1. 06 Jun, 2017 5 commits
    • Marc Zyngier's avatar
      arm: KVM: Allow unaligned accesses at HYP · 33b5c388
      Marc Zyngier authored
      We currently have the HSCTLR.A bit set, trapping unaligned accesses
      at HYP, but we're not really prepared to deal with it.
      
      Since the rest of the kernel is pretty happy about that, let's follow
      its example and set HSCTLR.A to zero. Modern CPUs don't really care.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      33b5c388
    • Marc Zyngier's avatar
      arm64: KVM: Allow unaligned accesses at EL2 · 78fd6dcf
      Marc Zyngier authored
      We currently have the SCTLR_EL2.A bit set, trapping unaligned accesses
      at EL2, but we're not really prepared to deal with it. So far, this
      has been unnoticed, until GCC 7 started emitting those (in particular
      64bit writes on a 32bit boundary).
      
      Since the rest of the kernel is pretty happy about that, let's follow
      its example and set SCTLR_EL2.A to zero. Modern CPUs don't really
      care.
      
      Cc: stable@vger.kernel.org
      Reported-by: default avatarAlexander Graf <agraf@suse.de>
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      78fd6dcf
    • Marc Zyngier's avatar
      arm64: KVM: Preserve RES1 bits in SCTLR_EL2 · d68c1f7f
      Marc Zyngier authored
      __do_hyp_init has the rather bad habit of ignoring RES1 bits and
      writing them back as zero. On a v8.0-8.2 CPU, this doesn't do anything
      bad, but may end-up being pretty nasty on future revisions of the
      architecture.
      
      Let's preserve those bits so that we don't have to fix this later on.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      d68c1f7f
    • Marc Zyngier's avatar
      KVM: arm/arm64: Handle possible NULL stage2 pud when ageing pages · d6dbdd3c
      Marc Zyngier authored
      Under memory pressure, we start ageing pages, which amounts to parsing
      the page tables. Since we don't want to allocate any extra level,
      we pass NULL for our private allocation cache. Which means that
      stage2_get_pud() is allowed to fail. This results in the following
      splat:
      
      [ 1520.409577] Unable to handle kernel NULL pointer dereference at virtual address 00000008
      [ 1520.417741] pgd = ffff810f52fef000
      [ 1520.421201] [00000008] *pgd=0000010f636c5003, *pud=0000010f56f48003, *pmd=0000000000000000
      [ 1520.429546] Internal error: Oops: 96000006 [#1] PREEMPT SMP
      [ 1520.435156] Modules linked in:
      [ 1520.438246] CPU: 15 PID: 53550 Comm: qemu-system-aar Tainted: G        W       4.12.0-rc4-00027-g1885c397eaec #7205
      [ 1520.448705] Hardware name: FOXCONN R2-1221R-A4/C2U4N_MB, BIOS G31FB12A 10/26/2016
      [ 1520.463726] task: ffff800ac5fb4e00 task.stack: ffff800ce04e0000
      [ 1520.469666] PC is at stage2_get_pmd+0x34/0x110
      [ 1520.474119] LR is at kvm_age_hva_handler+0x44/0xf0
      [ 1520.478917] pc : [<ffff0000080b137c>] lr : [<ffff0000080b149c>] pstate: 40000145
      [ 1520.486325] sp : ffff800ce04e33d0
      [ 1520.489644] x29: ffff800ce04e33d0 x28: 0000000ffff40064
      [ 1520.494967] x27: 0000ffff27e00000 x26: 0000000000000000
      [ 1520.500289] x25: ffff81051ba65008 x24: 0000ffff40065000
      [ 1520.505618] x23: 0000ffff40064000 x22: 0000000000000000
      [ 1520.510947] x21: ffff810f52b20000 x20: 0000000000000000
      [ 1520.516274] x19: 0000000058264000 x18: 0000000000000000
      [ 1520.521603] x17: 0000ffffa6fe7438 x16: ffff000008278b70
      [ 1520.526940] x15: 000028ccd8000000 x14: 0000000000000008
      [ 1520.532264] x13: ffff7e0018298000 x12: 0000000000000002
      [ 1520.537582] x11: ffff000009241b93 x10: 0000000000000940
      [ 1520.542908] x9 : ffff0000092ef800 x8 : 0000000000000200
      [ 1520.548229] x7 : ffff800ce04e36a8 x6 : 0000000000000000
      [ 1520.553552] x5 : 0000000000000001 x4 : 0000000000000000
      [ 1520.558873] x3 : 0000000000000000 x2 : 0000000000000008
      [ 1520.571696] x1 : ffff000008fd5000 x0 : ffff0000080b149c
      [ 1520.577039] Process qemu-system-aar (pid: 53550, stack limit = 0xffff800ce04e0000)
      [...]
      [ 1521.510735] [<ffff0000080b137c>] stage2_get_pmd+0x34/0x110
      [ 1521.516221] [<ffff0000080b149c>] kvm_age_hva_handler+0x44/0xf0
      [ 1521.522054] [<ffff0000080b0610>] handle_hva_to_gpa+0xb8/0xe8
      [ 1521.527716] [<ffff0000080b3434>] kvm_age_hva+0x44/0xf0
      [ 1521.532854] [<ffff0000080a58b0>] kvm_mmu_notifier_clear_flush_young+0x70/0xc0
      [ 1521.539992] [<ffff000008238378>] __mmu_notifier_clear_flush_young+0x88/0xd0
      [ 1521.546958] [<ffff00000821eca0>] page_referenced_one+0xf0/0x188
      [ 1521.552881] [<ffff00000821f36c>] rmap_walk_anon+0xec/0x250
      [ 1521.558370] [<ffff000008220f78>] rmap_walk+0x78/0xa0
      [ 1521.563337] [<ffff000008221104>] page_referenced+0x164/0x180
      [ 1521.569002] [<ffff0000081f1af0>] shrink_active_list+0x178/0x3b8
      [ 1521.574922] [<ffff0000081f2058>] shrink_node_memcg+0x328/0x600
      [ 1521.580758] [<ffff0000081f23f4>] shrink_node+0xc4/0x328
      [ 1521.585986] [<ffff0000081f2718>] do_try_to_free_pages+0xc0/0x340
      [ 1521.592000] [<ffff0000081f2a64>] try_to_free_pages+0xcc/0x240
      [...]
      
      The trivial fix is to handle this NULL pud value early, rather than
      dereferencing it blindly.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      d6dbdd3c
    • Christoffer Dall's avatar
      KVM: arm/arm64: vgic-v3: Fix nr_pre_bits bitfield extraction · d68356cc
      Christoffer Dall authored
      We used to extract PRIbits from the ICH_VT_EL2 which was the upper field
      in the register word, so a mask wasn't necessary, but as we switched to
      looking at PREbits, which is bits 26 through 28 with the PRIbits field
      being potentially non-zero, we really need to mask off the field value,
      otherwise fun things may happen.
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      d68356cc
  2. 24 May, 2017 1 commit
  3. 18 May, 2017 2 commits
    • Christoffer Dall's avatar
      KVM: arm/arm64: Hold slots_lock when unregistering kvm io bus devices · fa472fa9
      Christoffer Dall authored
      We were not holding the kvm->slots_lock as required when calling
      kvm_io_bus_unregister_dev() as required.
      
      This only affects the error path, but still, let's do our due
      diligence.
      
      Reported by: Eric Auger <eric.auger@redhat.com>
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
      fa472fa9
    • Christoffer Dall's avatar
      KVM: arm/arm64: Fix bug when registering redist iodevs · 552c9f47
      Christoffer Dall authored
      If userspace creates the VCPUs after initializing the VGIC, then we end
      up in a situation where we trigger a bug in kvm_vcpu_get_idx(), because
      it is called prior to adding the VCPU into the vcpus array on the VM.
      
      There is no tight coupling between the VCPU index and the area of the
      redistributor region used for the VCPU, so we can simply ensure that all
      creations of redistributors are serialized per VM, and increment an
      offset when we successfully add a redistributor.
      
      The vgic_register_redist_iodev() function can be called from two paths:
      vgic_redister_all_redist_iodev() which is called via the kvm_vgic_addr()
      device attribute handler.  This patch already holds the kvm->lock mutex.
      
      The other path is via kvm_vgic_vcpu_init, which is called through a
      longer chain from kvm_vm_ioctl_create_vcpu(), which releases the
      kvm->lock mutex just before calling kvm_arch_vcpu_create(), so we can
      simply take this mutex again later for our purposes.
      
      Fixes: ab6f468c10 ("KVM: arm/arm64: Register iodevs when setting redist base and creating VCPUs")
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      Tested-by: default avatarJean-Philippe Brucker <jean-philippe.brucker@arm.com>
      Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
      552c9f47
  4. 16 May, 2017 2 commits
  5. 15 May, 2017 9 commits
    • Zhichao Huang's avatar
      KVM: arm: rename pm_fake handler to trap_raz_wi · 9b619a8f
      Zhichao Huang authored
      pm_fake doesn't quite describe what the handler does (ignoring writes
      and returning 0 for reads).
      
      As we're about to use it (a lot) in a different context, rename it
      with a (admitedly cryptic) name that make sense for all users.
      Signed-off-by: default avatarZhichao Huang <zhichao.huang@linaro.org>
      Reviewed-by: default avatarAlex Bennee <alex.bennee@linaro.org>
      Acked-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
      Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Signed-off-by: default avatarAlex Bennée <alex.bennee@linaro.org>
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      9b619a8f
    • Zhichao Huang's avatar
      KVM: arm: plug potential guest hardware debug leakage · 661e6b02
      Zhichao Huang authored
      Hardware debugging in guests is not intercepted currently, it means
      that a malicious guest can bring down the entire machine by writing
      to the debug registers.
      
      This patch enable trapping of all debug registers, preventing the
      guests to access the debug registers. This includes access to the
      debug mode(DBGDSCR) in the guest world all the time which could
      otherwise mess with the host state. Reads return 0 and writes are
      ignored (RAZ_WI).
      
      The result is the guest cannot detect any working hardware based debug
      support. As debug exceptions are still routed to the guest normal
      debug using software based breakpoints still works.
      
      To support debugging using hardware registers we need to implement a
      debug register aware world switch as well as special trapping for
      registers that may affect the host state.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarZhichao Huang <zhichao.huang@linaro.org>
      Signed-off-by: default avatarAlex Bennée <alex.bennee@linaro.org>
      Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      661e6b02
    • Suzuki K Poulose's avatar
      kvm: arm/arm64: Fix race in resetting stage2 PGD · 6c0d706b
      Suzuki K Poulose authored
      In kvm_free_stage2_pgd() we check the stage2 PGD before holding
      the lock and proceed to take the lock if it is valid. And we unmap
      the page tables, followed by releasing the lock. We reset the PGD
      only after dropping this lock, which could cause a race condition
      where another thread waiting on or even holding the lock, could
      potentially see that the PGD is still valid and proceed to perform
      a stage2 operation and later encounter a NULL PGD.
      
      [223090.242280] Unable to handle kernel NULL pointer dereference at
      virtual address 00000040
      [223090.262330] PC is at unmap_stage2_range+0x8c/0x428
      [223090.262332] LR is at kvm_unmap_hva_handler+0x2c/0x3c
      [223090.262531] Call trace:
      [223090.262533] [<ffff0000080adb78>] unmap_stage2_range+0x8c/0x428
      [223090.262535] [<ffff0000080adf40>] kvm_unmap_hva_handler+0x2c/0x3c
      [223090.262537] [<ffff0000080ace2c>] handle_hva_to_gpa+0xb0/0x104
      [223090.262539] [<ffff0000080af988>] kvm_unmap_hva+0x5c/0xbc
      [223090.262543] [<ffff0000080a2478>]
      kvm_mmu_notifier_invalidate_page+0x50/0x8c
      [223090.262547] [<ffff0000082274f8>]
      __mmu_notifier_invalidate_page+0x5c/0x84
      [223090.262551] [<ffff00000820b700>] try_to_unmap_one+0x1d0/0x4a0
      [223090.262553] [<ffff00000820c5c8>] rmap_walk+0x1cc/0x2e0
      [223090.262555] [<ffff00000820c90c>] try_to_unmap+0x74/0xa4
      [223090.262557] [<ffff000008230ce4>] migrate_pages+0x31c/0x5ac
      [223090.262561] [<ffff0000081f869c>] compact_zone+0x3fc/0x7ac
      [223090.262563] [<ffff0000081f8ae0>] compact_zone_order+0x94/0xb0
      [223090.262564] [<ffff0000081f91c0>] try_to_compact_pages+0x108/0x290
      [223090.262569] [<ffff0000081d5108>] __alloc_pages_direct_compact+0x70/0x1ac
      [223090.262571] [<ffff0000081d64a0>] __alloc_pages_nodemask+0x434/0x9f4
      [223090.262572] [<ffff0000082256f0>] alloc_pages_vma+0x230/0x254
      [223090.262574] [<ffff000008235e5c>] do_huge_pmd_anonymous_page+0x114/0x538
      [223090.262576] [<ffff000008201bec>] handle_mm_fault+0xd40/0x17a4
      [223090.262577] [<ffff0000081fb324>] __get_user_pages+0x12c/0x36c
      [223090.262578] [<ffff0000081fb804>] get_user_pages_unlocked+0xa4/0x1b8
      [223090.262579] [<ffff0000080a3ce8>] __gfn_to_pfn_memslot+0x280/0x31c
      [223090.262580] [<ffff0000080a3dd0>] gfn_to_pfn_prot+0x4c/0x5c
      [223090.262582] [<ffff0000080af3f8>] kvm_handle_guest_abort+0x240/0x774
      [223090.262584] [<ffff0000080b2bac>] handle_exit+0x11c/0x1ac
      [223090.262586] [<ffff0000080ab99c>] kvm_arch_vcpu_ioctl_run+0x31c/0x648
      [223090.262587] [<ffff0000080a1d78>] kvm_vcpu_ioctl+0x378/0x768
      [223090.262590] [<ffff00000825df5c>] do_vfs_ioctl+0x324/0x5a4
      [223090.262591] [<ffff00000825e26c>] SyS_ioctl+0x90/0xa4
      [223090.262595] [<ffff000008085d84>] el0_svc_naked+0x38/0x3c
      
      This patch moves the stage2 PGD manipulation under the lock.
      Reported-by: default avatarAlexander Graf <agraf@suse.de>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
      Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      6c0d706b
    • Marc Zyngier's avatar
      KVM: arm/arm64: vgic-v3: Use PREbits to infer the number of ICH_APxRn_EL2 registers · 15d2bffd
      Marc Zyngier authored
      The GICv3 documentation is extremely confusing, as it talks about
      the number of priorities represented by the ICH_APxRn_EL2 registers,
      while it should really talk about the number of preemption levels.
      
      This leads to a bug where we may access undefined ICH_APxRn_EL2
      registers, since PREbits is allowed to be smaller than PRIbits.
      Thankfully, nobody seem to have taken this path so far...
      
      The fix is to use ICH_VTR_EL2.PREbits instead.
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      15d2bffd
    • Marc Zyngier's avatar
      KVM: arm/arm64: vgic-v3: Do not use Active+Pending state for a HW interrupt · 3d6e77ad
      Marc Zyngier authored
      When an interrupt is injected with the HW bit set (indicating that
      deactivation should be propagated to the physical distributor),
      special care must be taken so that we never mark the corresponding
      LR with the Active+Pending state (as the pending state is kept in
      the physycal distributor).
      
      Cc: stable@vger.kernel.org
      Fixes: 59529f69 ("KVM: arm/arm64: vgic-new: Add GICv3 world switch backend")
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      3d6e77ad
    • Marc Zyngier's avatar
      KVM: arm/arm64: vgic-v2: Do not use Active+Pending state for a HW interrupt · ddf42d06
      Marc Zyngier authored
      When an interrupt is injected with the HW bit set (indicating that
      deactivation should be propagated to the physical distributor),
      special care must be taken so that we never mark the corresponding
      LR with the Active+Pending state (as the pending state is kept in
      the physycal distributor).
      
      Cc: stable@vger.kernel.org
      Fixes: 140b086d ("KVM: arm/arm64: vgic-new: Add GICv2 world switch backend")
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      ddf42d06
    • Marc Zyngier's avatar
      arm: KVM: Do not use stack-protector to compile HYP code · 501ad27c
      Marc Zyngier authored
      We like living dangerously. Nothing explicitely forbids stack-protector
      to be used in the HYP code, while distributions routinely compile their
      kernel with it. We're just lucky that no code actually triggers the
      instrumentation.
      
      Let's not try our luck for much longer, and disable stack-protector
      for code living at HYP.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Acked-by: default avatarChristoffer Dall <cdall@linaro.org>
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      501ad27c
    • Marc Zyngier's avatar
      arm64: KVM: Do not use stack-protector to compile EL2 code · cde13b5d
      Marc Zyngier authored
      We like living dangerously. Nothing explicitely forbids stack-protector
      to be used in the EL2 code, while distributions routinely compile their
      kernel with it. We're just lucky that no code actually triggers the
      instrumentation.
      
      Let's not try our luck for much longer, and disable stack-protector
      for code living at EL2.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Acked-by: default avatarChristoffer Dall <cdall@linaro.org>
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      cde13b5d
    • Marc Zyngier's avatar
      ARM: KVM: Fix tracepoint generation after move to virt/kvm/arm/ · 01630ab8
      Marc Zyngier authored
      Moving most of the shared code to virt/kvm/arm had for consequence
      that KVM/ARM doesn't build anymore, because the code that used to
      define the tracepoints is now somewhere else.
      
      Fix this by defining CREATE_TRACE_POINTS in coproc.c, and clean-up
      trace.h as well.
      
      Fixes: 35d2d5d4 ("KVM: arm/arm64: Move shared files to virt/kvm/arm")
      Reported-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
      01630ab8
  6. 13 May, 2017 5 commits
    • Linus Torvalds's avatar
      Linux 4.12-rc1 · 2ea659a9
      Linus Torvalds authored
      2ea659a9
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input · cd636458
      Linus Torvalds authored
      Pull some more input subsystem updates from Dmitry Torokhov:
       "An updated xpad driver with a few more recognized device IDs, and a
        new psxpad-spi driver, allowing connecting Playstation 1 and 2 joypads
        via SPI bus"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
        Input: cros_ec_keyb - remove extraneous 'const'
        Input: add support for PlayStation 1/2 joypads connected via SPI
        Input: xpad - add USB IDs for Mad Catz Brawlstick and Razer Sabertooth
        Input: xpad - sync supported devices with xboxdrv
        Input: xpad - sort supported devices by USB ID
      cd636458
    • Linus Torvalds's avatar
      Merge tag 'upstream-4.12-rc1' of git://git.infradead.org/linux-ubifs · b53c4d5e
      Linus Torvalds authored
      Pull UBI/UBIFS updates from Richard Weinberger:
      
       - new config option CONFIG_UBIFS_FS_SECURITY
      
       - minor improvements
      
       - random fixes
      
      * tag 'upstream-4.12-rc1' of git://git.infradead.org/linux-ubifs:
        ubi: Add debugfs file for tracking PEB state
        ubifs: Fix a typo in comment of ioctl2ubifs & ubifs2ioctl
        ubifs: Remove unnecessary assignment
        ubifs: Fix cut and paste error on sb type comparisons
        ubi: fastmap: Fix slab corruption
        ubifs: Add CONFIG_UBIFS_FS_SECURITY to disable/enable security labels
        ubi: Make mtd parameter readable
        ubi: Fix section mismatch
      b53c4d5e
    • Linus Torvalds's avatar
      Merge branch 'for-linus-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml · ec059019
      Linus Torvalds authored
      Pull UML fixes from Richard Weinberger:
       "No new stuff, just fixes"
      
      * 'for-linus-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
        um: Add missing NR_CPUS include
        um: Fix to call read_initrd after init_bootmem
        um: Include kbuild.h instead of duplicating its macros
        um: Fix PTRACE_POKEUSER on x86_64
        um: Set number of CPUs
        um: Fix _print_addr()
      ec059019
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew) · 1251704a
      Linus Torvalds authored
      Merge misc fixes from Andrew Morton:
       "15 fixes"
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>:
        mm, docs: update memory.stat description with workingset* entries
        mm: vmscan: scan until it finds eligible pages
        mm, thp: copying user pages must schedule on collapse
        dax: fix PMD data corruption when fault races with write
        dax: fix data corruption when fault races with write
        ext4: return to starting transaction in ext4_dax_huge_fault()
        mm: fix data corruption due to stale mmap reads
        dax: prevent invalidation of mapped DAX entries
        Tigran has moved
        mm, vmalloc: fix vmalloc users tracking properly
        mm/khugepaged: add missed tracepoint for collapse_huge_page_swapin
        gcov: support GCC 7.1
        mm, vmstat: Remove spurious WARN() during zoneinfo print
        time: delete current_fs_time()
        hwpoison, memcg: forcibly uncharge LRU pages
      1251704a
  7. 12 May, 2017 16 commits
    • Roman Gushchin's avatar
      mm, docs: update memory.stat description with workingset* entries · b340959e
      Roman Gushchin authored
      Commit 4b4cea91691d ("mm: vmscan: fix IO/refault regression in cache
      workingset transition") introduced three new entries in memory stat
      file:
      
       - workingset_refault
       - workingset_activate
       - workingset_nodereclaim
      
      This commit adds a corresponding description to the cgroup v2 docs.
      
      Link: http://lkml.kernel.org/r/1494530293-31236-1-git-send-email-guro@fb.comSigned-off-by: default avatarRoman Gushchin <guro@fb.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@kernel.org>
      Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Li Zefan <lizefan@huawei.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b340959e
    • Minchan Kim's avatar
      mm: vmscan: scan until it finds eligible pages · 791b48b6
      Minchan Kim authored
      Although there are a ton of free swap and anonymous LRU page in elgible
      zones, OOM happened.
      
        balloon invoked oom-killer: gfp_mask=0x17080c0(GFP_KERNEL_ACCOUNT|__GFP_ZERO|__GFP_NOTRACK), nodemask=(null),  order=0, oom_score_adj=0
        CPU: 7 PID: 1138 Comm: balloon Not tainted 4.11.0-rc6-mm1-zram-00289-ge228d67e9677-dirty #17
        Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
        Call Trace:
         oom_kill_process+0x21d/0x3f0
         out_of_memory+0xd8/0x390
         __alloc_pages_slowpath+0xbc1/0xc50
         __alloc_pages_nodemask+0x1a5/0x1c0
         pte_alloc_one+0x20/0x50
         __pte_alloc+0x1e/0x110
         __handle_mm_fault+0x919/0x960
         handle_mm_fault+0x77/0x120
         __do_page_fault+0x27a/0x550
         trace_do_page_fault+0x43/0x150
         do_async_page_fault+0x2c/0x90
         async_page_fault+0x28/0x30
        Mem-Info:
        active_anon:424716 inactive_anon:65314 isolated_anon:0
         active_file:52 inactive_file:46 isolated_file:0
         unevictable:0 dirty:27 writeback:0 unstable:0
         slab_reclaimable:3967 slab_unreclaimable:4125
         mapped:133 shmem:43 pagetables:1674 bounce:0
         free:4637 free_pcp:225 free_cma:0
        Node 0 active_anon:1698864kB inactive_anon:261256kB active_file:208kB inactive_file:184kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:532kB dirty:108kB writeback:0kB shmem:172kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no
        DMA free:7316kB min:32kB low:44kB high:56kB active_anon:8064kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15992kB managed:15908kB mlocked:0kB slab_reclaimable:464kB slab_unreclaimable:40kB kernel_stack:0kB pagetables:24kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
        lowmem_reserve[]: 0 992 992 1952
        DMA32 free:9088kB min:2048kB low:3064kB high:4080kB active_anon:952176kB inactive_anon:0kB active_file:36kB inactive_file:0kB unevictable:0kB writepending:88kB present:1032192kB managed:1019388kB mlocked:0kB slab_reclaimable:13532kB slab_unreclaimable:16460kB kernel_stack:3552kB pagetables:6672kB bounce:0kB free_pcp:56kB local_pcp:24kB free_cma:0kB
        lowmem_reserve[]: 0 0 0 959
        Movable free:3644kB min:1980kB low:2960kB high:3940kB active_anon:738560kB inactive_anon:261340kB active_file:188kB inactive_file:640kB unevictable:0kB writepending:20kB present:1048444kB managed:1010816kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:832kB local_pcp:60kB free_cma:0kB
        lowmem_reserve[]: 0 0 0 0
        DMA: 1*4kB (E) 0*8kB 18*16kB (E) 10*32kB (E) 10*64kB (E) 9*128kB (ME) 8*256kB (E) 2*512kB (E) 2*1024kB (E) 0*2048kB 0*4096kB = 7524kB
        DMA32: 417*4kB (UMEH) 181*8kB (UMEH) 68*16kB (UMEH) 48*32kB (UMEH) 14*64kB (MH) 3*128kB (M) 1*256kB (H) 1*512kB (M) 2*1024kB (M) 0*2048kB 0*4096kB = 9836kB
        Movable: 1*4kB (M) 1*8kB (M) 1*16kB (M) 1*32kB (M) 0*64kB 1*128kB (M) 2*256kB (M) 4*512kB (M) 1*1024kB (M) 0*2048kB 0*4096kB = 3772kB
        378 total pagecache pages
        17 pages in swap cache
        Swap cache stats: add 17325, delete 17302, find 0/27
        Free swap  = 978940kB
        Total swap = 1048572kB
        524157 pages RAM
        0 pages HighMem/MovableOnly
        12629 pages reserved
        0 pages cma reserved
        0 pages hwpoisoned
        [ pid ]   uid  tgid total_vm      rss nr_ptes nr_pmds swapents oom_score_adj name
        [  433]     0   433     4904        5      14       3       82             0 upstart-udev-br
        [  438]     0   438    12371        5      27       3      191         -1000 systemd-udevd
      
      With investigation, skipping page of isolate_lru_pages makes reclaim
      void because it returns zero nr_taken easily so LRU shrinking is
      effectively nothing and just increases priority aggressively.  Finally,
      OOM happens.
      
      The problem is that get_scan_count determines nr_to_scan with eligible
      zones so although priority drops to zero, it couldn't reclaim any pages
      if the LRU contains mostly ineligible pages.
      
      get_scan_count:
      
              size = lruvec_lru_size(lruvec, lru, sc->reclaim_idx);
      	size = size >> sc->priority;
      
      Assumes sc->priority is 0 and LRU list is as follows.
      
      	N-N-N-N-H-H-H-H-H-H-H-H-H-H-H-H-H-H-H-H
      
      (Ie, small eligible pages are in the head of LRU but others are
       almost ineligible pages)
      
      In that case, size becomes 4 so VM want to scan 4 pages but 4 pages from
      tail of the LRU are not eligible pages.  If get_scan_count counts
      skipped pages, it doesn't reclaim any pages remained after scanning 4
      pages so it ends up OOM happening.
      
      This patch makes isolate_lru_pages try to scan pages until it encounters
      eligible zones's pages.
      
      [akpm@linux-foundation.org: clean up mind-bending `for' statement.  Tweak comment text]
      Fixes: 3db65812 ("Revert "mm, vmscan: account for skipped pages as a partial scan"")
      Link: http://lkml.kernel.org/r/1494457232-27401-1-git-send-email-minchan@kernel.orgSigned-off-by: default avatarMinchan Kim <minchan@kernel.org>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      791b48b6
    • David Rientjes's avatar
      mm, thp: copying user pages must schedule on collapse · 338a16ba
      David Rientjes authored
      We have encountered need_resched warnings in __collapse_huge_page_copy()
      while doing {clear,copy}_user_highpage() over HPAGE_PMD_NR source pages.
      
      mm->mmap_sem is held for write, but the iteration is well bounded.
      
      Reschedule as needed.
      
      Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1705101426380.109808@chino.kir.corp.google.comSigned-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      338a16ba
    • Ross Zwisler's avatar
      dax: fix PMD data corruption when fault races with write · 876f2946
      Ross Zwisler authored
      This is based on a patch from Jan Kara that fixed the equivalent race in
      the DAX PTE fault path.
      
      Currently DAX PMD read fault can race with write(2) in the following
      way:
      
      CPU1 - write(2)                 CPU2 - read fault
                                      dax_iomap_pmd_fault()
                                        ->iomap_begin() - sees hole
      
      dax_iomap_rw()
        iomap_apply()
          ->iomap_begin - allocates blocks
          dax_iomap_actor()
            invalidate_inode_pages2_range()
              - there's nothing to invalidate
      
                                        grab_mapping_entry()
      				  - we add huge zero page to the radix tree
      				    and map it to page tables
      
      The result is that hole page is mapped into page tables (and thus zeros
      are seen in mmap) while file has data written in that place.
      
      Fix the problem by locking exception entry before mapping blocks for the
      fault.  That way we are sure invalidate_inode_pages2_range() call for
      racing write will either block on entry lock waiting for the fault to
      finish (and unmap stale page tables after that) or read fault will see
      already allocated blocks by write(2).
      
      Fixes: 9f141d6e ("dax: Call ->iomap_begin without entry lock during dax fault")
      Link: http://lkml.kernel.org/r/20170510172700.18991-1-ross.zwisler@linux.intel.comSigned-off-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
      Reviewed-by: default avatarJan Kara <jack@suse.cz>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      876f2946
    • Jan Kara's avatar
      dax: fix data corruption when fault races with write · 13e451fd
      Jan Kara authored
      Currently DAX read fault can race with write(2) in the following way:
      
      CPU1 - write(2)			CPU2 - read fault
      				dax_iomap_pte_fault()
      				  ->iomap_begin() - sees hole
      dax_iomap_rw()
        iomap_apply()
          ->iomap_begin - allocates blocks
          dax_iomap_actor()
            invalidate_inode_pages2_range()
              - there's nothing to invalidate
      				  grab_mapping_entry()
      				  - we add zero page in the radix tree
      				    and map it to page tables
      
      The result is that hole page is mapped into page tables (and thus zeros
      are seen in mmap) while file has data written in that place.
      
      Fix the problem by locking exception entry before mapping blocks for the
      fault.  That way we are sure invalidate_inode_pages2_range() call for
      racing write will either block on entry lock waiting for the fault to
      finish (and unmap stale page tables after that) or read fault will see
      already allocated blocks by write(2).
      
      Fixes: 9f141d6e
      Link: http://lkml.kernel.org/r/20170510085419.27601-5-jack@suse.czSigned-off-by: default avatarJan Kara <jack@suse.cz>
      Reviewed-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      13e451fd
    • Jan Kara's avatar
      ext4: return to starting transaction in ext4_dax_huge_fault() · fb26a1cb
      Jan Kara authored
      DAX will return to locking exceptional entry before mapping blocks for a
      page fault to fix possible races with concurrent writes.  To avoid lock
      inversion between exceptional entry lock and transaction start, start
      the transaction already in ext4_dax_huge_fault().
      
      Fixes: 9f141d6e
      Link: http://lkml.kernel.org/r/20170510085419.27601-4-jack@suse.czSigned-off-by: default avatarJan Kara <jack@suse.cz>
      Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      fb26a1cb
    • Jan Kara's avatar
      mm: fix data corruption due to stale mmap reads · cd656375
      Jan Kara authored
      Currently, we didn't invalidate page tables during invalidate_inode_pages2()
      for DAX.  That could result in e.g. 2MiB zero page being mapped into
      page tables while there were already underlying blocks allocated and
      thus data seen through mmap were different from data seen by read(2).
      The following sequence reproduces the problem:
      
       - open an mmap over a 2MiB hole
      
       - read from a 2MiB hole, faulting in a 2MiB zero page
      
       - write to the hole with write(3p). The write succeeds but we
         incorrectly leave the 2MiB zero page mapping intact.
      
       - via the mmap, read the data that was just written. Since the zero
         page mapping is still intact we read back zeroes instead of the new
         data.
      
      Fix the problem by unconditionally calling invalidate_inode_pages2_range()
      in dax_iomap_actor() for new block allocations and by properly
      invalidating page tables in invalidate_inode_pages2_range() for DAX
      mappings.
      
      Fixes: c6dcf52c
      Link: http://lkml.kernel.org/r/20170510085419.27601-3-jack@suse.czSigned-off-by: default avatarJan Kara <jack@suse.cz>
      Signed-off-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cd656375
    • Ross Zwisler's avatar
      dax: prevent invalidation of mapped DAX entries · 4636e70b
      Ross Zwisler authored
      Patch series "mm,dax: Fix data corruption due to mmap inconsistency",
      v4.
      
      This series fixes data corruption that can happen for DAX mounts when
      page faults race with write(2) and as a result page tables get out of
      sync with block mappings in the filesystem and thus data seen through
      mmap is different from data seen through read(2).
      
      The series passes testing with t_mmap_stale test program from Ross and
      also other mmap related tests on DAX filesystem.
      
      This patch (of 4):
      
      dax_invalidate_mapping_entry() currently removes DAX exceptional entries
      only if they are clean and unlocked.  This is done via:
      
        invalidate_mapping_pages()
          invalidate_exceptional_entry()
            dax_invalidate_mapping_entry()
      
      However, for page cache pages removed in invalidate_mapping_pages()
      there is an additional criteria which is that the page must not be
      mapped.  This is noted in the comments above invalidate_mapping_pages()
      and is checked in invalidate_inode_page().
      
      For DAX entries this means that we can can end up in a situation where a
      DAX exceptional entry, either a huge zero page or a regular DAX entry,
      could end up mapped but without an associated radix tree entry.  This is
      inconsistent with the rest of the DAX code and with what happens in the
      page cache case.
      
      We aren't able to unmap the DAX exceptional entry because according to
      its comments invalidate_mapping_pages() isn't allowed to block, and
      unmap_mapping_range() takes a write lock on the mapping->i_mmap_rwsem.
      
      Since we essentially never have unmapped DAX entries to evict from the
      radix tree, just remove dax_invalidate_mapping_entry().
      
      Fixes: c6dcf52c ("mm: Invalidate DAX radix tree entries only if appropriate")
      Link: http://lkml.kernel.org/r/20170510085419.27601-2-jack@suse.czSigned-off-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
      Reported-by: default avatarJan Kara <jack@suse.cz>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: <stable@vger.kernel.org>    [4.10+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4636e70b
    • Andrew Morton's avatar
      Tigran has moved · cea58224
      Andrew Morton authored
      Cc: Tigran Aivazian <aivazian.tigran@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cea58224
    • Michal Hocko's avatar
      mm, vmalloc: fix vmalloc users tracking properly · 8594a21c
      Michal Hocko authored
      Commit 1f5307b1 ("mm, vmalloc: properly track vmalloc users") has
      pulled asm/pgtable.h include dependency to linux/vmalloc.h and that
      turned out to be a bad idea for some architectures.  E.g.  m68k fails
      with
      
         In file included from arch/m68k/include/asm/pgtable_mm.h:145:0,
                          from arch/m68k/include/asm/pgtable.h:4,
                          from include/linux/vmalloc.h:9,
                          from arch/m68k/kernel/module.c:9:
         arch/m68k/include/asm/mcf_pgtable.h: In function 'nocache_page':
      >> arch/m68k/include/asm/mcf_pgtable.h:339:43: error: 'init_mm' undeclared (first use in this function)
          #define pgd_offset_k(address) pgd_offset(&init_mm, address)
      
      as spotted by kernel build bot. nios2 fails for other reason
      
        In file included from include/asm-generic/io.h:767:0,
                         from arch/nios2/include/asm/io.h:61,
                         from include/linux/io.h:25,
                         from arch/nios2/include/asm/pgtable.h:18,
                         from include/linux/mm.h:70,
                         from include/linux/pid_namespace.h:6,
                         from include/linux/ptrace.h:9,
                         from arch/nios2/include/uapi/asm/elf.h:23,
                         from arch/nios2/include/asm/elf.h:22,
                         from include/linux/elf.h:4,
                         from include/linux/module.h:15,
                         from init/main.c:16:
        include/linux/vmalloc.h: In function '__vmalloc_node_flags':
        include/linux/vmalloc.h:99:40: error: 'PAGE_KERNEL' undeclared (first use in this function); did you mean 'GFP_KERNEL'?
      
      which is due to the newly added #include <asm/pgtable.h>, which on nios2
      includes <linux/io.h> and thus <asm/io.h> and <asm-generic/io.h> which
      again includes <linux/vmalloc.h>.
      
      Tweaking that around just turns out a bigger headache than necessary.
      This patch reverts 1f5307b1 and reimplements the original fix in a
      different way.  __vmalloc_node_flags can stay static inline which will
      cover vmalloc* functions.  We only have one external user
      (kvmalloc_node) and we can export __vmalloc_node_flags_caller and
      provide the caller directly.  This is much simpler and it doesn't really
      need any games with header files.
      
      [akpm@linux-foundation.org: coding-style fixes]
      [mhocko@kernel.org: revert old comment]
        Link: http://lkml.kernel.org/r/20170509211054.GB16325@dhcp22.suse.cz
      Fixes: 1f5307b1 ("mm, vmalloc: properly track vmalloc users")
      Link: http://lkml.kernel.org/r/20170509153702.GR6481@dhcp22.suse.czSigned-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Tobias Klauser <tklauser@distanz.ch>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8594a21c
    • SeongJae Park's avatar
      mm/khugepaged: add missed tracepoint for collapse_huge_page_swapin · 835152a2
      SeongJae Park authored
      One return case of `__collapse_huge_page_swapin()` does not invoke
      tracepoint while every other return case does.  This commit adds a
      tracepoint invocation for the case.
      
      Link: http://lkml.kernel.org/r/20170507101813.30187-1-sj38.park@gmail.comSigned-off-by: default avatarSeongJae Park <sj38.park@gmail.com>
      Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      835152a2
    • Martin Liska's avatar
      gcov: support GCC 7.1 · 05384213
      Martin Liska authored
      Starting from GCC 7.1, __gcov_exit is a new symbol expected to be
      implemented in a profiling runtime.
      
      [akpm@linux-foundation.org: coding-style fixes]
      [mliska@suse.cz: v2]
        Link: http://lkml.kernel.org/r/e63a3c59-0149-c97e-4084-20ca8f146b26@suse.cz
      Link: http://lkml.kernel.org/r/8c4084fa-3885-29fe-5fc4-0d4ca199c785@suse.czSigned-off-by: default avatarMartin Liska <mliska@suse.cz>
      Acked-by: default avatarPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      05384213
    • Reza Arbab's avatar
      mm, vmstat: Remove spurious WARN() during zoneinfo print · 8d35bb31
      Reza Arbab authored
      After commit e2ecc8a7 ("mm, vmstat: print non-populated zones in
      zoneinfo"), /proc/zoneinfo will show unpopulated zones.
      
      A memoryless node, having no populated zones at all, was previously
      ignored, but will now trigger the WARN() in is_zone_first_populated().
      
      Remove this warning, as its only purpose was to warn of a situation that
      has since been enabled.
      
      Aside: The "per-node stats" are still printed under the first populated
      zone, but that's not necessarily the first stanza any more.  I'm not
      sure which criteria is more important with regard to not breaking
      parsers, but it looks a little weird to the eye.
      
      Fixes:  e2ecc8a7 ("mm, vmstat: print node-based stats in zoneinfo file")
      Link: http://lkml.kernel.org/r/1493854905-10918-1-git-send-email-arbab@linux.vnet.ibm.comSigned-off-by: default avatarReza Arbab <arbab@linux.vnet.ibm.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8d35bb31
    • Deepa Dinamani's avatar
      time: delete current_fs_time() · 572e0ca9
      Deepa Dinamani authored
      All uses of the current_fs_time() function have been replaced by other
      time interfaces.
      
      And, its use cases can be fulfilled by current_time() or ktime_get_*
      variants.
      
      Link: http://lkml.kernel.org/r/1491613030-11599-13-git-send-email-deepa.kernel@gmail.comSigned-off-by: default avatarDeepa Dinamani <deepa.kernel@gmail.com>
      Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
      Cc: John Stultz <john.stultz@linaro.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      572e0ca9
    • Michal Hocko's avatar
      hwpoison, memcg: forcibly uncharge LRU pages · 18365225
      Michal Hocko authored
      Laurent Dufour has noticed that hwpoinsoned pages are kept charged.  In
      his particular case he has hit a bad_page("page still charged to
      cgroup") when onlining a hwpoison page.  While this looks like something
      that shouldn't happen in the first place because onlining hwpages and
      returning them to the page allocator makes only little sense it shows a
      real problem.
      
      hwpoison pages do not get freed usually so we do not uncharge them (at
      least not since commit 0a31bc97 ("mm: memcontrol: rewrite uncharge
      API")).  Each charge pins memcg (since e8ea14cc ("mm: memcontrol:
      take a css reference for each charged page")) as well and so the
      mem_cgroup and the associated state will never go away.  Fix this leak
      by forcibly uncharging a LRU hwpoisoned page in delete_from_lru_cache().
      We also have to tweak uncharge_list because it cannot rely on zero ref
      count for these pages.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Fixes: 0a31bc97 ("mm: memcontrol: rewrite uncharge API")
      Link: http://lkml.kernel.org/r/20170502185507.GB19165@dhcp22.suse.czSigned-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Reported-by: default avatarLaurent Dufour <ldufour@linux.vnet.ibm.com>
      Tested-by: default avatarLaurent Dufour <ldufour@linux.vnet.ibm.com>
      Reviewed-by: default avatarBalbir Singh <bsingharora@gmail.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      18365225
    • Linus Torvalds's avatar
      Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm · 0fcc3ab2
      Linus Torvalds authored
      Pull libnvdimm fixes from Dan Williams:
       "Incremental fixes and a small feature addition on top of the main
        libnvdimm 4.12 pull request:
      
         - Geert noticed that tinyconfig was bloated by BLOCK selecting DAX.
           The size regression is fixed by moving all dax helpers into the
           dax-core and only specifying "select DAX" for FS_DAX and
           dax-capable drivers. He also asked for clarification of the
           NR_DEV_DAX config option which, on closer look, does not need to be
           a config option at all. Mike also throws in a DEV_DAX_PMEM fixup
           for good measure.
      
         - Ben's attention to detail on -stable patch submissions caught a
           case where the recent fixes to arch_copy_from_iter_pmem() missed a
           condition where we strand dirty data in the cache. This is tagged
           for -stable and will also be included in the rework of the pmem api
           to a proposed {memcpy,copy_user}_flushcache() interface for 4.13.
      
         - Vishal adds a feature that missed the initial pull due to pending
           review feedback. It allows the kernel to clear media errors when
           initializing a BTT (atomic sector update driver) instance on a pmem
           namespace.
      
         - Ross noticed that the dax_device + dax_operations conversion broke
           __dax_zero_page_range(). The nvdimm unit tests fail to check this
           path, but xfstests immediately trips over it. No excuse for missing
           this before submitting the 4.12 pull request.
      
        These all pass the nvdimm unit tests and an xfstests spot check. The
        set has received a build success notification from the kbuild robot"
      
      * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
        filesystem-dax: fix broken __dax_zero_page_range() conversion
        libnvdimm, btt: ensure that initializing metadata clears poison
        libnvdimm: add an atomic vs process context flag to rw_bytes
        x86, pmem: Fix cache flushing for iovec write < 8 bytes
        device-dax: kill NR_DEV_DAX
        block, dax: move "select DAX" from BLOCK to FS_DAX
        device-dax: Tell kbuild DEV_DAX_PMEM depends on DEV_DAX
      0fcc3ab2