Re: [RFC] tcp md5 use of alloc_percpu

Crestez Dan Leonard [off-list ref] wrote:

quoted

Yep, but the sg stuff does not allow for stack variables. Because of
possible offloading and DMA, I dont know...

A stack buffer is used in tcp_md5_hash_header to add a tcphdr to the 
hash. A quick grep for sg_init_one find a couple of additional instances 
of what looks like doing crypto on small stack buffers:

First of all crypto_hash_update is obsolete, don't use it in any
new code.  Thanks for reminding me to get rid of existing users.

You should either use crypto_shash_update for small data, e.g., headers
or crypto_ahash_update for large data such as whole packets.

If you use shash then you may allocate your buffer on the stack.  With
ahash stack memory is not allowed.

I hope this clears things up for you.

Cheers,
-- 
Email: Herbert Xu [off-list ref]
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