LCOV - app.info - toolkit/crashreporter/google-breakpad/src/common/linux/file_id.cc

LCOV - code coverage report
| Current view: | directory - toolkit/crashreporter/google-breakpad/src/common/linux - file_id.cc (source / functions) |  | Found | Hit | Coverage |
| Test: | app.info | Lines: | 85 | 67 | 78.8 %
| Date: | 2012-04-07 | Functions: | 7 | 5 | 71.4 %

           1                 : // Copyright (c) 2006, Google Inc.
           2                 : // All rights reserved.
           3                 : //
           4                 : // Redistribution and use in source and binary forms, with or without
           5                 : // modification, are permitted provided that the following conditions are
           6                 : // met:
           7                 : //
           8                 : //     * Redistributions of source code must retain the above copyright
           9                 : // notice, this list of conditions and the following disclaimer.
          10                 : //     * Redistributions in binary form must reproduce the above
          11                 : // copyright notice, this list of conditions and the following disclaimer
          12                 : // in the documentation and/or other materials provided with the
          13                 : // distribution.
          14                 : //     * Neither the name of Google Inc. nor the names of its
          15                 : // contributors may be used to endorse or promote products derived from
          16                 : // this software without specific prior written permission.
          17                 : //
          18                 : // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
          19                 : // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
          20                 : // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
          21                 : // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
          22                 : // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
          23                 : // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
          24                 : // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
          25                 : // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
          26                 : // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
          27                 : // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
          28                 : // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
          29                 : //
          30                 : // file_id.cc: Return a unique identifier for a file
          31                 : //
          32                 : // See file_id.h for documentation
          33                 : //
          34                 :
          35                 : #include "common/linux/file_id.h"
          36                 :
          37                 : #include <arpa/inet.h>
          38                 : #include <assert.h>
          39                 : #include <elf.h>
          40                 : #include <fcntl.h>
          41                 : #if defined(__ANDROID__)
          42                 : #include "client/linux/android_link.h"
          43                 : #else
          44                 : #include <link.h>
          45                 : #endif
          46                 : #include <stdio.h>
          47                 : #include <string.h>
          48                 : #include <sys/mman.h>
          49                 : #include <sys/stat.h>
          50                 : #include <unistd.h>
          51                 :
          52                 : #include <algorithm>
          53                 :
          54                 : #include "common/linux/linux_libc_support.h"
          55                 : #include "common/linux/linux_syscall_support.h"
          56                 :
          57                 : namespace google_breakpad {
          58                 :
          59             124 : FileID::FileID(const char* path) {
          60             124 :   strncpy(path_, path, sizeof(path_));
          61             124 : }
          62                 :
          63                 : struct ElfClass32 {
          64                 :   typedef Elf32_Ehdr Ehdr;
          65                 :   typedef Elf32_Shdr Shdr;
          66                 :   static const int kClass = ELFCLASS32;
          67                 : };
          68                 :
          69                 : struct ElfClass64 {
          70                 :   typedef Elf64_Ehdr Ehdr;
          71                 :   typedef Elf64_Shdr Shdr;
          72                 :   static const int kClass = ELFCLASS64;
          73                 : };
          74                 :
          75                 : // These three functions are also used inside the crashed process, so be safe
          76                 : // and use the syscall/libc wrappers instead of direct syscalls or libc.
          77                 : template<typename ElfClass>
          78             124 : static void FindElfClassTextSection(const char *elf_base,
          79                 :                                     const void **text_start,
          80                 :                                     int *text_size) {
          81                 :   typedef typename ElfClass::Ehdr Ehdr;
          82                 :   typedef typename ElfClass::Shdr Shdr;
          83                 :
          84             124 :   assert(elf_base);
          85             124 :   assert(text_start);
          86             124 :   assert(text_size);
          87                 :
          88             124 :   assert(my_strncmp(elf_base, ELFMAG, SELFMAG) == 0);
          89                 :
          90             124 :   const char* text_section_name = ".text";
          91             124 :   int name_len = my_strlen(text_section_name);
          92                 :
          93             124 :   const Ehdr* elf_header = reinterpret_cast<const Ehdr*>(elf_base);
          94             124 :   assert(elf_header->e_ident[EI_CLASS] == ElfClass::kClass);
          95                 :
          96                 :   const Shdr* sections =
          97             124 :       reinterpret_cast<const Shdr*>(elf_base + elf_header->e_shoff);
          98             124 :   const Shdr* string_section = sections + elf_header->e_shstrndx;
          99                 :
         100             124 :   const Shdr* text_section = NULL;
         101            1586 :   for (int i = 0; i < elf_header->e_shnum; ++i) {
         102            1586 :     if (sections[i].sh_type == SHT_PROGBITS) {
         103                 :       const char* section_name = (char*)(elf_base +
         104                 :                                          string_section->sh_offset +
         105             482 :                                          sections[i].sh_name);
         106             482 :       if (!my_strncmp(section_name, text_section_name, name_len)) {
         107             124 :         text_section = &sections[i];
         108             124 :         break;
         109                 :       }
         110                 :     }
         111                 :   }
         112             124 :   if (text_section != NULL && text_section->sh_size > 0) {
         113             124 :     *text_start = elf_base + text_section->sh_offset;
         114             124 :     *text_size = text_section->sh_size;
         115                 :   }
         116             124 : }
         117                 :
         118             124 : static bool FindElfTextSection(const void *elf_mapped_base,
         119                 :                                const void **text_start,
         120                 :                                int *text_size) {
         121             124 :   assert(elf_mapped_base);
         122             124 :   assert(text_start);
         123             124 :   assert(text_size);
         124                 :
         125                 :   const char* elf_base =
         126             124 :     static_cast<const char*>(elf_mapped_base);
         127                 :   const ElfW(Ehdr)* elf_header =
         128             124 :     reinterpret_cast<const ElfW(Ehdr)*>(elf_base);
         129             124 :   if (my_strncmp(elf_base, ELFMAG, SELFMAG) != 0)
         130               0 :     return false;
         131                 :
         132             124 :   if (elf_header->e_ident[EI_CLASS] == ELFCLASS32) {
         133             124 :     FindElfClassTextSection<ElfClass32>(elf_base, text_start, text_size);
         134               0 :   } else if (elf_header->e_ident[EI_CLASS] == ELFCLASS64) {
         135               0 :     FindElfClassTextSection<ElfClass64>(elf_base, text_start, text_size);
         136                 :   } else {
         137               0 :     return false;
         138                 :   }
         139                 :
         140             124 :   return true;
         141                 : }
         142                 :
         143                 : // static
         144             124 : bool FileID::ElfFileIdentifierFromMappedFile(void* base,
         145                 :                                              uint8_t identifier[kMDGUIDSize])
         146                 : {
         147             124 :   const void* text_section = NULL;
         148             124 :   int text_size = 0;
         149             124 :   bool success = false;
         150             124 :   if (FindElfTextSection(base, &text_section, &text_size) && (text_size > 0)) {
         151             124 :     my_memset(identifier, 0, kMDGUIDSize);
         152             124 :     const uint8_t* ptr = reinterpret_cast<const uint8_t*>(text_section);
         153             124 :     const uint8_t* ptr_end = ptr + std::min(text_size, 4096);
         154           31831 :     while (ptr < ptr_end) {
         155          536911 :       for (unsigned i = 0; i < kMDGUIDSize; i++)
         156          505328 :         identifier[i] ^= ptr[i];
         157           31583 :       ptr += kMDGUIDSize;
         158                 :     }
         159             124 :     success = true;
         160                 :   }
         161             124 :   return success;
         162                 : }
         163                 :
         164               0 : bool FileID::ElfFileIdentifier(uint8_t identifier[kMDGUIDSize]) {
         165               0 :   int fd = open(path_, O_RDONLY);
         166               0 :   if (fd < 0)
         167               0 :     return false;
         168                 :   struct stat st;
         169               0 :   if (fstat(fd, &st) != 0) {
         170               0 :     close(fd);
         171               0 :     return false;
         172                 :   }
         173                 :   void* base = mmap(NULL, st.st_size,
         174               0 :                     PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
         175               0 :   close(fd);
         176               0 :   if (base == MAP_FAILED)
         177               0 :     return false;
         178                 :
         179               0 :   bool success = ElfFileIdentifierFromMappedFile(base, identifier);
         180               0 :   munmap(base, st.st_size);
         181               0 :   return success;
         182                 : }
         183                 :
         184                 : // static
         185             124 : void FileID::ConvertIdentifierToString(const uint8_t identifier[kMDGUIDSize],
         186                 :                                        char* buffer, int buffer_length) {
         187                 :   uint8_t identifier_swapped[kMDGUIDSize];
         188                 :
         189                 :   // Endian-ness swap to match dump processor expectation.
         190             124 :   memcpy(identifier_swapped, identifier, kMDGUIDSize);
         191             124 :   uint32_t* data1 = reinterpret_cast<uint32_t*>(identifier_swapped);
         192             124 :   *data1 = htonl(*data1);
         193             124 :   uint16_t* data2 = reinterpret_cast<uint16_t*>(identifier_swapped + 4);
         194             124 :   *data2 = htons(*data2);
         195             124 :   uint16_t* data3 = reinterpret_cast<uint16_t*>(identifier_swapped + 6);
         196             124 :   *data3 = htons(*data3);
         197                 :
         198             124 :   int buffer_idx = 0;
         199            2108 :   for (unsigned int idx = 0;
         200                 :        (buffer_idx < buffer_length) && (idx < kMDGUIDSize);
         201                 :        ++idx) {
         202            1984 :     int hi = (identifier_swapped[idx] >> 4) & 0x0F;
         203            1984 :     int lo = (identifier_swapped[idx]) & 0x0F;
         204                 :
         205            1984 :     if (idx == 4 || idx == 6 || idx == 8 || idx == 10)
         206             496 :       buffer[buffer_idx++] = '-';
         207                 :
         208            1984 :     buffer[buffer_idx++] = (hi >= 10) ? 'A' + hi - 10 : '0' + hi;
         209            1984 :     buffer[buffer_idx++] = (lo >= 10) ? 'A' + lo - 10 : '0' + lo;
         210                 :   }
         211                 :
         212                 :   // NULL terminate
         213             124 :   buffer[(buffer_idx < buffer_length) ? buffer_idx : buffer_idx - 1] = 0;
         214             124 : }
         215                 :
         216                 : }  // namespace google_breakpad

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