Re: CryptoAPI: schedual while atomic

[James Morris]

On Mon, 30 Aug 2004, Jean-Luc Cooke wrote:

> On Mon, Aug 30, 2004 at 10:42:11AM -0400, James Morris wrote:
> > Where is the code which caused this?  The transforms are safe to use (but
> > not allocate) in process and softirq contexts.
> 
> In add_entropy_words of random.c my experimental code is calling
> crypto_digest_update().  In update() it calles crypto_yield.
> add_entropy_words() is being call ed directly from a keyboard_interrupt.  I
> was hoping to tidy up the code a bit by not using batch_entropy_stores... but
> I guess that's unavoidable then?

You can't call crypto routines from hardirq context.   Think about how 
slow crypto is and why you don't want it running in a hardware irq.


> Last question:
>  Would spin_lock_irqsave() spin_unlock_irqrestore() still needed to surround
>  crypto_digest_update() calls if they're going to be scattered/gathered
>  later?

Not sure exactly what you mean, but you need to serialize calls to 
crypto_digest_update(), yes.


- James
-- 
James Morris
<jmorris@xxxxxxxxxx>


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