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| 1 // Copyright 2014 The Crashpad Authors. All rights reserved. | |
| 2 // | |
| 3 // Licensed under the Apache License, Version 2.0 (the "License"); | |
| 4 // you may not use this file except in compliance with the License. | |
| 5 // You may obtain a copy of the License at | |
| 6 // | |
| 7 // http://www.apache.org/licenses/LICENSE-2.0 | |
| 8 // | |
| 9 // Unless required by applicable law or agreed to in writing, software | |
| 10 // distributed under the License is distributed on an "AS IS" BASIS, | |
| 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| 12 // See the License for the specific language governing permissions and | |
| 13 // limitations under the License. | |
| 14 | |
| 15 #include "util/mac/mach_o_image_reader.h" | |
| 16 | |
| 17 #include <AvailabilityMacros.h> | |
| 18 #include <dlfcn.h> | |
| 19 #include <mach-o/dyld.h> | |
| 20 #include <mach-o/dyld_images.h> | |
| 21 #include <mach-o/getsect.h> | |
| 22 #include <mach-o/ldsyms.h> | |
| 23 #include <mach-o/loader.h> | |
| 24 #include <mach-o/nlist.h> | |
| 25 #include <stdint.h> | |
| 26 | |
| 27 #include "base/strings/stringprintf.h" | |
| 28 #include "build/build_config.h" | |
| 29 #include "gtest/gtest.h" | |
| 30 #include "util/mac/mach_o_image_segment_reader.h" | |
| 31 #include "util/mac/process_reader.h" | |
| 32 #include "util/mac/process_types.h" | |
| 33 #include "util/misc/uuid.h" | |
| 34 #include "util/test/mac/dyld.h" | |
| 35 | |
| 36 // This file is responsible for testing MachOImageReader, | |
| 37 // MachOImageSegmentReader, and MachOImageSymbolTableReader. | |
| 38 | |
| 39 namespace crashpad { | |
| 40 namespace test { | |
| 41 namespace { | |
| 42 | |
| 43 // Native types and constants, in cases where the 32-bit and 64-bit versions | |
| 44 // are different. | |
| 45 #if defined(ARCH_CPU_64_BITS) | |
| 46 typedef mach_header_64 MachHeader; | |
| 47 const uint32_t kMachMagic = MH_MAGIC_64; | |
| 48 typedef segment_command_64 SegmentCommand; | |
| 49 const uint32_t kSegmentCommand = LC_SEGMENT_64; | |
| 50 typedef section_64 Section; | |
| 51 typedef nlist_64 Nlist; | |
| 52 #else | |
| 53 typedef mach_header MachHeader; | |
| 54 const uint32_t kMachMagic = MH_MAGIC; | |
| 55 typedef segment_command SegmentCommand; | |
| 56 const uint32_t kSegmentCommand = LC_SEGMENT; | |
| 57 typedef section Section; | |
| 58 | |
| 59 // This needs to be called “struct nlist” because “nlist” without the struct | |
| 60 // refers to the nlist() function. | |
| 61 typedef struct nlist Nlist; | |
| 62 #endif | |
| 63 | |
| 64 #if defined(ARCH_CPU_X86_64) | |
| 65 const int kCPUType = CPU_TYPE_X86_64; | |
| 66 #elif defined(ARCH_CPU_X86) | |
| 67 const int kCPUType = CPU_TYPE_X86; | |
| 68 #endif | |
| 69 | |
| 70 // Verifies that |expect_section| and |actual_section| agree. | |
| 71 void ExpectSection(const Section* expect_section, | |
| 72 const process_types::section* actual_section) { | |
| 73 ASSERT_TRUE(expect_section); | |
| 74 ASSERT_TRUE(actual_section); | |
| 75 | |
| 76 EXPECT_EQ( | |
| 77 MachOImageSegmentReader::SectionNameString(expect_section->sectname), | |
| 78 MachOImageSegmentReader::SectionNameString(actual_section->sectname)); | |
| 79 EXPECT_EQ( | |
| 80 MachOImageSegmentReader::SegmentNameString(expect_section->segname), | |
| 81 MachOImageSegmentReader::SegmentNameString(actual_section->segname)); | |
| 82 EXPECT_EQ(expect_section->addr, actual_section->addr); | |
| 83 EXPECT_EQ(expect_section->size, actual_section->size); | |
| 84 EXPECT_EQ(expect_section->offset, actual_section->offset); | |
| 85 EXPECT_EQ(expect_section->align, actual_section->align); | |
| 86 EXPECT_EQ(expect_section->reloff, actual_section->reloff); | |
| 87 EXPECT_EQ(expect_section->nreloc, actual_section->nreloc); | |
| 88 EXPECT_EQ(expect_section->flags, actual_section->flags); | |
| 89 EXPECT_EQ(expect_section->reserved1, actual_section->reserved1); | |
| 90 EXPECT_EQ(expect_section->reserved2, actual_section->reserved2); | |
| 91 } | |
| 92 | |
| 93 // Verifies that |expect_segment| is a valid Mach-O segment load command for the | |
| 94 // current system by checking its |cmd| field. Then, verifies that the | |
| 95 // information in |actual_segment| matches that in |expect_segment|. The | |
| 96 // |segname|, |vmaddr|, |vmsize|, and |fileoff| fields are examined. Each | |
| 97 // section within the segment is also examined by calling ExpectSection(). | |
| 98 // Access to each section via both MachOImageSegmentReader::GetSectionByName() | |
| 99 // and MachOImageReader::GetSectionByName() is verified, expecting that each | |
| 100 // call produces the same section. Segment and section data addresses are | |
| 101 // verified against data obtained by calling getsegmentdata() and | |
| 102 // getsectiondata(). The segment is checked to make sure that it behaves | |
| 103 // correctly when attempting to look up a nonexistent section by name. | |
| 104 // |section_index| is used to track the last-used section index in an image on | |
| 105 // entry, and is reset to the last-used section index on return after the | |
| 106 // sections are processed. This is used to test that | |
| 107 // MachOImageReader::GetSectionAtIndex() returns the correct result. | |
| 108 void ExpectSegmentCommand(const SegmentCommand* expect_segment, | |
| 109 const MachHeader* expect_image, | |
| 110 const MachOImageSegmentReader* actual_segment, | |
| 111 const MachOImageReader* actual_image, | |
| 112 size_t* section_index) { | |
| 113 ASSERT_TRUE(expect_segment); | |
| 114 ASSERT_TRUE(actual_segment); | |
| 115 | |
| 116 EXPECT_EQ(kSegmentCommand, expect_segment->cmd); | |
| 117 | |
| 118 std::string segment_name = actual_segment->Name(); | |
| 119 EXPECT_EQ(MachOImageSegmentReader::SegmentNameString(expect_segment->segname), | |
| 120 segment_name); | |
| 121 EXPECT_EQ(expect_segment->vmaddr, actual_segment->vmaddr()); | |
| 122 EXPECT_EQ(expect_segment->vmsize, actual_segment->vmsize()); | |
| 123 EXPECT_EQ(expect_segment->fileoff, actual_segment->fileoff()); | |
| 124 | |
| 125 if (actual_segment->SegmentSlides()) { | |
| 126 EXPECT_EQ(actual_segment->Address(), | |
| 127 actual_segment->vmaddr() + actual_image->Slide()); | |
| 128 | |
| 129 unsigned long expect_segment_size; | |
| 130 const uint8_t* expect_segment_data = getsegmentdata( | |
| 131 expect_image, segment_name.c_str(), &expect_segment_size); | |
| 132 mach_vm_address_t expect_segment_address = | |
| 133 reinterpret_cast<mach_vm_address_t>(expect_segment_data); | |
| 134 EXPECT_EQ(expect_segment_address, actual_segment->Address()); | |
| 135 EXPECT_EQ(expect_segment_size, actual_segment->vmsize()); | |
| 136 EXPECT_EQ(actual_segment->vmsize(), actual_segment->Size()); | |
| 137 } else { | |
| 138 // getsegmentdata() doesn’t return appropriate data for the __PAGEZERO | |
| 139 // segment because getsegmentdata() always adjusts for slide, but the | |
| 140 // __PAGEZERO segment never slides, it just grows. Skip the getsegmentdata() | |
| 141 // check for that segment according to the same rules that the kernel uses | |
| 142 // to identify __PAGEZERO. See 10.9.4 xnu-2422.110.17/bsd/kern/mach_loader.c | |
| 143 // load_segment(). | |
| 144 EXPECT_EQ(actual_segment->Address(), actual_segment->vmaddr()); | |
| 145 EXPECT_EQ(actual_segment->vmsize() + actual_image->Slide(), | |
| 146 actual_segment->Size()); | |
| 147 } | |
| 148 | |
| 149 ASSERT_EQ(expect_segment->nsects, actual_segment->nsects()); | |
| 150 | |
| 151 // Make sure that the expected load command is big enough for the number of | |
| 152 // sections that it claims to have, and set up a pointer to its first section | |
| 153 // structure. | |
| 154 ASSERT_EQ(sizeof(*expect_segment) + expect_segment->nsects * sizeof(Section), | |
| 155 expect_segment->cmdsize); | |
| 156 const Section* expect_sections = | |
| 157 reinterpret_cast<const Section*>(&expect_segment[1]); | |
| 158 | |
| 159 for (size_t index = 0; index < actual_segment->nsects(); ++index) { | |
| 160 const Section* expect_section = &expect_sections[index]; | |
| 161 const process_types::section* actual_section = | |
| 162 actual_segment->GetSectionAtIndex(index, nullptr); | |
| 163 ASSERT_NO_FATAL_FAILURE( | |
| 164 ExpectSection(&expect_sections[index], actual_section)); | |
| 165 | |
| 166 // Make sure that the section is accessible by GetSectionByName as well. | |
| 167 std::string section_name = | |
| 168 MachOImageSegmentReader::SectionNameString(expect_section->sectname); | |
| 169 const process_types::section* actual_section_by_name = | |
| 170 actual_segment->GetSectionByName(section_name, nullptr); | |
| 171 EXPECT_EQ(actual_section, actual_section_by_name); | |
| 172 | |
| 173 // Make sure that the section is accessible by the parent MachOImageReader’s | |
| 174 // GetSectionByName. | |
| 175 mach_vm_address_t actual_section_address; | |
| 176 const process_types::section* actual_section_from_image_by_name = | |
| 177 actual_image->GetSectionByName( | |
| 178 segment_name, section_name, &actual_section_address); | |
| 179 EXPECT_EQ(actual_section, actual_section_from_image_by_name); | |
| 180 | |
| 181 if (actual_segment->SegmentSlides()) { | |
| 182 EXPECT_EQ(actual_section_address, | |
| 183 actual_section->addr + actual_image->Slide()); | |
| 184 | |
| 185 unsigned long expect_section_size; | |
| 186 const uint8_t* expect_section_data = getsectiondata(expect_image, | |
| 187 segment_name.c_str(), | |
| 188 section_name.c_str(), | |
| 189 &expect_section_size); | |
| 190 mach_vm_address_t expect_section_address = | |
| 191 reinterpret_cast<mach_vm_address_t>(expect_section_data); | |
| 192 EXPECT_EQ(expect_section_address, actual_section_address); | |
| 193 EXPECT_EQ(expect_section_size, actual_section->size); | |
| 194 } else { | |
| 195 EXPECT_EQ(actual_section_address, actual_section->addr); | |
| 196 } | |
| 197 | |
| 198 // Test the parent MachOImageReader’s GetSectionAtIndex as well. | |
| 199 const MachOImageSegmentReader* containing_segment; | |
| 200 mach_vm_address_t actual_section_address_at_index; | |
| 201 const process_types::section* actual_section_from_image_at_index = | |
| 202 actual_image->GetSectionAtIndex(++(*section_index), | |
| 203 &containing_segment, | |
| 204 &actual_section_address_at_index); | |
| 205 EXPECT_EQ(actual_section, actual_section_from_image_at_index); | |
| 206 EXPECT_EQ(actual_segment, containing_segment); | |
| 207 EXPECT_EQ(actual_section_address, actual_section_address_at_index); | |
| 208 } | |
| 209 | |
| 210 EXPECT_EQ(nullptr, | |
| 211 actual_segment->GetSectionByName("NoSuchSection", nullptr)); | |
| 212 } | |
| 213 | |
| 214 // Walks through the load commands of |expect_image|, finding all of the | |
| 215 // expected segment commands. For each expected segment command, calls | |
| 216 // actual_image->GetSegmentByName() to obtain an actual segment command, and | |
| 217 // calls ExpectSegmentCommand() to compare the expected and actual segments. A | |
| 218 // series of by-name lookups is also performed on the segment to ensure that it | |
| 219 // behaves correctly when attempting to look up segment and section names that | |
| 220 // are not present. |test_section_indices| should be true to test | |
| 221 // MachOImageReader::GetSectionAtIndex() using out-of-range section indices. | |
| 222 // This should be tested for at least one module, but it’s very noisy in terms | |
| 223 // of logging output, so this knob is provided to suppress this portion of the | |
| 224 // test when looping over all modules. | |
| 225 void ExpectSegmentCommands(const MachHeader* expect_image, | |
| 226 const MachOImageReader* actual_image, | |
| 227 bool test_section_index_bounds) { | |
| 228 ASSERT_TRUE(expect_image); | |
| 229 ASSERT_TRUE(actual_image); | |
| 230 | |
| 231 // &expect_image[1] points right past the end of the mach_header[_64], to the | |
| 232 // start of the load commands. | |
| 233 const char* commands_base = reinterpret_cast<const char*>(&expect_image[1]); | |
| 234 uint32_t position = 0; | |
| 235 size_t section_index = 0; | |
| 236 for (uint32_t index = 0; index < expect_image->ncmds; ++index) { | |
| 237 ASSERT_LT(position, expect_image->sizeofcmds); | |
| 238 const load_command* command = | |
| 239 reinterpret_cast<const load_command*>(&commands_base[position]); | |
| 240 ASSERT_LE(position + command->cmdsize, expect_image->sizeofcmds); | |
| 241 if (command->cmd == kSegmentCommand) { | |
| 242 ASSERT_GE(command->cmdsize, sizeof(SegmentCommand)); | |
| 243 const SegmentCommand* expect_segment = | |
| 244 reinterpret_cast<const SegmentCommand*>(command); | |
| 245 std::string segment_name = | |
| 246 MachOImageSegmentReader::SegmentNameString(expect_segment->segname); | |
| 247 const MachOImageSegmentReader* actual_segment = | |
| 248 actual_image->GetSegmentByName(segment_name); | |
| 249 ASSERT_NO_FATAL_FAILURE(ExpectSegmentCommand(expect_segment, | |
| 250 expect_image, | |
| 251 actual_segment, | |
| 252 actual_image, | |
| 253 §ion_index)); | |
| 254 } | |
| 255 position += command->cmdsize; | |
| 256 } | |
| 257 EXPECT_EQ(expect_image->sizeofcmds, position); | |
| 258 | |
| 259 if (test_section_index_bounds) { | |
| 260 // GetSectionAtIndex uses a 1-based index. Make sure that the range is | |
| 261 // correct. | |
| 262 EXPECT_EQ(nullptr, actual_image->GetSectionAtIndex(0, nullptr, nullptr)); | |
| 263 EXPECT_EQ( | |
| 264 nullptr, | |
| 265 actual_image->GetSectionAtIndex(section_index + 1, nullptr, nullptr)); | |
| 266 } | |
| 267 | |
| 268 // Make sure that by-name lookups for names that don’t exist work properly: | |
| 269 // they should return nullptr. | |
| 270 EXPECT_FALSE(actual_image->GetSegmentByName("NoSuchSegment")); | |
| 271 EXPECT_FALSE(actual_image->GetSectionByName( | |
| 272 "NoSuchSegment", "NoSuchSection", nullptr)); | |
| 273 | |
| 274 // Make sure that there’s a __TEXT segment so that this can do a valid test of | |
| 275 // a section that doesn’t exist within a segment that does. | |
| 276 EXPECT_TRUE(actual_image->GetSegmentByName(SEG_TEXT)); | |
| 277 EXPECT_FALSE( | |
| 278 actual_image->GetSectionByName(SEG_TEXT, "NoSuchSection", nullptr)); | |
| 279 | |
| 280 // Similarly, make sure that a section name that exists in one segment isn’t | |
| 281 // accidentally found during a lookup for that section in a different segment. | |
| 282 // | |
| 283 // If the image has no sections (unexpected), then any section lookup should | |
| 284 // fail, and these initial values of test_segment and test_section are fine | |
| 285 // for the EXPECT_FALSE checks on GetSectionByName() below. | |
| 286 std::string test_segment = SEG_DATA; | |
| 287 std::string test_section = SECT_TEXT; | |
| 288 | |
| 289 const process_types::section* section = | |
| 290 actual_image->GetSectionAtIndex(1, nullptr, nullptr); | |
| 291 if (section) { | |
| 292 // Use the name of the first section in the image as the section that | |
| 293 // shouldn’t appear in a different segment. If the first section is in the | |
| 294 // __TEXT segment (as it is normally), then a section by the same name | |
| 295 // wouldn’t be expected in the __DATA segment. But if the first section is | |
| 296 // in any other segment, then it wouldn’t be expected in the __TEXT segment. | |
| 297 if (MachOImageSegmentReader::SegmentNameString(section->segname) == | |
| 298 SEG_TEXT) { | |
| 299 test_segment = SEG_DATA; | |
| 300 } else { | |
| 301 test_segment = SEG_TEXT; | |
| 302 } | |
| 303 test_section = | |
| 304 MachOImageSegmentReader::SectionNameString(section->sectname); | |
| 305 | |
| 306 // It should be possible to look up the first section by name. | |
| 307 EXPECT_EQ(section, | |
| 308 actual_image->GetSectionByName( | |
| 309 section->segname, section->sectname, nullptr)); | |
| 310 } | |
| 311 EXPECT_FALSE( | |
| 312 actual_image->GetSectionByName("NoSuchSegment", test_section, nullptr)); | |
| 313 EXPECT_FALSE( | |
| 314 actual_image->GetSectionByName(test_segment, test_section, nullptr)); | |
| 315 | |
| 316 // The __LINKEDIT segment normally does exist but doesn’t have any sections. | |
| 317 EXPECT_FALSE( | |
| 318 actual_image->GetSectionByName(SEG_LINKEDIT, "NoSuchSection", nullptr)); | |
| 319 EXPECT_FALSE( | |
| 320 actual_image->GetSectionByName(SEG_LINKEDIT, SECT_TEXT, nullptr)); | |
| 321 } | |
| 322 | |
| 323 // In some cases, the expected slide value for an image is unknown, because no | |
| 324 // reasonable API to return it is provided. When this happens, use kSlideUnknown | |
| 325 // to avoid checking the actual slide value against anything. | |
| 326 const mach_vm_size_t kSlideUnknown = std::numeric_limits<mach_vm_size_t>::max(); | |
| 327 | |
| 328 // Verifies that |expect_image| is a vaild Mach-O header for the current system | |
| 329 // by checking its |magic| and |cputype| fields. Then, verifies that the | |
| 330 // information in |actual_image| matches that in |expect_image|. The |filetype| | |
| 331 // field is examined, actual_image->Address() is compared to | |
| 332 // |expect_image_address|, and actual_image->Slide() is compared to | |
| 333 // |expect_image_slide|, unless |expect_image_slide| is kSlideUnknown. Various | |
| 334 // other attributes of |actual_image| are sanity-checked depending on the Mach-O | |
| 335 // file type. Finally, ExpectSegmentCommands() is called to verify all that all | |
| 336 // of the segments match; |test_section_index_bounds| is used as an argument to | |
| 337 // that function. | |
| 338 void ExpectMachImage(const MachHeader* expect_image, | |
| 339 mach_vm_address_t expect_image_address, | |
| 340 mach_vm_size_t expect_image_slide, | |
| 341 const MachOImageReader* actual_image, | |
| 342 bool test_section_index_bounds) { | |
| 343 ASSERT_TRUE(expect_image); | |
| 344 ASSERT_TRUE(actual_image); | |
| 345 | |
| 346 EXPECT_EQ(kMachMagic, expect_image->magic); | |
| 347 EXPECT_EQ(kCPUType, expect_image->cputype); | |
| 348 | |
| 349 EXPECT_EQ(expect_image->filetype, actual_image->FileType()); | |
| 350 EXPECT_EQ(expect_image_address, actual_image->Address()); | |
| 351 if (expect_image_slide != kSlideUnknown) { | |
| 352 EXPECT_EQ(expect_image_slide, actual_image->Slide()); | |
| 353 } | |
| 354 | |
| 355 const MachOImageSegmentReader* actual_text_segment = | |
| 356 actual_image->GetSegmentByName(SEG_TEXT); | |
| 357 ASSERT_TRUE(actual_text_segment); | |
| 358 EXPECT_EQ(expect_image_address, actual_text_segment->Address()); | |
| 359 EXPECT_EQ(actual_image->Size(), actual_text_segment->Size()); | |
| 360 EXPECT_EQ(expect_image_address - actual_text_segment->vmaddr(), | |
| 361 actual_image->Slide()); | |
| 362 | |
| 363 uint32_t file_type = actual_image->FileType(); | |
| 364 EXPECT_TRUE(file_type == MH_EXECUTE || file_type == MH_DYLIB || | |
| 365 file_type == MH_DYLINKER || file_type == MH_BUNDLE); | |
| 366 | |
| 367 if (file_type == MH_EXECUTE || file_type == MH_DYLINKER) { | |
| 368 EXPECT_EQ("/usr/lib/dyld", actual_image->DylinkerName()); | |
| 369 } | |
| 370 | |
| 371 // For these, just don’t crash or anything. | |
| 372 if (file_type == MH_DYLIB) { | |
| 373 actual_image->DylibVersion(); | |
| 374 } | |
| 375 actual_image->SourceVersion(); | |
| 376 UUID uuid; | |
| 377 actual_image->UUID(&uuid); | |
| 378 | |
| 379 ASSERT_NO_FATAL_FAILURE(ExpectSegmentCommands( | |
| 380 expect_image, actual_image, test_section_index_bounds)); | |
| 381 } | |
| 382 | |
| 383 // Verifies the symbol whose Nlist structure is |entry| and whose name is |name| | |
| 384 // matches the value of a symbol by the same name looked up in |actual_image|. | |
| 385 // MachOImageReader::LookUpExternalDefinedSymbol() is used for this purpose. | |
| 386 // Only external defined symbols are considered, other types of symbols are | |
| 387 // excluded because LookUpExternalDefinedSymbol() only deals with external | |
| 388 // defined symbols. | |
| 389 void ExpectSymbol(const Nlist* entry, | |
| 390 const char* name, | |
| 391 const MachOImageReader* actual_image) { | |
| 392 SCOPED_TRACE(name); | |
| 393 | |
| 394 uint32_t entry_type = entry->n_type & N_TYPE; | |
| 395 if ((entry->n_type & N_STAB) == 0 && (entry->n_type & N_PEXT) == 0 && | |
| 396 entry_type != N_UNDF && entry_type != N_PBUD && | |
| 397 (entry->n_type & N_EXT) == 1) { | |
| 398 // Note that this catches more symbols than MachOImageSymbolTableReader | |
| 399 // does. This test looks for all external defined symbols, but the | |
| 400 // implementation excludes indirect (N_INDR) symbols. This is intentional, | |
| 401 // because indirect symbols are currently not seen in the wild, but if they | |
| 402 // begin to be used more widely, this test is expected to catch them so that | |
| 403 // a decision can be made regarding whether support ought to be implemented. | |
| 404 mach_vm_address_t actual_address; | |
| 405 ASSERT_TRUE( | |
| 406 actual_image->LookUpExternalDefinedSymbol(name, &actual_address)); | |
| 407 | |
| 408 // Since the nlist interface was used to read the symbol, use it to compute | |
| 409 // the symbol address too. This isn’t perfect, and it should be possible in | |
| 410 // theory to use dlsym() to get the expected address of a symbol. In | |
| 411 // practice, dlsym() is difficult to use when only a MachHeader* is | |
| 412 // available as in this function, as opposed to a void* opaque handle. It is | |
| 413 // possible to get a void* handle by using dladdr() to find the file name | |
| 414 // corresponding to the MachHeader*, and using dlopen() again on that name, | |
| 415 // assuming it hasn’t changed on disk since being loaded. However, even with | |
| 416 // that being done, dlsym() can only deal with symbols whose names begin | |
| 417 // with an underscore (and requires that the leading underscore be trimmed). | |
| 418 // dlsym() will also return different addresses for symbols that are | |
| 419 // resolved via symbol resolver. | |
| 420 mach_vm_address_t expect_address = entry->n_value; | |
| 421 if (entry_type == N_SECT) { | |
| 422 EXPECT_GE(entry->n_sect, 1u); | |
| 423 expect_address += actual_image->Slide(); | |
| 424 } else { | |
| 425 EXPECT_EQ(NO_SECT, entry->n_sect); | |
| 426 } | |
| 427 | |
| 428 EXPECT_EQ(expect_address, actual_address); | |
| 429 } | |
| 430 | |
| 431 // You’d think that it might be a good idea to verify that if the conditions | |
| 432 // above weren’t met, that the symbol didn’t show up in actual_image’s symbol | |
| 433 // table at all. Unfortunately, it’s possible for the same name to show up as | |
| 434 // both an external defined symbol and as something else, so it’s not possible | |
| 435 // to verify this reliably. | |
| 436 } | |
| 437 | |
| 438 // Locates the symbol table in |expect_image| and verifies that all of the | |
| 439 // external defined symbols found there are also present and have the same | |
| 440 // values in |actual_image|. ExpectSymbol() is used to verify the actual symbol. | |
| 441 void ExpectSymbolTable(const MachHeader* expect_image, | |
| 442 const MachOImageReader* actual_image) { | |
| 443 // This intentionally consults only LC_SYMTAB and not LC_DYSYMTAB so that it | |
| 444 // can look at the larger set of all symbols. The actual implementation being | |
| 445 // tested is free to consult LC_DYSYMTAB, but that’s considered an | |
| 446 // optimization. It’s not necessary for the test, and it’s better for the test | |
| 447 // to expose bugs in that optimization rather than duplicate them. | |
| 448 const char* commands_base = reinterpret_cast<const char*>(&expect_image[1]); | |
| 449 uint32_t position = 0; | |
| 450 const symtab_command* symtab = nullptr; | |
| 451 const SegmentCommand* linkedit = nullptr; | |
| 452 for (uint32_t index = 0; index < expect_image->ncmds; ++index) { | |
| 453 ASSERT_LT(position, expect_image->sizeofcmds); | |
| 454 const load_command* command = | |
| 455 reinterpret_cast<const load_command*>(&commands_base[position]); | |
| 456 ASSERT_LE(position + command->cmdsize, expect_image->sizeofcmds); | |
| 457 if (command->cmd == LC_SYMTAB) { | |
| 458 ASSERT_FALSE(symtab); | |
| 459 ASSERT_EQ(sizeof(symtab_command), command->cmdsize); | |
| 460 symtab = reinterpret_cast<const symtab_command*>(command); | |
| 461 } else if (command->cmd == kSegmentCommand) { | |
| 462 ASSERT_GE(command->cmdsize, sizeof(SegmentCommand)); | |
| 463 const SegmentCommand* segment = | |
| 464 reinterpret_cast<const SegmentCommand*>(command); | |
| 465 std::string segment_name = | |
| 466 MachOImageSegmentReader::SegmentNameString(segment->segname); | |
| 467 if (segment_name == SEG_LINKEDIT) { | |
| 468 ASSERT_FALSE(linkedit); | |
| 469 linkedit = segment; | |
| 470 } | |
| 471 } | |
| 472 position += command->cmdsize; | |
| 473 } | |
| 474 | |
| 475 if (symtab) { | |
| 476 ASSERT_TRUE(linkedit); | |
| 477 | |
| 478 const char* linkedit_base = | |
| 479 reinterpret_cast<const char*>(linkedit->vmaddr + actual_image->Slide()); | |
| 480 const Nlist* nlist = reinterpret_cast<const Nlist*>( | |
| 481 linkedit_base + symtab->symoff - linkedit->fileoff); | |
| 482 const char* strtab = linkedit_base + symtab->stroff - linkedit->fileoff; | |
| 483 | |
| 484 for (uint32_t index = 0; index < symtab->nsyms; ++index) { | |
| 485 const Nlist* entry = nlist + index; | |
| 486 const char* name = strtab + entry->n_un.n_strx; | |
| 487 ASSERT_NO_FATAL_FAILURE(ExpectSymbol(entry, name, actual_image)); | |
| 488 } | |
| 489 } | |
| 490 | |
| 491 mach_vm_address_t ignore; | |
| 492 EXPECT_FALSE(actual_image->LookUpExternalDefinedSymbol("", &ignore)); | |
| 493 EXPECT_FALSE( | |
| 494 actual_image->LookUpExternalDefinedSymbol("NoSuchSymbolName", &ignore)); | |
| 495 EXPECT_FALSE( | |
| 496 actual_image->LookUpExternalDefinedSymbol("_NoSuchSymbolName", &ignore)); | |
| 497 } | |
| 498 | |
| 499 TEST(MachOImageReader, Self_MainExecutable) { | |
| 500 ProcessReader process_reader; | |
| 501 ASSERT_TRUE(process_reader.Initialize(mach_task_self())); | |
| 502 | |
| 503 const MachHeader* mh_execute_header = | |
| 504 reinterpret_cast<MachHeader*>(dlsym(RTLD_MAIN_ONLY, MH_EXECUTE_SYM)); | |
| 505 ASSERT_NE(nullptr, mh_execute_header); | |
| 506 mach_vm_address_t mh_execute_header_address = | |
| 507 reinterpret_cast<mach_vm_address_t>(mh_execute_header); | |
| 508 | |
| 509 MachOImageReader image_reader; | |
| 510 ASSERT_TRUE(image_reader.Initialize( | |
| 511 &process_reader, mh_execute_header_address, "executable")); | |
| 512 | |
| 513 EXPECT_EQ(static_cast<uint32_t>(MH_EXECUTE), image_reader.FileType()); | |
| 514 | |
| 515 // The main executable has image index 0. | |
| 516 intptr_t image_slide = _dyld_get_image_vmaddr_slide(0); | |
| 517 | |
| 518 ASSERT_NO_FATAL_FAILURE(ExpectMachImage(mh_execute_header, | |
| 519 mh_execute_header_address, | |
| 520 image_slide, | |
| 521 &image_reader, | |
| 522 true)); | |
| 523 | |
| 524 // This symbol, __mh_execute_header, is known to exist in all MH_EXECUTE | |
| 525 // Mach-O files. | |
| 526 mach_vm_address_t symbol_address; | |
| 527 ASSERT_TRUE(image_reader.LookUpExternalDefinedSymbol(_MH_EXECUTE_SYM, | |
| 528 &symbol_address)); | |
| 529 EXPECT_EQ(mh_execute_header_address, symbol_address); | |
| 530 | |
| 531 ASSERT_NO_FATAL_FAILURE(ExpectSymbolTable(mh_execute_header, &image_reader)); | |
| 532 } | |
| 533 | |
| 534 TEST(MachOImageReader, Self_DyldImages) { | |
| 535 ProcessReader process_reader; | |
| 536 ASSERT_TRUE(process_reader.Initialize(mach_task_self())); | |
| 537 | |
| 538 uint32_t count = _dyld_image_count(); | |
| 539 ASSERT_GE(count, 1u); | |
| 540 | |
| 541 for (uint32_t index = 0; index < count; ++index) { | |
| 542 const char* image_name = _dyld_get_image_name(index); | |
| 543 SCOPED_TRACE(base::StringPrintf("index %u, image %s", index, image_name)); | |
| 544 | |
| 545 // _dyld_get_image_header() is poorly-declared: it’s declared as returning | |
| 546 // const mach_header* in both 32-bit and 64-bit environments, but in the | |
| 547 // 64-bit environment, it should be const mach_header_64*. | |
| 548 const MachHeader* mach_header = | |
| 549 reinterpret_cast<const MachHeader*>(_dyld_get_image_header(index)); | |
| 550 mach_vm_address_t image_address = | |
| 551 reinterpret_cast<mach_vm_address_t>(mach_header); | |
| 552 | |
| 553 MachOImageReader image_reader; | |
| 554 ASSERT_TRUE( | |
| 555 image_reader.Initialize(&process_reader, image_address, image_name)); | |
| 556 | |
| 557 uint32_t file_type = image_reader.FileType(); | |
| 558 if (index == 0) { | |
| 559 EXPECT_EQ(static_cast<uint32_t>(MH_EXECUTE), file_type); | |
| 560 } else { | |
| 561 EXPECT_TRUE(file_type == MH_DYLIB || file_type == MH_BUNDLE); | |
| 562 } | |
| 563 | |
| 564 intptr_t image_slide = _dyld_get_image_vmaddr_slide(index); | |
| 565 ASSERT_NO_FATAL_FAILURE(ExpectMachImage( | |
| 566 mach_header, image_address, image_slide, &image_reader, false)); | |
| 567 | |
| 568 ASSERT_NO_FATAL_FAILURE(ExpectSymbolTable(mach_header, &image_reader)); | |
| 569 } | |
| 570 | |
| 571 // Now that all of the modules have been verified, make sure that dyld itself | |
| 572 // can be read properly too. | |
| 573 const struct dyld_all_image_infos* dyld_image_infos = | |
| 574 _dyld_get_all_image_infos(); | |
| 575 ASSERT_GE(dyld_image_infos->version, 1u); | |
| 576 EXPECT_EQ(count, dyld_image_infos->infoArrayCount); | |
| 577 | |
| 578 if (dyld_image_infos->version >= 2) { | |
| 579 SCOPED_TRACE("dyld"); | |
| 580 | |
| 581 // dyld_all_image_infos::dyldImageLoadAddress is poorly-declared too. | |
| 582 const MachHeader* mach_header = reinterpret_cast<const MachHeader*>( | |
| 583 dyld_image_infos->dyldImageLoadAddress); | |
| 584 mach_vm_address_t image_address = | |
| 585 reinterpret_cast<mach_vm_address_t>(mach_header); | |
| 586 | |
| 587 MachOImageReader image_reader; | |
| 588 ASSERT_TRUE( | |
| 589 image_reader.Initialize(&process_reader, image_address, "dyld")); | |
| 590 | |
| 591 EXPECT_EQ(static_cast<uint32_t>(MH_DYLINKER), image_reader.FileType()); | |
| 592 | |
| 593 // There’s no good API to get dyld’s slide, so don’t bother checking it. | |
| 594 ASSERT_NO_FATAL_FAILURE(ExpectMachImage( | |
| 595 mach_header, image_address, kSlideUnknown, &image_reader, false)); | |
| 596 | |
| 597 ASSERT_NO_FATAL_FAILURE(ExpectSymbolTable(mach_header, &image_reader)); | |
| 598 } | |
| 599 | |
| 600 #if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7 | |
| 601 // If dyld is new enough to record UUIDs, check the UUID of any module that | |
| 602 // it says has one. Note that dyld doesn’t record UUIDs of anything that | |
| 603 // loaded out of the shared cache, but it should at least have a UUID for the | |
| 604 // main executable if it has one. | |
| 605 if (dyld_image_infos->version >= 8 && dyld_image_infos->uuidArray) { | |
| 606 for (uint32_t index = 0; | |
| 607 index < dyld_image_infos->uuidArrayCount; | |
| 608 ++index) { | |
| 609 const dyld_uuid_info* dyld_image = &dyld_image_infos->uuidArray[index]; | |
| 610 SCOPED_TRACE(base::StringPrintf("uuid index %u", index)); | |
| 611 | |
| 612 // dyld_uuid_info::imageLoadAddress is poorly-declared too. | |
| 613 const MachHeader* mach_header = | |
| 614 reinterpret_cast<const MachHeader*>(dyld_image->imageLoadAddress); | |
| 615 mach_vm_address_t image_address = | |
| 616 reinterpret_cast<mach_vm_address_t>(mach_header); | |
| 617 | |
| 618 MachOImageReader image_reader; | |
| 619 ASSERT_TRUE( | |
| 620 image_reader.Initialize(&process_reader, image_address, "uuid")); | |
| 621 | |
| 622 // There’s no good way to get the image’s slide here, although the image | |
| 623 // should have already been checked along with its slide above, in the | |
| 624 // loop through all images. | |
| 625 ExpectMachImage( | |
| 626 mach_header, image_address, kSlideUnknown, &image_reader, false); | |
| 627 | |
| 628 UUID expected_uuid; | |
| 629 expected_uuid.InitializeFromBytes(dyld_image->imageUUID); | |
| 630 UUID actual_uuid; | |
| 631 image_reader.UUID(&actual_uuid); | |
| 632 EXPECT_EQ(expected_uuid, actual_uuid); | |
| 633 } | |
| 634 } | |
| 635 #endif | |
| 636 } | |
| 637 | |
| 638 } // namespace | |
| 639 } // namespace test | |
| 640 } // namespace crashpad | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 666483002:
Create snapshot/mac and move some files from snapshot and util to there (Closed)
Base URL: https://chromium.googlesource.com/crashpad/crashpad/+/master