Messages in this thread |  | | Date | Thu, 22 Nov 2001 13:43:03 +0100 (CET) | From | Richard Guenther <> | Subject | Re: fs/exec.c and binfmt-xxx in 2.4.14 |
| |
On Thu, 22 Nov 2001, Heinz-Ado Arnolds wrote:
> Andreas Ferber wrote: > > > > On Wed, Nov 21, 2001 at 05:58:26PM +0100, Heinz-Ado Arnolds wrote: > > > > > > When i now try to start an older binary in a.out format, which has a > > > magic number of 0x010b0064, it is translated with the 'new' code to a > > > request for "binfmt-0064" instead of "binfmt-267" as expected and > > > properly handled by modprobe. > > > > Then add > > > > alias binfmt-0064 binfmt_aout > > > > to /etc/modules.conf. Simple, isn't it? > > That's a nice idea but I wouldn't rely on the fact that the third > and the fourth byte of a file are sufficient to identify the type. > If you look at the magic numbers in /etc/magic, you'll find: > > 0x00640107 Linux/i386 impure executable (OMAGIC) > 0x00640108 Linux/i386 pure executable (NMAGIC) > 0x0064010b Linux/i386 demand-paged executable (ZMAGIC) > 0x006400cc Linux/i386 demand-paged executable (QMAGIC) > =0514 80386 COFF executable > > It's standard to count on the first (and eventually following) bytes. > > And if you look further on in /etc/magic, you'll see that there are > other file types having 0x0064 as 3rd and 4th byte.
Note that the 3rd and 4th byte are not used to identify a binary format, but just to auto-load a possibly available module that can possibly handle that format. So it doesnt really matter if there are multiple filetypes causing the load of the same binary handler module.
Richard.
-- Richard Guenther <richard.guenther@uni-tuebingen.de> WWW: http://www.tat.physik.uni-tuebingen.de/~rguenth/ The GLAME Project: http://www.glame.de/
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |