Re: [Patch]: write_kmem above high_memory
Andi Kleen (ak@muc.de)
Tue, 4 Jan 2000 15:14:16 +0100
On Tue, Jan 04, 2000 at 03:00:18PM +0100, Alan Cox wrote:
> > > functions, and instead protect the read/writes with a exception table
> > > entry similar to copy_from/to_user. Only drawback is that it needs
> > > per architecture support.
> > >
> >
> > set_fs(KERNEL_DS) + get_user()/__get_user()?
> >
> > BUT: that's dangerous, because we might read from the mmap'ed io space
> > of a hardware device.
>
> You are not guaranteed to get exception faults on invalid writes. Not all
> platforms support them even. Eg i386 writes to user pages marked R/O will
> not fault.
/dev/mem should not care about page protections I think.
-Andi
--
This is like TV. I don't like TV.
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