Re: [9fans] Memory management questions/not plan-9 specific

[Paul Lalonde <plalonde@telus.net>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Ah, I see the light.

I'll give it a shot :-)

Paul

On Nov 6, 2007, at 10:28 AM, ron minnich wrote:

> On 11/6/07, Robert William Fuller <hydrologiccycle@gmail.com> wrote:
>> Paul Lalonde wrote:
>>>
>>> On Nov 6, 2007, at 10:29 AM, Robert William Fuller wrote:
>>>>> In UNIX, set up a signal handler for SIGSEGV.
>>>
>>> Not quite enough - I still need to reserve some address space.  mmap
>>> doesn't let me reserve it without backing it.
>>
>> It does by default on Linux :-)
>>
>
> mmap /dev/zero over the region you want. Or not, you can just any
> piece of your address space, actually.
>
> mprotect it (page-aligned, now!0 so you can't access it. record the
> fact that you did this. i.e. set up data structures that allow you to
> tell, in the segv handler, that it's a "page fault" and not a true
> screwup in your code.
>
> in the segv handler, get the fault address and type, search your
> structs, figure out what to do. Be sure to compute page frame from the
> address, etc. etc. fix it up with memprotect. record what you did.
> return.
>
> that's pretty much what I did.
>
> ron

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.3 (Darwin)

iD8DBQFHMMqypJeHo/Fbu1wRAqUQAJ4hn3Di6umwfmDRkz2l9vGoxlAoZACgsXgc
ejFMKTf4qP4qJLIOPkzcwMQ=
=HC5E
-----END PGP SIGNATURE-----