c disassembly linux

 filename::text.c

 

#include<stdio.h>

int main(){

printf("hello world");

}

 

>> gcc test.c -o test && test

hello world

[Done] exited with code=0 in 0.044 seconds

 

decompile this test binary:

objdump  -d test

 
test: file format elf64-x86-64


Disassembly of section .init:

0000000000001000 <_init>:
1000: f3 0f 1e fa endbr64
1004: 48 83 ec 08 sub $0x8,%rsp
1008: 48 8b 05 d9 2f 00 00 mov 0x2fd9(%rip),%rax # 3fe8 <__gmon_start__>
100f: 48 85 c0 test %rax,%rax
1012: 74 02 je 1016 <_init+0x16>
1014: ff d0 call *%rax
1016: 48 83 c4 08 add $0x8,%rsp
101a: c3 ret

Disassembly of section .plt:

0000000000001020 <[email protected]>:
1020: ff 35 e2 2f 00 00 push 0x2fe2(%rip) # 4008 <_GLOBAL_OFFSET_TABLE_+0x8>
1026: ff 25 e4 2f 00 00 jmp *0x2fe4(%rip) # 4010 <_GLOBAL_OFFSET_TABLE_+0x10>
102c: 0f 1f 40 00 nopl 0x0(%rax)

0000000000001030 <[email protected]>:
1030: ff 25 e2 2f 00 00 jmp *0x2fe2(%rip) # 4018 <[email protected]_2.2.5>
1036: 68 00 00 00 00 push $0x0
103b: e9 e0 ff ff ff jmp 1020 <_init+0x20>

Disassembly of section .text:

0000000000001040 <_start>:
1040: f3 0f 1e fa endbr64
1044: 31 ed xor %ebp,%ebp
1046: 49 89 d1 mov %rdx,%r9
1049: 5e pop %rsi
104a: 48 89 e2 mov %rsp,%rdx
104d: 48 83 e4 f0 and $0xfffffffffffffff0,%rsp
1051: 50 push %rax
1052: 54 push %rsp
1053: 4c 8d 05 76 01 00 00 lea 0x176(%rip),%r8 # 11d0 <__libc_csu_fini>
105a: 48 8d 0d ff 00 00 00 lea 0xff(%rip),%rcx # 1160 <__libc_csu_init>
1061: 48 8d 3d d1 00 00 00 lea 0xd1(%rip),%rdi # 1139 <main>
1068: ff 15 72 2f 00 00 call *0x2f72(%rip) # 3fe0 <[email protected]_2.2.5>
106e: f4 hlt
106f: 90 nop

0000000000001070 <deregister_tm_clones>:
1070: 48 8d 3d b9 2f 00 00 lea 0x2fb9(%rip),%rdi # 4030 <__TMC_END__>
1077: 48 8d 05 b2 2f 00 00 lea 0x2fb2(%rip),%rax # 4030 <__TMC_END__>
107e: 48 39 f8 cmp %rdi,%rax
1081: 74 15 je 1098 <deregister_tm_clones+0x28>
1083: 48 8b 05 4e 2f 00 00 mov 0x2f4e(%rip),%rax # 3fd8 <_ITM_deregisterTMCloneTable>
108a: 48 85 c0 test %rax,%rax
108d: 74 09 je 1098 <deregister_tm_clones+0x28>
108f: ff e0 jmp *%rax
1091: 0f 1f 80 00 00 00 00 nopl 0x0(%rax)
1098: c3 ret
1099: 0f 1f 80 00 00 00 00 nopl 0x0(%rax)

00000000000010a0 <register_tm_clones>:
10a0: 48 8d 3d 89 2f 00 00 lea 0x2f89(%rip),%rdi # 4030 <__TMC_END__>
10a7: 48 8d 35 82 2f 00 00 lea 0x2f82(%rip),%rsi # 4030 <__TMC_END__>
10ae: 48 29 fe sub %rdi,%rsi
10b1: 48 89 f0 mov %rsi,%rax
10b4: 48 c1 ee 3f shr $0x3f,%rsi
10b8: 48 c1 f8 03 sar $0x3,%rax
10bc: 48 01 c6 add %rax,%rsi
10bf: 48 d1 fe sar %rsi
10c2: 74 14 je 10d8 <register_tm_clones+0x38>
10c4: 48 8b 05 25 2f 00 00 mov 0x2f25(%rip),%rax # 3ff0 <_ITM_registerTMCloneTable>
10cb: 48 85 c0 test %rax,%rax
10ce: 74 08 je 10d8 <register_tm_clones+0x38>
10d0: ff e0 jmp *%rax
10d2: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1)
10d8: c3 ret
10d9: 0f 1f 80 00 00 00 00 nopl 0x0(%rax)

00000000000010e0 <__do_global_dtors_aux>:
10e0: f3 0f 1e fa endbr64
10e4: 80 3d 45 2f 00 00 00 cmpb $0x0,0x2f45(%rip) # 4030 <__TMC_END__>
10eb: 75 33 jne 1120 <__do_global_dtors_aux+0x40>
10ed: 55 push %rbp
10ee: 48 83 3d 02 2f 00 00 cmpq $0x0,0x2f02(%rip) # 3ff8 <[email protected]_2.2.5>
10f5: 00
10f6: 48 89 e5 mov %rsp,%rbp
10f9: 74 0d je 1108 <__do_global_dtors_aux+0x28>
10fb: 48 8b 3d 26 2f 00 00 mov 0x2f26(%rip),%rdi # 4028 <__dso_handle>
1102: ff 15 f0 2e 00 00 call *0x2ef0(%rip) # 3ff8 <[email protected]_2.2.5>
1108: e8 63 ff ff ff call 1070 <deregister_tm_clones>
110d: c6 05 1c 2f 00 00 01 movb $0x1,0x2f1c(%rip) # 4030 <__TMC_END__>
1114: 5d pop %rbp
1115: c3 ret
1116: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1)
111d: 00 00 00
1120: c3 ret
1121: 66 66 2e 0f 1f 84 00 data16 cs nopw 0x0(%rax,%rax,1)
1128: 00 00 00 00
112c: 0f 1f 40 00 nopl 0x0(%rax)

0000000000001130 <frame_dummy>:
1130: f3 0f 1e fa endbr64
1134: e9 67 ff ff ff jmp 10a0 <register_tm_clones>

0000000000001139 <main>:
1139: 55 push %rbp
113a: 48 89 e5 mov %rsp,%rbp
113d: 48 8d 05 c0 0e 00 00 lea 0xec0(%rip),%rax # 2004 <_IO_stdin_used+0x4>
1144: 48 89 c7 mov %rax,%rdi
1147: b8 00 00 00 00 mov $0x0,%eax
114c: e8 df fe ff ff call 1030 <[email protected]>
1151: b8 00 00 00 00 mov $0x0,%eax
1156: 5d pop %rbp
1157: c3 ret
1158: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1)
115f: 00

0000000000001160 <__libc_csu_init>:
1160: f3 0f 1e fa endbr64
1164: 41 57 push %r15
1166: 4c 8d 3d 7b 2c 00 00 lea 0x2c7b(%rip),%r15 # 3de8 <__frame_dummy_init_array_entry>
116d: 41 56 push %r14
116f: 49 89 d6 mov %rdx,%r14
1172: 41 55 push %r13
1174: 49 89 f5 mov %rsi,%r13
1177: 41 54 push %r12
1179: 41 89 fc mov %edi,%r12d
117c: 55 push %rbp
117d: 48 8d 2d 6c 2c 00 00 lea 0x2c6c(%rip),%rbp # 3df0 <__do_global_dtors_aux_fini_array_entry>
1184: 53 push %rbx
1185: 4c 29 fd sub %r15,%rbp
1188: 48 83 ec 08 sub $0x8,%rsp
118c: e8 6f fe ff ff call 1000 <_init>
1191: 48 c1 fd 03 sar $0x3,%rbp
1195: 74 1f je 11b6 <__libc_csu_init+0x56>
1197: 31 db xor %ebx,%ebx
1199: 0f 1f 80 00 00 00 00 nopl 0x0(%rax)
11a0: 4c 89 f2 mov %r14,%rdx
11a3: 4c 89 ee mov %r13,%rsi
11a6: 44 89 e7 mov %r12d,%edi
11a9: 41 ff 14 df call *(%r15,%rbx,8)
11ad: 48 83 c3 01 add $0x1,%rbx
11b1: 48 39 dd cmp %rbx,%rbp
11b4: 75 ea jne 11a0 <__libc_csu_init+0x40>
11b6: 48 83 c4 08 add $0x8,%rsp
11ba: 5b pop %rbx
11bb: 5d pop %rbp
11bc: 41 5c pop %r12
11be: 41 5d pop %r13
11c0: 41 5e pop %r14
11c2: 41 5f pop %r15
11c4: c3 ret
11c5: 66 66 2e 0f 1f 84 00 data16 cs nopw 0x0(%rax,%rax,1)
11cc: 00 00 00 00

00000000000011d0 <__libc_csu_fini>:
11d0: f3 0f 1e fa endbr64
11d4: c3 ret

Disassembly of section .fini:

00000000000011d8 <_fini>:
11d8: f3 0f 1e fa endbr64
11dc: 48 83 ec 08 sub $0x8,%rsp
11e0: 48 83 c4 08 add $0x8,%rsp
11e4: c3 ret
 

 

 src::https://unix.stackexchange.com/questions/418354/understanding-what-a-linux-binary-is-doing