While scrutinizing vm_mmap.c I noticed that a "hint" address
(non-zero address when the MAP_FIXED flag is NOT set) does
not appear to be checked to make sure it is in user space.

Should the "in user space" checks be applied both with and
without the MAP_FIXED flag?  I know that address zero is
special (means the kernel should choose) but otherwise it
seems to me that the address should be in user space.

Any opinions?

Maybe I should try a test program that supplies a "hint"
address somwhere beyond the end of user space...

Gordon