| Age | Commit message (Collapse) | Author |
|---|
|
This patch removes the NUMA PTE bits and associated helpers. As a
side-effect it increases the maximum possible swap space on x86-64.
One potential source of problems is races between the marking of PTEs
PROT_NONE, NUMA hinting faults and migration. It must be guaranteed that
a PTE being protected is not faulted in parallel, seen as a pte_none and
corrupting memory. The base case is safe but transhuge has problems in
the past due to an different migration mechanism and a dependance on page
lock to serialise migrations and warrants a closer look.
task_work hinting update parallel fault
------------------------ --------------
change_pmd_range
change_huge_pmd
__pmd_trans_huge_lock
pmdp_get_and_clear
__handle_mm_fault
pmd_none
do_huge_pmd_anonymous_page
read? pmd_lock blocks until hinting complete, fail !pmd_none test
write? __do_huge_pmd_anonymous_page acquires pmd_lock, checks pmd_none
pmd_modify
set_pmd_at
task_work hinting update parallel migration
------------------------ ------------------
change_pmd_range
change_huge_pmd
__pmd_trans_huge_lock
pmdp_get_and_clear
__handle_mm_fault
do_huge_pmd_numa_page
migrate_misplaced_transhuge_page
pmd_lock waits for updates to complete, recheck pmd_same
pmd_modify
set_pmd_at
Both of those are safe and the case where a transhuge page is inserted
during a protection update is unchanged. The case where two processes try
migrating at the same time is unchanged by this series so should still be
ok. I could not find a case where we are accidentally depending on the
PTE not being cleared and flushed. If one is missed, it'll manifest as
corruption problems that start triggering shortly after this series is
merged and only happen when NUMA balancing is enabled.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
LKP has triggered a compiler warning after my recent patch "mm: account
pmd page tables to the process":
mm/mmap.c: In function 'exit_mmap':
>> mm/mmap.c:2857:2: warning: right shift count >= width of type [enabled by default]
The code:
> 2857 WARN_ON(mm_nr_pmds(mm) >
2858 round_up(FIRST_USER_ADDRESS, PUD_SIZE) >> PUD_SHIFT);
In this, on tile, we have FIRST_USER_ADDRESS defined as 0. round_up() has
the same type -- int. PUD_SHIFT.
I think the best way to fix it is to define FIRST_USER_ADDRESS as unsigned
long. On every arch for consistency.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
We've replaced remap_file_pages(2) implementation with emulation. Nobody
creates non-linear mapping anymore.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull additional xen update from David Vrabel:
"Xen: additional features for 3.19-rc0
- Linear p2m for x86 PV guests which simplifies the p2m code,
improves performance and will allow for > 512 GB PV guests in the
future.
A last-minute, configuration specific issue was discovered with this
change which is why it was not included in my previous pull request.
This is now been fixed and tested"
* tag 'stable/for-linus-3.19-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: switch to post-init routines in xen mmu.c earlier
Revert "swiotlb-xen: pass dev_addr to swiotlb_tbl_unmap_single"
xen: annotate xen_set_identity_and_remap_chunk() with __init
xen: introduce helper functions to do safe read and write accesses
xen: Speed up set_phys_to_machine() by using read-only mappings
xen: switch to linear virtual mapped sparse p2m list
xen: Hide get_phys_to_machine() to be able to tune common path
x86: Introduce function to get pmd entry pointer
xen: Delay invalidating extra memory
xen: Delay m2p_override initialization
xen: Delay remapping memory of pv-domain
xen: use common page allocation function in p2m.c
xen: Make functions static
xen: fix some style issues in p2m.c
|
|
Introduces lookup_pmd_address() to get the address of the pmd entry
related to a virtual address in the current address space. This
function is needed for support of a virtual mapped sparse p2m list
in xen pv domains, as we need the address of the pmd entry, not the
one of the pte in that case.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
|
|
Update the translation tables from cache mode to pgprot values
according to the PAT settings. This enables changing the cache
attributes of a PAT index in just one place without having to change
at the users side.
With this change it is possible to use the same kernel with different
PAT configurations, e.g. supporting Xen.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stefan.bader@canonical.com
Cc: xen-devel@lists.xensource.com
Cc: ville.syrjala@linux.intel.com
Cc: david.vrabel@citrix.com
Cc: jbeulich@suse.com
Cc: plagnioj@jcrosoft.com
Cc: tomi.valkeinen@ti.com
Cc: bhelgaas@google.com
Link: http://lkml.kernel.org/r/1415019724-4317-18-git-send-email-jgross@suse.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
Remove no longer used defines from pgtable_types.h as they are not
used any longer.
Switch __PAGE_KERNEL_NOCACHE to use cache mode type instead of pte
bits.
Based-on-patch-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stefan.bader@canonical.com
Cc: xen-devel@lists.xensource.com
Cc: konrad.wilk@oracle.com
Cc: ville.syrjala@linux.intel.com
Cc: david.vrabel@citrix.com
Cc: jbeulich@suse.com
Cc: toshi.kani@hp.com
Cc: plagnioj@jcrosoft.com
Cc: tomi.valkeinen@ti.com
Cc: bhelgaas@google.com
Link: http://lkml.kernel.org/r/1415019724-4317-15-git-send-email-jgross@suse.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
At the moment there are a lot of places that handle setting or getting
the page cache mode by treating the pgprot bits equal to the cache mode.
This is only true because there are a lot of assumptions about the setup
of the PAT MSR. Otherwise the cache type needs to get translated into
pgprot bits and vice versa.
This patch tries to prepare for that by introducing a separate type
for the cache mode and adding functions to translate between those and
pgprot values.
To avoid too much performance penalty the translation between cache mode
and pgprot values is done via tables which contain the relevant
information. Write-back cache mode is hard-wired to be 0, all other
modes are configurable via those tables. For large pages there are
translation functions as the PAT bit is located at different positions
in the ptes of 4k and large pages.
Based-on-patch-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stefan.bader@canonical.com
Cc: xen-devel@lists.xensource.com
Cc: konrad.wilk@oracle.com
Cc: ville.syrjala@linux.intel.com
Cc: david.vrabel@citrix.com
Cc: jbeulich@suse.com
Cc: toshi.kani@hp.com
Cc: plagnioj@jcrosoft.com
Cc: tomi.valkeinen@ti.com
Cc: bhelgaas@google.com
Link: http://lkml.kernel.org/r/1415019724-4317-2-git-send-email-jgross@suse.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen updates from David Vrabel:
"Features and fixes:
- Add pvscsi frontend and backend drivers.
- Remove _PAGE_IOMAP PTE flag, freeing it for alternate uses.
- Try and keep memory contiguous during PV memory setup (reduces
SWIOTLB usage).
- Allow front/back drivers to use threaded irqs.
- Support large initrds in PV guests.
- Fix PVH guests in preparation for Xen 4.5"
* tag 'stable/for-linus-3.18-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (22 commits)
xen: remove DEFINE_XENBUS_DRIVER() macro
xen/xenbus: Remove BUG_ON() when error string trucated
xen/xenbus: Correct the comments for xenbus_grant_ring()
x86/xen: Set EFER.NX and EFER.SCE in PVH guests
xen: eliminate scalability issues from initrd handling
xen: sync some headers with xen tree
xen: make pvscsi frontend dependant on xenbus frontend
arm{,64}/xen: Remove "EXPERIMENTAL" in the description of the Xen options
xen-scsifront: don't deadlock if the ring becomes full
x86: remove the Xen-specific _PAGE_IOMAP PTE flag
x86/xen: do not use _PAGE_IOMAP PTE flag for I/O mappings
x86: skip check for spurious faults for non-present faults
xen/efi: Directly include needed headers
xen-scsiback: clean up a type issue in scsiback_make_tpg()
xen-scsifront: use GFP_ATOMIC under spin_lock
MAINTAINERS: Add xen pvscsi maintainer
xen-scsiback: Add Xen PV SCSI backend driver
xen-scsifront: Add Xen PV SCSI frontend driver
xen: Add Xen pvSCSI protocol description
xen/events: support threaded irqs for interdomain event channels
...
|
|
ARCH_USES_NUMA_PROT_NONE was defined for architectures that implemented
_PAGE_NUMA using _PROT_NONE. This saved using an additional PTE bit and
relied on the fact that PROT_NONE vmas were skipped by the NUMA hinting
fault scanner. This was found to be conceptually confusing with a lot of
implicit assumptions and it was asked that an alternative be found.
Commit c46a7c81 "x86: define _PAGE_NUMA by reusing software bits on the
PMD and PTE levels" redefined _PAGE_NUMA on x86 to be one of the swap PTE
bits and shrunk the maximum possible swap size but it did not go far
enough. There are no architectures that reuse _PROT_NONE as _PROT_NUMA
but the relics still exist.
This patch removes ARCH_USES_NUMA_PROT_NONE and removes some unnecessary
duplication in powerpc vs the generic implementation by defining the types
the core NUMA helpers expected to exist from x86 with their ppc64
equivalent. This necessitated that a PTE bit mask be created that
identified the bits that distinguish present from NUMA pte entries but it
is expected this will only differ between arches based on _PAGE_PROTNONE.
The naming for the generic helpers was taken from x86 originally but ppc64
has types that are equivalent for the purposes of the helper so they are
mapped instead of duplicating code.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The _PAGE_IO_MAP PTE flag was only used by Xen PV guests to mark PTEs
that were used to map I/O regions that are 1:1 in the p2m. This
allowed Xen to obtain the correct PFN when converting the MFNs read
from a PTE back to their PFN.
Xen guests no longer use _PAGE_IOMAP for this. Instead mfn_to_pfn()
returns the correct PFN by using a combination of the m2p and p2m to
determine if an MFN corresponds to a 1:1 mapping in the the p2m.
Remove _PAGE_IOMAP, replacing it with _PAGE_UNUSED2 to allow for
future uses of the PTE flag.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
|
|
_PAGE_NUMA is currently an alias of _PROT_PROTNONE to trap NUMA hinting
faults on x86. Care is taken such that _PAGE_NUMA is used only in
situations where the VMA flags distinguish between NUMA hinting faults
and prot_none faults. This decision was x86-specific and conceptually
it is difficult requiring special casing to distinguish between PROTNONE
and NUMA ptes based on context.
Fundamentally, we only need the _PAGE_NUMA bit to tell the difference
between an entry that is really unmapped and a page that is protected
for NUMA hinting faults as if the PTE is not present then a fault will
be trapped.
Swap PTEs on x86-64 use the bits after _PAGE_GLOBAL for the offset.
This patch shrinks the maximum possible swap size and uses the bit to
uniquely distinguish between NUMA hinting ptes and swap ptes.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Noonan <steven@uplinklabs.net>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 vdso changes from Peter Anvin:
"This is the revamp of the 32-bit vdso and the associated cleanups.
This adds timekeeping support to the 32-bit vdso that we already have
in the 64-bit vdso. Although 32-bit x86 is legacy, it is likely to
remain in the embedded space for a very long time to come.
This removes the traditional COMPAT_VDSO support; the configuration
variable is reused for simply removing the 32-bit vdso, which will
produce correct results but obviously suffer a performance penalty.
Only one beta version of glibc was affected, but that version was
unfortunately included in one OpenSUSE release.
This is not the end of the vdso cleanups. Stefani and Andy have
agreed to continue work for the next kernel cycle; in fact Andy has
already produced another set of cleanups that came too late for this
cycle.
An incidental, but arguably important, change is that this ensures
that unused space in the VVAR page is properly zeroed. It wasn't
before, and would contain whatever garbage was left in memory by BIOS
or the bootloader. Since the VVAR page is accessible to user space
this had the potential of information leaks"
* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
x86, vdso: Fix the symbol versions on the 32-bit vDSO
x86, vdso, build: Don't rebuild 32-bit vdsos on every make
x86, vdso: Actually discard the .discard sections
x86, vdso: Fix size of get_unmapped_area()
x86, vdso: Finish removing VDSO32_PRELINK
x86, vdso: Move more vdso definitions into vdso.h
x86: Load the 32-bit vdso in place, just like the 64-bit vdsos
x86, vdso32: handle 32 bit vDSO larger one page
x86, vdso32: Disable stack protector, adjust optimizations
x86, vdso: Zero-pad the VVAR page
x86, vdso: Add 32 bit VDSO time support for 64 bit kernel
x86, vdso: Add 32 bit VDSO time support for 32 bit kernel
x86, vdso: Patch alternatives in the 32-bit VDSO
x86, vdso: Introduce VVAR marco for vdso32
x86, vdso: Cleanup __vdso_gettimeofday()
x86, vdso: Replace VVAR(vsyscall_gtod_data) by gtod macro
x86, vdso: __vdso_clock_gettime() cleanup
x86, vdso: Revamp vclock_gettime.c
mm: Add new func _install_special_mapping() to mmap.c
x86, vdso: Make vsyscall_gtod_data handling x86 generic
...
|
|
The only reason that the user bit was set was to support userspace
access to the compat vDSO in the fixmap. The compat vDSO is gone,
so the user bit can be removed.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/e240a977f3c7cbd525a091fd6521499ec4b8e94f.1394751608.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
|
|
Conflicts:
arch/x86/kernel/setup.c
arch/x86/platform/efi/efi.c
arch/x86/platform/efi/efi_64.c
|
|
Now that we have EFI-specific page tables we need to lookup the pgd when
dumping those page tables, rather than assuming that swapper_pgdir is
the current pgdir.
Remove the double underscore prefix, which is usually reserved for
static functions.
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
|
|
We will use it in efi so expose it.
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
|
|
The SOFT_DIRTY bit shows that the content of memory was changed after a
defined point in the past. mprotect() doesn't change the content of
memory, so it must not change the SOFT_DIRTY bit.
This bug causes a malfunction: on the first iteration all pages are
dumped. On other iterations only pages with the SOFT_DIRTY bit are
dumped. So if the SOFT_DIRTY bit is cleared from a page by mistake, the
page is not dumped and its content will be restored incorrectly.
This patch does nothing with _PAGE_SWP_SOFT_DIRTY, becase pte_modify()
is called only for present pages.
Fixes commit 0f8975ec4db2 ("mm: soft-dirty bits for user memory changes
tracking").
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/efi
Pull EFI virtual mapping changes from Matt Fleming:
* New static EFI runtime services virtual mapping layout which is
groundwork for kexec support on EFI. (Borislav Petkov)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
We map the EFI regions needed for runtime services non-contiguously,
with preserved alignment on virtual addresses starting from -4G down
for a total max space of 64G. This way, we provide for stable runtime
services addresses across kernels so that a kexec'd kernel can still use
them.
Thus, they're mapped in a separate pagetable so that we don't pollute
the kernel namespace.
Add an efi= kernel command line parameter for passing miscellaneous
options and chicken bits from the command line.
While at it, add a chicken bit called "efi=old_map" which can be used as
a fallback to the old runtime services mapping method in case there's
some b0rkage with a particular EFI implementation (haha, it is hard to
hold up the sarcasm here...).
Also, add the UEFI RT VA space to Documentation/x86/x86_64/mm.txt.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
|
|
_PAGE_SOFT_DIRTY bit should never be set on present pte so add VM_BUG_ON
to catch any potential future abuse.
Also add a comment on _PAGE_SWP_SOFT_DIRTY definition explaining scope of
its usage.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Andy reported that if file page get reclaimed we lose the soft-dirty bit
if it was there, so save _PAGE_BIT_SOFT_DIRTY bit when page address get
encoded into pte entry. Thus when #pf happens on such non-present pte
we can restore it back.
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Andy Lutomirski reported that if a page with _PAGE_SOFT_DIRTY bit set
get swapped out, the bit is getting lost and no longer available when
pte read back.
To resolve this we introduce _PTE_SWP_SOFT_DIRTY bit which is saved in
pte entry for the page being swapped out. When such page is to be read
back from a swap cache we check for bit presence and if it's there we
clear it and restore the former _PAGE_SOFT_DIRTY bit back.
One of the problem was to find a place in pte entry where we can save
the _PTE_SWP_SOFT_DIRTY bit while page is in swap. The _PAGE_PSE was
chosen for that, it doesn't intersect with swap entry format stored in
pte.
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The soft-dirty is a bit on a PTE which helps to track which pages a task
writes to. In order to do this tracking one should
1. Clear soft-dirty bits from PTEs ("echo 4 > /proc/PID/clear_refs)
2. Wait some time.
3. Read soft-dirty bits (55'th in /proc/PID/pagemap2 entries)
To do this tracking, the writable bit is cleared from PTEs when the
soft-dirty bit is. Thus, after this, when the task tries to modify a
page at some virtual address the #PF occurs and the kernel sets the
soft-dirty bit on the respective PTE.
Note, that although all the task's address space is marked as r/o after
the soft-dirty bits clear, the #PF-s that occur after that are processed
fast. This is so, since the pages are still mapped to physical memory,
and thus all the kernel does is finds this fact out and puts back
writable, dirty and soft-dirty bits on the PTE.
Another thing to note, is that when mremap moves PTEs they are marked
with soft-dirty as well, since from the user perspective mremap modifies
the virtual memory at mremap's new address.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
So basically we're generating the pte_t * from a struct page and
we're handing it down to the __split_large_page() internal version
which then goes and gets back struct page * from it because it
needs it.
Change the caller to hand down struct page * directly and the
callee can compute the pte_t itself.
Net save is one virt_to_page() call and simpler code. While at
it, make __split_large_page() static.
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1363886217-24703-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
When memory is removed, the corresponding pagetables should alse be
removed. This patch introduces some common APIs to support vmemmap
pagetable and x86_64 architecture direct mapping pagetable removing.
All pages of virtual mapping in removed memory cannot be freed if some
pages used as PGD/PUD include not only removed memory but also other
memory. So this patch uses the following way to check whether a page
can be freed or not.
1) When removing memory, the page structs of the removed memory are
filled with 0FD.
2) All page structs are filled with 0xFD on PT/PMD, PT/PMD can be
cleared. In this case, the page used as PT/PMD can be freed.
For direct mapping pages, update direct_pages_count[level] when we freed
their pagetables. And do not free the pages again because they were
freed when offlining.
For vmemmap pages, free the pages and their pagetables.
For larger pages, do not split them into smaller ones because there is
no way to know if the larger page has been split. As a result, there is
no way to decide when to split. We deal the larger pages in the
following way:
1) For direct mapped pages, all the pages were freed when they were
offlined. And since menmory offline is done section by section, all
the memory ranges being removed are aligned to PAGE_SIZE. So only need
to deal with unaligned pages when freeing vmemmap pages.
2) For vmemmap pages being used to store page_struct, if part of the
larger page is still in use, just fill the unused part with 0xFD. And
when the whole page is fulfilled with 0xFD, then free the larger page.
[akpm@linux-foundation.org: fix typo in comment]
[tangchen@cn.fujitsu.com: do not calculate direct mapping pages when freeing vmemmap pagetables]
[tangchen@cn.fujitsu.com: do not free direct mapping pages twice]
[tangchen@cn.fujitsu.com: do not free page split from hugepage one by one]
[tangchen@cn.fujitsu.com: do not split pages when freeing pagetable pages]
[akpm@linux-foundation.org: use pmd_page_vaddr()]
[akpm@linux-foundation.org: fix used-uninitialised bug]
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Explicitly merging these two branches due to nontrivial conflicts and
to allow further work.
Resolved Conflicts:
arch/x86/kernel/head32.c
arch/x86/kernel/head64.c
arch/x86/mm/init_64.c
arch/x86/realmode/init.c
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
|
|
Coming patches to x86/mm2 require the changes and advanced baseline in
x86/boot.
Resolved Conflicts:
arch/x86/kernel/setup.c
mm/nobootmem.c
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
|
|
This is necessary because __pa() does not work on some kinds of
memory, like vmalloc() or the alloc_remap() areas on 32-bit
NUMA systems. We have some functions to do conversions _like_
this in the vmalloc() code (like vmalloc_to_page()), but they
do not work on sizes other than 4k pages. We would potentially
need to be able to handle all the page sizes that we use for
the kernel linear mapping (4k, 2M, 1G).
In practice, on 32-bit NUMA systems, the percpu areas get stuck
in the alloc_remap() area. Any __pa() call on them will break
and basically return garbage.
This patch introduces a new function slow_virt_to_phys(), which
walks the kernel page tables on x86 and should do precisely
the same logical thing as __pa(), but actually work on a wider
range of memory. It should work on the normal linear mapping,
vmalloc(), kmap(), etc...
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20130122212433.4D1FCA62@kernel.stglabs.ibm.com
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
|
|
I plan to use lookup_address() to walk the kernel pagetables
in a later patch. It returns a "pte" and the level in the
pagetables where the "pte" was found. The level is just an
enum and needs to be converted to a useful value in order to
do address calculations with it. These helpers will be used
in at least two places.
This also gives the anonymous enum a real name so that no one
gets confused about what they should be passing in to these
helpers.
"PTE_SHIFT" was chosen for naming consistency with the other
pagetable levels (PGD/PUD/PMD_SHIFT).
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20130122212431.405D3A8C@kernel.stglabs.ibm.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
|
|
The objective of _PAGE_NUMA is to be able to trigger NUMA hinting page
faults to identify the per NUMA node working set of the thread at
runtime.
Arming the NUMA hinting page fault mechanism works similarly to
setting up a mprotect(PROT_NONE) virtual range: the present bit is
cleared at the same time that _PAGE_NUMA is set, so when the fault
triggers we can identify it as a NUMA hinting page fault.
_PAGE_NUMA on x86 shares the same bit number of _PAGE_PROTNONE (but it
could also use a different bitflag, it's up to the architecture to
decide).
It would be confusing to call the "NUMA hinting page faults" as
"do_prot_none faults". They're different events and _PAGE_NUMA doesn't
alter the semantics of mprotect(PROT_NONE) in any way.
Sharing the same bitflag with _PAGE_PROTNONE in fact complicates
things: it requires us to ensure the code paths executed by
_PAGE_PROTNONE remains mutually exclusive to the code paths executed
by _PAGE_NUMA at all times, to avoid _PAGE_NUMA and _PAGE_PROTNONE to
step into each other toes.
Because we want to be able to set this bitflag in any established pte
or pmd (while clearing the present bit at the same time) without
losing information, this bitflag must never be set when the pte and
pmd are present, so the bitflag picked for _PAGE_NUMA usage, must not
be used by the swap entry format.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
|
|
Page table area are pre-mapped now after
x86, mm: setup page table in top-down
x86, mm: Remove early_memremap workaround for page table accessing on 64bit
mapping_pagetable_reserve is not used anymore, so remove it.
Also remove operation in mask_rw_pte(), as modified allow_low_page
always return pages that are already mapped, moreover
xen_alloc_pte_init, xen_alloc_pmd_init, etc, will mark the page RO
before hooking it into the pagetable automatically.
-v2: add changelog about mask_rw_pte() from Stefano.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-27-git-send-email-yinghai@kernel.org
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
|
|
system headers
Convert #include "..." to #include <path/...> in kernel system headers.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
|
|
At this stage x86_init.paging.pagetable_setup_done is only used in the
XEN case. Move its content in the x86_init.paging.pagetable_init setup
function and remove the now unused x86_init.paging.pagetable_setup_done
remaining infrastructure.
Signed-off-by: Attilio Rao <attilio.rao@citrix.com>
Acked-by: <konrad.wilk@oracle.com>
Cc: <Ian.Campbell@citrix.com>
Cc: <Stefano.Stabellini@eu.citrix.com>
Cc: <xen-devel@lists.xensource.com>
Link: http://lkml.kernel.org/r/1345580561-8506-5-git-send-email-attilio.rao@citrix.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
Move the paging_init() call to the platform specific pagetable_init()
function, so we can get rid of the extra pagetable_setup_done()
function pointer.
Signed-off-by: Attilio Rao <attilio.rao@citrix.com>
Acked-by: <konrad.wilk@oracle.com>
Cc: <Ian.Campbell@citrix.com>
Cc: <Stefano.Stabellini@eu.citrix.com>
Cc: <xen-devel@lists.xensource.com>
Link: http://lkml.kernel.org/r/1345580561-8506-4-git-send-email-attilio.rao@citrix.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
In preparation for unifying the pagetable_setup_start() and
pagetable_setup_done() setup functions, rename appropriately all the
infrastructure related to pagetable_setup_start().
Signed-off-by: Attilio Rao <attilio.rao@citrix.com>
Ackedd-by: <konrad.wilk@oracle.com>
Cc: <Ian.Campbell@citrix.com>
Cc: <Stefano.Stabellini@eu.citrix.com>
Cc: <xen-devel@lists.xensource.com>
Link: http://lkml.kernel.org/r/1345580561-8506-3-git-send-email-attilio.rao@citrix.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
We either use swapper_pg_dir or the argument is unused. Preparatory
patch to simplify platform pagetable setup further.
Signed-off-by: Attilio Rao <attilio.rao@citrix.com>
Ackedb-by: <konrad.wilk@oracle.com>
Cc: <Ian.Campbell@citrix.com>
Cc: <Stefano.Stabellini@eu.citrix.com>
Cc: <xen-devel@lists.xensource.com>
Link: http://lkml.kernel.org/r/1345580561-8506-2-git-send-email-attilio.rao@citrix.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
Currently the HPET mapping is a user-accessible syscall
instruction at a fixed address some of the time.
A sufficiently determined hacker might be able to guess when.
Signed-off-by: Andy Lutomirski <luto@mit.edu>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: richard -rw- weinberger <richard.weinberger@gmail.com>
Cc: Mikael Pettersson <mikpe@it.uu.se>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
Cc: Valdis.Kletnieks@vt.edu
Cc: pageexec@freemail.hu
Link: http://lkml.kernel.org/r/ab41b525a4ca346b1ca1145d16fb8d181861a8aa.1307292171.git.luto@mit.edu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
Move vvars out of the vsyscall page into their own page and mark
it NX.
Without this patch, an attacker who can force a daemon to call
some fixed address could wait until the time contains, say,
0xCD80, and then execute the current time.
Signed-off-by: Andy Lutomirski <luto@mit.edu>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: richard -rw- weinberger <richard.weinberger@gmail.com>
Cc: Mikael Pettersson <mikpe@it.uu.se>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
Cc: Valdis.Kletnieks@vt.edu
Cc: pageexec@freemail.hu
Link: http://lkml.kernel.org/r/b1460f81dc4463d66ea3f2b5ce240f58d48effec.1307292171.git.luto@mit.edu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
Introduce a new x86_init hook called pagetable_reserve that at the end
of init_memory_mapping is used to reserve a range of memory addresses for
the kernel pagetable pages we used and free the other ones.
On native it just calls memblock_x86_reserve_range while on xen it also
takes care of setting the spare memory previously allocated
for kernel pagetable pages from RO to RW, so that it can be used for
other purposes.
A detailed explanation of the reason why this hook is needed follows.
As a consequence of the commit:
commit 4b239f458c229de044d6905c2b0f9fe16ed9e01e
Author: Yinghai Lu <yinghai@kernel.org>
Date: Fri Dec 17 16:58:28 2010 -0800
x86-64, mm: Put early page table high
at some point init_memory_mapping is going to reach the pagetable pages
area and map those pages too (mapping them as normal memory that falls
in the range of addresses passed to init_memory_mapping as argument).
Some of those pages are already pagetable pages (they are in the range
pgt_buf_start-pgt_buf_end) therefore they are going to be mapped RO and
everything is fine.
Some of these pages are not pagetable pages yet (they fall in the range
pgt_buf_end-pgt_buf_top; for example the page at pgt_buf_end) so they
are going to be mapped RW. When these pages become pagetable pages and
are hooked into the pagetable, xen will find that the guest has already
a RW mapping of them somewhere and fail the operation.
The reason Xen requires pagetables to be RO is that the hypervisor needs
to verify that the pagetables are valid before using them. The validation
operations are called "pinning" (more details in arch/x86/xen/mmu.c).
In order to fix the issue we mark all the pages in the entire range
pgt_buf_start-pgt_buf_top as RO, however when the pagetable allocation
is completed only the range pgt_buf_start-pgt_buf_end is reserved by
init_memory_mapping. Hence the kernel is going to crash as soon as one
of the pages in the range pgt_buf_end-pgt_buf_top is reused (b/c those
ranges are RO).
For this reason we need a hook to reserve the kernel pagetable pages we
used and free the other ones so that they can be reused for other
purposes.
On native it just means calling memblock_x86_reserve_range, on Xen it
also means marking RW the pagetable pages that we allocated before but
that haven't been used before.
Another way to fix this is without using the hook is by adding a 'if
(xen_pv_domain)' in the 'init_memory_mapping' code and calling the Xen
counterpart, but that is just nasty.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
|
|
Add pmd_modify() for use with mprotect() on huge pmds.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
These returns 0 at compile time when the config option is disabled, to
allow gcc to eliminate the transparent hugepage function calls at compile
time without additional #ifdefs (only the export of those functions have
to be visible to gcc but they won't be required at link time and
huge_memory.o can be not built at all).
_PAGE_BIT_UNUSED1 is never used for pmd, only on pte.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen into x86/urgent
|
|
Move the NX setup into a separate file so that it can be compiled
without stack-protection while leaving the rest of the mm/init code
protected.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
|
|
Replace more paravirt hackery by proper x86_init_ops.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
Only _PAGE_HIDDEN when CONFIG_KMEMCHECK is defined, otherwise set it
to 0. Allows later cleanups.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
|
|
General description: kmemcheck is a patch to the linux kernel that
detects use of uninitialized memory. It does this by trapping every
read and write to memory that was allocated dynamically (e.g. using
kmalloc()). If a memory address is read that has not previously been
written to, a message is printed to the kernel log.
Thanks to Andi Kleen for the set_memory_4k() solution.
Andrew Morton suggested documenting the shadow member of struct page.
Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
[export kmemcheck_mark_initialized]
[build fix for setup_max_cpus]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
|
|
This patch unifies noexec handling on 32-bit and 64-bit.
[ Impact: cleanup ]
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
[ mingo@elte.hu: build fix ]
LKML-Reference: <1240303167.771.69.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
Impact: build fix
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1236257708-27269-14-git-send-email-penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
PAGETABLE_LEVELS and the PTE masks should be in pgtable*.h
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
|
Mel Gorman
Kirill A. Shutemov
Linus Torvalds
Juergen Gross
David Vrabel
Andy Lutomirski
Matt Fleming
Borislav Petkov
Andrey Vagin
Ingo Molnar
Cyrill Gorcunov
Pavel Emelyanov
Wen Congyang
H. Peter Anvin
Dave Hansen
Andrea Arcangeli
Yinghai Lu
David Howells
Attilio Rao
Andy Lutomirski
Stefano Stabellini
Johannes Weiner
Ingo Molnar
Jeremy Fitzhardinge
Thomas Gleixner
Jeremy Fitzhardinge
Vegard Nossum
Pekka Enberg