From: Antonio Quartulli <antonio@meshcoding.com>
To: The list for a Better Approach To Mobile Ad-hoc Networking
<b.a.t.m.a.n@lists.open-mesh.org>
Cc: netdev@vger.kernel.org, linux@arm.linux.org.uk
Subject: Re: [B.A.T.M.A.N.] [PATCH] Fix ARM BUILD_BUG_ON() errors with batman-adv
Date: Sun, 01 Dec 2013 21:40:24 +0100 [thread overview]
Message-ID: <529B9EB8.8080306@meshcoding.com> (raw)
In-Reply-To: <20131201.142135.880608909113540809.davem@davemloft.net>
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On 01/12/13 20:21, David Miller wrote:
> From: Antonio Quartulli <antonio@meshcoding.com> Date: Sun, 01 Dec
> 2013 15:28:58 +0100
>
>> Am I wrong or this is a problem in the ARM compiler not doing
>> the right assumption? On x86 and x86_64 offset_of dest is 4, as
>> expected.
>
> These alignment behaviors are defined by the processor ABI, there
> is no set of global rules that apply, so it behaves differently on
> different CPUs. What you observe is correct behavior for
> compilation on ARM processors.
>
Ok. So, as far as I understand from your and Russell's explanation,
the only way to allow ARM to support batman-adv is to ensure that all
the _structures_ (no matter if it is a parent structure or not) sent
over the wire have a size multiple of 32bits.
If we want to fix this, I think we have to re-work a little more the
packet layout before 3.13 is released.
People using batman-adv on ARM-equipped smartphones (and similar) will
be happy about this :)
Thanks to both for the hints and for the explanations.
- --
Antonio Quartulli
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next prev parent reply other threads:[~2013-12-01 20:40 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-30 19:15 [B.A.T.M.A.N.] [PATCH] Fix ARM BUILD_BUG_ON() errors with batman-adv Russell King - ARM Linux
2013-11-30 19:15 ` Russell King - ARM Linux
2013-11-30 20:12 ` [B.A.T.M.A.N.] " Antonio Quartulli
2013-11-30 20:12 ` Antonio Quartulli
2013-11-30 23:05 ` [B.A.T.M.A.N.] " Russell King - ARM Linux
2013-11-30 23:05 ` Russell King - ARM Linux
2013-12-01 0:27 ` Antonio Quartulli
2013-12-01 0:27 ` Antonio Quartulli
2013-12-01 14:28 ` [B.A.T.M.A.N.] " Antonio Quartulli
2013-12-01 14:28 ` Antonio Quartulli
2013-12-01 17:13 ` Russell King - ARM Linux
2013-12-01 17:13 ` Russell King - ARM Linux
2013-12-02 10:24 ` [B.A.T.M.A.N.] [PATCH] Fix ARM BUILD_BUG_ON() errors withbatman-adv David Laight
2013-12-02 10:24 ` David Laight
2013-12-02 12:50 ` Antonio Quartulli
2013-12-02 12:50 ` Antonio Quartulli
2013-12-02 13:10 ` David Laight
2013-12-02 13:10 ` David Laight
2013-12-02 16:20 ` David Miller
2013-12-02 16:20 ` David Miller
2013-12-01 19:21 ` [B.A.T.M.A.N.] [PATCH] Fix ARM BUILD_BUG_ON() errors with batman-adv David Miller
2013-12-01 19:21 ` David Miller
2013-12-01 20:40 ` Antonio Quartulli [this message]
2013-11-30 21:05 ` [B.A.T.M.A.N.] " David Miller
2013-11-30 21:05 ` David Miller
2013-11-30 23:03 ` [B.A.T.M.A.N.] " Russell King - ARM Linux
2013-11-30 23:03 ` Russell King - ARM Linux
2013-12-02 17:58 ` [B.A.T.M.A.N.] " Simon Wunderlich
2013-12-02 17:58 ` Simon Wunderlich
2013-12-02 18:38 ` [B.A.T.M.A.N.] " David Miller
2013-12-02 18:38 ` David Miller
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