Re: [PATCH v2 net] tcp: md5: do not use alloc_percpu()

From: Eric Dumazet <redacted>
Date: Thu, 23 Oct 2014 12:58:58 -0700

From: Eric Dumazet <edumazet@google.com>

percpu tcp_md5sig_pool contains memory blobs that ultimately
go through sg_set_buf().

-> sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));

This requires that whole area is in a physically contiguous portion
of memory. And that @buf is not backed by vmalloc().

Given that alloc_percpu() can use vmalloc() areas, this does not
fit the requirements.

Replace alloc_percpu() by a static DEFINE_PER_CPU() as tcp_md5sig_pool
is small anyway, there is no gain to dynamically allocate it.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 765cf9976e93 ("tcp: md5: remove one indirection level in tcp_md5sig_pool")
Reported-by: Crestez Dan Leonard <redacted>

Applied and queued up for -stable, thanks Eric.

Longer term we should do a proper shash/ahash conversion of the tcp md5
code, using the rules provided by Herbert Xu.

Thanks.