linux.git/include/linux, branch v4.15-rc2

Merge tag 'riscv-for-linus-4.15-rc2_cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux

2017-12-02T00:39:12+00:00

Pull RISC-V cleanups and ABI fixes from Palmer Dabbelt:
"This contains a handful of small cleanups that are a result of
feedback that didn't make it into our original patch set, either
because the feedback hadn't been given yet, I missed the original
emails, or we weren't ready to submit the changes yet.

I've been maintaining the various cleanup patch sets I have as their
own branches, which I then merged together and signed. Each merge
commit has a short summary of the changes, and each branch is based on
your latest tag (4.15-rc1, in this case). If this isn't the right way
to do this then feel free to suggest something else, but it seems sane
to me.

Here's a short summary of the changes, roughly in order of how
interesting they are.

- libgcc.h has been moved from include/lib, where it's the only
member, to include/linux. This is meant to avoid tab completion
conflicts.

- VDSO entries for clock_get/gettimeofday/getcpu have been added.
These are simple syscalls now, but we want to let glibc use them
from the start so we can make them faster later.

- A VDSO entry for instruction cache flushing has been added so
userspace can flush the instruction cache.

- The VDSO symbol versions for __vdso_cmpxchg{32,64} have been
removed, as those VDSO entries don't actually exist.

- __io_writes has been corrected to respect the given type.

- A new READ_ONCE in arch_spin_is_locked().

- __test_and_op_bit_ord() is now actually ordered.

- Various small fixes throughout the tree to enable allmodconfig to
build cleanly.

- Removal of some dead code in our atomic support headers.

- Improvements to various comments in our atomic support headers"

* tag 'riscv-for-linus-4.15-rc2_cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux: (23 commits)
RISC-V: __io_writes should respect the length argument
move libgcc.h to include/linux
RISC-V: Clean up an unused include
RISC-V: Allow userspace to flush the instruction cache
RISC-V: Flush I$ when making a dirty page executable
RISC-V: Add missing include
RISC-V: Use define for get_cycles like other architectures
RISC-V: Provide stub of setup_profiling_timer()
RISC-V: Export some expected symbols for modules
RISC-V: move empty_zero_page definition to C and export it
RISC-V: io.h: type fixes for warnings
RISC-V: use RISCV_{INT,SHORT} instead of {INT,SHORT} for asm macros
RISC-V: use generic serial.h
RISC-V: remove spin_unlock_wait()
RISC-V: `sfence.vma` orderes the instruction cache
RISC-V: Add READ_ONCE in arch_spin_is_locked()
RISC-V: __test_and_op_bit_ord should be strongly ordered
RISC-V: Remove smb_mb__{before,after}_spinlock()
RISC-V: Remove __smp_bp__{before,after}_atomic
RISC-V: Comment on why {,cmp}xchg is ordered how it is
...

move libgcc.h to include/linux

2017-12-01T21:09:40+00:00

Introducing a new include/lib directory just for this file totally
messes up tab completion for include/linux, which is highly annoying.

Move it to include/linux where we have headers for all kinds of other
lib/ code as well.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Palmer Dabbelt

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2017-11-30T16:15:19+00:00

Pull KVM fixes from Paolo Bonzini:

 - x86 bugfixes: APIC, nested virtualization, IOAPIC

 - PPC bugfix: HPT guests on a POWER9 radix host

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (26 commits)
  KVM: Let KVM_SET_SIGNAL_MASK work as advertised
  KVM: VMX: Fix vmx->nested freeing when no SMI handler
  KVM: VMX: Fix rflags cache during vCPU reset
  KVM: X86: Fix softlockup when get the current kvmclock
  KVM: lapic: Fixup LDR on load in x2apic
  KVM: lapic: Split out x2apic ldr calculation
  KVM: PPC: Book3S HV: Fix migration and HPT resizing of HPT guests on radix hosts
  KVM: vmx: use X86_CR4_UMIP and X86_FEATURE_UMIP
  KVM: x86: Fix CPUID function for word 6 (80000001_ECX)
  KVM: nVMX: Fix vmx_check_nested_events() return value in case an event was reinjected to L2
  KVM: x86: ioapic: Preserve read-only values in the redirection table
  KVM: x86: ioapic: Clear Remote IRR when entry is switched to edge-triggered
  KVM: x86: ioapic: Remove redundant check for Remote IRR in ioapic_set_irq
  KVM: x86: ioapic: Don't fire level irq when Remote IRR set
  KVM: x86: ioapic: Fix level-triggered EOI and IOAPIC reconfigure race
  KVM: x86: inject exceptions produced by x86_decode_insn
  KVM: x86: Allow suppressing prints on RDMSR/WRMSR of unhandled MSRs
  KVM: x86: fix em_fxstor() sleeping while in atomic
  KVM: nVMX: Fix mmu context after VMLAUNCH/VMRESUME failure
  KVM: nVMX: Validate the IA32_BNDCFGS on nested VM-entry
  ...

Merge branch 'akpm' (patches from Andrew)

2017-11-30T03:12:44+00:00

Mergr misc fixes from Andrew Morton:
 "28 fixes"

* emailed patches from Andrew Morton : (28 commits)
  fs/hugetlbfs/inode.c: change put_page/unlock_page order in hugetlbfs_fallocate()
  mm/hugetlb: fix NULL-pointer dereference on 5-level paging machine
  autofs: revert "autofs: fix AT_NO_AUTOMOUNT not being honored"
  autofs: revert "autofs: take more care to not update last_used on path walk"
  fs/fat/inode.c: fix sb_rdonly() change
  mm, memcg: fix mem_cgroup_swapout() for THPs
  mm: migrate: fix an incorrect call of prep_transhuge_page()
  kmemleak: add scheduling point to kmemleak_scan()
  scripts/bloat-o-meter: don't fail with division by 0
  fs/mbcache.c: make count_objects() more robust
  Revert "mm/page-writeback.c: print a warning if the vm dirtiness settings are illogical"
  mm/madvise.c: fix madvise() infinite loop under special circumstances
  exec: avoid RLIMIT_STACK races with prlimit()
  IB/core: disable memory registration of filesystem-dax vmas
  v4l2: disable filesystem-dax mapping support
  mm: fail get_vaddr_frames() for filesystem-dax mappings
  mm: introduce get_user_pages_longterm
  device-dax: implement ->split() to catch invalid munmap attempts
  mm, hugetlbfs: introduce ->split() to vm_operations_struct
  scripts/faddr2line: extend usage on generic arch
  ...

autofs: revert "autofs: fix AT_NO_AUTOMOUNT not being honored"

2017-11-30T02:40:43+00:00

Commit 42f461482178 ("autofs: fix AT_NO_AUTOMOUNT not being honored")
allowed the fstatat(2) system call to properly honor the AT_NO_AUTOMOUNT
flag but introduced a semantic change.

In order to honor AT_NO_AUTOMOUNT a semantic change was made to the
negative dentry case for stat family system calls in follow_automount().

This changed the unconditional triggering of an automount in this case
to no longer be done and an error returned instead.

This has caused more problems than I expected so reverting the change is
needed.

In a discussion with Neil Brown it was concluded that the automount(8)
daemon can implement this change without kernel modifications.  So that
will be done instead and the autofs module documentation updated with a
description of the problem and what needs to be done by module users for
this specific case.

Link: http://lkml.kernel.org/r/151174730120.6162.3848002191530283984.stgit@pluto.themaw.net
Fixes: 42f4614821 ("autofs: fix AT_NO_AUTOMOUNT not being honored")
Signed-off-by: Ian Kent 
Cc: Neil Brown 
Cc: Al Viro 
Cc: David Howells 
Cc: Colin Walters 
Cc: Ondrej Holy 
Cc: 	[4.11+]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: migrate: fix an incorrect call of prep_transhuge_page()

2017-11-30T02:40:43+00:00

In https://lkml.org/lkml/2017/11/20/411, Andrea reported that during
memory hotplug/hot remove prep_transhuge_page() is called incorrectly on
non-THP pages for migration, when THP is on but THP migration is not
enabled.  This leads to a bad state of target pages for migration.

By inspecting the code, if called on a non-THP, prep_transhuge_page()
will

 1) change the value of the mapping of (page + 2), since it is used for
    THP deferred list;

 2) change the lru value of (page + 1), since it is used for THP's dtor.

Both can lead to data corruption of these two pages.

Andrea said:
 "Pragmatically and from the point of view of the memory_hotplug subsys,
  the effect is a kernel crash when pages are being migrated during a
  memory hot remove offline and migration target pages are found in a
  bad state"

This patch fixes it by only calling prep_transhuge_page() when we are
certain that the target page is THP.

Link: http://lkml.kernel.org/r/20171121021855.50525-1-zi.yan@sent.com
Fixes: 8135d8926c08 ("mm: memory_hotplug: memory hotremove supports thp migration")
Signed-off-by: Zi Yan 
Reported-by: Andrea Reale 
Cc: Naoya Horiguchi 
Cc: Michal Hocko 
Cc: "Jérôme Glisse" 
Cc: 	[4.14]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: introduce get_user_pages_longterm

2017-11-30T02:40:42+00:00

Patch series "introduce get_user_pages_longterm()", v2.

Here is a new get_user_pages api for cases where a driver intends to
keep an elevated page count indefinitely.  This is distinct from usages
like iov_iter_get_pages where the elevated page counts are transient.
The iov_iter_get_pages cases immediately turn around and submit the
pages to a device driver which will put_page when the i/o operation
completes (under kernel control).

In the longterm case userspace is responsible for dropping the page
reference at some undefined point in the future.  This is untenable for
filesystem-dax case where the filesystem is in control of the lifetime
of the block / page and needs reasonable limits on how long it can wait
for pages in a mapping to become idle.

Fixing filesystems to actually wait for dax pages to be idle before
blocks from a truncate/hole-punch operation are repurposed is saved for
a later patch series.

Also, allowing longterm registration of dax mappings is a future patch
series that introduces a "map with lease" semantic where the kernel can
revoke a lease and force userspace to drop its page references.

I have also tagged these for -stable to purposely break cases that might
assume that longterm memory registrations for filesystem-dax mappings
were supported by the kernel.  The behavior regression this policy
change implies is one of the reasons we maintain the "dax enabled.
Warning: EXPERIMENTAL, use at your own risk" notification when mounting
a filesystem in dax mode.

It is worth noting the device-dax interface does not suffer the same
constraints since it does not support file space management operations
like hole-punch.

This patch (of 4):

Until there is a solution to the dma-to-dax vs truncate problem it is
not safe to allow long standing memory registrations against
filesytem-dax vmas.  Device-dax vmas do not have this problem and are
explicitly allowed.

This is temporary until a "memory registration with layout-lease"
mechanism can be implemented for the affected sub-systems (RDMA and
V4L2).

[akpm@linux-foundation.org: use kcalloc()]
Link: http://lkml.kernel.org/r/151068939435.7446.13560129395419350737.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings")
Signed-off-by: Dan Williams 
Suggested-by: Christoph Hellwig 
Cc: Doug Ledford 
Cc: Hal Rosenstock 
Cc: Inki Dae 
Cc: Jan Kara 
Cc: Jason Gunthorpe 
Cc: Jeff Moyer 
Cc: Joonyoung Shim 
Cc: Kyungmin Park 
Cc: Mauro Carvalho Chehab 
Cc: Mel Gorman 
Cc: Ross Zwisler 
Cc: Sean Hefty 
Cc: Seung-Woo Kim 
Cc: Vlastimil Babka 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, hugetlbfs: introduce ->split() to vm_operations_struct

2017-11-30T02:40:42+00:00

Patch series "device-dax: fix unaligned munmap handling"

When device-dax is operating in huge-page mode we want it to behave like
hugetlbfs and fail attempts to split vmas into unaligned ranges.  It
would be messy to teach the munmap path about device-dax alignment
constraints in the same (hstate) way that hugetlbfs communicates this
constraint.  Instead, these patches introduce a new ->split() vm
operation.

This patch (of 2):

The device-dax interface has similar constraints as hugetlbfs in that it
requires the munmap path to unmap in huge page aligned units.  Rather
than add more custom vma handling code in __split_vma() introduce a new
vm operation to perform this vma specific check.

Link: http://lkml.kernel.org/r/151130418135.4029.6783191281930729710.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: dee410792419 ("/dev/dax, core: file operations and dax-mmap")
Signed-off-by: Dan Williams 
Cc: Jeff Moyer 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: fix device-dax pud write-faults triggered by get_user_pages()

2017-11-30T02:40:42+00:00

Currently only get_user_pages_fast() can safely handle the writable gup
case due to its use of pud_access_permitted() to check whether the pud
entry is writable.  In the gup slow path pud_write() is used instead of
pud_access_permitted() and to date it has been unimplemented, just calls
BUG_ON().

    kernel BUG at ./include/linux/hugetlb.h:244!
    [..]
    RIP: 0010:follow_devmap_pud+0x482/0x490
    [..]
    Call Trace:
     follow_page_mask+0x28c/0x6e0
     __get_user_pages+0xe4/0x6c0
     get_user_pages_unlocked+0x130/0x1b0
     get_user_pages_fast+0x89/0xb0
     iov_iter_get_pages_alloc+0x114/0x4a0
     nfs_direct_read_schedule_iovec+0xd2/0x350
     ? nfs_start_io_direct+0x63/0x70
     nfs_file_direct_read+0x1e0/0x250
     nfs_file_read+0x90/0xc0

For now this just implements a simple check for the _PAGE_RW bit similar
to pmd_write.  However, this implies that the gup-slow-path check is
missing the extra checks that the gup-fast-path performs with
pud_access_permitted.  Later patches will align all checks to use the
'access_permitted' helper if the architecture provides it.

Note that the generic 'access_permitted' helper fallback is the simple
_PAGE_RW check on architectures that do not define the
'access_permitted' helper(s).

[dan.j.williams@intel.com: fix powerpc compile error]
  Link: http://lkml.kernel.org/r/151129126165.37405.16031785266675461397.stgit@dwillia2-desk3.amr.corp.intel.com
Link: http://lkml.kernel.org/r/151043109938.2842.14834662818213616199.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: a00cc7d9dd93 ("mm, x86: add support for PUD-sized transparent hugepages")
Signed-off-by: Dan Williams 
Reported-by: Stephen Rothwell 
Acked-by: Thomas Gleixner 	[x86]
Cc: Kirill A. Shutemov 
Cc: Catalin Marinas 
Cc: "David S. Miller" 
Cc: Dave Hansen 
Cc: Will Deacon 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Arnd Bergmann 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'nfsd-4.15-1' of git://linux-nfs.org/~bfields/linux

2017-11-29T22:49:26+00:00

Pull nfsd fixes from Bruce Fields:
 "I screwed up my merge window pull request; I only sent half of what I
  meant to.

  There were no new features, just bugfixes of various importance and
  some very minor cleanup, so I think it's all still appropriate for
  -rc2.

  Highlights:

   - Fixes from Trond for some races in the NFSv4 state code.

   - Fix from Naofumi Honda for a typo in the blocked lock notificiation
     code

   - Fixes from Vasily Averin for some problems starting and stopping
     lockd especially in network namespaces"

* tag 'nfsd-4.15-1' of git://linux-nfs.org/~bfields/linux: (23 commits)
  lockd: fix "list_add double add" caused by legacy signal interface
  nlm_shutdown_hosts_net() cleanup
  race of nfsd inetaddr notifiers vs nn->nfsd_serv change
  race of lockd inetaddr notifiers vs nlmsvc_rqst change
  SUNRPC: make cache_detail structures const
  NFSD: make cache_detail structures const
  sunrpc: make the function arg as const
  nfsd: check for use of the closed special stateid
  nfsd: fix panic in posix_unblock_lock called from nfs4_laundromat
  lockd: lost rollback of set_grace_period() in lockd_down_net()
  lockd: added cleanup checks in exit_net hook
  grace: replace BUG_ON by WARN_ONCE in exit_net hook
  nfsd: fix locking validator warning on nfs4_ol_stateid->st_mutex class
  lockd: remove net pointer from messages
  nfsd: remove net pointer from debug messages
  nfsd: Fix races with check_stateid_generation()
  nfsd: Ensure we check stateid validity in the seqid operation checks
  nfsd: Fix race in lock stateid creation
  nfsd4: move find_lock_stateid
  nfsd: Ensure we don't recognise lock stateids after freeing them
  ...