如何在信号处理程序中更改FPU上下文(C ++/Linux) [英] How to change FPU context in signal handler (C++/Linux)

问题描述

我写了一个信号处理程序来捕获FPE错误.即使发生这种情况，我也需要继续执行.我收到ucontext_t作为参数，我可以将错误的操作数从0更改为另一个值，但是FPU上下文仍然很糟糕，并且我遇到了无限循环?

I wrote a signal handler to catch FPE errors. I need to continue execution even if this happens. I receive a ucontext_t as parameter, I can change the bad operand from 0 to another value but the FPU context is still bad and I run into an infinite loop ?

有人已经在Linux上操纵过ucontext_t结构吗?

Does someone already manupulate the ucontext_t structure on Linux ?

我终于找到了一种通过清除ucontext_t的状态标志来处理这些情况的方法，如下所示:

I finally found a way to handle these situations by clearing the status flag of ucontext_t like this:

...
const long int cFPUStatusFlag = 0x3F;
aContext->uc_mcontext.fpregs->sw &= ~cFPUStatusFlag;
...

0x3F取反，则将0放置在FPU(x87)的状态寄存器的6位中.这样做意味着在计算后检查FPE异常.

0x3F is negated to put 0 in the 6 bits of the status register of the FPU (x87). Doing this implies to check for FPE exceptions after calculation.

推荐答案

在64位linux内核上，我没有找到实现同一目标的任何方法.

On 64 bits linux kernel, I did not find any way to achieve the same thing.

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