Re: IOUserClient size limit?
Re: IOUserClient size limit?
- Subject: Re: IOUserClient size limit?
- From: Kevin Elliott <email@hidden>
- Date: Tue, 11 Nov 2008 09:47:29 -0800
On Nov 10, 2008, at 5:35 PM, Duane Murphy wrote:
Thanks Chris! I would have completely missed the prepare() and
complete() methods.
On a follow up question. My user client APIs map to kernel functions
that expect to get a buffer that they can write into.
IOMemoryDescriptors are setup to use readBytes() and writeBytes()
rather
than direct memory access (e.g. a pointer).
I really hope your doing something different than what it sounds like
your describing. Your UserClient should be exporting an API specific
to your needs, not a generic copy of kernel API's. Generic API's make
it easier to subvert your UserClient and force it do things contrary
to it's intended purpose. If your API is generic, much of your
security comes from secretiveness- Security through obscurity at it's
worse.
Is there a way of getting "buffer" access? Some way of writing
directly
to the underlying memory by address? Is that what map() and
IOMemoryMap
is for?
Map gives you pointer level access to the memory described by the
descriptor.
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