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Linus Torvalds ea25c43179 Merge branch 'mmu_notifier_fixes' 
Merge mmu_notifier fixes from Jérôme Glisse:
 "The invalidate_page callback suffered from 2 pitfalls. First it used
  to happen after page table lock was release and thus a new page might
  have been setup for the virtual address before the call to
  invalidate_page().

  This is in a weird way fixed by commit c7ab0d2fdc ("mm: convert
  try_to_unmap_one() to use page_vma_mapped_walk()") which moved the
  callback under the page table lock. Which also broke several existing
  user of the mmu_notifier API that assumed they could sleep inside this
  callback.

  The second pitfall was invalidate_page being the only callback not
  taking a range of address in respect to invalidation but was giving an
  address and a page. Lot of the callback implementer assumed this could
  never be THP and thus failed to invalidate the appropriate range for
  THP pages.

  By killing this callback we unify the mmu_notifier callback API to
  always take a virtual address range as input.

  There is now two clear API (I am not mentioning the youngess API which
  is seldomly used):

   - invalidate_range_start()/end() callback (which allow you to sleep)

   - invalidate_range() where you can not sleep but happen right after
     page table update under page table lock

  Note that a lot of existing user feels broken in respect to
  range_start/ range_end. Many user only have range_start() callback but
  there is nothing preventing them to undo what was invalidated in their
  range_start() callback after it returns but before any CPU page table
  update take place.

  The code pattern use in kvm or umem odp is an example on how to
  properly avoid such race. In a nutshell use some kind of sequence
  number and active range invalidation counter to block anything that
  might undo what the range_start() callback did.

  If you do not care about keeping fully in sync with CPU page table (ie
  you can live with CPU page table pointing to new different page for a
  given virtual address) then you can take a reference on the pages
  inside the range_start callback and drop it in range_end or when your
  driver is done with those pages.

  Last alternative is to use invalidate_range() if you can do
  invalidation without sleeping as invalidate_range() callback happens
  under the CPU page table spinlock right after the page table is
  updated.

  The first two patches convert existing mmu_notifier_invalidate_page()
  calls to mmu_notifier_invalidate_range() and bracket those call with
  call to mmu_notifier_invalidate_range_start()/end().

  The next ten patches remove existing invalidate_page() callback as it
  can no longer happen.

  Finally the last page remove the invalidate_page() callback completely
  so it can RIP.

  Changes since v1:
   - remove more dead code in kvm (no testing impact)
   - more accurate end address computation (patch 2) in page_mkclean_one
     and try_to_unmap_one
   - added tested-by/reviewed-by gotten so far"

* emailed patches from Jérôme Glisse <jglisse@redhat.com>:
  mm/mmu_notifier: kill invalidate_page
  KVM: update to new mmu_notifier semantic v2
  xen/gntdev: update to new mmu_notifier semantic
  sgi-gru: update to new mmu_notifier semantic
  misc/mic/scif: update to new mmu_notifier semantic
  iommu/intel: update to new mmu_notifier semantic
  iommu/amd: update to new mmu_notifier semantic
  IB/hfi1: update to new mmu_notifier semantic
  IB/umem: update to new mmu_notifier semantic
  drm/amdgpu: update to new mmu_notifier semantic
  powerpc/powernv: update to new mmu_notifier semantic
  mm/rmap: update to new mmu_notifier semantic v2
  dax: update to new mmu_notifier semantic
2017-08-31 17:30:01 -07:00
arch KVM: update to new mmu_notifier semantic v2 2017-08-31 16:13:00 -07:00
block blk-mq-debugfs: Add names for recently added flags 2017-08-25 08:07:44 -06:00
certs modsign: add markers to endif-statements in certs/Makefile 2017-07-14 11:01:37 +10:00
crypto crypto: authencesn - Fix digest_null crash 2017-07-18 17:01:11 +08:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-08-21 13:16:27 -07:00
drivers xen/gntdev: update to new mmu_notifier semantic 2017-08-31 16:13:00 -07:00
firmware firmware/Makefile: force recompilation if makefile changes 2017-05-08 17:15:10 -07:00
fs Merge branch 'mmu_notifier_fixes' 2017-08-31 17:30:01 -07:00
include mm/mmu_notifier: kill invalidate_page 2017-08-31 16:13:00 -07:00
init random: do not ignore early device randomness 2017-07-12 16:26:00 -07:00
ipc ipc: add missing container_of()s for randstruct 2017-08-02 17:16:12 -07:00
kernel Merge branch 'for-4.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2017-08-29 11:16:21 -07:00
lib kernel/watchdog: Prevent false positives with turbo modes 2017-08-18 12:35:02 +02:00
mm mm/mmu_notifier: kill invalidate_page 2017-08-31 16:13:00 -07:00
net Two nfsd bugfixes, neither 4.13 regressions, but both potentially 2017-08-25 17:27:26 -07:00
samples samples/bpf: fix bpf tunnel cleanup 2017-07-31 22:02:47 -07:00
scripts Kbuild fixes for v4.13 2017-08-24 14:22:27 -07:00
security Now that IPC and other changes have landed, enable manual markings for 2017-07-19 08:55:18 -07:00
sound ASoC: rt5677: Reintroduce I2C device IDs 2017-08-24 18:04:29 +02:00
tools NTB bug fixes to address an incorrect ntb_mw_count reference in the NTB 2017-08-27 17:01:54 -07:00
usr ramfs: clarify help text that compression applies to ramfs as well as legacy ramdisk. 2017-07-06 16:24:30 -07:00
virt KVM: update to new mmu_notifier semantic v2 2017-08-31 16:13:00 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support to generate LLVM assembly files 2017-04-25 08:13:52 +09:00
.mailmap power supply and reset changes for the v4.12 series (part 2) 2017-05-12 12:02:21 -07:00
COPYING
CREDITS avr32: remove support for AVR32 architecture 2017-05-01 09:27:15 +02:00
Kbuild kbuild: Consolidate header generation from ASM offset information 2017-04-13 05:43:37 +09:00
Kconfig
MAINTAINERS Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-08-20 09:07:56 -07:00
Makefile Linux 4.13-rc7 2017-08-27 17:20:40 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README 

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.