mirror of
https://github.com/torvalds/linux.git
synced 2024-11-15 00:21:59 +00:00
536788fe2d
Calculate TASK_SIZE at run-time by figuring out the host's VMSPLIT - this is needed on i386 if UML is to run on hosts with varying VMSPLITs without recompilation. TASK_SIZE is now defined in terms of a variable, task_size. This gets rid of an include of pgtable.h from processor.h, which can cause include loops. On i386, task_size is calculated early in boot by probing the address space in a binary search to figure out where the boundary between usable and non-usable memory is. This tries to make sure that a page that is considered to be in userspace is, or can be made, read-write. I'm concerned about a system-global VDSO page in kernel memory being hit and considered to be a userspace page. On x86_64, task_size is just the old value of CONFIG_TOP_ADDR. A bunch of config variable are gone now. CONFIG_TOP_ADDR is directly replaced by TASK_SIZE. NEST_LEVEL is gone since the relocation of the stubs makes it irrelevant. All the HOST_VMSPLIT stuff is gone. All references to these in arch/um/Makefile are also gone. I noticed and fixed a missing extern in os.h when adding os_get_task_size. Note: This has been revised to fix the 32-bit UML on 64-bit host bug that Miklos ran into. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
52 lines
870 B
Plaintext
52 lines
870 B
Plaintext
menu "Host processor type and features"
|
|
|
|
source "arch/x86/Kconfig.cpu"
|
|
|
|
endmenu
|
|
|
|
config UML_X86
|
|
bool
|
|
default y
|
|
|
|
config X86_32
|
|
bool
|
|
default y
|
|
|
|
config RWSEM_XCHGADD_ALGORITHM
|
|
def_bool y
|
|
|
|
config 64BIT
|
|
bool
|
|
default n
|
|
|
|
config SEMAPHORE_SLEEPERS
|
|
bool
|
|
default y
|
|
|
|
config 3_LEVEL_PGTABLES
|
|
bool "Three-level pagetables (EXPERIMENTAL)"
|
|
default n
|
|
depends on EXPERIMENTAL
|
|
help
|
|
Three-level pagetables will let UML have more than 4G of physical
|
|
memory. All the memory that can't be mapped directly will be treated
|
|
as high memory.
|
|
|
|
However, this it experimental on 32-bit architectures, so if unsure say
|
|
N (on x86-64 it's automatically enabled, instead, as it's safe there).
|
|
|
|
config ARCH_HAS_SC_SIGNALS
|
|
bool
|
|
default y
|
|
|
|
config ARCH_REUSE_HOST_VSYSCALL_AREA
|
|
bool
|
|
default y
|
|
|
|
config GENERIC_HWEIGHT
|
|
bool
|
|
default y
|
|
|
|
config ARCH_SUPPORTS_AOUT
|
|
def_bool y
|