c - 仅在不使用调试器时出现段错误

Question

我有一个多线程 C 程序，它始终在程序的特定点生成段错误。当我用 gdb 运行它时，没有显示任何错误。您能想到为什么只有在不使用调试器时才会出现故障吗？不能用它来发现问题是很烦人的!

Answer 1

经典Heisenbug .来自维基百科:

Time can also be a factor in heisenbugs. Executing a program under control of a debugger can change the execution timing of the program as compared to normal execution. Time-sensitive bugs such as race conditions may not reproduce when the program is slowed down by single-stepping source lines in the debugger. This is particularly true when the behavior involves interaction with an entity not under the control of a debugger, such as when debugging network packet processing between two machines and only one is under debugger control.

调试器可能正在改变时序，并隐藏竞争条件。

在 Linux 上，GDB 还禁用地址空间随机化，您的崩溃可能与地址空间布局有关。尝试 (gdb) set disable-randomization off。

最后，ulimit -c unlimited 和事后调试(已由 Robie 建议)可能会起作用。