uml: deal with inaccessible address space start
authorTom Spink <tspink@gmail.com>
Fri, 6 Jun 2008 05:46:12 +0000 (22:46 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 6 Jun 2008 18:29:10 +0000 (11:29 -0700)
commit40fb16a360d9c6459afee91dc793c1e3374feb94
treebbe5f8a4185ac6784d82ee8c938bb246518f6791
parent9f31287b443f30a591539e448fb628e3827a8f61
uml: deal with inaccessible address space start

This patch makes os_get_task_size locate the bottom of the address space,
as well as the top.  This is for systems which put a lower limit on mmap
addresses.  It works by manually scanning pages from zero onwards until a
valid page is found.

Because the bottom of the address space may not be zero, it's not
sufficient to assume the top of the address space is the size of the
address space.  The size is the difference between the top address and
bottom address.

[jdike@addtoit.com: changed the name to reflect that this function is
supposed to return the top of the process address space, not its size and
changed the return value to reflect that.  Also some minor formatting
changes]
Signed-off-by: Tom Spink <tspink@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/um/include/os.h
arch/um/kernel/um_arch.c
arch/um/os-Linux/sys-i386/task_size.c
arch/um/os-Linux/sys-x86_64/task_size.c