readelf 与 ELF 文件格式分析

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readelf 与 ELF 文件格式分析

ELF 格式

可执行与可链接格式（英语：Executable and Linkable Format，缩写为 ELF），常被称为 ELF 格式，在计算机科学中，是一种用于可执行文件、目标文件、共享库和核心转储的标准文件格式。

可以通过 ELF 格式读取 ELF 文件的一些信息。

ELF 文件类型：

1. 可重定位的对象文件 (Relocatable file)

  由汇编器汇编生成的 .o 文件

2. 可执行的对象文件 (Executable file)

  可执行应用程序

3. 可被共享的对象文件 (Shared object file)

  动态库文件，也即 .so 文件

ELF 文件组成：

• ELF 头（ELF header）
• 程序标头表（Program header table）
• Section 标头表（Section header table）：链接与重定义需要的数据
• 程序标头与 Section 标头需要的数据：.text（可执行代码），.data（被初始化的数据），.bss（未初始化的数据），.symtab 或 .dynsym（符号信息），strtab 或 dynstr（字符串信息）等

实际的 ELF 文件不一定如下图所示的包含其中的信息和位置顺序。

只有 ELF 头的位置是固定的，其它信息包含在 ELF 头中。

ELF 头（ELF header）

#define EI_NIDENT 16

typedef struct {
　　unsigned char e_ident[EI_NIDENT]; // 开头 3 个字节固定不变，为 0x7F, 'E', 'L', 'F'，其它是与机器无关的信息
　　Elf32_Half e_type;                // 标识该文件的类型
　　Elf32_Half e_machine;             // 运行该程序需要的体系结构
　　Elf32_Word e_version;             // 文件的版本
　　Elf32_Addr e_entry;               // 程序的入口地址
　　Elf32_Off  e_phoff;               // Program header table 在文件中的偏移量（以字节计数）
　　Elf32_Off  e_shoff;               // Section header table 在文件中的偏移量（以字节计数）
　　Elf32_Word e_flags;               // 其它
　　Elf32_Half e_ehsize;              // ELF header 大小（以字节计数）
　　Elf32_Half e_phentsize;           // Program header table 中每一个条目的大小
　　Elf32_Half e_phnum;               // Program header table 中条目数量
　　Elf32_Half e_shentsize;           // Section header table 中的每一个条目的大小
　　Elf32_Half e_shnum;               // Section header table 中条目数量
　　Elf32_Half e_shstrndx;            // 包含节名称的字符串是第几个节（从零开始计数）
} Elf32_Ehdr;

数据类型说明：

数据类型	大小	对齐	用途
Elf32_Addr	4	4	无符号程序地址
Elf32_Half	2	2	无符号中等大小整数
Elf32_Off	4	4	无符号文件偏移
Elf32_Sword	4	4	有符号大整数
Elf32_Word	4	4	无符号大整数
unsigned char	1	1	无符号小整数

程序标头

Program header 描述的是一个段在文件中的位置、大小以及它被放进内存后所在的位置和大小。

typedef struct {
    Elf32_Word p_type;      // 当前 Program header 所描述的段的类型
    Elf32_Off  p_offset;    // 第一个字节在文件中的偏移
    Elf32_Addr p_vaddr;     // 一个字节在内存中的虚拟地址
    Elf32_Addr p_paddr;     // 在物理内存定位相关的系统中，此项是为物理地址保留
    Elf32_Word p_filesz;    // 文件中的长度
    Elf32_Word p_memsz;     // 内存中的长度
    Elf32_Word p_flags;     // 与段相关的标志
    Elf32_Word p_align;     // 根据此项值来确定段在文件及内存中如何对齐
}

通过 readelf 命令分析 ELF 文件

不同的架构下也有不同的 readelf 命令，比如 android 的命令：arm-linux-androideabi-readelf

readelf 命令主要参数：

  -a --all               Equivalent to: -h -l -S -s -r -d -V -A -I
  -h --file-header       Display the ELF file header
  -l --program-headers   Display the program headers
     --segments          An alias for --program-headers
  -S --section-headers   Display the sections' header
     --sections          An alias for --section-headers
  -g --section-groups    Display the section groups
  -t --section-details   Display the section details
  -e --headers           Equivalent to: -h -l -S
  -s --syms              Display the symbol table
     --symbols           An alias for --syms
  --dyn-syms             Display the dynamic symbol table
  -n --notes             Display the core notes (if present)
  -r --relocs            Display the relocations (if present)
  -u --unwind            Display the unwind info (if present)
  -d --dynamic           Display the dynamic section (if present)
  -V --version-info      Display the version sections (if present)
  -A --arch-specific     Display architecture specific information (if any)
  -c --archive-index     Display the symbol/file index in an archive
  -D --use-dynamic       Use the dynamic section info when displaying symbols
  -x --hex-dump=<number|name>
                         Dump the contents of section <number|name> as bytes
  -p --string-dump=<number|name>
                         Dump the contents of section <number|name> as strings
  -R --relocated-dump=<number|name>
                         Dump the contents of section <number|name> as relocated bytes
  -z --decompress        Decompress section before dumping it
  -w[lLiaprmfFsoRt] or
  --debug-dump[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,
               =frames-interp,=str,=loc,=Ranges,=pubtypes,
               =gdb_index,=trace_info,=trace_abbrev,=trace_aranges,
               =addr,=cu_index]
                         Display the contents of DWARF2 debug sections
  --dwarf-depth=N        Do not display DIEs at depth N or greater
  --dwarf-start=N        Display DIEs starting with N, at the same depth
                         or deeper
  -I --histogram         Display histogram of bucket list lengths
  -W --wide              Allow output width to exceed 80 characters
  @<file>                Read options from <file>
  -H --help              Display this information
  -v --version           Display the version number of readelf

查看 .so 文件依赖库：arm-linux-androideabi-readelf -d libtest.so

Dynamic section at offset 0x2e8c contains 30 entries:
  Tag        Type                         Name/Value
 0x00000003 (PLTGOT)                     0x3fb8
 0x00000002 (PLTRELSZ)                   120 (bytes)
 0x00000017 (JMPREL)                     0x7b4
 0x00000014 (PLTREL)                     REL
 0x00000011 (REL)                        0x6ec
 0x00000012 (RELSZ)                      200 (bytes)
 0x00000013 (RELENT)                     8 (bytes)
 0x6ffffffa (RELCOUNT)                   23
 0x00000006 (SYMTAB)                     0x1f0
 0x0000000b (SYMENT)                     16 (bytes)
 0x00000005 (STRTAB)                     0x360
 0x0000000a (STRSZ)                      600 (bytes)
 0x00000004 (HASH)                       0x5b8
 0x00000001 (NEEDED)                     Shared library: [liblog.so]
 0x00000001 (NEEDED)                     Shared library: [../../../../src/main/jniLibs/armeabi-v7a/libjudgehdr.so]
 0x00000001 (NEEDED)                     Shared library: [../../../../src/main/jniLibs/armeabi-v7a/libldr2hdr.so]
 0x00000001 (NEEDED)                     Shared library: [libm.so]
 0x00000001 (NEEDED)                     Shared library: [libdl.so]
 0x00000001 (NEEDED)                     Shared library: [libc.so]
 0x0000000e (SONAME)                     Library soname: [libcvteresearch_facehdr.so]
 0x0000001a (FINI_ARRAY)                 0x3e3c
 0x0000001c (FINI_ARRAYSZ)               8 (bytes)
 0x0000001e (FLAGS)                      BIND_NOW
 0x6ffffffb (FLAGS_1)                    Flags: NOW
 0x6ffffff0 (VERSYM)                     0x660
 0x6ffffffc (VERDEF)                     0x690
 0x6ffffffd (VERDEFNUM)                  1
 0x6ffffffe (VERNEED)                    0x6ac
 0x6fffffff (VERNEEDNUM)                 2
 0x00000000 (NULL)                       0x0

查看 ELF 头：arm-linux-androideabi-readelf -h libtest.so

ELF Header:
  Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
  Class:                             ELF32
  Data:                              2's complement, little endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              DYN (Shared object file)
  Machine:                           ARM
  Version:                           0x1
  Entry point address:               0x0
  Start of program headers:          52 (bytes into file)
  Start of section headers:          148172 (bytes into file)
  Flags:                             0x5000200, Version5 EABI, soft-float ABI
  Size of this header:               52 (bytes)
  Size of program headers:           32 (bytes)
  Number of program headers:         8
  Size of section headers:           40 (bytes)
  Number of section headers:         39
  Section header string table index: 38

完整信息：arm-linux-androideabi-readelf -all libtest.so

ELF Header:
  Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
  Class:                             ELF32
  Data:                              2's complement, little endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              DYN (Shared object file)
  Machine:                           ARM
  Version:                           0x1
  Entry point address:               0x0
  Start of program headers:          52 (bytes into file)
  Start of section headers:          148172 (bytes into file)
  Flags:                             0x5000200, Version5 EABI, soft-float ABI
  Size of this header:               52 (bytes)
  Size of program headers:           32 (bytes)
  Number of program headers:         8
  Size of section headers:           40 (bytes)
  Number of section headers:         39
  Section header string table index: 38

Section Headers:
  [Nr] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
  [ 0]                   NULL            00000000 000000 000000 00      0   0  0
  [ 1] .note.android.ide NOTE            00000134 000134 000098 00   A  0   0  4
  [ 2] .note.gnu.build-i NOTE            000001cc 0001cc 000024 00   A  0   0  4
  [ 3] .dynsym           DYNSYM          000001f0 0001f0 000170 10   A  4   1  4
  [ 4] .dynstr           STRTAB          00000360 000360 000258 00   A  0   0  1
  [ 5] .hash             HASH            000005b8 0005b8 0000a8 04   A  3   0  4
  [ 6] .gnu.version      VERSYM          00000660 000660 00002e 02   A  3   0  2
  [ 7] .gnu.version_d    VERDEF          00000690 000690 00001c 00   A  4   1  4
  [ 8] .gnu.version_r    VERNEED         000006ac 0006ac 000040 00   A  4   2  4
  [ 9] .rel.dyn          REL             000006ec 0006ec 0000c8 08   A  3   0  4
  [10] .rel.plt          REL             000007b4 0007b4 000078 08   A  3   0  4
  [11] .plt              PROGBITS        0000082c 00082c 0000c8 00  AX  0   0  4
  [12] .text             PROGBITS        000008f4 0008f4 00179c 00  AX  0   0  4
  [13] .ARM.exidx        ARM_EXIDX       00002090 002090 0001a0 08  AL 12   0  4
  [14] .ARM.extab        PROGBITS        00002230 002230 000198 00   A  0   0  4
  [15] .rodata           PROGBITS        000023c8 0023c8 00048e 01 AMS  0   0  1
  [16] .fini_array       FINI_ARRAY      00003e3c 002e3c 000008 00  WA  0   0  4
  [17] .data.rel.ro      PROGBITS        00003e44 002e44 000048 00  WA  0   0  4
  [18] .dynamic          DYNAMIC         00003e8c 002e8c 000118 08  WA  4   0  4
  [19] .got              PROGBITS        00003fa4 002fa4 00005c 00  WA  0   0  4
  [20] .data             PROGBITS        00004000 003000 000008 00  WA  0   0  4
  [21] .bss              NOBITS          00004008 003008 000001 00  WA  0   0  1
  [22] .comment          PROGBITS        00000000 003008 000108 01  MS  0   0  1
  [23] .debug_str        PROGBITS        00000000 003110 008369 01  MS  0   0  1
  [24] .debug_abbrev     PROGBITS        00000000 00b479 000b09 00      0   0  1
  [25] .debug_info       PROGBITS        00000000 00bf82 009860 00      0   0  1
  [26] .debug_ranges     PROGBITS        00000000 0157e2 0003d0 00      0   0  1
  [27] .debug_macinfo    PROGBITS        00000000 015bb2 000003 00      0   0  1
  [28] .debug_pubnames   PROGBITS        00000000 015bb5 001479 00      0   0  1
  [29] .debug_pubtypes   PROGBITS        00000000 01702e 000e7c 00      0   0  1
  [30] .debug_frame      PROGBITS        00000000 017eac 0006ec 00      0   0  4
  [31] .debug_line       PROGBITS        00000000 018598 001e0d 00      0   0  1
  [32] .debug_loc        PROGBITS        00000000 01a3a5 002028 00      0   0  1
  [33] .debug_aranges    PROGBITS        00000000 01c3cd 000040 00      0   0  1
  [34] .note.gnu.gold-ve NOTE            00000000 01c410 00001c 00      0   0  4
  [35] .ARM.attributes   ARM_ATTRIBUTES  00000000 01c42c 000034 00      0   0  1
  [36] .symtab           SYMTAB          00000000 01c460 006b30 10     37 1693  4
  [37] .strtab           STRTAB          00000000 022f90 00118b 00      0   0  1
  [38] .shstrtab         STRTAB          00000000 02411b 0001b0 00      0   0  1
Key to Flags:
  W (write), A (alloc), X (execute), M (merge), S (strings), I (info),
  L (link order), O (extra OS processing required), G (group), T (TLS),
  C (compressed), x (unknown), o (OS specific), E (exclude),
  y (noread), p (processor specific)

There are no section groups in this file.

Program Headers:
  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
  PHDR           0x000034 0x00000034 0x00000034 0x00100 0x00100 R   0x4
  LOAD           0x000000 0x00000000 0x00000000 0x02856 0x02856 R E 0x1000
  LOAD           0x002e3c 0x00003e3c 0x00003e3c 0x001cc 0x001cd RW  0x1000
  DYNAMIC        0x002e8c 0x00003e8c 0x00003e8c 0x00118 0x00118 RW  0x4
  NOTE           0x000134 0x00000134 0x00000134 0x000bc 0x000bc R   0x4
  GNU_STACK      0x000000 0x00000000 0x00000000 0x00000 0x00000 RW  0x10
  EXIDX          0x002090 0x00002090 0x00002090 0x001a0 0x001a0 R   0x4
  GNU_RELRO      0x002e3c 0x00003e3c 0x00003e3c 0x001c4 0x001c4 RW  0x4

 Section to Segment mapping:
  Segment Sections...
   00
   01     .note.android.ident .note.gnu.build-id .dynsym .dynstr .hash .gnu.version .gnu.version_d .gnu.version_r .rel.dyn .rel.plt .plt .text .ARM.exidx .ARM.extab .rodata
   02     .fini_array .data.rel.ro .dynamic .got .data .bss
   03     .dynamic
   04     .note.android.ident .note.gnu.build-id
   05
   06     .ARM.exidx
   07     .fini_array .data.rel.ro .dynamic .got

Dynamic section at offset 0x2e8c contains 30 entries:
  Tag        Type                         Name/Value
 0x00000003 (PLTGOT)                     0x3fb8
 0x00000002 (PLTRELSZ)                   120 (bytes)
 0x00000017 (JMPREL)                     0x7b4
 0x00000014 (PLTREL)                     REL
 0x00000011 (REL)                        0x6ec
 0x00000012 (RELSZ)                      200 (bytes)
 0x00000013 (RELENT)                     8 (bytes)
 0x6ffffffa (RELCOUNT)                   23
 0x00000006 (SYMTAB)                     0x1f0
 0x0000000b (SYMENT)                     16 (bytes)
 0x00000005 (STRTAB)                     0x360
 0x0000000a (STRSZ)                      600 (bytes)
 0x00000004 (HASH)                       0x5b8
 0x00000001 (NEEDED)                     Shared library: [liblog.so]
 0x00000001 (NEEDED)                     Shared library: [../../../../src/main/jniLibs/armeabi-v7a/libjudgehdr.so]
 0x00000001 (NEEDED)                     Shared library: [../../../../src/main/jniLibs/armeabi-v7a/libldr2hdr.so]
 0x00000001 (NEEDED)                     Shared library: [libm.so]
 0x00000001 (NEEDED)                     Shared library: [libdl.so]
 0x00000001 (NEEDED)                     Shared library: [libc.so]
 0x0000000e (SONAME)                     Library soname: [libcvteresearch_facehdr.so]
 0x0000001a (FINI_ARRAY)                 0x3e3c
 0x0000001c (FINI_ARRAYSZ)               8 (bytes)
 0x0000001e (FLAGS)                      BIND_NOW
 0x6ffffffb (FLAGS_1)                    Flags: NOW
 0x6ffffff0 (VERSYM)                     0x660
 0x6ffffffc (VERDEF)                     0x690
 0x6ffffffd (VERDEFNUM)                  1
 0x6ffffffe (VERNEED)                    0x6ac
 0x6fffffff (VERNEEDNUM)                 2
 0x00000000 (NULL)                       0x0

Relocation section '.rel.dyn' at offset 0x6ec contains 25 entries:
 Offset     Info    Type            Sym.Value  Sym. Name
00003e3c  00000017 R_ARM_RELATIVE
00003e40  00000017 R_ARM_RELATIVE
00003e4c  00000017 R_ARM_RELATIVE
00003e50  00000017 R_ARM_RELATIVE
00003e54  00000017 R_ARM_RELATIVE
00003e58  00000017 R_ARM_RELATIVE
00003e5c  00000017 R_ARM_RELATIVE
00003e60  00000017 R_ARM_RELATIVE
00003e64  00000017 R_ARM_RELATIVE
00003e68  00000017 R_ARM_RELATIVE
00003e6c  00000017 R_ARM_RELATIVE
00003e70  00000017 R_ARM_RELATIVE
00003e74  00000017 R_ARM_RELATIVE
00003e78  00000017 R_ARM_RELATIVE
00003e7c  00000017 R_ARM_RELATIVE
00003e80  00000017 R_ARM_RELATIVE
00003e84  00000017 R_ARM_RELATIVE
00003e88  00000017 R_ARM_RELATIVE
00003fac  00000017 R_ARM_RELATIVE
00003fb0  00000017 R_ARM_RELATIVE
00003fb4  00000017 R_ARM_RELATIVE
00004000  00000017 R_ARM_RELATIVE
00004004  00000017 R_ARM_RELATIVE
00003fa8  00000c15 R_ARM_GLOB_DAT    00000000   __sF@LIBC
00003fa4  00000f15 R_ARM_GLOB_DAT    00000000   __stack_chk_guard@LIBC

Relocation section '.rel.plt' at offset 0x7b4 contains 15 entries:
 Offset     Info    Type            Sym.Value  Sym. Name
00003fc4  00000216 R_ARM_JUMP_SLOT   00000000   __cxa_finalize@LIBC
00003fc8  00000116 R_ARM_JUMP_SLOT   00000000   __cxa_atexit@LIBC
00003fcc  00000916 R_ARM_JUMP_SLOT   000009a1   _ZN7_JNIEnv20GetByteAr
00003fd0  00000816 R_ARM_JUMP_SLOT   00000000   JudgeHdr
00003fd4  00000a16 R_ARM_JUMP_SLOT   000009d7   _ZN7_JNIEnv24ReleaseBy
00003fd8  00000b16 R_ARM_JUMP_SLOT   00000000   ldr2hdr
00003fdc  00000e16 R_ARM_JUMP_SLOT   00000000   __stack_chk_fail@LIBC
00003fe0  00001116 R_ARM_JUMP_SLOT   00000000   fprintf@LIBC
00003fe4  00001016 R_ARM_JUMP_SLOT   00000000   fflush@LIBC
00003fe8  00000d16 R_ARM_JUMP_SLOT   00000000   abort@LIBC
00003fec  00001316 R_ARM_JUMP_SLOT   00000000   __aeabi_memcpy
00003ff0  00001216 R_ARM_JUMP_SLOT   00000000   __aeabi_memclr8
00003ff4  00001516 R_ARM_JUMP_SLOT   00000000   dladdr@LIBC
00003ff8  00001616 R_ARM_JUMP_SLOT   00000000   snprintf@LIBC
00003ffc  00001416 R_ARM_JUMP_SLOT   00000000   __gnu_Unwind_Find_exid

Unwind table index '.ARM.exidx' at offset 0x2090 contains 52 entries:

0x8f4 <__on_dlclose>: 0x1 [cantunwind]

0x938 <Java_org_cvte_research_faceapi_FaceApiNative_JniJudgeHdr>: @0x2230
  Compact model index: 1
  0x97      vsp = r7
  0x43      vsp = vsp - 16
  0x80 0x10 pop {r8}
  0xab      pop {r4, r5, r6, r7, r14}
  0xb0      finish

0x9a0 <_ZN7_JNIEnv20GetByteArrayElementsEP11_jbyteArrayPh>: @0x223c
  Compact model index: 1
  0x97      vsp = r7
  0x41      vsp = vsp - 8
  0x84 0x0d pop {r4, r6, r7, r14}
  0xb0      finish
  0xb0      finish

...

0x1bf0 <_ZN9libunwind13Registers_arm15getRegisterNameEi>: 0x80b0b0b0
  Compact model index: 0
  0xb0      finish
  0xb0      finish
  0xb0      finish

0x2034 <_ZN9libunwind13Registers_arm20restoreCoreAndJumpToEv>: 0x1 [cantunwind]


Symbol table '.dynsym' contains 23 entries:
   Num:    Value  Size Type    Bind   Vis      Ndx Name
     0: 00000000     0 NOTYPE  LOCAL  DEFAULT  UND
     1: 00000000     0 FUNC    GLOBAL DEFAULT  UND __cxa_atexit@LIBC (2)
     2: 00000000     0 FUNC    GLOBAL DEFAULT  UND __cxa_finalize@LIBC (2)
     3: 00004008     0 NOTYPE  GLOBAL DEFAULT  ABS _edata
     4: 00004009     0 NOTYPE  GLOBAL DEFAULT  ABS _end
     5: 00004008     0 NOTYPE  GLOBAL DEFAULT  ABS __bss_start
     6: 00000939   104 FUNC    GLOBAL DEFAULT   12 Java_org_cvte_research_fa
     7: 00000a1f   142 FUNC    GLOBAL DEFAULT   12 Java_org_cvte_research_fa
     8: 00000000     0 FUNC    GLOBAL DEFAULT  UND JudgeHdr
     9: 000009a1    54 FUNC    WEAK   DEFAULT   12 _ZN7_JNIEnv20GetByteArray
    10: 000009d7    72 FUNC    WEAK   DEFAULT   12 _ZN7_JNIEnv24ReleaseByteA
    11: 00000000     0 FUNC    GLOBAL DEFAULT  UND ldr2hdr
    12: 00000000     0 OBJECT  GLOBAL DEFAULT  UND __sF@LIBC (2)
    13: 00000000     0 FUNC    GLOBAL DEFAULT  UND abort@LIBC (2)
    14: 00000000     0 FUNC    GLOBAL DEFAULT  UND __stack_chk_fail@LIBC (2)
    15: 00000000     0 OBJECT  GLOBAL DEFAULT  UND __stack_chk_guard@LIBC (2)
    16: 00000000     0 FUNC    GLOBAL DEFAULT  UND fflush@LIBC (2)
    17: 00000000     0 FUNC    GLOBAL DEFAULT  UND fprintf@LIBC (2)
    18: 00000000     0 FUNC    GLOBAL DEFAULT  UND __aeabi_memclr8
    19: 00000000     0 FUNC    GLOBAL DEFAULT  UND __aeabi_memcpy
    20: 00000000     0 FUNC    GLOBAL DEFAULT  UND __gnu_Unwind_Find_exidx
    21: 00000000     0 FUNC    GLOBAL DEFAULT  UND dladdr@LIBC (3)
    22: 00000000     0 FUNC    GLOBAL DEFAULT  UND snprintf@LIBC (2)

Symbol table '.symtab' contains 1715 entries:
   Num:    Value  Size Type    Bind   Vis      Ndx Name
     0: 00000000     0 NOTYPE  LOCAL  DEFAULT  UND
     1: 00000000     0 FILE    LOCAL  DEFAULT  ABS crtbegin_so.c
     2: 000008f4     0 NOTYPE  LOCAL  DEFAULT   12 $a.0
     3: 00000904     0 NOTYPE  LOCAL  DEFAULT   12 $a.2
     4: 00000900     0 NOTYPE  LOCAL  DEFAULT   12 $d.1
     5: 00000930     0 NOTYPE  LOCAL  DEFAULT   12 $d.3

     ...

  1712: 00000000     0 FUNC    GLOBAL DEFAULT  UND __gnu_Unwind_Find_exidx
  1713: 00000000     0 FUNC    GLOBAL DEFAULT  UND dladdr
  1714: 00000000     0 FUNC    GLOBAL DEFAULT  UND snprintf

Histogram for bucket list length (total of 17 buckets):
 Length  Number     % of total  Coverage
      0  10         ( 58.8%)
      1  5          ( 29.4%)     55.6%
      2  2          ( 11.8%)    100.0%

Version symbols section '.gnu.version' contains 23 entries:
 Addr: 0000000000000660  Offset: 0x000660  Link: 3 (.dynsym)
  000:   0 (*local*)       2 (LIBC)          2 (LIBC)          1 (*global*)
  004:   1 (*global*)      1 (*global*)      1 (*global*)      1 (*global*)
  008:   0 (*local*)       1 (*global*)      1 (*global*)      0 (*local*)
  00c:   2 (LIBC)          2 (LIBC)          2 (LIBC)          2 (LIBC)
  010:   2 (LIBC)          2 (LIBC)          0 (*local*)       0 (*local*)
  014:   0 (*local*)       3 (LIBC)          2 (LIBC)

Version definition section '.gnu.version_d' contains 1 entries:
  Addr: 0x0000000000000690  Offset: 0x000690  Link: 4 (.dynstr)  000000: Rev: 1  Flags: BASE   Index: 1  Cnt: 1  Name: libcvteresearch_facehdr.so
  Version definition past end of section

Version needs section '.gnu.version_r' contains 2 entries:
 Addr: 0x00000000000006ac  Offset: 0x0006ac  Link: 4 (.dynstr)
  000000: Version: 1  File: libc.so  Cnt: 1
  0x0010:   Name: LIBC  Flags: none  Version: 2
  0x0020: Version: 1  File: libdl.so  Cnt: 1
  0x0030:   Name: LIBC  Flags: none  Version: 3

Displaying notes found at file offset 0x00000134 with length 0x00000098:
  Owner                 Data size       Description
  Android              0x00000084       NT_VERSION (version)

Displaying notes found at file offset 0x000001cc with length 0x00000024:
  Owner                 Data size       Description
  GNU                  0x00000014       NT_GNU_BUILD_ID (unique build ID bitstring)
    Build ID: 295b5876f2176311314bd316c97325d34d7a33ee

Displaying notes found at file offset 0x0001c410 with length 0x0000001c:
  Owner                 Data size       Description
  GNU                  0x00000009       NT_GNU_GOLD_VERSION (gold version)
    Version: gold 1.12
Attribute Section: aeabi
File Attributes
  Tag_CPU_name: "ARM v7"
  Tag_CPU_arch: v7
  Tag_CPU_arch_profile: Application
  Tag_ARM_ISA_use: Yes
  Tag_THUMB_ISA_use: Thumb-2
  Tag_FP_arch: VFPv3
  Tag_ABI_PCS_GOT_use: GOT-indirect
  Tag_ABI_PCS_wchar_t: 4
  Tag_ABI_FP_denormal: Needed
  Tag_ABI_FP_exceptions: Needed
  Tag_ABI_FP_number_model: IEEE 754
  Tag_ABI_align_needed: 8-byte
  Tag_ABI_enum_size: int
  Tag_CPU_unaligned_access: v6
  Tag_ABI_FP_16bit_format: IEEE 754