what does extra symbol and assembly code mean?

I have a simple c file:

// filename: test.cvoid fun() {}

Then I compile test.c to libtest.so using commands:

gcc -shared -fPIC -Wl,--gc-sections -ffunction-sections -fdata-sections -o libtest.so test.cstrip -s ./libtest.so

Then use readelf to print symbols and its size:

readelf -sW ./libtest.so

I got:

Symbol table '.dynsym' contains 11 entries:   Num:    Value          Size Type    Bind   Vis      Ndx Name     0: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT  UND     1: 0000000000000420     0 SECTION LOCAL  DEFAULT    9     2: 0000000000000000     0 NOTYPE  WEAK   DEFAULT  UND __gmon_start__     3: 0000000000000000     0 NOTYPE  WEAK   DEFAULT  UND _Jv_RegisterClasses     4: 0000000000000000     0 FUNC    WEAK   DEFAULT  UND __cxa_finalize@GLIBC_2.2.5 (2)     5: 00000000002007c8     0 NOTYPE  GLOBAL DEFAULT  ABS _end     6: 00000000002007b8     0 NOTYPE  GLOBAL DEFAULT  ABS _edata     7: 00000000002007b8     0 NOTYPE  GLOBAL DEFAULT  ABS __bss_start     8: 0000000000000420     0 FUNC    GLOBAL DEFAULT    9 _init     9: 000000000000052a     6 FUNC    GLOBAL DEFAULT   11 fun    10: 0000000000000568     0 FUNC    GLOBAL DEFAULT   12 _fini

Then use objdump to disassemble .text section of libtest.so:

objdump -S -d -j .text ./libtest.so

I got:

./libtest.so:     file format elf64-x86-64Disassembly of section .text:0000000000000460 <fun-0xca>: 460:   48 83 ec 08             sub    $0x8,%rsp 464:   48 8b 05 15 03 20 00    mov    0x200315(%rip),%rax        # 200780 <_fini+0x200218> 46b:   48 85 c0                test   %rax,%rax 46e:   74 02                   je     472 <__cxa_finalize@plt+0x2a> 470:   ff d0                   callq  *%rax 472:   48 83 c4 08             add    $0x8,%rsp 476:   c3                      retq 477:   90                      nop 478:   90                      nop 479:   90                      nop 47a:   90                      nop 47b:   90                      nop 47c:   90                      nop 47d:   90                      nop 47e:   90                      nop 47f:   90                      nop 480:   55                      push   %rbp 481:   80 3d 30 03 20 00 00    cmpb   $0x0,0x200330(%rip)        # 2007b8 <__bss_start> 488:   48 89 e5                mov    %rsp,%rbp 48b:   41 54                   push   %r12 48d:   53                      push   %rbx 48e:   75 62                   jne    4f2 <__cxa_finalize@plt+0xaa> 490:   48 83 3d f8 02 20 00    cmpq   $0x0,0x2002f8(%rip)        # 200790 <_fini+0x200228> 497:   00 498:   74 0c                   je     4a6 <__cxa_finalize@plt+0x5e> 49a:   48 8d 3d 57 01 20 00    lea    0x200157(%rip),%rdi        # 2005f8 <_fini+0x200090> 4a1:   e8 a2 ff ff ff          callq  448 <__cxa_finalize@plt> 4a6:   48 8d 1d 3b 01 20 00    lea    0x20013b(%rip),%rbx        # 2005e8 <_fini+0x200080> 4ad:   4c 8d 25 2c 01 20 00    lea    0x20012c(%rip),%r12        # 2005e0 <_fini+0x200078> 4b4:   48 8b 05 05 03 20 00    mov    0x200305(%rip),%rax        # 2007c0 <__bss_start+0x8> 4bb:   4c 29 e3                sub    %r12,%rbx 4be:   48 c1 fb 03             sar    $0x3,%rbx 4c2:   48 83 eb 01             sub    $0x1,%rbx 4c6:   48 39 d8                cmp    %rbx,%rax 4c9:   73 20                   jae    4eb <__cxa_finalize@plt+0xa3> 4cb:   0f 1f 44 00 00          nopl   0x0(%rax,%rax,1) 4d0:   48 83 c0 01             add    $0x1,%rax 4d4:   48 89 05 e5 02 20 00    mov    %rax,0x2002e5(%rip)        # 2007c0 <__bss_start+0x8> 4db:   41 ff 14 c4             callq  *(%r12,%rax,8) 4df:   48 8b 05 da 02 20 00    mov    0x2002da(%rip),%rax        # 2007c0 <__bss_start+0x8> 4e6:   48 39 d8                cmp    %rbx,%rax 4e9:   72 e5                   jb     4d0 <__cxa_finalize@plt+0x88> 4eb:   c6 05 c6 02 20 00 01    movb   $0x1,0x2002c6(%rip)        # 2007b8 <__bss_start> 4f2:   5b                      pop    %rbx 4f3:   41 5c                   pop    %r12 4f5:   c9                      leaveq 4f6:   c3                      retq 4f7:   66 0f 1f 84 00 00 00    nopw   0x0(%rax,%rax,1) 4fe:   00 00 500:   48 83 3d e8 00 20 00    cmpq   $0x0,0x2000e8(%rip)        # 2005f0 <_fini+0x200088> 507:   00 508:   55                      push   %rbp 509:   48 89 e5                mov    %rsp,%rbp 50c:   74 1a                   je     528 <__cxa_finalize@plt+0xe0> 50e:   48 8b 05 73 02 20 00    mov    0x200273(%rip),%rax        # 200788 <_fini+0x200220> 515:   48 85 c0                test   %rax,%rax 518:   74 0e                   je     528 <__cxa_finalize@plt+0xe0> 51a:   48 8d 3d cf 00 20 00    lea    0x2000cf(%rip),%rdi        # 2005f0 <_fini+0x200088> 521:   c9                      leaveq 522:   ff e0                   jmpq   *%rax 524:   0f 1f 40 00             nopl   0x0(%rax) 528:   c9                      leaveq 529:   c3                      retq000000000000052a <fun>: 52a:   55                      push   %rbp 52b:   48 89 e5                mov    %rsp,%rbp 52e:   c9                      leaveq 52f:   c3                      retq 530:   55                      push   %rbp 531:   48 89 e5                mov    %rsp,%rbp 534:   53                      push   %rbx 535:   48 83 ec 08             sub    $0x8,%rsp 539:   48 8b 05 90 00 20 00    mov    0x200090(%rip),%rax        # 2005d0 <_fini+0x200068> 540:   48 83 f8 ff             cmp    $0xffffffffffffffff,%rax 544:   74 19                   je     55f <fun+0x35> 546:   48 8d 1d 83 00 20 00    lea    0x200083(%rip),%rbx        # 2005d0 <_fini+0x200068> 54d:   0f 1f 00                nopl   (%rax) 550:   48 83 eb 08             sub    $0x8,%rbx 554:   ff d0                   callq  *%rax 556:   48 8b 03                mov    (%rbx),%rax 559:   48 83 f8 ff             cmp    $0xffffffffffffffff,%rax 55d:   75 f1                   jne    550 <fun+0x26> 55f:   48 83 c4 08             add    $0x8,%rsp 563:   5b                      pop    %rbx 564:   c9                      leaveq 565:   c3                      retq

We can tell that the size of symbol fun is 6 which is correspond to virtual address 0x52a ~ 0x52f.

I have two question:

1. what does symbol fun-0xca do?

2. what does assembly code from 0x530 to 0x565 in symbol fun do?