Linux内核中用于信号处理的堆栈框架 [英] Stack frame for signal handling in the Linux Kernel

问题描述

我看到在功能setup_rt_frame()中分配了处理信号所需的堆栈帧.

I see that the stack frame the process needs to handle signals is allocated in the function setup_rt_frame().

我的问题是:它在哪里被取消分配?

My question is: where it is de-allocated?

谢谢！

推荐答案

setup_rt_frame()为实时信号设置堆栈(请参见

setup_rt_frame() sets stack for Real-time signals (see man 7 signal). It does 2 main things:

1. 将用户进程的CPU上下文(在中断之前)从内核堆栈保存到用户堆栈.
   对于ARM体系结构，它是在 setup_sigframe().
2. 将返回地址(信号处理程序返回的位置)保存到用户堆栈.
   返回地址将指向rt_sigreturn()系统调用(请参见 man 2 sigreturn 了解详情).
   对于ARM体系结构，它是在 setup_return().

1. Saves CPU context of user process (before it was interrupted) from kernel stack to user stack.
   For ARM architecture it's done in setup_sigframe().
2. Saves return address (where signal handler returns) to user stack.
   Return address will point to rt_sigreturn() syscall (see man 2 sigreturn for details).
   For ARM architecture it's done in setup_return().

如您所见，信号处理程序完成后，它将自动返回到内核中的sys_rt_sigreturn()函数.此功能将从用户堆栈中恢复内核堆栈，并返回到中断的用户空间进程.

As you can see, once signal handler is finished, it will automatically return to sys_rt_sigreturn() function in kernel. This function will restore kernel stack from user stack and get back to interrupted user-space process.

所以，回答您的问题:

在哪里取消分配?

where it is de-allocated?

正在使用sys_rt_sigreturn()功能对其进行恢复.

It's being restored in sys_rt_sigreturn() function.

另请参阅:

[1] 信号如何在内部起作用?

[2] 谁使用POSIX实时信号，为什么?

[3] 信号处理的实现(请参见小节从传递信号(7)"到传递信号(12)")

[3] Implementation of signal handling (see sections "Delivering Signals (7)" to "Delivering Signals (12)")

这篇关于Linux内核中用于信号处理的堆栈框架的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！