Am using Redhat 9.0 (Kernel version: 2.4.20-8)
I hv installed UML (kernel 2.4.20 & uml patch 2.4.20-1) in my PC

The procedure tat i followed was

1) root# cd ~/uml/
   root# tar -xjvf linux-2.4.20.tar.bz2

2) root# cd ~/uml/linux-2.4.20
   root# bzcat uml-patch-2.4.20-1.bz2 | patch -p1

3) root# make config ARCH=um
         (set default values)

4) root# make linux ARCH=um

5) root# make modules ARCH=um

6) root# bunzip2 root_fs.rh-7.2-full.pristine20020312.bz

7) root# mkdir mnt

8) root# mount root_fs.rh-7.2-full.pristine20020312 mnt -o loop

9) root# umount mnt

   Things went fine till i started the kernel

10) root# ./linux ubd0=root_fs.rh-7.2-full.pristine20020312

resulted in

Checking for the skas3 patch in the host...not found
Checking for /proc/mm...not found
tracing thread pid = 32175
Linux version 2.4.20-1um (root@localhost.localdomain ) (gcc version 3.2.2 20030222 (Red Hat Linux 3.2.2-5)) #1 Mon Mar 27 12:06:10 IST 2006
On node 0 totalpages: 8192
zone(0): 8192 pages.
zone(1): 0 pages.
zone(2): 0 pages.
Kernel command line: ubd0=root_fs root=/dev/ubd0
Calibrating delay loop... 570.73 BogoMIPS
Memory: 29328k available
Dentry cache hash table entries: 4096 (order: 3, 32768 bytes)
Inode cache hash table entries: 2048 (order: 2, 16384 bytes)
Mount-cache hash table entries: 512 (order: 0, 4096 bytes)
Buffer-cache hash table entries: 1024 (order: 0, 4096 bytes)
Page-cache hash table entries: 8192 (order: 3, 32768 bytes)
Checking for host processor cmov support...Yes
Checking for host processor xmm support...No
Checking that ptrace can change system call numbers...OK
Checking that host ptys support output SIGIO...Yes
Checking that host ptys support SIGIO on close...No, enabling workaround
POSIX conformance testing by UNIFIX
Linux NET4.0 for Linux 2.4
Based upon Swansea University Computer Society NET3.039
Initializing RT netlink socket
Starting kswapd
Kernel panic: outer trampoline didn't exit with SIGKILL

I dont know wat went wrong... Can u plz help me...
Thanks & Regards