Re: In-kernel process exit hooks?

[Paul Goyette <paul%vps1.whooppee.com@localhost>]

On Fri, 8 Jan 2016, Taylor R Campbell wrote:

>   > Next, I'm going to have a look at fd_getfile2()/fclose() and see if that
>   > is a viable approach.
>
>   Hmmm.  The comments in kern/kern_descrip.c for fd_getfile2() require
>   that the process is not allowed to fork or exit "across this call"
>   (which I assume means "until the reference to the struct file is
>   released").
>
> I don't think that's what it means.  I think it means the process
> whose descriptor we're asking for can't fork or exit *during the call*
> to fd_getfile2.  In this case, it's the current process, so that's not
> an issue.
>
> The reason it is an issue stated in a comment is that the routine
> appears to have been written for the purpose of procfs, in which case
> the calling process is often not the same as the process passed to
> fd_getfile2.

Ah, OK, that makes sense.




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