From: David Laight <David.Laight@ACULAB.COM>
To: 'Qian Cai' <cai@lca.pw>,
"vyasevich@gmail.com" <vyasevich@gmail.com>,
"nhorman@tuxdriver.com" <nhorman@tuxdriver.com>,
"marcelo.leitner@gmail.com" <marcelo.leitner@gmail.com>
Cc: "linux-sctp@vger.kernel.org" <linux-sctp@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] net/sctp: fix GCC8+ -Wpacked-not-aligned warnings
Date: Mon, 29 Jul 2019 10:39:16 +0000 [thread overview]
Message-ID: <158b26b6f3b24164aceacd2428095315@AcuMS.aculab.com> (raw)
In-Reply-To: <1564174659-21211-1-git-send-email-cai@lca.pw>
From: Qian Cai
> Sent: 26 July 2019 21:58
>
> There are a lot of those warnings with GCC8+ 64bit,
>
...
> Fix them by aligning the structures and fields to 8 bytes instead.
...
> struct sctp_setpeerprim {
> sctp_assoc_t sspp_assoc_id;
> - struct sockaddr_storage sspp_addr;
> -} __attribute__((packed, aligned(4)));
> + struct sockaddr_storage sspp_addr __attribute__((aligned(8)));
> +} __attribute__((packed, aligned(8)));
What happens to this one if you change both to aligned(4) ?
Much the same way as:
struct {
int a;
long b __attribute__((aligned(4));
};
is only 12 bytes on (most) 64bit systems.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2019-07-29 10:39 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-26 20:57 [PATCH] net/sctp: fix GCC8+ -Wpacked-not-aligned warnings Qian Cai
2019-07-26 21:30 ` Marcelo Ricardo Leitner
2019-07-28 17:05 ` Qian Cai
2019-07-28 19:41 ` Marcelo Ricardo Leitner
2019-07-29 10:39 ` David Laight [this message]
2019-07-29 15:16 ` Qian Cai
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