Re: modularized SYSENTER support

Manfred Spraul
2001-05-04T18:14:55Z

> Q. How come the handler doesn't manage so called "bottom halves" or
> "soft IRQs"?
> A. There is no need for this. Soft IRQs can only appear at exit from
> hardware interrupt handlers. Indeed, we can't count on user app.
> being around and performing a system call when it comes to
> interrupt handling, right?

That's probably a bug.
syscall
* spin_lock_bh()
* hardware interrupt arrives
* BH's are blocked, delayed
* spin_unlock_bh()
* return from syscall.

You must check for softirq's before returning.

--
Manfred