summaryrefslogtreecommitdiff
path: root/src/node_win32_etw_provider.cc
blob: 8a854767d6aed856b1e221083cd944f02f547104 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

#include "node_win32_etw_provider.h"
#include "node_etw_provider.h"
#include "node_win32_etw_provider-inl.h"

namespace node {

using v8::JitCodeEvent;
using v8::V8;

HMODULE advapi;
REGHANDLE node_provider;
EventRegisterFunc event_register;
EventUnregisterFunc event_unregister;
EventWriteFunc event_write;
int events_enabled;
static uv_async_t dispatch_etw_events_change_async;

struct v8tags {
  char prefix[32 - sizeof(size_t)];
  size_t prelen;
};

// The v8 CODE_ADDED event name has a prefix indicating the type of event.
// Many of these are internal to v8.
// The trace_codes array specifies which types are written.
struct v8tags trace_codes[] = {
#define MAKE_V8TAG(s) { s, sizeof(s) - 1 }
  MAKE_V8TAG("LazyCompile:"),
  MAKE_V8TAG("Script:"),
  MAKE_V8TAG("Function:"),
  MAKE_V8TAG("RegExp:"),
  MAKE_V8TAG("Eval:")
#undef MAKE_V8TAG
};

/* Below are some code prefixes which are not being written.
 *    "Builtin:"
 *    "Stub:"
 *    "CallIC:"
 *    "LoadIC:"
 *    "KeyedLoadIC:"
 *    "StoreIC:"
 *    "KeyedStoreIC:"
 *    "CallPreMonomorphic:"
 *    "CallInitialize:"
 *    "CallMiss:"
 *    "CallMegamorphic:"
 */

// v8 sometimes puts a '*' or '~' in front of the name.
#define V8_MARKER1 '*'
#define V8_MARKER2 '~'


// If prefix is not in filtered list return -1,
// else return length of prefix and marker.
int FilterCodeEvents(const char* name, size_t len) {
  for (size_t i = 0; i < arraysize(trace_codes); i++) {
    size_t prelen = trace_codes[i].prelen;
    if (prelen < len) {
      if (strncmp(name, trace_codes[i].prefix, prelen) == 0) {
        if (name[prelen] == V8_MARKER1 || name[prelen] == V8_MARKER2)
          prelen++;
        return prelen;
      }
    }
  }
  return -1;
}


// callback from V8 module passes symbol and address info for stack walk
void CodeAddressNotification(const JitCodeEvent* jevent) {
  int pre_offset = 0;
  if (NODE_V8SYMBOL_ENABLED()) {
    switch (jevent->type) {
    case JitCodeEvent::CODE_ADDED:
      pre_offset = FilterCodeEvents(jevent->name.str, jevent->name.len);
      if (pre_offset >= 0) {
        // skip over prefix and marker
        NODE_V8SYMBOL_ADD(jevent->name.str + pre_offset,
                          jevent->name.len - pre_offset,
                          jevent->code_start,
                          jevent->code_len);
      }
      break;
    case JitCodeEvent::CODE_REMOVED:
      NODE_V8SYMBOL_REMOVE(jevent->code_start, 0);
      break;
    case JitCodeEvent::CODE_MOVED:
      NODE_V8SYMBOL_MOVE(jevent->code_start, jevent->new_code_start);
      break;
    default:
      break;
    }
  }
}


// Call v8 to enable or disable code event callbacks.
// Must be on default thread to do this.
// Note: It is possible to call v8 from ETW thread, but then
//       event callbacks are received in the same thread. Attempts
//       to write ETW events in this thread will fail.
void etw_events_change_async(uv_async_t* handle) {
  if (events_enabled > 0) {
    NODE_V8SYMBOL_RESET();
    v8::Isolate::GetCurrent()->SetJitCodeEventHandler(
        v8::kJitCodeEventEnumExisting,
        CodeAddressNotification);
  } else {
    v8::Isolate::GetCurrent()->SetJitCodeEventHandler(
        v8::kJitCodeEventDefault,
        nullptr);
  }
}


// This callback is called by ETW when consumers of our provider
// are enabled or disabled.
// The callback is dispatched on ETW thread.
// Before calling into V8 to enable code events, switch to default thread.
void NTAPI etw_events_enable_callback(
  LPCGUID SourceId,
  ULONG IsEnabled,
  UCHAR Level,
  ULONGLONG MatchAnyKeyword,
  ULONGLONG MatchAllKeywords,
  PEVENT_FILTER_DESCRIPTOR FilterData,
  PVOID CallbackContext) {
  if (IsEnabled) {
    events_enabled++;
    if (events_enabled == 1) {
      uv_async_send(&dispatch_etw_events_change_async);
    }
  } else {
    events_enabled--;
    if (events_enabled == 0) {
      uv_async_send(&dispatch_etw_events_change_async);
    }
  }
}


void init_etw() {
  events_enabled = 0;

  advapi = LoadLibraryW(L"advapi32.dll");
  if (advapi) {
    event_register = (EventRegisterFunc)
      GetProcAddress(advapi, "EventRegister");
    event_unregister = (EventUnregisterFunc)
      GetProcAddress(advapi, "EventUnregister");
    event_write = (EventWriteFunc)GetProcAddress(advapi, "EventWrite");

    // create async object used to invoke main thread from callback
    CHECK_EQ(0, uv_async_init(uv_default_loop(),
                              &dispatch_etw_events_change_async,
                              etw_events_change_async));
    uv_unref(reinterpret_cast<uv_handle_t*>(&dispatch_etw_events_change_async));

    if (event_register) {
      DWORD status = event_register(&NODE_ETW_PROVIDER,
                                    etw_events_enable_callback,
                                    nullptr,
                                    &node_provider);
      CHECK_EQ(status, ERROR_SUCCESS);
    }
  }
}


void shutdown_etw() {
  if (advapi && event_unregister && node_provider) {
    event_unregister(node_provider);
    node_provider = 0;
  }

  events_enabled = 0;
  v8::Isolate::GetCurrent()->SetJitCodeEventHandler(
      v8::kJitCodeEventDefault,
      nullptr);

  if (advapi) {
    FreeLibrary(advapi);
    advapi = nullptr;
  }
}

}  // namespace node