28 Apr, 2008
1 commit
-
s390 for one, cannot implement VM_MIXEDMAP with pfn_valid, due to their memory
model (which is more dynamic than most). Instead, they had proposed to
implement it with an additional path through vm_normal_page(), using a bit in
the pte to determine whether or not the page should be refcounted:vm_normal_page()
{
...
if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
if (vma->vm_flags & VM_MIXEDMAP) {
#ifdef s390
if (!mixedmap_refcount_pte(pte))
return NULL;
#else
if (!pfn_valid(pfn))
return NULL;
#endif
goto out;
}
...
}This is fine, however if we are allowed to use a bit in the pte to determine
refcountedness, we can use that to _completely_ replace all the vma based
schemes. So instead of adding more cases to the already complex vma-based
scheme, we can have a clearly seperate and simple pte-based scheme (and get
slightly better code generation in the process):vm_normal_page()
{
#ifdef s390
if (!mixedmap_refcount_pte(pte))
return NULL;
return pte_page(pte);
#else
...
#endif
}And finally, we may rather make this concept usable by any architecture rather
than making it s390 only, so implement a new type of pte state for this.
Unfortunately the old vma based code must stay, because some architectures may
not be able to spare pte bits. This makes vm_normal_page a little bit more
ugly than we would like, but the 2 cases are clearly seperate.So introduce a pte_special pte state, and use it in mm/memory.c. It is
currently a noop for all architectures, so this doesn't actually result in any
compiled code changes to mm/memory.o.BTW:
I haven't put vm_normal_page() into arch code as-per an earlier suggestion.
The reason is that, regardless of where vm_normal_page is actually
implemented, the *abstraction* is still exactly the same. Also, while it
depends on whether the architecture has pte_special or not, that is the
only two possible cases, and it really isn't an arch specific function --
the role of the arch code should be to provide primitive functions and
accessors with which to build the core code; pte_special does that. We do
not want architectures to know or care about vm_normal_page itself, and
we definitely don't want them being able to invent something new there
out of sight of mm/ code. If we made vm_normal_page an arch function, then
we have to make vm_insert_mixed (next patch) an arch function too. So I
don't think moving it to arch code fundamentally improves any abstractions,
while it does practically make the code more difficult to follow, for both
mm and arch developers, and easier to misuse.[akpm@linux-foundation.org: build fix]
Signed-off-by: Nick Piggin
Acked-by: Carsten Otte
Cc: Jared Hulbert
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Apr, 2008
1 commit
-
Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility. Thanks to Peter Zijlstra for fixing the lockdep
warning. Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.Signed-off-by: Matthew Wilcox
Acked-by: Ingo Molnar
16 Apr, 2008
1 commit
-
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
03 Apr, 2008
1 commit
-
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 bycommit fb56dbb31c4738a3918db81fd24da732ce3b4ae6
Author: Avi Kivity
Date: Sun Dec 2 10:50:06 2007 +0200KVM: 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
09 Feb, 2008
5 commits
-
%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 -
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 -
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 -
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 -
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
06 Feb, 2008
19 commits
-
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 -
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 -
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 -
Customize the hooks in tlb.h to optimize TLB flushing some more.
Add start and end fields to tlb_gather_mmu, which are used to limit
the address space range scanned when a region is unmapped.The interfaces which just free page tables, without actually changing
mappings, don't need to cause a TLB flush.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Some 64-bit tlb fixes -
moved pmd_page_vaddr to pgtable.h since it's the same for both
2-level and 3-level page tables
fixed a bogus cast on pud_page_vaddr
made the address checking in update_*_range more carefulSigned-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Give the stubs a VMA. This allows the removal of a truly nasty kludge to make
sure that mm->nr_ptes was correct in exit_mmap. The underlying problem was
always that the stubs, which have ptes, and thus allocated a page table,
weren't covered by a VMA.This patch fixes that by using install_special_mapping in arch_dup_mmap and
activate_context to create the VMA. The stubs have to be moved, since
shift_arg_pages seems to assume that the stack is the only VMA present at that
point during exec, and uses vma_adjust to fiddle its VMA. However, that
extends the stub VMA by the amount removed from the stack VMA.To avoid this problem, the stubs were moved to a different fixed location at
the start of the address space.The init_stub_pte calls were moved from init_new_context to arch_dup_mmap
because I was occasionally seeing arch_dup_mmap not being called, causing
exit_mmap to die. Rather than figure out what was really happening, I decided
it was cleaner to just move the calls so that there's no doubt that both the
pte and VMA creation happen, no matter what. arch_exit_mmap is used to clear
the stub ptes at exit time.The STUB_* constants in as-layout.h no longer depend on UM_TASK_SIZE, that
that definition is removed, along with the comments complaining about gcc.Because the stubs are no longer at the top of the address space, some care is
needed while flushing TLBs. update_pte_range checks for addresses in the stub
range and skips them. flush_thread now issues two unmaps, one for the range
before STUB_START and one for the range after STUB_END.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Clean up the calculation and use of the usable address space size on the host.
task_size is gone, replaced with TASK_SIZE, which is calculated from
CONFIG_TOP_ADDR. get_kmem_end and set_task_sizes_skas are also gone.host_task_size, which refers to the entire address space usable by the UML
kernel and which may be larger than the address space usable by a UML process,
since that has to end on a pgdir boundary, is replaced by CONFIG_TOP_ADDR.STACK_TOP is now TASK_SIZE minus the two stub pages.
Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Turn um_virt_to_phys into virt_to_pte, cleaning up a horrid interface.
It's also made non-static and declared in pgtable.h because it'll be
needed when the stubs get a vma.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Get the sizes of various pieces of data right when using three-level
page tables. pgd and pmd entries remain at 32 bits in a 32-bit
compilation because page tables will remain in low memory. So,
PGDIR_SHIFT, the PTRS_PER_* values, set_pud, set_pmd are conditional
on 64BIT.More use of phys_t is made when there are physical memory addresses
floating around.ObCheckpatchViolationJustification - the new typedef is an alternate
definition of pmd_t, which I can't really live without.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Tidy current-related stuff. There was a comment in current.h saying
that current_thread was obsolete, so this patch turns all instances of
current_thread into current_thread_info(). There's some simplifying
of the result in arch/um/sys-i386/signal.c.current.h and thread_info also get style cleanups.
Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Style fixes in elf-i386.h and arch/um/kernel/mem.c.
update the copyright
get rid of an emacs formatting comment
some formatting fixes
inclusion trimming
whitespace fixesSigned-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Untangle UML headers somewhat and add some includes where they were
needed explicitly, but gotten accidentally via some other header.arch/um/include/um_uaccess.h loses asm/fixmap.h because it uses no
fixmap stuff and gains elf.h, because it needs FIXADDR_USER_*, and
archsetjmp.h, because it needs jmp_buf.pmd_alloc_one is uninlined because it needs mm_struct, and that's
inconvenient to provide in asm-um/pgtable-3level.h.elf_core_copy_fpregs is also uninlined from elf-i386.h and
elf-x86_64.h, which duplicated the code anyway, to
arch/um/kernel/process.c, so that the reference to current_thread
doesn't pull sched.h or anything related into asm/elf.h.arch/um/sys-i386/ldt.c, arch/um/kernel/tlb.c and
arch/um/kernel/skas/uaccess.c got sched.h because they dereference
task_structs. Its includes of linux and asm headers got turned from
"" to <>.arch/um/sys-i386/bug.c gets asm/errno.h because it needs errno
constants.asm/elf-i386 gets asm/user.h because it needs user_regs_struct.
asm/fixmap.h gets page.h because it needs PAGE_SIZE and PAGE_MASK and
system.h for BUG_ON.asm/pgtable doesn't need sched.h.
asm/processor-generic.h defined mm_segment_t, but didn't use it. So,
that definition is moved to uaccess.h, which defines a bunch of
mm_segment_t-related stuff. thread_info.h uses mm_segment_t, and
includes uaccess.h, which causes a recursion. So, the definition is
placed above the include of thread_info. in uaccess.h. thread_info.h
also gets page.h because it needs PAGE_SIZE.ObCheckpatchViolationJustification - I'm not adding a typedef; I'm
moving mm_segment_t from one place to another.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patchset makes UML build and run with three-level page tables on
32-bit hosts. This is an uncommon use case, but the code here needed
fixing and cleaning up, so 32-bit three-level pages tables were tested
to make sure the changes are good.Patch 1 - code movement
Patch 2 - header untangling
Patch 3 - style fixups in files affected so far
Patch 4 - clean up use of current.h
Patch 5 - fix sizes of types that are different between 2 and 3-level
page tables - three-level page table support should build at
this point
Patch 6 - tidy (i.e. eliminate much of) the code that figures out how
big the address space is
Patch 7 - change um_virt_to_phys into virt_to_pte, clean its
interface, and clean its (so far) one caller
Patch 8 - the stub pages are covered with a VMA, allowing some nasty
code to be thrown out - three-level page tables now workThis patch:
um_virt_to_phys only has one user, so it can be moved to the same file
and made static. Its declarations in pgtable.h and ksyms.c are also
gone.current_cmd was another apparent user, but it itself isn't used, so it
is deleted.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The earlier pgtable.h tidying patch made things a bit too tidy. Add
back a header which is needed in VMALLOC_START and friend. Also add
back a definition of pmd_page_vaddr, which is needed on x86_64.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Large pieces of include/asm/pgtable.h were unused cruft.
This uncovered arch/um/kernel/trap.c needing skas.h in order to get
ptrace_faultinfo.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Get rid of asmlinkage and remove some old cruft from asm/linkage.h.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Implement get_wchan - the algorithm is similar to x86. It starts with the
stack pointer of the process in question and looks above that for addresses
that are kernel text. The second one which isn't in the scheduler is the one
that's returned. The first one is ignored because that will be UML's own
context switching routine.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch removes some code which ran at every boot, but does not seem to do
anything anymore. Please test. It works for me but mistakes can happen.Signed-off-by: Karol Swietlicki
Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
(with Martin Schwidefsky )
The pgd/pud/pmd/pte page table allocation functions get a mm_struct pointer as
first argument. The free functions do not get the mm_struct argument. This
is 1) asymmetrical and 2) to do mm related page table allocations the mm
argument is needed on the free function as well.[kamalesh@linux.vnet.ibm.com: i386 fix]
[akpm@linux-foundation.org: coding-syle fixes]
Signed-off-by: Benjamin Herrenschmidt
Signed-off-by: Martin Schwidefsky
Cc:
Signed-off-by: Kamalesh Babulal
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Jan, 2008
3 commits
-
Acked-by: Jeff Dike
Signed-off-by: WANG Cong
Signed-off-by: Andrew Morton
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner -
git-x86.patch introduces asm-x86/asm.h. UML needs to follow this with
an asm/asm.h of its own.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner -
With the x86 removal, FASTCALL is always empty now.
Signed-off-by: Harvey Harrison
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
15 Nov, 2007
1 commit
-
pud_clear wasn't setting the _PAGE_NEWPAGE bit, fooling tlb_flush into
thinking that this area of the address space was up-to-date and not unmapping
whatever was covered by the pud.This manifested itself as ldconfig on x86_64 complaining about the first
library it looked at not being a valid ELF file. A config file is mapped at
0x4000000, as the only thing mapped under its pud, and unmapped. The
unmapping caused a pud_clear, which, due to this bug, didn't actually unmap
the config file data on the host. The first library is then mapped at the
same location, but is not actually mapped on the host because accesses to it
cause no page faults. As a result, ldconfig sees the old config file data.[akpm@linux-foundation.org: coding-style cleanups]
Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Oct, 2007
1 commit
-
Don't undef __i386__/__x86_64__ in uml anymore, make sure that (few) places
that required adjusting the ifdefs got those.Signed-off-by: Al Viro
Signed-off-by: Linus Torvalds
20 Oct, 2007
2 commits
-
forbid asm/bitops.h direct inclusion
Because of compile errors that may occur after bit changes if asm/bitops.h is
included directly without e.g. linux/kernel.h which includes linux/bitops.h,
forbid direct inclusion of asm/bitops.h. Thanks to Adrian Bunk.Signed-off-by: Jiri Slaby
Cc: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Nobody uses flush_tlb_pgtables anymore, this patch removes all remaining
traces of it from all archs.Signed-off-by: Benjamin Herrenschmidt
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
18 Oct, 2007
1 commit
-
.i is an ending used for preprocessed stuff.
This patch therefore renames assembler include files to .h and guards
the contents with an #ifdef __ASSEMBLY__.[ tglx: arch/x86 adaptation ]
Signed-off-by: Adrian Bunk
Signed-off-by: Andi Kleen
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
17 Oct, 2007
4 commits
-
All asm/ipc.h files do only #include .
This patch therefore removes all include/asm-*/ipc.h files and moves the
contents of include/asm-generic/ipc.h to include/linux/ipc.h.Signed-off-by: Adrian Bunk
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Tidy the code affected by the floating point fixes.
A bunch of unused stuff is gone, including two sigcontext.c files,
which turned out to be entirely unneeded.There are the usual fixes -
whitespace and style cleanups
copyright updates
emacs formatting comments gone
include cleanups
adding severities to printksSigned-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix core dumping of floating point state. ELF_CORE_COPY_FPREGS gets a
definitions, and as a result, dump_fpu no longer needs to exist. Also,
elf_fpregset_t needed a real definition.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Handle floating point state better in ptrace. The code now correctly
distinguishes between PTRACE_[GS]ETFPREGS and PTRACE_[GS]ETFPXREGS. The FPX
requests get handed off to arch-specific code because that's not generic.get_fpregs, set_fpregs, set_fpregs, and set_fpxregs needed real
implementations.Something here exposed a missing include in asm/page.h, which needed
linux/types.h in order to get gfp_t, so that's fixed here.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds