“gdb”和“valgrind”以不同的方式执行二进制文件？

Question

我的程序出现堆内存损坏错误。

osboxes@osboxes:/mnt/hgfs/VM_Shared/ISSUES/_[02]$ ./shuf /dev/null
*** Error in `./shuf': corrupted double-linked list: 0xb7f01ac0 ***

在仅使用gdb进行调试时，我遇到了valgrind。（感谢Here）并且......我使用valgrind获取日志。

（对不起，长日志，我会在提问之前将其缩写，但我担心我可能会错过分析所需的一些信息。）

osboxes@osboxes:~/Desktop/VM_Shared/ISSUES/_[02]$ valgrind --run-libc-freeres=no ./shuf /dev/null
==23373== Command: ./shuf /dev/null
==23373== 
==23373== Invalid read of size 4
==23373==    at 0x40B7859: _IO_file_close_it@@GLIBC_2.1 (fileops.c:178)
==23373==    by 0x40B4AE6: freopen64 (freopen64.c:49)
==23373==    by 0x804EECF: ??? (shuf.s:22773)
==23373==  Address 0x20 is not stack'd, malloc'd or (recently) free'd
==23373== 
==23373== Process terminating with default action of signal 11 (SIGSEGV)
==23373==  Access not within mapped region at address 0x20
==23373==    at 0x40B7859: _IO_file_close_it@@GLIBC_2.1 (fileops.c:178)
==23373==    by 0x40B4AE6: freopen64 (freopen64.c:49)
==23373==    by 0x804EECF: ??? (shuf.s:22773)
==23373==  If you believe this happened as a result of a stack
==23373==  overflow in your program's main thread (unlikely but
==23373==  possible), you can try to increase the size of the
==23373==  main thread stack using the --main-stacksize= flag.
==23373==  The main thread stack size used in this run was 8388608.
==23373== 
==23373== HEAP SUMMARY:
==23373==     in use at exit: 2,020 bytes in 31 blocks
==23373==   total heap usage: 32 allocs, 1 frees, 2,025 bytes allocated
==23373== 
==23373== LEAK SUMMARY:
==23373==    definitely lost: 0 bytes in 0 blocks
==23373==    indirectly lost: 0 bytes in 0 blocks
==23373==      possibly lost: 0 bytes in 0 blocks
==23373==    still reachable: 2,020 bytes in 31 blocks
==23373==         suppressed: 0 bytes in 0 blocks
==23373== Rerun with --leak-check=full to see details of leaked memory
==23373== 
==23373== For counts of detected and suppressed errors, rerun with: -v
==23373== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
Segmentation fault (core dumped)

问题： valgrind说在178 line in fileopc.c发生了无效的阅读。但是，我发现这个程序在被178 line in fileopc.c淘汰时从未去过gdb！控制流程的方式与下面不同。

pwndbg> 
176 in fileops.c
────────────────────────────[ DISASM ]────────────────────────────
   0xb7e7184f <_IO_file_close_it+63>     mov    edx, dword ptr [ebx + 0x68]
   0xb7e71852 <_IO_file_close_it+66>     test   edx, edx
 > 0xb7e71854 <_IO_file_close_it+68>   ✔ jle    _IO_file_close_it+151 <0xb7e718a7>
    ↓
   0xb7e718a7 <_IO_file_close_it+151>    push   0
   0xb7e718a9 <_IO_file_close_it+153>    push   0
   0xb7e718ab <_IO_file_close_it+155>    push   0


pwndbg> 
185 in fileops.c
────────────────────────────[ DISASM ]────────────────────────────
   0xb7e7184f <_IO_file_close_it+63>     mov    edx, dword ptr [ebx + 0x68]
   0xb7e71852 <_IO_file_close_it+66>     test   edx, edx
   0xb7e71854 <_IO_file_close_it+68>     jle    _IO_file_close_it+151 <0xb7e718a7>
    ↓
 > 0xb7e718a7 <_IO_file_close_it+151>    push   0
   0xb7e718a9 <_IO_file_close_it+153>    push   0
   0xb7e718ab <_IO_file_close_it+155>    push   0

问题（续）：正如你所看到的，控制流没有达到178 line in fileopc.c，valgrind说bug嵌套在。相反，控制流程直接从176 in fileops.c跳到185 in fileops.c。

题：这里发生了什么？为什么控制流量在valgrind和gdb之间有所不同？是因为这两个工具在产生被检查程序时使用不同的方式吗？