Re: Address translation

From: Pavel Machek (pavel@suse.cz)
Date: Wed Nov 22 2000 - 19:49:29 EST


Hi!

> otherwise valid) I think the access macros are unnecessary. I would be
> *very* glad if someone could confirm this, or shoot me down. :)
>
> For instance, a kernel module I am writing allocates some memory in
> the current process's address space as follows:
>
> down(&mm->mmap_sem);
> s->table = (void **)get_unmapped_area(0, SIZEOF_TABLE);
> if ( s->table != NULL )
> do_brk((unsigned long)s->table, SIZEOF_TABLE);
> up(&mm->mmap_sem);
>
> Some questions:
> (1) In a "top half" thread, can I now access this memory without the
> access macros (since I know the address range is valid)?
> (2) Can I also access this memory from an interrupt/exception
> context, or must I lock it? (ie. can faults be handled from such
> a context)

poof! I've shooted you.

You may definitely access such memory from interrupt.

-- 
Philips Velo 1: 1"x4"x8", 300gram, 60, 12MB, 40bogomips, linux, mutt,
details at http://atrey.karlin.mff.cuni.cz/~pavel/velo/index.html.

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