linux-kernel - {PATCH] fix __packed in exported kernel headers

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20110624135100.GB1708@x4.trippels.de>
Date:	Fri, 24 Jun 2011 15:51:00 +0200
From:	Markus Trippelsdorf <markus@...ppelsdorf.de>
To:	Michal Marek <mmarek@...e.cz>
Cc:	Joe Perches <joe@...ches.com>,
	Nick Bowler <nbowler@...iptictech.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Mike Frysinger <vapier@...too.org>,
	Sam Ravnborg <sam@...nborg.org>,
	Artem Bityutskiy <Artem.Bityutskiy@...ia.com>
Subject: {PATCH] fix __packed in exported kernel headers

On 2011.06.24 at 15:07 +0200, Michal Marek wrote:
> On 23.6.2011 18:57, Joe Perches wrote:
> > On Thu, 2011-06-23 at 17:02 +0200, Markus Trippelsdorf wrote:
> >> On 2011.06.23 at 09:42 -0400, Nick Bowler wrote:
> >>> On 2011-06-22 08:34 +0200, Markus Trippelsdorf wrote:
> >>>> One possible solution would be to let the "scripts/headers_install.pl"
> >>>> script automatically substitute __packed with __attribute__((packed)):
> >>>>
> >>>> diff --git a/scripts/headers_install.pl b/scripts/headers_install.pl
> > []
> >> I'm not an expert of Perl regular expressions, but maybe this:
> >>   $line =~ s/\s__packed;$/ __attribute__((packed));/g
> >> is a little bit closer to the intention?
> >
> > Maybe:
> >
> > s/\b__packed\b/__attribute__((packed))/g
> 
> Markus, will you post a patch with this fix?
> 

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.

Cc: Artem Bityutskiy <Artem.Bityutskiy@...ia.com>
CC: Joe Perches <joe@...ches.com>
Signed-off-by: Markus Trippelsdorf <markus@...ppelsdorf.de>
---
 scripts/headers_install.pl |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/scripts/headers_install.pl b/scripts/headers_install.pl
index efb3be1..48462be 100644
--- a/scripts/headers_install.pl
+++ b/scripts/headers_install.pl
@@ -35,6 +35,7 @@ foreach my $file (@files) {
 		$line =~ s/([\s(])__iomem\s/$1/g;
 		$line =~ s/\s__attribute_const__\s/ /g;
 		$line =~ s/\s__attribute_const__$//g;
+		$line =~ s/\b__packed\b/__attribute__((packed))/g;
 		$line =~ s/^#include <linux\/compiler.h>//;
 		$line =~ s/(^|\s)(inline)\b/$1__$2__/g;
 		$line =~ s/(^|\s)(asm)\b(\s|[(]|$)/$1__$2__$3/g;
-- 
Markus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/