From mboxrd@z Thu Jan  1 00:00:00 1970
From: Luca Boccassi <bluca@debian.org>
Subject: Re: [PATCH] hash: document rte_jhash() boundary behavior
Date: Tue, 19 Sep 2017 11:07:55 +0100
Message-ID: <1505815675.19272.19.camel@debian.org>
References: <20170918194740.23057-1-3chas3@gmail.com>
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Cc: bruce.richardson@intel.com, pablo.de.lara.guarch@intel.com, Chas
 Williams <chas3@att.com>
To: Chas Williams <3chas3@gmail.com>, dev@dpdk.org
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On Mon, 2017-09-18 at 15:47 -0400, Chas Williams wrote:
> From: Chas Williams <chas3@att.com>
>=20
> Due to the uint32_t accesses in the hash computation, keys that
> aren't
> aligned to a uint32_t boundary or multiples of uint32_t in length,
> may
> see accesses beyond the end of the key.=C2=A0=C2=A0This may cross a page
> boundary.
>=20
> Signed-off-by: Chas Williams <chas3@att.com>
> ---
> =C2=A0lib/librte_hash/rte_jhash.h | 5 ++++-
> =C2=A01 file changed, 4 insertions(+), 1 deletion(-)
>=20
> diff --git a/lib/librte_hash/rte_jhash.h
> b/lib/librte_hash/rte_jhash.h
> index 207478c..3eca138 100644
> --- a/lib/librte_hash/rte_jhash.h
> +++ b/lib/librte_hash/rte_jhash.h
> @@ -290,7 +290,10 @@ rte_jhash_32b_2hashes(const uint32_t *k,
> uint32_t length, uint32_t *pc, uint32_t
> =C2=A0/**
> =C2=A0 * The most generic version, hashes an arbitrary sequence
> =C2=A0 * of bytes.=C2=A0=C2=A0No alignment or length assumptions are made=
 about
> - * the input key.
> + * the input key.=C2=A0=C2=A0For keys not aligned to four byte boundarie=
s
> + * or a multiple of four bytes in length, the memory region
> + * just after may be read (but not used in the computation).
> + * This may cross a page boundary.
> =C2=A0 *
> =C2=A0 * @param key
> =C2=A0 *=C2=A0=C2=A0=C2=A0Key to calculate hash of.

Acked-by: Luca Boccassi <bluca@debian.org>

--=20
Kind regards,
Luca Boccassi