executing from loopback mounts crashes A500

Make an fs in a file, mount it, copy bash in, unmount, lots of disk traffic to flush memory, mount it again, try and execute bash. Random problems, generally resulting in a hung system. With a smaller binary I got a few random errors and then it started working.

Richard

slab:/usr/src/boot-floppies# cd /tmp
slab:/tmp# dd if=/dev/zero of=img bs=1M count=8
8+0 records in
8+0 records out
slab:/tmp# mke2fs img  
mke2fs 1.19, 13-Jul-2000 for EXT2 FS 0.5b, 95/08/09
img is not a block special device.
Proceed anyway? (y,n) y
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
2048 inodes, 8192 blocks
409 blocks (4.99%) reserved for the super user
First data block=1
1 block group
8192 blocks per group, 8192 fragments per group
2048 inodes per group

Writing inode tables: done
Writing superblocks and filesystem accounting information: done

slab:/tmp# mkdir mnt
slab:/tmp# mount -o loop img mnt
slab:/tmp# cp /bin/bash mnt
slab:/tmp# umount mnt
slab:/tmp# dd if=/dev/sda of=/dev/null bs=1M count=256
256+0 records in
256+0 records out
slab:/tmp# mount -o loop img mnt
slab:/tmp# mnt/bash
mnt/bash: error while loading shared libraries: cannot load shared object file: Error 21
slab:/tmp# mnt/bash
Illegal instruction
slab:/tmp# mnt/bash
Illegal instruction
slab:/tmp# mnt/bash
Trace/breakpoint trap

(hung system)