  41. break;
  42. if (retaddr == 0)
  43. break;
  44. backtrace.append(retaddr);
  45. if (backtrace.size() == PerformanceEvent::max_stack_frame_count)
  46. break;
  47. stack_ptr = stack_ptr_copy;
  48. }
  49. return backtrace;
  50. }
  51. KResult PerformanceEventBuffer::append_with_eip_and_ebp(ProcessID pid, ThreadID tid,
  52. u32 eip, u32 ebp, int type, u32 lost_samples, FlatPtr arg1, FlatPtr arg2, const StringView& arg3)
  53. {
  54. if (count() >= capacity())
  55. return ENOBUFS;
  56. PerformanceEvent event;
  57. event.type = type;
  58. event.lost_samples = lost_samples;
  59. switch (type) {
  60. case PERF_EVENT_SAMPLE:
  61. break;
  62. case PERF_EVENT_MALLOC:
  63. event.data.malloc.size = arg1;
  64. event.data.malloc.ptr = arg2;
  65. break;
  66. case PERF_EVENT_FREE:
  67. event.data.free.ptr = arg1;
  68. break;
  69. case PERF_EVENT_MMAP:
  70. event.data.mmap.ptr = arg1;
  71. event.data.mmap.size = arg2;
  72. memset(event.data.mmap.name, 0, sizeof(event.data.mmap.name));
  73. if (!arg3.is_empty())
  74. memcpy(event.data.mmap.name, arg3.characters_without_null_termination(), min(arg3.length(), sizeof(event.data.mmap.name) - 1));
  75. break;
  76. case PERF_EVENT_MUNMAP:
  77. event.data.munmap.ptr = arg1;
  78. event.data.munmap.size = arg2;
  79. break;
  80. case PERF_EVENT_PROCESS_CREATE:
  81. event.data.process_create.parent_pid = arg1;
  82. memset(event.data.process_create.executable, 0, sizeof(event.data.process_create.executable));
  83. if (!arg3.is_empty()) {
  84. memcpy(event.data.process_create.executable, arg3.characters_without_null_termination(),
  85. min(arg3.length(), sizeof(event.data.process_create.executable) - 1));
  86. }
  87. break;
  88. case PERF_EVENT_PROCESS_EXEC:
  89. memset(event.data.process_exec.executable, 0, sizeof(event.data.process_exec.executable));
  90. if (!arg3.is_empty()) {
  91. memcpy(event.data.process_exec.executable, arg3.characters_without_null_termination(),
  92. min(arg3.length(), sizeof(event.data.process_exec.executable) - 1));
  93. }
  94. break;
  95. case PERF_EVENT_PROCESS_EXIT:
  96. break;
  97. case PERF_EVENT_THREAD_CREATE:
  98. event.data.thread_create.parent_tid = arg1;
  99. break;
  100. case PERF_EVENT_THREAD_EXIT:
  101. break;
  102. default:
  103. return EINVAL;
  104. }
  105. auto backtrace = raw_backtrace(ebp, eip);
  106. event.stack_size = min(sizeof(event.stack) / sizeof(FlatPtr), static_cast<size_t>(backtrace.size()));
  107. memcpy(event.stack, backtrace.data(), event.stack_size * sizeof(FlatPtr));
  108. event.pid = pid.value();
  109. event.tid = tid.value();
  110. event.timestamp = TimeManagement::the().uptime_ms();
  111. at(m_count++) = event;
  112. return KSuccess;
  113. }
  114. PerformanceEvent& PerformanceEventBuffer::at(size_t index)
  115. {
  116. VERIFY(index < capacity());
  117. auto* events = reinterpret_cast<PerformanceEvent*>(m_buffer->data());
  118. return events[index];
  119. }
  120. template<typename Serializer>
  121. bool PerformanceEventBuffer::to_json_impl(Serializer& object) const
  122. {
  123. auto array = object.add_array("events");
  124. for (size_t i = 0; i < m_count; ++i) {
  125. auto& event = at(i);
  126. auto event_object = array.add_object();
  127. switch (event.type) {
  128. case PERF_EVENT_SAMPLE:
  129. event_object.add("type", "sample");
  130. break;
  131. case PERF_EVENT_MALLOC:
  132. event_object.add("type", "malloc");
  133. event_object.add("ptr", static_cast<u64>(event.data.malloc.ptr));
  134. event_object.add("size", static_cast<u64>(event.data.malloc.size));
  135. break;
  136. case PERF_EVENT_FREE:
  137. event_object.add("type", "free");
  138. event_object.add("ptr", static_cast<u64>(event.data.free.ptr));
  139. break;
  140. case PERF_EVENT_MMAP:
  141. event_object.add("type", "mmap");
  142. event_object.add("ptr", static_cast<u64>(event.data.mmap.ptr));
  143. event_object.add("size", static_cast<u64>(event.data.mmap.size));
  144. event_object.add("name", event.data.mmap.name);
  145. break;
  146. case PERF_EVENT_MUNMAP:
  147. event_object.add("type", "munmap");
  148. event_object.add("ptr", static_cast<u64>(event.data.munmap.ptr));
  149. event_object.add("size", static_cast<u64>(event.data.munmap.size));
  150. break;
  151. case PERF_EVENT_PROCESS_CREATE:
  152. event_object.add("type", "process_create");
  153. event_object.add("parent_pid", static_cast<u64>(event.data.process_create.parent_pid));
  154. event_object.add("executable", event.data.process_create.executable);
  155. break;
  156. case PERF_EVENT_PROCESS_EXEC:
  157. event_object.add("type", "process_exec");
  158. event_object.add("executable", event.data.process_exec.executable);
  159. break;
  160. case PERF_EVENT_PROCESS_EXIT:
  161. event_object.add("type", "process_exit");
  162. break;
  163. case PERF_EVENT_THREAD_CREATE:
  164. event_object.add("type", "thread_create");
  165. event_object.add("parent_tid", static_cast<u64>(event.data.thread_create.parent_tid));
  166. break;
  167. case PERF_EVENT_THREAD_EXIT:
  168. event_object.add("type", "thread_exit");
  169. break;
  170. }
  171. event_object.add("pid", event.pid);
  172. event_object.add("tid", event.tid);
  173. event_object.add("timestamp", event.timestamp);
  174. event_object.add("lost_samples", i != 0 ? event.lost_samples : 0);
  175. auto stack_array = event_object.add_array("stack");
  176. for (size_t j = 0; j < event.stack_size; ++j) {
  177. stack_array.add(event.stack[j]);
  178. }
  179. stack_array.finish();
  180. event_object.finish();
  181. }
  182. array.finish();
  183. object.finish();
  184. return true;
  185. }
  186. bool PerformanceEventBuffer::to_json(KBufferBuilder& builder) const
  187. {
  188. JsonObjectSerializer object(builder);
  189. return to_json_impl(object);
  190. }
  191. OwnPtr<PerformanceEventBuffer> PerformanceEventBuffer::try_create_with_size(size_t buffer_size)
  192. {
  193. auto buffer = KBuffer::try_create_with_size(buffer_size, Region::Access::Read | Region::Access::Write, "Performance events", AllocationStrategy::AllocateNow);
  194. if (!buffer)
  195. return {};
  196. return adopt_own(*new PerformanceEventBuffer(buffer.release_nonnull()));
  197. }
  198. void PerformanceEventBuffer::add_process(const Process& process, ProcessEventType event_type)
  199. {
  200. ScopedSpinLock locker(process.space().get_lock());
  201. String executable;
  202. if (process.executable())
  203. executable = process.executable()->absolute_path();
  204. else
  205. executable = String::formatted("<{}>", process.name());
  206. [[maybe_unused]] auto rc = append_with_eip_and_ebp(process.pid(), 0, 0, 0,
  207. event_type == ProcessEventType::Create ? PERF_EVENT_PROCESS_CREATE : PERF_EVENT_PROCESS_EXEC,
  208. 0, process.pid().value(), 0, executable);
  209. process.for_each_thread([&](auto& thread) {
  210. [[maybe_unused]] auto rc = append_with_eip_and_ebp(process.pid(), thread.tid().value(),
  211. 0, 0, PERF_EVENT_THREAD_CREATE, 0, 0, 0, nullptr);
  212. return IterationDecision::Continue;
  213. });
  214. for (auto& region : process.space().regions()) {
  215. [[maybe_unused]] auto rc = append_with_eip_and_ebp(process.pid(), 0,
  216. 0, 0, PERF_EVENT_MMAP, 0, region->range().base().get(), region->range().size(), region->name());
  217. }
  218. }
  219. }