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1# Copyright 2015 The Chromium Authors. All rights reserved.
2# Use of this source code is governed by a BSD-style license that can be
3# found in the LICENSE file.
4
5import("//build/config/coverage/coverage.gni")
6import("//build/toolchain/toolchain.gni")
7
8if (!build_xts && defined(ext_sanitizer_check_list_path)) {
9  import("${ext_sanitizer_check_list_path}")
10}
11
12declare_args() {
13  # Compile for Address Sanitizer to find memory bugs.
14  is_asan = false
15
16  # Compile for Hardware-Assisted Address Sanitizer to find memory bugs.
17  use_hwasan = false
18
19  # Customize asan detection.
20  asan_detector = false
21
22  # Compile for Leak Sanitizer to find leaks.
23  is_lsan = false
24
25  # Compile for Memory Sanitizer to find uninitialized reads.
26  is_msan = false
27
28  # Compile for Thread Sanitizer to find threading bugs.
29  is_tsan = false
30
31  # Compile for Undefined Behavior Sanitizer to find various types of
32  # undefined behavior (excludes vptr checks).
33  is_ubsan = false
34
35  # Halt the program if a problem is detected.
36  is_ubsan_no_recover = false
37
38  # Compile for Undefined Behavior Sanitizer's null pointer checks.
39  is_ubsan_null = false
40
41  # Compile for Undefined Behavior Sanitizer's vptr checks.
42  is_ubsan_vptr = false
43
44  # Compile with SafeStack shadow stack support.
45  is_safestack = false
46
47  # Track where uninitialized memory originates from. From fastest to slowest:
48  # 0 - no tracking, 1 - track only the initial allocation site, 2 - track the
49  # chain of stores leading from allocation site to use site.
50  msan_track_origins = 2
51
52  # Use dynamic libraries instrumented by one of the sanitizers instead of the
53  # standard system libraries. Set this flag to download prebuilt binaries from
54  # GCS.
55  use_prebuilt_instrumented_libraries = false
56
57  # Use dynamic libraries instrumented by one of the sanitizers instead of the
58  # standard system libraries. Set this flag to build the libraries from source.
59  use_locally_built_instrumented_libraries = false
60
61  # Compile with Control Flow Integrity to protect virtual calls and casts.
62  # See http://clang.llvm.org/docs/ControlFlowIntegrity.html
63  is_cfi = target_os == "linux" && !is_chromeos && target_cpu == "x64" &&
64           is_official_build
65
66  # Enable checks for bad casts: derived cast and unrelated cast.
67  use_cfi_cast = false
68
69  # Enable checks for indirect function calls via a function pointer.
70  use_cfi_icall = target_os == "linux" && !is_chromeos && target_cpu == "x64" &&
71                  is_official_build
72
73  # Print detailed diagnostics when Control Flow Integrity detects a violation.
74  use_cfi_diag = false
75
76  # Let Control Flow Integrity continue execution instead of crashing when
77  # printing diagnostics (use_cfi_diag = true).
78  use_cfi_recover = false
79
80  # Compile for fuzzing with LLVM LibFuzzer.
81  # See http://www.chromium.org/developers/testing/libfuzzer
82  use_libfuzzer = false
83
84  # Compile for fuzzing with AFL.
85  use_afl = false
86
87  # Enables core ubsan security features. Will later be removed once it matches
88  # is_ubsan.
89  is_ubsan_security = false
90
91  # Compile for fuzzing with Dr. Fuzz
92  # See http://www.chromium.org/developers/testing/dr-fuzz
93  use_drfuzz = false
94
95  # Helper variable for testing builds with disabled libfuzzer.
96  # Not for client use.
97  disable_libfuzzer = false
98
99  # Optimize for coverage guided fuzzing (balance between speed and number of
100  # branches). Can be also used to remove non-determinism and other issues.
101  optimize_for_fuzzing = false
102
103  # Value for -fsanitize-coverage flag. Setting this causes
104  # use_sanitizer_coverage to be enabled.
105  # This flag is not used for libFuzzer (use_libfuzzer=true) unless we are on
106  # Mac. Instead, we use:
107  #     -fsanitize=fuzzer-no-link
108  # Default value when unset and use_fuzzing_engine=true:
109  #     trace-pc-guard
110  # Default value when unset and use_sanitizer_coverage=true:
111  #     trace-pc-guard,indirect-calls
112  sanitizer_coverage_flags = ""
113
114  # The global switch of cfi. Disable it to improve compiling efficiency while
115  # being vulnerable to cfi attack.
116  use_cfi = true
117}
118
119is_v8_host_toolchain =
120    current_toolchain == "//build/toolchain/linux:clang_x64_v8_arm64" ||
121    current_toolchain == "//build/toolchain/linux:clang_x86_v8_arm"
122
123# Disable sanitizers for non-default toolchains.
124if (current_toolchain == host_toolchain || is_v8_host_toolchain) {
125  is_asan = false
126  is_cfi = false
127  is_lsan = false
128  is_msan = false
129  is_tsan = false
130  is_ubsan = false
131  is_ubsan_null = false
132  is_ubsan_no_recover = false
133  is_ubsan_security = false
134  is_ubsan_vptr = false
135  msan_track_origins = 0
136  sanitizer_coverage_flags = ""
137  use_afl = false
138  use_cfi_diag = false
139  use_cfi_recover = false
140  use_drfuzz = false
141  use_libfuzzer = false
142  use_prebuilt_instrumented_libraries = false
143  use_locally_built_instrumented_libraries = false
144  use_sanitizer_coverage = false
145}
146
147# Whether we are doing a fuzzer build. Normally this should be checked instead
148# of checking "use_libfuzzer || use_afl" because often developers forget to
149# check for "use_afl".
150use_fuzzing_engine = use_libfuzzer || use_afl
151
152# Args that are in turn dependent on other args must be in a separate
153# declare_args block. User overrides are only applied at the end of a
154# declare_args block.
155declare_args() {
156  use_sanitizer_coverage =
157      !use_clang_coverage &&
158      (use_fuzzing_engine || sanitizer_coverage_flags != "")
159
160  # Detect overflow/underflow for global objects.
161  #
162  # Mac: http://crbug.com/352073
163  asan_globals = !is_mac
164}
165
166if (use_fuzzing_engine && sanitizer_coverage_flags == "") {
167  sanitizer_coverage_flags = "trace-pc-guard"
168} else if (use_sanitizer_coverage && sanitizer_coverage_flags == "") {
169  sanitizer_coverage_flags = "trace-pc-guard,indirect-calls"
170}
171
172# Whether we are linking against a debugging sanitizer runtime library. Among
173# other things, this changes the default symbol level and other settings in
174# order to prepare to create stack traces "live" using the sanitizer runtime.
175using_sanitizer =
176    is_asan || is_lsan || is_tsan || is_msan || is_ubsan || is_ubsan_null ||
177    is_ubsan_vptr || is_ubsan_security || use_sanitizer_coverage || use_cfi_diag
178
179if (!is_ohos) {
180  using_sanitizer = false
181}
182
183assert(!using_sanitizer || is_clang,
184       "Sanitizers (is_*san) require setting is_clang = true in 'gn args'")
185
186assert(!is_cfi || is_clang,
187       "is_cfi requires setting is_clang = true in 'gn args'")
188
189assert(!is_safestack || is_clang,
190       "is_safestack requires setting is_clang = true in 'gn args'")
191
192prebuilt_instrumented_libraries_available =
193    is_msan && (msan_track_origins == 0 || msan_track_origins == 2)
194
195if (use_libfuzzer && is_linux) {
196  if (is_asan) {
197    # We do leak checking with libFuzzer on Linux. Set is_lsan for code that
198    # relies on LEAK_SANITIZER define to avoid false positives.
199    is_lsan = true
200  }
201  if (is_msan) {
202    use_prebuilt_instrumented_libraries = true
203  }
204}
205
206# MSan only links Chrome properly in release builds (brettw -- 9/1/2015). The
207# same is possibly true for the other non-ASan sanitizers. But regardless of
208# whether it links, one would normally never run a sanitizer in debug mode.
209# Running in debug mode probably indicates you forgot to set the "is_debug =
210# false" flag in the build args. ASan seems to run fine in debug mode.
211#
212# If you find a use-case where you want to compile a sanitizer in debug mode
213# and have verified it works, ask brettw and we can consider removing it from
214# this condition. We may also be able to find another way to enable your case
215# without having people accidentally get broken builds by compiling an
216# unsupported or unadvisable configurations.
217#
218# For one-off testing, just comment this assertion out.
219assert(!is_debug || !(is_msan || is_ubsan || is_ubsan_null || is_ubsan_vptr),
220       "Sanitizers should generally be used in release (set is_debug=false).")
221
222assert(!is_msan || (is_linux && current_cpu == "x64"),
223       "MSan currently only works on 64-bit Linux and ChromeOS builds.")
224
225assert(!is_lsan || is_asan, "is_lsan = true requires is_asan = true also.")
226
227# ASAN build on Windows is not working in debug mode. Intercepting memory
228# allocation functions is hard on Windows and not yet implemented in LLVM.
229assert(!is_win || !is_debug || !is_asan,
230       "ASan on Windows doesn't work in debug (set is_debug=false).")
231
232# Make sure that if we recover on detection (i.e. not crash), diagnostics are
233# printed.
234assert(!use_cfi_recover || use_cfi_diag,
235       "Only use CFI recovery together with diagnostics.")
236
237assert(
238    !(use_sanitizer_coverage && is_mac && target_os == "ios"),
239    "crbug.com/753445: use_sanitizer_coverage=true is not supported by the " +
240        "Chromium mac_clang_x64 toolchain on iOS distribution. Please set " +
241        "the argument value to false.")
242
243# Use these lists of configs to disable instrumenting code that is part of a
244# fuzzer, but which isn't being targeted (such as libprotobuf-mutator, *.pb.cc
245# and libprotobuf when they are built as part of a proto fuzzer). Adding or
246# removing these lists does not have any effect if use_libfuzzer or use_afl are
247# not passed as arguments to gn.
248not_fuzzed_remove_configs = []
249not_fuzzed_remove_nonasan_configs = []
250
251if (use_fuzzing_engine) {
252  # Removing coverage should always just work.
253  not_fuzzed_remove_configs += [ "//build/config/coverage:default_coverage" ]
254  not_fuzzed_remove_nonasan_configs +=
255      [ "//build/config/coverage:default_coverage" ]
256
257  if (!is_msan) {
258    # Allow sanitizer instrumentation to be removed if we are not using MSan
259    # since binaries cannot be partially instrumented with MSan.
260    not_fuzzed_remove_configs +=
261        [ "//build/config/sanitizers:default_sanitizer_flags" ]
262
263    # Certain parts of binaries must be instrumented with ASan if the rest of
264    # the binary is. For these, only remove non-ASan sanitizer instrumentation.
265    if (!is_asan) {
266      not_fuzzed_remove_nonasan_configs +=
267          [ "//build/config/sanitizers:default_sanitizer_flags" ]
268      assert(not_fuzzed_remove_nonasan_configs == not_fuzzed_remove_configs)
269    }
270  }
271}
272
273template("ohos_sanitizer_config") {
274  config(target_name) {
275    forward_variables_from(invoker, [ "sanitize" ])
276    if (defined(sanitize)) {
277      configs = [ "//build/config/sanitizers:sanitizer_trap_all_flags" ]
278      _mode = "release"
279      _debug = (defined(sanitize.debug) && sanitize.debug) || is_asan
280      if (_debug) {
281        _mode = "debug"
282      }
283      _cfi = use_cfi && defined(sanitize.cfi) && sanitize.cfi && !is_asan
284      if (_cfi) {
285        if (defined(sanitize.cfi_cross_dso) && sanitize.cfi_cross_dso) {
286          configs += [ "//build/config/sanitizers:cfi_cross_dso_" + _mode ]
287        } else {
288          configs += [ "//build/config/sanitizers:cfi_config_" + _mode ]
289        }
290      }
291      _scudo = defined(sanitize.scudo) && sanitize.scudo && !is_asan && !is_tsan
292      if (_scudo) {
293        configs += [ "//build/config/sanitizers:scudo_config" ]
294      }
295      _ubsan = defined(sanitize.ubsan) && sanitize.ubsan && !is_asan
296      if (_ubsan) {
297        configs +=
298            [ "//build/config/sanitizers:undefined_behavior_sanitize_config_" +
299              _mode ]
300      }
301      _all_ubsan = defined(sanitize.all_ubsan) && sanitize.all_ubsan && !is_asan
302      if (_all_ubsan) {
303        configs += [
304          "//build/config/sanitizers:all_undefined_behavior_sanitize_config_" +
305              _mode,
306        ]
307      }
308      _scs = defined(sanitize.scs) && sanitize.scs
309      if (_scs) {
310        configs += [ "//build/config/sanitizers:shadow_call_stack_config" ]
311      }
312      _boundary_sanitize = defined(sanitize.boundary_sanitize) &&
313                           sanitize.boundary_sanitize && !is_asan
314      if (_boundary_sanitize) {
315        configs +=
316            [ "//build/config/sanitizers:boundary_sanitize_config_" + _mode ]
317      }
318
319      _integer_overflow = defined(sanitize.integer_overflow) &&
320                          sanitize.integer_overflow && !is_asan
321      _unsigned_integer_overflow =
322          defined(sanitize.unsigned_integer_overflow) &&
323          sanitize.unsigned_integer_overflow && !is_asan
324      _signed_integer_overflow = defined(sanitize.signed_integer_overflow) &&
325                                 sanitize.signed_integer_overflow && !is_asan
326      if (_unsigned_integer_overflow || _integer_overflow) {
327        configs +=
328            [ "//build/config/sanitizers:unsigned_integer_overflow_config" ]
329      }
330      if (_signed_integer_overflow || _integer_overflow) {
331        configs +=
332            [ "//build/config/sanitizers:signed_integer_overflow_config" ]
333      }
334      if (_integer_overflow || _unsigned_integer_overflow ||
335          _signed_integer_overflow) {
336        configs +=
337            [ "//build/config/sanitizers:common_integer_overflow_config_" +
338              _mode ]
339      }
340
341      if (defined(sanitize.blocklist)) {
342        cflags = [ "-fsanitize-blacklist=" +
343                   rebase_path(get_path_info(sanitize.blocklist, "abspath"),
344                               root_build_dir) ]
345      }
346      configs += [ "//build/config/sanitizers:compiler_rt_" + _mode ]
347    }
348  }
349}
350
351template("ohos_sanitizer_check") {
352  config(target_name) {
353    forward_variables_from(invoker,
354                           [
355                             "sanitize",
356                             "build_name",
357                             "part_name",
358                           ])
359    need_check_cfi = false
360    need_check_intsan = false
361    bypass_cfi_target_list = []
362    foreach(component_name, enable_cfi_part_and_bypass_list) {
363      if (part_name == component_name[0]) {
364        need_check_cfi = true
365        bypass_cfi_target_list = component_name[1]
366      }
367    }
368    foreach(component_name, enable_intsan_part_list) {
369      if (part_name == component_name) {
370        need_check_intsan = true
371      }
372    }
373    foreach(cfi_target, bypass_cfi_target_list) {
374      if (build_name == cfi_target) {
375        need_check_cfi = false
376      }
377    }
378    foreach(intsan_target, bypass_intsan_target_list) {
379      if (build_name == intsan_target) {
380        need_check_intsan = false
381      }
382    }
383
384    if (need_check_cfi) {
385      assert(
386          defined(sanitize) && defined(sanitize.cfi) && sanitize.cfi == true &&
387              defined(sanitize.cfi_cross_dso) &&
388              sanitize.cfi_cross_dso == true &&
389              ((defined(sanitize.debug) && sanitize.debug == false) ||
390                   !defined(sanitize.debug)) && !defined(sanitize.blocklist),
391          "Build targets in ${part_name} should fully enable cfi(cfi, cfi_cross_dso, !debug). For local debug, try to build with '--gn-args allow_sanitize_debug=true' to bypass sanitize check. If this target ${build_name} cannot enable cfi, add the target to ${ext_sanitizer_check_list_path} in bypass_cfi_target_list.")
392    }
393    if (need_check_intsan) {
394      assert(
395          defined(sanitize) && defined(sanitize.integer_overflow) &&
396              sanitize.integer_overflow,
397          "Build targets in ${part_name} should enable intsan. For local debug, try to build with '--gn-args allow_sanitize_debug=true' to bypass sanitize check. If this target ${build_name} cannot enable intsan, add the target to ${ext_sanitizer_check_list_path} in bypass_intsan_target_list.")
398    }
399    not_needed([
400                 "sanitize",
401                 "build_name",
402                 "part_name",
403               ])
404  }
405}
406