: 40052d: 55 push %rbp 40052e: 48 89 e5 mov %rsp,%rbp 400531: bf e0 05 40 00 mov $0x4005e0,%edi 400536: e8 d5 fe ff ff callq 400410 40053b: b8 00 00 00 00 mov $0x0,%eax 400540: 5d pop %rbp 400541: c3 retq 400542: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 400549: 00 00 00 40054c: 0f 1f 40 00 nopl 0x0(%rax) ... # strace 　　strace常用来跟踪进程执行时的系统调用和所接收的信号。在Linux世界，进程不能直接访问硬件设备，当进程需要访问硬件设备(比如读取磁盘文件，接收网络数据等等)时，必须由用户态模式切换至内核态模式，通 过系统调用访问硬件设备。strace可以跟踪到一个进程产生的系统调用,包括参数，返回值，执行消耗的时间。 $ strace ./exe execve(＂./exe＂, [＂./exe＂], [/* 27 vars */]) = 0 brk(NULL) = 0xe22000 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0e1780e000 access(＂/etc/ld.so.preload＂, R_OK) = -1 ENOENT (No such file or directory) open(＂/etc/ld.so.cache＂, O_RDONLY|O_CLOEXEC) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=83540, ...}) = 0 mmap(NULL, 83540, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f0e177f9000 close(3) = 0 open(＂/lib64/libc.so.6＂, O_RDONLY|O_CLOEXEC) = 3 read(3, ＂177ELF21133>120&2＂..., 832) = 832 fstat(3, {st_mode=S_IFREG|0755, st_size=2156160, ...}) = 0 mmap(NULL, 3985888, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f0e17220000 mprotect(0x7f0e173e3000, 2097152, PROT_NONE) = 0 mmap(0x7f0e175e3000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1c3000) = 0x7f0e175e3000 mmap(0x7f0e175e9000, 16864, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f0e175e9000 close(3) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0e177f8000 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0e177f6000 arch_prctl(ARCH_SET_FS, 0x7f0e177f6740) = 0 mprotect(0x7f0e175e3000, 16384, PROT_READ) = 0 mprotect(0x600000, 4096, PROT_READ) = 0 mprotect(0x7f0e1780f000, 4096, PROT_READ) = 0 munmap(0x7f0e177f9000, 83540) = 0 fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 0), ...}) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0e1780d000 write(1, ＂hello ＂, 6hello ) = 6 exit_group(0) = ? +++ exited with 0 +++ 　　# nm 　　nm 是name的缩写，它显示指定文件中的符号信息，文件可以是对象文件、可执行文件或对象文件库。如果文件中没有包含符号信息，nm报告该情况，但不把他解释为出错。nm缺省情况下报告十进制符号表示法下的数字值。 $ nm exe 0000000000601034 B __bss_start 0000000000601034 b completed.6355 0000000000601030 D __data_start 0000000000601030 W data_start 0000000000400470 t deregister_tm_clones 00000000004004e0 t __do_global_dtors_aux 0000000000600e18 t __do_global_dtors_aux_fini_array_entry 00000000004005d8 R __dso_handle 0000000000600e28 d _DYNAMIC 0000000000601034 D _edata 0000000000601038 B _end 00000000004005c4 T _fini 0000000000400500 t frame_dummy 0000000000600e10 t __frame_dummy_init_array_entry 0000000000400710 r __FRAME_END__ 0000000000601000 d _GLOBAL_OFFSET_TABLE_ w __gmon_start__ 00000000004005e8 r __GNU_EH_FRAME_HDR 00000000004003e0 T _init 0000000000600e18 t __init_array_end 0000000000600e10 t __init_array_start 00000000004005d0 R _IO_stdin_used 0000000000600e20 d __JCR_END__ 0000000000600e20 d __JCR_LIST__ 00000000004005c0 T __libc_csu_fini 0000000000400550 T __libc_csu_init U __libc_start_main@@GLIBC_2.2.5 000000000040052d T main U puts@@GLIBC_2.2.5 00000000004004a0 t register_tm_clones 0000000000400440 T _start 0000000000601038 D __TMC_END__ ... 　　# gdb 　　gdb是GNU开源组织发布的一个强大的Linux下的程序调试工具。 $ gcc -g -o exe exe.c $ gdb exe GNU gdb (GDB) Red Hat Enterprise Linux 7.6.1-115.el7 Copyright (C) 2013 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type ＂show copying＂ and ＂show warranty＂ for details. This GDB was configured as ＂x86_64-redhat-linux-gnu＂. For bug reporting instructions, please see: ... Reading symbols from /home/study/exe...done. (gdb) list 1 #include 2 int main() 3 { 4 5 printf(＂hello ＂); 6 return 0; 7 8 } (gdb) b 5 Breakpoint 1 at 0x400531: file exe.c, line 5. (gdb) r Starting program: /home/study/exe Breakpoint 1, main () at exe.c:5 5 printf(＂hello ＂); (gdb) n hello 6 return 0; (gdb)