linux-toradex.git/include/asm-um, branch v2.6.25.10

uml: compile error fix

2008-04-16T02:35:40+00:00

This patch fixes this error:

In file included from /home/wangcong/projects/linux-2.6/arch/um/kernel/smp.c:9:
include2/asm/tlb.h: In function `tlb_remove_page':
include2/asm/tlb.h:101: error: implicit declaration of function `page_cache_release'

And since including  in  will break sparc,
we add this #include in uml's own header.

Acked-by: Jeff Dike 
Signed-off-by: WANG Cong 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kvm: provide kvm.h for all architecture: fixes headers_install

2008-04-02T22:28:18+00:00

Currently include/linux/kvm.h is not considered by make headers_install,
because Kbuild cannot handle " unifdef-$(CONFIG_FOO) += foo.h.  This problem
was introduced by

commit fb56dbb31c4738a3918db81fd24da732ce3b4ae6
Author: Avi Kivity 
Date:   Sun Dec 2 10:50:06 2007 +0200

    KVM: Export include/linux/kvm.h only if $ARCH actually supports KVM

    Currently, make headers_check barfs due to , which 
    includes, not existing.  Rather than add a zillion s, export kvm.
    only if the arch actually supports it.

    Signed-off-by: Avi Kivity 

which makes this an 2.6.25 regression.

One way of solving the issue is to enhance Kbuild, but Avi and David conviced
me, that changing headers_install is not the way to go.  This patch changes
the definition for linux/kvm.h to unifdef-y.

If  unifdef-y is used for linux/kvm.h "make headers_check" will fail on all
architectures without asm/kvm.h.  Therefore, this patch also provides
asm/kvm.h on all architectures.

Signed-off-by: Christian Borntraeger 
Acked-by: Avi Kivity 
Cc: Sam Ravnborg 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

uml: x86_64 should copy %fs during fork

2008-02-08T17:22:43+00:00

%fs needs to be copied from parent to child during fork.

Tidied up some whitespace while I was here.

Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

uml: runtime host VMSPLIT detection

2008-02-08T17:22:42+00:00

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 
Cc: Miklos Szeredi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

CONFIG_HIGHPTE vs. sub-page page tables.

2008-02-08T17:22:42+00:00

Background: I've implemented 1K/2K page tables for s390.  These sub-page
page tables are required to properly support the s390 virtualization
instruction with KVM.  The SIE instruction requires that the page tables
have 256 page table entries (pte) followed by 256 page status table entries
(pgste).  The pgstes are only required if the process is using the SIE
instruction.  The pgstes are updated by the hardware and by the hypervisor
for a number of reasons, one of them is dirty and reference bit tracking.
To avoid wasting memory the standard pte table allocation should return
1K/2K (31/64 bit) and 2K/4K if the process is using SIE.

Problem: Page size on s390 is 4K, page table size is 1K or 2K.  That means
the s390 version for pte_alloc_one cannot return a pointer to a struct
page.  Trouble is that with the CONFIG_HIGHPTE feature on x86 pte_alloc_one
cannot return a pointer to a pte either, since that would require more than
32 bit for the return value of pte_alloc_one (and the pte * would not be
accessible since its not kmapped).

Solution: The only solution I found to this dilemma is a new typedef: a
pgtable_t.  For s390 pgtable_t will be a (pte *) - to be introduced with a
later patch.  For everybody else it will be a (struct page *).  The
additional problem with the initialization of the ptl lock and the
NR_PAGETABLE accounting is solved with a constructor pgtable_page_ctor and
a destructor pgtable_page_dtor.  The page table allocation and free
functions need to call these two whenever a page table page is allocated or
freed.  pmd_populate will get a pgtable_t instead of a struct page pointer.
 To get the pgtable_t back from a pmd entry that has been installed with
pmd_populate a new function pmd_pgtable is added.  It replaces the pmd_page
call in free_pte_range and apply_to_pte_range.

Signed-off-by: Martin Schwidefsky 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

aout: suppress A.OUT library support if !CONFIG_ARCH_SUPPORTS_AOUT

2008-02-08T17:22:30+00:00

Suppress A.OUT library support if CONFIG_ARCH_SUPPORTS_AOUT is not set.

Not all architectures support the A.OUT binfmt, so the ELF binfmt should not
be permitted to go looking for A.OUT libraries to load in such a case.  Not
only that, but under such conditions A.OUT core dumps are not produced either.

To make this work, this patch also does the following:

 (1) Makes the existence of the contents of linux/a.out.h contingent on
     CONFIG_ARCH_SUPPORTS_AOUT.

 (2) Renames dump_thread() to aout_dump_thread() as it's only called by A.OUT
     core dumping code.

 (3) Moves aout_dump_thread() into asm/a.out-core.h and makes it inline.  This
     is then included only where needed.  This means that this bit of arch
     code will be stored in the appropriate A.OUT binfmt module rather than
     the core kernel.

 (4) Drops A.OUT support for Blackfin (according to Mike Frysinger it's not
     needed) and FRV.

This patch depends on the previous patch to move STACK_TOP[_MAX] out of
asm/a.out.h and into asm/processor.h as they're required whether or not A.OUT
format is available.

[jdike@addtoit.com: uml: re-remove accidentally restored code]
Signed-off-by: David Howells 
Cc: 
Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

aout: move STACK_TOP[_MAX] to asm/processor.h

2008-02-08T17:22:29+00:00

Move STACK_TOP[_MAX] out of asm/a.out.h and into asm/processor.h as they're
required whether or not A.OUT format is available.

Signed-off-by: David Howells 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

uml: LDT mutex conversion

2008-02-05T17:44:31+00:00

The ldt.semaphore conforms to the new struct mutex requirments, so I converted
it to use the new API and changed the name.

Signed-off-by: Daniel Walker 
Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

uml: add back CONFIG_HZ

2008-02-05T17:44:31+00:00

avoid-overflows-in-kernel-timec.patch makes CONFIG_HZ necessary for a
successful build.  UML lacks a definition, so this patch adds one.  It also
changes the hard-wired definition of HZ to CONFIG_HZ.

Note: this patch is a good idea even in the absence of hpa's time fixes.

Cc: "H. Peter Anvin" 
Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

uml: get rid of syscall counters

2008-02-05T17:44:30+00:00

Get rid of some syscall counters which haven't been useful in ages.

Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds