signal design questions
youshi10 at u.washington.edu
Sun Nov 12 06:37:37 UTC 2006
On Nov 11, 2006, at 10:55 AM, Wenyen, Shih wrote:
> Hi all,
> I have some questions.
> (1) I know how to delivery of a signal to a
> 1. The kernel places a signal context on the
> user's stack.(user level)
> 2. The kernel places a signal-handler frame on
> the user's stack.(kernel level)
> 3. The user's signal handler returns to the
> sigtramp() routine, which pops the signal-handler
> context from the user's stack.(user level)
> 4. The sigtramp() routine finishes by calling
> the sigreturn system call.
> But, why don't implement signal handler routine
> in kernel level? Are there having any ideas to
> implement signal handler routine in kernel level?
> (2) The system-call exit code first checks for a
> posted signal and check to see whether any process has
> a priority higher than that of the currently running
> But, I don't know the signal be checked when
> returning from kernel mode to user mode.
> Anyone have any other methods to checked the
> signal in the other occasion ?
I would suggest asking this question on the freebsd-hackers list.
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