From: Arnd Bergmann <arnd@arndb.de>
To: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Michal Marek <mmarek@suse.cz>, Joe Perches <joe@perches.com>,
Nick Bowler <nbowler@elliptictech.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Mike Frysinger <vapier@gentoo.org>,
Sam Ravnborg <sam@ravnborg.org>,
Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Subject: Re: {PATCH] fix __packed in exported kernel headers
Date: Fri, 24 Jun 2011 18:33:15 +0200 [thread overview]
Message-ID: <201106241833.15424.arnd@arndb.de> (raw)
In-Reply-To: <20110624135100.GB1708@x4.trippels.de>
On Friday 24 June 2011, Markus Trippelsdorf wrote:
> checkpatch.pl warns about using __attribute__((packed)) in kernel
> headers: "__packed is preferred over __attribute__((packed))". If one
> follows that advice it could cause problems in the exported header
> files, because the outside world doesn't know about this shortcut.
>
> For example busybox will fail to compile:
> CC miscutils/ubi_attach_detach.o
> In file included from miscutils/ubi_attach_detach.c:27:0:
> /usr/include/mtd/ubi-user.h:330:3: error: conflicting types for ‘__packed’
> /usr/include/mtd/ubi-user.h:314:3: note: previous declaration of ‘__packed’ was here
> ...
>
> Fix the problem by substituting __packed with __attribute__((packed)) in
> the header_install.pl script.
No objections to the patch, but it should probably be noted that user
visible data structures should ideally not have any attributes, because
that requires building all applictions using that interface with gcc.
We generally try to add no such requirements on user applications.
Arnd
next prev parent reply other threads:[~2011-06-24 16:34 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-22 6:34 __packed vs. __attribute__((packed)) in kernel headers Markus Trippelsdorf
2011-06-23 13:42 ` Nick Bowler
2011-06-23 15:02 ` Markus Trippelsdorf
2011-06-23 16:57 ` Joe Perches
2011-06-24 13:07 ` Michal Marek
2011-06-24 13:51 ` {PATCH] fix __packed in exported " Markus Trippelsdorf
2011-06-24 15:17 ` Michal Marek
2011-06-24 16:33 ` Arnd Bergmann [this message]
2011-06-24 17:00 ` Mike Frysinger
2011-06-30 18:26 ` H. Peter Anvin
2011-06-30 18:48 ` Mike Frysinger
2011-06-30 18:52 ` H. Peter Anvin
2011-06-30 18:58 ` Mike Frysinger
2011-06-30 19:01 ` H. Peter Anvin
2011-06-30 19:13 ` Mike Frysinger
2011-06-30 20:02 ` H. Peter Anvin
2011-06-30 21:56 ` Mike Frysinger
2011-06-24 17:01 ` Markus Trippelsdorf
2011-06-23 17:04 ` __packed vs. __attribute__((packed)) in " richard -rw- weinberger
2011-06-23 17:46 ` Markus Trippelsdorf
2011-06-23 17:54 ` Mike Frysinger
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