linux.git/arch/ia64, branch v4.13

mm: fix MADV_[FREE|DONTNEED] TLB flush miss problem

2017-08-10T22:54:07+00:00

Nadav reported parallel MADV_DONTNEED on same range has a stale TLB
problem and Mel fixed it[1] and found same problem on MADV_FREE[2].

Quote from Mel Gorman:
 "The race in question is CPU 0 running madv_free and updating some PTEs
  while CPU 1 is also running madv_free and looking at the same PTEs.
  CPU 1 may have writable TLB entries for a page but fail the pte_dirty
  check (because CPU 0 has updated it already) and potentially fail to
  flush.

  Hence, when madv_free on CPU 1 returns, there are still potentially
  writable TLB entries and the underlying PTE is still present so that a
  subsequent write does not necessarily propagate the dirty bit to the
  underlying PTE any more. Reclaim at some unknown time at the future
  may then see that the PTE is still clean and discard the page even
  though a write has happened in the meantime. I think this is possible
  but I could have missed some protection in madv_free that prevents it
  happening."

This patch aims for solving both problems all at once and is ready for
other problem with KSM, MADV_FREE and soft-dirty story[3].

TLB batch API(tlb_[gather|finish]_mmu] uses [inc|dec]_tlb_flush_pending
and mmu_tlb_flush_pending so that when tlb_finish_mmu is called, we can
catch there are parallel threads going on.  In that case, forcefully,
flush TLB to prevent for user to access memory via stale TLB entry
although it fail to gather page table entry.

I confirmed this patch works with [4] test program Nadav gave so this
patch supersedes "mm: Always flush VMA ranges affected by zap_page_range
v2" in current mmotm.

NOTE:

This patch modifies arch-specific TLB gathering interface(x86, ia64,
s390, sh, um).  It seems most of architecture are straightforward but
s390 need to be careful because tlb_flush_mmu works only if
mm->context.flush_mm is set to non-zero which happens only a pte entry
really is cleared by ptep_get_and_clear and friends.  However, this
problem never changes the pte entries but need to flush to prevent
memory access from stale tlb.

[1] http://lkml.kernel.org/r/20170725101230.5v7gvnjmcnkzzql3@techsingularity.net
[2] http://lkml.kernel.org/r/20170725100722.2dxnmgypmwnrfawp@suse.de
[3] http://lkml.kernel.org/r/BD3A0EBE-ECF4-41D4-87FA-C755EA9AB6BD@gmail.com
[4] https://patchwork.kernel.org/patch/9861621/

[minchan@kernel.org: decrease tlb flush pending count in tlb_finish_mmu]
  Link: http://lkml.kernel.org/r/20170808080821.GA31730@bbox
Link: http://lkml.kernel.org/r/20170802000818.4760-7-namit@vmware.com
Signed-off-by: Minchan Kim 
Signed-off-by: Nadav Amit 
Reported-by: Nadav Amit 
Reported-by: Mel Gorman 
Acked-by: Mel Gorman 
Cc: Ingo Molnar 
Cc: Russell King 
Cc: Tony Luck 
Cc: Martin Schwidefsky 
Cc: "David S. Miller" 
Cc: Heiko Carstens 
Cc: Yoshinori Sato 
Cc: Jeff Dike 
Cc: Andrea Arcangeli 
Cc: Andy Lutomirski 
Cc: Hugh Dickins 
Cc: Mel Gorman 
Cc: Nadav Amit 
Cc: Rik van Riel 
Cc: Sergey Senozhatsky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: refactor TLB gathering API

2017-08-10T22:54:07+00:00

This patch is a preparatory patch for solving race problems caused by
TLB batch.  For that, we will increase/decrease TLB flush pending count
of mm_struct whenever tlb_[gather|finish]_mmu is called.

Before making it simple, this patch separates architecture specific part
and rename it to arch_tlb_[gather|finish]_mmu and generic part just
calls it.

It shouldn't change any behavior.

Link: http://lkml.kernel.org/r/20170802000818.4760-5-namit@vmware.com
Signed-off-by: Minchan Kim 
Signed-off-by: Nadav Amit 
Acked-by: Mel Gorman 
Cc: Ingo Molnar 
Cc: Russell King 
Cc: Tony Luck 
Cc: Martin Schwidefsky 
Cc: "David S. Miller" 
Cc: Heiko Carstens 
Cc: Yoshinori Sato 
Cc: Jeff Dike 
Cc: Andrea Arcangeli 
Cc: Andy Lutomirski 
Cc: Hugh Dickins 
Cc: Mel Gorman 
Cc: Nadav Amit 
Cc: Rik van Riel 
Cc: Sergey Senozhatsky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2017-07-15T18:17:52+00:00

Pull uacess-unaligned removal from Al Viro:
 "That stuff had just one user, and an exotic one, at that - binfmt_flat
  on arm and m68k"

* 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  kill {__,}{get,put}_user_unaligned()
  binfmt_flat: flat_{get,put}_addr_from_rp() should be able to fail

Merge tag 'kbuild-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2017-07-13T20:37:57+00:00

Pull more Kbuild updates from Masahiro Yamada:

 - Move generic-y of exported headers to uapi/asm/Kbuild for complete
   de-coupling of UAPI

 - Clean up scripts/Makefile.headersinst

 - Fix host programs for 32 bit machine with XFS file system

* tag 'kbuild-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (29 commits)
  kbuild: Enable Large File Support for hostprogs
  kbuild: remove wrapper files handling from Makefile.headersinst
  kbuild: split exported generic header creation into uapi-asm-generic
  kbuild: do not include old-kbuild-file from Makefile.headersinst
  xtensa: move generic-y of exported headers to uapi/asm/Kbuild
  unicore32: move generic-y of exported headers to uapi/asm/Kbuild
  tile: move generic-y of exported headers to uapi/asm/Kbuild
  sparc: move generic-y of exported headers to uapi/asm/Kbuild
  sh: move generic-y of exported headers to uapi/asm/Kbuild
  parisc: move generic-y of exported headers to uapi/asm/Kbuild
  openrisc: move generic-y of exported headers to uapi/asm/Kbuild
  nios2: move generic-y of exported headers to uapi/asm/Kbuild
  nios2: remove unneeded arch/nios2/include/(generated/)asm/signal.h
  microblaze: move generic-y of exported headers to uapi/asm/Kbuild
  metag: move generic-y of exported headers to uapi/asm/Kbuild
  m68k: move generic-y of exported headers to uapi/asm/Kbuild
  m32r: move generic-y of exported headers to uapi/asm/Kbuild
  ia64: remove redundant generic-y += kvm_para.h from asm/Kbuild
  hexagon: move generic-y of exported headers to uapi/asm/Kbuild
  h8300: move generic-y of exported headers to uapi/asm/Kbuild
  ...

ia64: sn: pci: move inline before type

2017-07-12T23:26:04+00:00

Make the use of inline like the rest of the kernel.

Link: http://lkml.kernel.org/r/f42b2202bd0d4e7ccf79ce5348bb255a035e67bb.1499284835.git.joe@perches.com
Signed-off-by: Joe Perches 
Cc: Tony Luck 
Cc: Fenghua Yu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ia64: move inline before return type

2017-07-12T23:26:04+00:00

Make the use of inline like the rest of the kernel.

Link: http://lkml.kernel.org/r/d47074493af80ce12590340294bc49618165c30d.1499284835.git.joe@perches.com
Signed-off-by: Joe Perches 
Cc: Tony Luck 
Cc: Fenghua Yu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kexec: move vmcoreinfo out of the kernel's .bss section

2017-07-12T23:25:59+00:00

As Eric said,
 "what we need to do is move the variable vmcoreinfo_note out of the
  kernel's .bss section. And modify the code to regenerate and keep this
  information in something like the control page.

  Definitely something like this needs a page all to itself, and ideally
  far away from any other kernel data structures. I clearly was not
  watching closely the data someone decided to keep this silly thing in
  the kernel's .bss section."

This patch allocates extra pages for these vmcoreinfo_XXX variables, one
advantage is that it enhances some safety of vmcoreinfo, because
vmcoreinfo now is kept far away from other kernel data structures.

Link: http://lkml.kernel.org/r/1493281021-20737-1-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang 
Tested-by: Michael Holzheu 
Reviewed-by: Juergen Gross 
Suggested-by: Eric Biederman 
Cc: Benjamin Herrenschmidt 
Cc: Dave Young 
Cc: Hari Bathini 
Cc: Mahesh Salgaonkar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ia64: remove redundant generic-y += kvm_para.h from asm/Kbuild

2017-07-09T18:43:27+00:00

"generic-y += kvm_para.h" is doubled in asm/Kbuild and uapi/asm/Kbuild.
The one in the former should be simply removed because kvm_para.h is
exported.

Signed-off-by: Masahiro Yamada

Merge tag 'kbuild-thinar-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2017-07-07T22:11:12+00:00

Pull Kbuild thin archives updates from Masahiro Yamada:
 "Thin archives migration by Nicholas Piggin.

  THIN_ARCHIVES has been available for a while as an optional feature
  only for PowerPC architecture, but we do not need two different
  intermediate-artifact schemes.

  Using thin archives instead of conventional incremental linking has
  various advantages:

   - save disk space for builds

   - speed-up building a little

   - fix some link issues (for example, allyesconfig on ARM) due to more
     flexibility for the final linking

   - work better with dead code elimination we are planning

  As discussed before, this migration has been done unconditionally so
  that any problems caused by this will show up with "git bisect".

  With testing with 0-day and linux-next, some architectures actually
  showed up problems, but they were trivial and all fixed now"

* tag 'kbuild-thinar-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  tile: remove unneeded extra-y in Makefile
  kbuild: thin archives make default for all archs
  x86/um: thin archives build fix
  tile: thin archives fix linking
  ia64: thin archives fix linking
  sh: thin archives fix linking
  kbuild: handle libs-y archives separately from built-in.o archives
  kbuild: thin archives use P option to ar
  kbuild: thin archives final link close --whole-archives option
  ia64: remove unneeded extra-y in Makefile.gate
  tile: fix dependency and .*.cmd inclusion for incremental build
  sparc64: Use indirect calls in hamming weight stubs

Merge branch 'akpm' (patches from Andrew)

2017-07-07T05:27:08+00:00

Merge misc updates from Andrew Morton:

 - a few hotfixes

 - various misc updates

 - ocfs2 updates

 - most of MM

* emailed patches from Andrew Morton : (108 commits)
  mm, memory_hotplug: move movable_node to the hotplug proper
  mm, memory_hotplug: drop CONFIG_MOVABLE_NODE
  mm, memory_hotplug: drop artificial restriction on online/offline
  mm: memcontrol: account slab stats per lruvec
  mm: memcontrol: per-lruvec stats infrastructure
  mm: memcontrol: use generic mod_memcg_page_state for kmem pages
  mm: memcontrol: use the node-native slab memory counters
  mm: vmstat: move slab statistics from zone to node counters
  mm/zswap.c: delete an error message for a failed memory allocation in zswap_dstmem_prepare()
  mm/zswap.c: improve a size determination in zswap_frontswap_init()
  mm/zswap.c: delete an error message for a failed memory allocation in zswap_pool_create()
  mm/swapfile.c: sort swap entries before free
  mm/oom_kill: count global and memory cgroup oom kills
  mm: per-cgroup memory reclaim stats
  mm: kmemleak: treat vm_struct as alternative reference to vmalloc'ed objects
  mm: kmemleak: factor object reference updating out of scan_block()
  mm: kmemleak: slightly reduce the size of some structures on 64-bit architectures
  mm, mempolicy: don't check cpuset seqlock where it doesn't matter
  mm, cpuset: always use seqlock when changing task's nodemask
  mm, mempolicy: simplify rebinding mempolicies when updating cpusets
  ...