linux-kernel - Re: [PATCH -mm 1/3] swsusp: Add ioctl for swap files support

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: <200609302237.22086.arnd@arndb.de>
Date:	Sat, 30 Sep 2006 22:37:21 +0200
From:	Arnd Bergmann <arnd@...db.de>
To:	"Rafael J. Wysocki" <rjw@...k.pl>
Cc:	Pavel Machek <pavel@....cz>, Andrew Morton <akpm@...l.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH -mm 1/3] swsusp: Add ioctl for swap files support

Am Saturday 30 September 2006 21:58 schrieb Rafael J. Wysocki:
> > Your definition looks wrong, '_IOW(SNAPSHOT_IOC_MAGIC, 13, void *)' means
> > your ioctl passes a pointer to a 'void *'.
> >
> > You probably mean
> >
> > #define SNAPSHOT_SET_SWAP_AREA _IOW(SNAPSHOT_IOC_MAGIC, 13, \
> >                                               struct resume_swap_area)
>
> No.  I mean the ioctl passes a pointer, the size of which is sizeof(void *).

That's a very bad thing to do. It means that the ioctl number is different
between 32 and 64 bit and you need to write a conversion handler that
first reads your pointer and then then writes the real data.

Also, it needs to be at least _IOR() in the case you're describing,
because the pointer is read, not written (I hope).

	Arnd <><
-
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/