Linux下如何使用objdump进行反汇编

objdump命令是Linux下的反汇编目标文件或者可执行文件的命令，它以一种可阅读的格式让你更多地了解二进制文件可能带有的附加信息。

1 objdump反汇编示例

源文件main.c：

/* main.c */#include void swap(int* first, int* second){   int temp = *first;   *first = *second;   *second = temp;}int main(void){   int a = 10;   int b = 20;   printf("a = %d; b = %d;\n", a, b);   swap(&a, &b);   printf("a = %d; b = %d;\n", a, b);   return 0;}123456789101112131415161718192021

1.1 显示main.c的汇编代码

gcc -S -o main.s main.c1

汇编文件main.s

   .file   "main.c"   .text   .globl  swap   .type   swap, @functionswap:.LFB0:   .cfi_startproc   pushq   %rbp   .cfi_def_cfa_offset 16   .cfi_offset 6, -16   movq    %rsp, %rbp   .cfi_def_cfa_register 6   movq    %rdi, -24(%rbp)   movq    %rsi, -32(%rbp)   movq    -24(%rbp), %rax   ...12345678910111213141516

1.2 目标文件反汇编

gcc -c -o main.o main.cobjdump -s -d main.o > main.o.txt12

目标文件main.o的反汇编结果输出到文件main.o.txt 反汇编同时显示源代码

gcc -g -c -o main.o main.cobjdump -S -d main.o > main.o.txt12

显示源代码同时显示行号

objdump -j .text -ld -C -S main.o > main.o.txt1

1.3 可执行文件反汇编

gcc -o main main.cobjdump -s -d main > main.txt12

反汇编同时显示源代码

gcc -g -o main main.cobjdump -S -d main > main.txt12

1.4 objdump反汇编常用参数

• objdump -d: 将代码段反汇编；
• objdump -S: 将代码段反汇编的同时，将反汇编代码与源代码交替显示，编译时需要使用-g参数，即需要调试信息；
• objdump -C: 将C++符号名逆向解析
• objdump -l: 反汇编代码中插入文件名和行号
• objdump -j section: 仅反汇编指定的section

2 objdump帮助信息

输出objdump帮助信息： objdump --help 或者 man objdump

Usage: objdump     Display information from object .   At least one of the following switches must be given:   -a, --archive-headers    Display archive header information   -f, --file-headers       Display the contents of the overall file header   -p, --private-headers    Display object format specific file header contents   -P, --private=OPT,OPT... Display object format specific contents   -h, --[section-]headers  Display the contents of the section headers   -x, --all-headers        Display the contents of all headers   -d, --disassemble        Display assembler contents of executable sections   -D, --disassemble-all    Display assembler contents of all sections   -S, --source             Intermix source code with disassembly   -s, --full-contents      Display the full contents of all sections requested   -g, --debugging          Display debug information in object file   -e, --debugging-tags     Display debug information using ctags style   -G, --stabs              Display (in raw form) any STABS info in the file   -W[lLiaprmfFsoRt] or   --dwarf[=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 DWARF info in the file   -t, --syms               Display the contents of the symbol table(s)   -T, --dynamic-syms       Display the contents of the dynamic symbol table   -r, --reloc              Display the relocation entries in the file   -R, --dynamic-reloc      Display the dynamic relocation entries in the file @                  Read options from    -v, --version            Display this program's version number   -i, --info               List object formats and architectures supported   -H, --help               Display this informationThe following switches are optional:   -b, --target=BFDNAME     Specify the target object format as BFDNAME   -m, --architecture=MACHINE     Specify the target architecture as MACHINE   -j, --section=NAME       Only display information for section NAME   -M, --disassembler-options=OPT Pass text OPT on to the disassembler   -EB --endian=big         Assume big endian format when disassembling   -EL --endian=little      Assume little endian format when disassembling     --file-start-context   Include context from start of file (with -S)   -I, --include=DIR        Add DIR to search list for source files   -l, --line-numbers       Include line numbers and filenames in output   -F, --file-offsets       Include file offsets when displaying information   -C, --demangle[=STYLE]   Decode mangled/processed symbol names                            The STYLE, if specified, can be `auto', `gnu',                                 `lucid', `arm', `hp', `edg', `gnu-v3', `java'                                 or `gnat'   -w, --wide               Format output for more than 80 columns   -z, --disassemble-zeroes       Do not skip blocks of zeroes when disassembling     --start-address=ADDR   Only process data whose address is >= ADDR     --stop-address=ADDR    Only process data whose address is for -d     --adjust-vma=OFFSET    Add OFFSET to all displayed section addresses     --special-syms         Include special symbols in symbol dumps     --prefix=PREFIX        Add PREFIX to absolute paths for -S     --prefix-strip=LEVEL   Strip initial directory names for -S     --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     --dwarf-check          Make additional dwarf internal consistency checks.      objdump: supported targets: elf64-x86-64 elf32-i386 elf32-x86-64 a.out-i386-linux pei-i386 pei-x86-64 elf64-l1om elf64-k1om elf64-little elf64-big elf32-little elf32-big plugin srec symbolsrec verilog tekhex binary ihexobjdump: supported architectures: i386 i386:x86-64 i386:x64-32 i8086 i386:intel i386:x86-64:intel i386:x64-32:intel l1om l1om:intel k1om k1om:intel pluginThe following i386/x86-64 specific disassembler options are supported for usewith the -M switch (multiple options should be separated by commas):   x86-64      Disassemble in 64bit mode   i386        Disassemble in 32bit mode   i8086       Disassemble in 16bit mode   att         Display instruction in AT&T syntax   intel       Display instruction in Intel syntax   att-mnemonic               Display instruction in AT&T mnemonic   intel-mnemonic               Display instruction in Intel mnemonic   addr64      Assume 64bit address size   addr32      Assume 32bit address size   addr16      Assume 16bit address size   data32      Assume 32bit data size   data16      Assume 16bit data size   suffix      Always display instruction suffix in AT&T syntaxReport bugs to .12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182