I tried to build 2.6.17 and 2.6.17.4 UML on x86-64 with the attached 
.config on a Fedora Core 5 OS, and it broke:

>   CC      arch/um/os-Linux/sys-x86_64/registers.o
> arch/um/os-Linux/sys-x86_64/registers.c: In function ‘get_thread_regs’:
> arch/um/os-Linux/sys-x86_64/registers.c:85: error: ‘JB_PC’ undeclared (first use in this function)
> arch/um/os-Linux/sys-x86_64/registers.c:85: error: (Each undeclared identifier is reported only once
> arch/um/os-Linux/sys-x86_64/registers.c:85: error: for each function it appears in.)
> arch/um/os-Linux/sys-x86_64/registers.c:86: error: ‘JB_RSP’ undeclared (first use in this function)
> arch/um/os-Linux/sys-x86_64/registers.c:87: error: ‘JB_RBP’ undeclared (first use in this function)
> make[2]: *** [arch/um/os-Linux/sys-x86_64/registers.o] Error 1
> make[1]: *** [arch/um/os-Linux/sys-x86_64] Error 2
> make: *** [arch/um/os-Linux] Error 2


Then I tried the latest linux-2.6.git, and it also broke:

>   CC      arch/um/kernel/syscall.o
> arch/um/kernel/syscall.c: In function ‘sys_uname’:
> arch/um/kernel/syscall.c:113: warning: implicit declaration of function ‘utsname’
> arch/um/kernel/syscall.c:113: warning: passing argument 2 of ‘copy_to_user’ makes pointer from integer without a cast
> arch/um/kernel/syscall.c: In function ‘sys_olduname’:
> arch/um/kernel/syscall.c:129: error: invalid type argument of ‘->’
> arch/um/kernel/syscall.c:132: error: invalid type argument of ‘->’
> arch/um/kernel/syscall.c:135: error: invalid type argument of ‘->’
> arch/um/kernel/syscall.c:138: error: invalid type argument of ‘->’
> arch/um/kernel/syscall.c:141: error: invalid type argument of ‘->’
> make[1]: *** [arch/um/kernel/syscall.o] Error 1
> make: *** [arch/um/kernel] Error 2


Would you be kind enough to fix both the stable series (2.6.17.x) and 
upstream to build again?

	Jeff