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Re: Is it possible to preserve flags for fetestexcept() inside signal handler
On Thu, Jun 7, 2012 at 3:58 PM, Carlos O'Donell
<carlos_odonell@mentor.com> wrote:
> For example: Why can't you use systemtap to solve your debugging problem?
>
> The answer might be: Because this is easier to setup.
Yes, our general solution is more portable for the funky environments
described in the last section. The information we can provide with
this mechanism would be richer if we could get fetestexcept(). For
more complicated cases, we recommend that users work out a way to use
a debugger or similar tool, this is just lightweight and does not
affect performance until it is triggered.
> Next steps:
>
> - Determine why fetestexcept doesn't work from a signal handler.
>
> Looking at sysdeps/i386/fpu/ftestexcept.c[1], it seems like it *should*
> just work from a signal, but it's likely the kernel saves but doesn't
> restore this state when it delivers the signal. I suggest you go talk
> to the kernel people about this.
Okay, thank you.