From: Arnd Bergmann <arnd@arndb.de>
To: linux-arm-kernel@lists.infradead.org
Cc: Alan Stern <stern@rowland.harvard.edu>,
Nicolas Pitre <nico@fluxnic.net>,
gregkh@suse.de, linux-usb@vger.kernel.org,
lkml <linux-kernel@vger.kernel.org>, Rabin Vincent <rabin@rab.in>,
Alexander Holler <holler@ahsoftware.de>
Subject: Re: [PATCH] USB: ehci: use packed,aligned(4) instead of removing the packed attribute
Date: Sun, 19 Jun 2011 22:11:00 +0200 [thread overview]
Message-ID: <201106192211.01076.arnd@arndb.de> (raw)
In-Reply-To: <201106192202.23989.arnd@arndb.de>
On Sunday 19 June 2011 22:02:23 Arnd Bergmann wrote:
> In this case, we would have to do
>
> struct s {
> char c[2];
> } __packed;
>
> struct t {
> struct s t1;
> unsigned short t2[3] __aligned(2);
> } __packed;
>
> To tell the compiler that t2 is indeed aligned, while struct t
> is packed to include no padding around t.
>
> I actually recently stumbled over code that gets this wrong,
> see
>
> http://git.kernel.org/?p=linux/kernel/git/arnd/playground.git;a=commit;h=284cef173aafd531a708f48e71a9cc7249fc8a98
>
Just to be clear: none of the ehci structures fall into this category.
I would assume that we actually have a few more drivers with this
bug in the kernel, but the patch proposed by Alexander would not
help with this problem, and the EHCI driver is still correct without
__packed.
Arnd
WARNING: multiple messages have this Message-ID (diff)
From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] USB: ehci: use packed, aligned(4) instead of removing the packed attribute
Date: Sun, 19 Jun 2011 22:11:00 +0200 [thread overview]
Message-ID: <201106192211.01076.arnd@arndb.de> (raw)
In-Reply-To: <201106192202.23989.arnd@arndb.de>
On Sunday 19 June 2011 22:02:23 Arnd Bergmann wrote:
> In this case, we would have to do
>
> struct s {
> char c[2];
> } __packed;
>
> struct t {
> struct s t1;
> unsigned short t2[3] __aligned(2);
> } __packed;
>
> To tell the compiler that t2 is indeed aligned, while struct t
> is packed to include no padding around t.
>
> I actually recently stumbled over code that gets this wrong,
> see
>
> http://git.kernel.org/?p=linux/kernel/git/arnd/playground.git;a=commit;h=284cef173aafd531a708f48e71a9cc7249fc8a98
>
Just to be clear: none of the ehci structures fall into this category.
I would assume that we actually have a few more drivers with this
bug in the kernel, but the patch proposed by Alexander would not
help with this problem, and the EHCI driver is still correct without
__packed.
Arnd
next prev parent reply other threads:[~2011-06-19 20:12 UTC|newest]
Thread overview: 124+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-27 14:34 [PATCH] echi: remove structure packing from ehci_def Rabin Vincent
2011-04-27 14:34 ` Rabin Vincent
2011-04-27 15:15 ` Sergei Shtylyov
2011-04-27 15:15 ` Sergei Shtylyov
2011-04-27 15:37 ` [PATCHv2] " Rabin Vincent
2011-04-27 15:37 ` Rabin Vincent
2011-06-16 16:17 ` [PATCH] USB: ehci: use packed,aligned(4) instead of removing the packed attribute Alexander Holler
2011-06-16 16:17 ` [PATCH] USB: ehci: use packed, aligned(4) " Alexander Holler
2011-06-16 17:09 ` [PATCH] USB: ehci: use packed,aligned(4) " Alan Stern
2011-06-16 17:09 ` Alan Stern
2011-06-16 17:55 ` Arnd Bergmann
2011-06-16 17:55 ` [PATCH] USB: ehci: use packed, aligned(4) " Arnd Bergmann
2011-06-16 19:25 ` [PATCH] USB: ehci: use packed,aligned(4) " Alexander Holler
2011-06-16 19:25 ` Alexander Holler
2011-06-16 19:46 ` Alan Stern
2011-06-16 19:46 ` Alan Stern
2011-06-16 20:10 ` Alexander Holler
2011-06-16 20:10 ` Alexander Holler
2011-06-16 20:20 ` Arnd Bergmann
2011-06-16 20:20 ` [PATCH] USB: ehci: use packed, aligned(4) " Arnd Bergmann
2011-06-19 15:02 ` [PATCH] USB: ehci: use packed,aligned(4) " Nicolas Pitre
2011-06-19 15:02 ` [PATCH] USB: ehci: use packed, aligned(4) " Nicolas Pitre
2011-06-19 19:00 ` [PATCH] USB: ehci: use packed,aligned(4) " Alan Stern
2011-06-19 19:00 ` Alan Stern
2011-06-19 20:02 ` Arnd Bergmann
2011-06-19 20:02 ` [PATCH] USB: ehci: use packed, aligned(4) " Arnd Bergmann
2011-06-19 20:11 ` Arnd Bergmann [this message]
2011-06-19 20:11 ` Arnd Bergmann
2011-06-19 21:39 ` [PATCH] USB: ehci: use packed,aligned(4) " Nicolas Pitre
2011-06-19 21:39 ` [PATCH] USB: ehci: use packed, aligned(4) " Nicolas Pitre
2011-06-19 21:27 ` [PATCH] USB: ehci: use packed,aligned(4) " Nicolas Pitre
2011-06-19 21:27 ` [PATCH] USB: ehci: use packed, aligned(4) " Nicolas Pitre
2011-06-20 15:03 ` [PATCH] USB: ehci: use packed,aligned(4) " Alan Stern
2011-06-20 15:03 ` Alan Stern
2011-06-20 16:16 ` Nicolas Pitre
2011-06-20 16:16 ` [PATCH] USB: ehci: use packed, aligned(4) " Nicolas Pitre
2011-06-20 16:48 ` [PATCH] USB: ehci: use packed,aligned(4) " Alan Stern
2011-06-20 16:48 ` Alan Stern
2011-06-20 16:58 ` Arnd Bergmann
2011-06-20 16:58 ` [PATCH] USB: ehci: use packed, aligned(4) " Arnd Bergmann
2011-06-20 19:02 ` Russell King - ARM Linux
2011-06-20 19:02 ` Russell King - ARM Linux
2011-06-20 19:20 ` Nicolas Pitre
2011-06-20 19:20 ` Nicolas Pitre
2011-06-20 19:29 ` Nicolas Pitre
2011-06-20 19:29 ` Nicolas Pitre
2011-06-20 17:10 ` [PATCH] USB: ehci: use packed,aligned(4) " Nicolas Pitre
2011-06-20 17:10 ` [PATCH] USB: ehci: use packed, aligned(4) " Nicolas Pitre
2011-06-20 17:35 ` [PATCH] USB: ehci: use packed,aligned(4) " Alan Stern
2011-06-20 17:35 ` Alan Stern
2011-06-20 18:48 ` Russell King - ARM Linux
2011-06-20 18:48 ` Russell King - ARM Linux
2011-06-20 20:26 ` Arnd Bergmann
2011-06-20 20:26 ` [PATCH] USB: ehci: use packed, aligned(4) " Arnd Bergmann
2011-06-20 20:50 ` Nicolas Pitre
2011-06-20 20:50 ` Nicolas Pitre
2011-06-20 20:55 ` [PATCH] USB: ehci: use packed,aligned(4) " Russell King - ARM Linux
2011-06-20 20:55 ` Russell King - ARM Linux
2011-06-20 21:23 ` Arnd Bergmann
2011-06-20 21:23 ` [PATCH] USB: ehci: use packed, aligned(4) " Arnd Bergmann
2011-06-20 22:23 ` [PATCH] USB: ehci: use packed,aligned(4) " Nicolas Pitre
2011-06-20 22:23 ` [PATCH] USB: ehci: use packed, aligned(4) " Nicolas Pitre
2011-06-21 11:25 ` [PATCH] USB: ehci: use packed,aligned(4) " Arnd Bergmann
2011-06-21 11:25 ` [PATCH] USB: ehci: use packed, aligned(4) " Arnd Bergmann
2011-06-25 1:25 ` Nicolas Pitre
2011-06-25 8:09 ` Arnd Bergmann
2011-06-28 18:51 ` Nicolas Pitre
2011-06-29 10:56 ` Arnd Bergmann
2011-06-20 19:14 ` [PATCH] USB: ehci: use packed,aligned(4) " Nicolas Pitre
2011-06-20 19:14 ` [PATCH] USB: ehci: use packed, aligned(4) " Nicolas Pitre
2011-06-20 19:32 ` Russell King - ARM Linux
2011-06-20 19:32 ` Russell King - ARM Linux
2011-06-20 20:14 ` Arnd Bergmann
2011-06-20 20:14 ` Arnd Bergmann
2011-06-20 20:42 ` [PATCH] USB: ehci: use packed,aligned(4) " Alan Stern
2011-06-20 20:42 ` Alan Stern
2011-06-20 22:36 ` Nicolas Pitre
2011-06-20 22:36 ` [PATCH] USB: ehci: use packed, aligned(4) " Nicolas Pitre
2011-06-21 15:06 ` [PATCH] USB: ehci: use packed,aligned(4) " Alan Stern
2011-06-21 15:06 ` Alan Stern
2011-06-20 17:39 ` Alexander Holler
2011-06-20 17:39 ` Alexander Holler
2011-06-20 18:39 ` Alan Stern
2011-06-20 18:39 ` Alan Stern
2011-06-20 18:46 ` Alexander Holler
2011-06-20 18:46 ` Alexander Holler
2011-06-20 18:57 ` Alan Stern
2011-06-20 18:57 ` Alan Stern
2011-06-20 19:56 ` Nicolas Pitre
2011-06-20 19:56 ` [PATCH] USB: ehci: use packed, aligned(4) " Nicolas Pitre
2011-06-20 21:04 ` [PATCH] USB: ehci: use packed,aligned(4) " Alan Stern
2011-06-20 21:04 ` Alan Stern
2011-06-20 22:31 ` Nicolas Pitre
2011-06-20 22:31 ` [PATCH] USB: ehci: use packed, aligned(4) " Nicolas Pitre
2011-06-21 14:58 ` [PATCH] USB: ehci: use packed,aligned(4) " Alan Stern
2011-06-21 14:58 ` Alan Stern
2011-06-21 20:41 ` Nicolas Pitre
2011-06-21 20:41 ` [PATCH] USB: ehci: use packed, aligned(4) " Nicolas Pitre
2011-06-22 6:23 ` [PATCH] USB: ehci: use packed,aligned(4) " Alexander Holler
2011-06-22 6:23 ` Alexander Holler
2011-06-20 20:09 ` Arnd Bergmann
2011-06-20 20:09 ` [PATCH] USB: ehci: use packed, aligned(4) " Arnd Bergmann
2011-06-20 21:05 ` [PATCH] USB: ehci: use packed,aligned(4) " Alan Stern
2011-06-20 21:05 ` Alan Stern
2011-06-20 20:07 ` Arnd Bergmann
2011-06-20 20:07 ` [PATCH] USB: ehci: use packed, aligned(4) " Arnd Bergmann
2011-06-20 20:28 ` [PATCH] USB: ehci: use packed,aligned(4) " Nicolas Pitre
2011-06-20 20:28 ` [PATCH] USB: ehci: use packed, aligned(4) " Nicolas Pitre
2011-06-20 20:39 ` Arnd Bergmann
2011-06-20 20:39 ` Arnd Bergmann
2011-06-20 21:03 ` Nicolas Pitre
2011-06-20 21:03 ` Nicolas Pitre
2011-06-23 9:47 ` Alexander Holler
2011-06-23 9:47 ` Alexander Holler
2011-06-23 14:25 ` Alan Stern
2011-06-23 14:25 ` Alan Stern
2011-06-24 11:40 ` Alexander Holler
2011-06-24 11:40 ` Alexander Holler
2011-06-20 16:26 ` [PATCH] USB: ehci: use packed,aligned(4) " Arnd Bergmann
2011-06-20 16:26 ` [PATCH] USB: ehci: use packed, aligned(4) " Arnd Bergmann
2011-06-16 20:30 ` [PATCH] USB: ehci: use packed,aligned(4) " Alan Stern
2011-06-16 20:30 ` Alan Stern
2011-06-16 18:16 ` Alexander Holler
2011-06-16 18:16 ` Alexander Holler
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