如何使用 gdb 调试加载 LD_PRELOAD 的动态库中的函数？
我正在尝试调试动态共享库 libexecHook.so 中的一些函数。该库已预先加载并设置 LD_PRELOAD，以便拦截和重写对 execve() 等的一些调用。为了调试目的，我用符号构建了 gmake。从我在其他问题中读到的内容来看，这应该可行：
gdb ~/tmp/make-dfsg-3.81/make
set exec-wrapper env LD_PRELOAD=/home/marko/execHook.C027/lib/libexecHook.so.0.0.0
start
break execve
break execvp
cont
我确实看到断点设置正确，例如
4 breakpoint keep y 0x00007ffff7bd92e0 in execvp at execHook.c:128
，但 gdb 永远不会在我预加载的 exec..() 函数处中断。在执行期间观察调试输出，我看到正在调用我的库函数。
I'm trying to debug some functions in a dynamic shared library libexecHook.so. This library is preloaded setting LD_PRELOAD in order to intercept and rewrite some calls to execve() and friends. For debugging purposes I have built gmake with symbols. From what I read in other questions this should work:
gdb ~/tmp/make-dfsg-3.81/make
set exec-wrapper env LD_PRELOAD=/home/marko/execHook.C027/lib/libexecHook.so.0.0.0
start
break execve
break execvp
cont
I do see the breakpoints being set properly, e.g.
4 breakpoint keep y 0x00007ffff7bd92e0 in execvp at execHook.c:128
but gdb never breaks at my preloaded exec..() functions. Watching the debug output during execution I see that the my library functions are being called.
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gdb 没有在我的预加载包装器函数处中断的原因是，这些函数是从 gdb 未附加的子进程执行的。在 Linux 上，我可以
使 gdb 附加到在 vfork() 中创建的子级。
The reason gdb did not break at my preloaded wrapper functions is that these are executed from a child process to which gdb was not attached. On Linux I can
to make gdb attach to the child that gets created in a
vfork().在设置断点之前尝试说
start。这将开始运行程序，这将导致库依赖关系得到满足，希望使用您的 LD_PRELOAD 路径。然后启动后设置断点，然后继续。Try saying
startbefore setting your breakpoints. This will begin running the program which will cause the library dependencies to be satisfied, hopefully using your LD_PRELOAD path. Then set the breakpoints after start, and then do continue.