Here is a patch to fix a problem of might-sleep-in-atomic which David
Mosberger mentioned at
http://www.gelato.unsw.edu.au/linux-ia64/0407/10526.html

On IA64 platform, a might-sleep-in-atomic warning raise while dumping a
multi-thread process.  That is because elf_core_dump holds the tasklist_lock
before the kernel does a access_process_vm in elf_core_copy_task_regs,

This patch detached elf_core_copy_task_regs function from inside
tasklist_lock to remove the warning.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>