Re: [PATCH v8 3/3] crypto: Add Inside Secure SafeXcel EIP-93 crypto engine support

Herbert Xu
2024-12-11T09:31:29Z

On Tue, Dec 10, 2024 at 09:48:33PM +0100, Christian Marangi wrote:
>
> + /*
> + * Consume remaining data.
> + * 1. Loop until we consume all the data in block of 64bytes
> + * 2. Send full block of 64bytes
> + * 3. Skip sending last block for future update() or for final() to
> + * enable HASH_FINALIZE bit.
> + */
> + while (to_consume > 0) {
> + int to_read = min(to_consume, SHA256_BLOCK_SIZE);
> +
> + block = kzalloc(sizeof(*block), GFP_KERNEL);

You should avoid allocating memory. If you really must do it,
then it needs to be GFP_ATOMIC, and your algorithm needs to set
CRYPTO_ALG_ALLOCATES_MEMORY which means that it won't be used
by the storage layer as memory allocations may lead to dead-lock.

The preferred way to access extra memory is through the request
context structure.

Cheers,
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
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