Re: [BUG] crypto: caam - RSA encrypt doesn't always complete new data in out_buf

[Herbert Xu]

On Thu, Feb 26, 2026 at 08:17:18AM +0100, Lukas Wunner wrote:
>
> That's fine for the RSA software implementation in crypto/rsa.c but
> I could very well imagine it causes problems with an RSA accelerator,
> particularly because rsa_edesc_alloc() in drivers/crypto/caam/caampkc.c
> now maps the same buffer with DMA_TO_DEVICE and then DMA_FROM_DEVICE.

That's definitely not good.  It needs to handle in-place encryption
by using DMA_BIDIRECTIONAL.  If the hardware is not capable of that
then an extra copy must be performed by the driver.

Thanks,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
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