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  1. 04 10月, 2018 2 次提交
    • P
      KVM: VMX: hide flexpriority from guest when disabled at the module level · 2cf7ea9f
      由 Paolo Bonzini 提交于 
      As of commit 8d860bbe ("kvm: vmx: Basic APIC virtualization controls
have three settings"), KVM will disable VIRTUALIZE_APIC_ACCESSES when
a nested guest writes APIC_BASE MSR and kvm-intel.flexpriority=0,
whereas previously KVM would allow a nested guest to enable
VIRTUALIZE_APIC_ACCESSES so long as it's supported in hardware.  That is,
KVM now advertises VIRTUALIZE_APIC_ACCESSES to a guest but doesn't
(always) allow setting it when kvm-intel.flexpriority=0, and may even
initially allow the control and then clear it when the nested guest
writes APIC_BASE MSR, which is decidedly odd even if it doesn't cause
functional issues.

Hide the control completely when the module parameter is cleared.
reported-by: NSean Christopherson <sean.j.christopherson@intel.com>
Fixes: 8d860bbe ("kvm: vmx: Basic APIC virtualization controls have three settings")
Cc: Jim Mattson <jmattson@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      2cf7ea9f
    • S
      KVM: VMX: check for existence of secondary exec controls before accessing · fd6b6d9b
      由 Sean Christopherson 提交于 
      Return early from vmx_set_virtual_apic_mode() if the processor doesn't
support VIRTUALIZE_APIC_ACCESSES or VIRTUALIZE_X2APIC_MODE, both of
which reside in SECONDARY_VM_EXEC_CONTROL.  This eliminates warnings
due to VMWRITEs to SECONDARY_VM_EXEC_CONTROL (VMCS field 401e) failing
on processors without secondary exec controls.

Remove the similar check for TPR shadowing as it is incorporated in the
flexpriority_enabled check and the APIC-related code in
vmx_update_msr_bitmap() is further gated by VIRTUALIZE_X2APIC_MODE.
Reported-by: NGerhard Wiesinger <redhat@wiesinger.com>
Fixes: 8d860bbe ("kvm: vmx: Basic APIC virtualization controls have three settings")
Cc: Jim Mattson <jmattson@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      fd6b6d9b
  3. 01 10月, 2018 5 次提交
  5. 25 9月, 2018 1 次提交
    • P
      KVM: x86: never trap MSR_KERNEL_GS_BASE · 4679b61f
      由 Paolo Bonzini 提交于 
      KVM has an old optimization whereby accesses to the kernel GS base MSR
are trapped when the guest is in 32-bit and not when it is in 64-bit mode.
The idea is that swapgs is not available in 32-bit mode, thus the
guest has no reason to access the MSR unless in 64-bit mode and
32-bit applications need not pay the price of switching the kernel GS
base between the host and the guest values.

However, this optimization adds complexity to the code for little
benefit (these days most guests are going to be 64-bit anyway) and in fact
broke after commit 678e315e ("KVM: vmx: add dedicated utility to
access guest's kernel_gs_base", 2018-08-06); the guest kernel GS base
can be corrupted across SMIs and UEFI Secure Boot is therefore broken
(a secure boot Linux guest, for example, fails to reach the login prompt
about half the time).  This patch just removes the optimization; the
kernel GS base MSR is now never trapped by KVM, similarly to the FS and
GS base MSRs.

Fixes: 678e315eReviewed-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      4679b61f
  7. 21 9月, 2018 17 次提交
    • G
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm · a27fb6d9
      由 Greg Kroah-Hartman 提交于 
      Paolo writes:
  "It's mostly small bugfixes and cleanups, mostly around x86 nested
   virtualization.  One important change, not related to nested
   virtualization, is that the ability for the guest kernel to trap
   CPUID instructions (in Linux that's the ARCH_SET_CPUID arch_prctl) is
   now masked by default.  This is because the feature is detected
   through an MSR; a very bad idea that Intel seems to like more and
   more.  Some applications choke if the other fields of that MSR are
   not initialized as on real hardware, hence we have to disable the
   whole MSR by default, as was the case before Linux 4.12."

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (23 commits)
  KVM: nVMX: Fix bad cleanup on error of get/set nested state IOCTLs
  kvm: selftests: Add platform_info_test
  KVM: x86: Control guest reads of MSR_PLATFORM_INFO
  KVM: x86: Turbo bits in MSR_PLATFORM_INFO
  nVMX x86: Check VPID value on vmentry of L2 guests
  nVMX x86: check posted-interrupt descriptor addresss on vmentry of L2
  KVM: nVMX: Wake blocked vCPU in guest-mode if pending interrupt in virtual APICv
  KVM: VMX: check nested state and CR4.VMXE against SMM
  kvm: x86: make kvm_{load|put}_guest_fpu() static
  x86/hyper-v: rename ipi_arg_{ex,non_ex} structures
  KVM: VMX: use preemption timer to force immediate VMExit
  KVM: VMX: modify preemption timer bit only when arming timer
  KVM: VMX: immediately mark preemption timer expired only for zero value
  KVM: SVM: Switch to bitmap_zalloc()
  KVM/MMU: Fix comment in walk_shadow_page_lockless_end()
  kvm: selftests: use -pthread instead of -lpthread
  KVM: x86: don't reset root in kvm_mmu_setup()
  kvm: mmu: Don't read PDPTEs when paging is not enabled
  x86/kvm/lapic: always disable MMIO interface in x2APIC mode
  KVM: s390: Make huge pages unavailable in ucontrol VMs
  ...
      a27fb6d9
    • G
      Merge tag 'upstream-4.19-rc4' of git://git.infradead.org/linux-ubifs · 0eba8697
      由 Greg Kroah-Hartman 提交于 
      Richard writes:
  "This pull request contains fixes for UBIFS:
   - A wrong UBIFS assertion in mount code
   - Fix for a NULL pointer deref in mount code
   - Revert of a bad fix for xattrs"

* tag 'upstream-4.19-rc4' of git://git.infradead.org/linux-ubifs:
  Revert "ubifs: xattr: Don't operate on deleted inodes"
  ubifs: drop false positive assertion
  ubifs: Check for name being NULL while mounting
      0eba8697
    • G
      Merge tag 'for-linus-20180920' of git://git.kernel.dk/linux-block · 211b100a
      由 Greg Kroah-Hartman 提交于 
      Jens writes:
  "Storage fixes for 4.19-rc5

  - Fix for leaking kernel pointer in floppy ioctl (Andy Whitcroft)

  - NVMe pull request from Christoph, and a single ANA log page fix
    (Hannes)

  - Regression fix for libata qd32 support, where we trigger an illegal
    active command transition. This fixes a CD-ROM detection issue that
    was reported, but could also trigger premature completion of the
    internal tag (me)"

* tag 'for-linus-20180920' of git://git.kernel.dk/linux-block:
  floppy: Do not copy a kernel pointer to user memory in FDGETPRM ioctl
  libata: mask swap internal and hardware tag
  nvme: count all ANA groups for ANA Log page
      211b100a
    • G
      Merge tag 'drm-fixes-2018-09-21' of git://anongit.freedesktop.org/drm/drm · a38fd7d8
      由 Greg Kroah-Hartman 提交于 
      David writes:
  "drm fixes for 4.19-rc5:

   - core: fix debugfs for atomic, fix the check for atomic for
     non-modesetting drivers
   - amdgpu: adds a new PCI id, some kfd fixes and a sdma fix
   - i915: a bunch of GVT fixes.
   - vc4: scaling fix
   - vmwgfx: modesetting fixes and a old buffer eviction fix
   - udl: framebuffer destruction fix
   - sun4i: disable on R40 fix until next kernel
   - pl111: NULL termination on table fix"

* tag 'drm-fixes-2018-09-21' of git://anongit.freedesktop.org/drm/drm: (21 commits)
  drm/amdkfd: Fix ATS capablity was not reported correctly on some APUs
  drm/amdkfd: Change the control stack MTYPE from UC to NC on GFX9
  drm/amdgpu: Fix SDMA HQD destroy error on gfx_v7
  drm/vmwgfx: Fix buffer object eviction
  drm/vmwgfx: Don't impose STDU limits on framebuffer size
  drm/vmwgfx: limit mode size for all display unit to texture_max
  drm/vmwgfx: limit screen size to stdu_max during check_modeset
  drm/vmwgfx: don't check for old_crtc_state enable status
  drm/amdgpu: add new polaris pci id
  drm: sun4i: drop second PLL from A64 HDMI PHY
  drm: fix drm_drv_uses_atomic_modeset on non modesetting drivers.
  drm/i915/gvt: clear ggtt entries when destroy vgpu
  drm/i915/gvt: request srcu_read_lock before checking if one gfn is valid
  drm/i915/gvt: Add GEN9_CLKGATE_DIS_4 to default BXT mmio handler
  drm/i915/gvt: Init PHY related registers for BXT
  drm/atomic: Use drm_drv_uses_atomic_modeset() for debugfs creation
  drm/fb-helper: Remove set but not used variable 'connector_funcs'
  drm: udl: Destroy framebuffer only if it was initialized
  drm/sun4i: Remove R40 display pipeline compatibles
  drm/pl111: Make sure of_device_id tables are NULL terminated
  ...
      a38fd7d8
    • D
      Merge branch 'drm-fixes-4.19' of git://people.freedesktop.org/~agd5f/linux into drm-fixes · 4fcb7f8b
      由 Dave Airlie 提交于 
      A few fixes for 4.19:
- Add a new polaris pci id
- KFD fixes for raven and gfx7
Signed-off-by: NDave Airlie <airlied@redhat.com>
From: Alex Deucher <alexdeucher@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180920155850.5455-1-alexander.deucher@amd.com
      4fcb7f8b
    • D
      Merge branch 'vmwgfx-fixes-4.19' of git://people.freedesktop.org/~thomash/linux into drm-fixes · 618cc151
      由 Dave Airlie 提交于 
      A couple of modesetting fixes and a fix for a long-standing buffer-eviction
problem cc'd stable.
Signed-off-by: NDave Airlie <airlied@redhat.com>
From: Thomas Hellstrom <thellstrom@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180920063935.35492-1-thellstrom@vmware.com
      618cc151
    • J
      ocfs2: fix ocfs2 read block panic · 234b69e3
      由 Junxiao Bi 提交于 
      While reading block, it is possible that io error return due to underlying
storage issue, in this case, BH_NeedsValidate was left in the buffer head.
Then when reading the very block next time, if it was already linked into
journal, that will trigger the following panic.

[203748.702517] kernel BUG at fs/ocfs2/buffer_head_io.c:342!
[203748.702533] invalid opcode: 0000 [#1] SMP
[203748.702561] Modules linked in: ocfs2 ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue configfs sunrpc dm_switch dm_queue_length dm_multipath bonding be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i iw_cxgb4 cxgb4 cxgb3i libcxgbi iw_cxgb3 cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr ipv6 iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ipmi_devintf iTCO_wdt iTCO_vendor_support dcdbas ipmi_ssif i2c_core ipmi_si ipmi_msghandler acpi_pad pcspkr sb_edac edac_core lpc_ich mfd_core shpchp sg tg3 ptp pps_core ext4 jbd2 mbcache2 sr_mod cdrom sd_mod ahci libahci megaraid_sas wmi dm_mirror dm_region_hash dm_log dm_mod
[203748.703024] CPU: 7 PID: 38369 Comm: touch Not tainted 4.1.12-124.18.6.el6uek.x86_64 #2
[203748.703045] Hardware name: Dell Inc. PowerEdge R620/0PXXHP, BIOS 2.5.2 01/28/2015
[203748.703067] task: ffff880768139c00 ti: ffff88006ff48000 task.ti: ffff88006ff48000
[203748.703088] RIP: 0010:[<ffffffffa05e9f09>]  [<ffffffffa05e9f09>] ocfs2_read_blocks+0x669/0x7f0 [ocfs2]
[203748.703130] RSP: 0018:ffff88006ff4b818  EFLAGS: 00010206
[203748.703389] RAX: 0000000008620029 RBX: ffff88006ff4b910 RCX: 0000000000000000
[203748.703885] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00000000023079fe
[203748.704382] RBP: ffff88006ff4b8d8 R08: 0000000000000000 R09: ffff8807578c25b0
[203748.704877] R10: 000000000f637376 R11: 000000003030322e R12: 0000000000000000
[203748.705373] R13: ffff88006ff4b910 R14: ffff880732fe38f0 R15: 0000000000000000
[203748.705871] FS:  00007f401992c700(0000) GS:ffff880bfebc0000(0000) knlGS:0000000000000000
[203748.706370] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[203748.706627] CR2: 00007f4019252440 CR3: 00000000a621e000 CR4: 0000000000060670
[203748.707124] Stack:
[203748.707371]  ffff88006ff4b828 ffffffffa0609f52 ffff88006ff4b838 0000000000000001
[203748.707885]  0000000000000000 0000000000000000 ffff880bf67c3800 ffffffffa05eca00
[203748.708399]  00000000023079ff ffffffff81c58b80 0000000000000000 0000000000000000
[203748.708915] Call Trace:
[203748.709175]  [<ffffffffa0609f52>] ? ocfs2_inode_cache_io_unlock+0x12/0x20 [ocfs2]
[203748.709680]  [<ffffffffa05eca00>] ? ocfs2_empty_dir_filldir+0x80/0x80 [ocfs2]
[203748.710185]  [<ffffffffa05ec0cb>] ocfs2_read_dir_block_direct+0x3b/0x200 [ocfs2]
[203748.710691]  [<ffffffffa05f0fbf>] ocfs2_prepare_dx_dir_for_insert.isra.57+0x19f/0xf60 [ocfs2]
[203748.711204]  [<ffffffffa065660f>] ? ocfs2_metadata_cache_io_unlock+0x1f/0x30 [ocfs2]
[203748.711716]  [<ffffffffa05f4f3a>] ocfs2_prepare_dir_for_insert+0x13a/0x890 [ocfs2]
[203748.712227]  [<ffffffffa05f442e>] ? ocfs2_check_dir_for_entry+0x8e/0x140 [ocfs2]
[203748.712737]  [<ffffffffa061b2f2>] ocfs2_mknod+0x4b2/0x1370 [ocfs2]
[203748.713003]  [<ffffffffa061c385>] ocfs2_create+0x65/0x170 [ocfs2]
[203748.713263]  [<ffffffff8121714b>] vfs_create+0xdb/0x150
[203748.713518]  [<ffffffff8121b225>] do_last+0x815/0x1210
[203748.713772]  [<ffffffff812192e9>] ? path_init+0xb9/0x450
[203748.714123]  [<ffffffff8121bca0>] path_openat+0x80/0x600
[203748.714378]  [<ffffffff811bcd45>] ? handle_pte_fault+0xd15/0x1620
[203748.714634]  [<ffffffff8121d7ba>] do_filp_open+0x3a/0xb0
[203748.714888]  [<ffffffff8122a767>] ? __alloc_fd+0xa7/0x130
[203748.715143]  [<ffffffff81209ffc>] do_sys_open+0x12c/0x220
[203748.715403]  [<ffffffff81026ddb>] ? syscall_trace_enter_phase1+0x11b/0x180
[203748.715668]  [<ffffffff816f0c9f>] ? system_call_after_swapgs+0xe9/0x190
[203748.715928]  [<ffffffff8120a10e>] SyS_open+0x1e/0x20
[203748.716184]  [<ffffffff816f0d5e>] system_call_fastpath+0x18/0xd7
[203748.716440] Code: 00 00 48 8b 7b 08 48 83 c3 10 45 89 f8 44 89 e1 44 89 f2 4c 89 ee e8 07 06 11 e1 48 8b 03 48 85 c0 75 df 8b 5d c8 e9 4d fa ff ff <0f> 0b 48 8b 7d a0 e8 dc c6 06 00 48 b8 00 00 00 00 00 00 00 10
[203748.717505] RIP  [<ffffffffa05e9f09>] ocfs2_read_blocks+0x669/0x7f0 [ocfs2]
[203748.717775]  RSP <ffff88006ff4b818>

Joesph ever reported a similar panic.
Link: https://oss.oracle.com/pipermail/ocfs2-devel/2013-May/008931.html

Link: http://lkml.kernel.org/r/20180912063207.29484-1-junxiao.bi@oracle.comSigned-off-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Changwei Ge <ge.changwei@h3c.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      234b69e3
    • R
      mm: slowly shrink slabs with a relatively small number of objects · 172b06c3
      由 Roman Gushchin 提交于 
      9092c71b ("mm: use sc->priority for slab shrink targets") changed the
way that the target slab pressure is calculated and made it
priority-based:

    delta = freeable >> priority;
    delta *= 4;
    do_div(delta, shrinker->seeks);

The problem is that on a default priority (which is 12) no pressure is
applied at all, if the number of potentially reclaimable objects is less
than 4096 (1<<12).

This causes the last objects on slab caches of no longer used cgroups to
(almost) never get reclaimed.  It's obviously a waste of memory.

It can be especially painful, if these stale objects are holding a
reference to a dying cgroup.  Slab LRU lists are reparented on memcg
offlining, but corresponding objects are still holding a reference to the
dying cgroup.  If we don't scan these objects, the dying cgroup can't go
away.  Most likely, the parent cgroup hasn't any directly charged objects,
only remaining objects from dying children cgroups.  So it can easily hold
a reference to hundreds of dying cgroups.

If there are no big spikes in memory pressure, and new memory cgroups are
created and destroyed periodically, this causes the number of dying
cgroups grow steadily, causing a slow-ish and hard-to-detect memory
"leak".  It's not a real leak, as the memory can be eventually reclaimed,
but it could not happen in a real life at all.  I've seen hosts with a
steadily climbing number of dying cgroups, which doesn't show any signs of
a decline in months, despite the host is loaded with a production
workload.

It is an obvious waste of memory, and to prevent it, let's apply a minimal
pressure even on small shrinker lists.  E.g.  if there are freeable
objects, let's scan at least min(freeable, scan_batch) objects.

This fix significantly improves a chance of a dying cgroup to be
reclaimed, and together with some previous patches stops the steady growth
of the dying cgroups number on some of our hosts.

Link: http://lkml.kernel.org/r/20180905230759.12236-1-guro@fb.com
Fixes: 9092c71b ("mm: use sc->priority for slab shrink targets")
Signed-off-by: NRoman Gushchin <guro@fb.com>
Acked-by: NRik van Riel <riel@surriel.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      172b06c3
    • Y
      kernel/sys.c: remove duplicated include · 3bf181bc
      由 YueHaibing 提交于 
      Link: http://lkml.kernel.org/r/20180821133424.18716-1-yuehaibing@huawei.comSigned-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3bf181bc
    • J
      mm: shmem.c: Correctly annotate new inodes for lockdep · b45d71fb
      由 Joel Fernandes (Google) 提交于 
      Directories and inodes don't necessarily need to be in the same lockdep
class.  For ex, hugetlbfs splits them out too to prevent false positives
in lockdep.  Annotate correctly after new inode creation.  If its a
directory inode, it will be put into a different class.

This should fix a lockdep splat reported by syzbot:

> ======================================================
> WARNING: possible circular locking dependency detected
> 4.18.0-rc8-next-20180810+ #36 Not tainted
> ------------------------------------------------------
> syz-executor900/4483 is trying to acquire lock:
> 00000000d2bfc8fe (&sb->s_type->i_mutex_key#9){++++}, at: inode_lock
> include/linux/fs.h:765 [inline]
> 00000000d2bfc8fe (&sb->s_type->i_mutex_key#9){++++}, at:
> shmem_fallocate+0x18b/0x12e0 mm/shmem.c:2602
>
> but task is already holding lock:
> 0000000025208078 (ashmem_mutex){+.+.}, at: ashmem_shrink_scan+0xb4/0x630
> drivers/staging/android/ashmem.c:448
>
> which lock already depends on the new lock.
>
> -> #2 (ashmem_mutex){+.+.}:
>        __mutex_lock_common kernel/locking/mutex.c:925 [inline]
>        __mutex_lock+0x171/0x1700 kernel/locking/mutex.c:1073
>        mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
>        ashmem_mmap+0x55/0x520 drivers/staging/android/ashmem.c:361
>        call_mmap include/linux/fs.h:1844 [inline]
>        mmap_region+0xf27/0x1c50 mm/mmap.c:1762
>        do_mmap+0xa10/0x1220 mm/mmap.c:1535
>        do_mmap_pgoff include/linux/mm.h:2298 [inline]
>        vm_mmap_pgoff+0x213/0x2c0 mm/util.c:357
>        ksys_mmap_pgoff+0x4da/0x660 mm/mmap.c:1585
>        __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline]
>        __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline]
>        __x64_sys_mmap+0xe9/0x1b0 arch/x86/kernel/sys_x86_64.c:91
>        do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> -> #1 (&mm->mmap_sem){++++}:
>        __might_fault+0x155/0x1e0 mm/memory.c:4568
>        _copy_to_user+0x30/0x110 lib/usercopy.c:25
>        copy_to_user include/linux/uaccess.h:155 [inline]
>        filldir+0x1ea/0x3a0 fs/readdir.c:196
>        dir_emit_dot include/linux/fs.h:3464 [inline]
>        dir_emit_dots include/linux/fs.h:3475 [inline]
>        dcache_readdir+0x13a/0x620 fs/libfs.c:193
>        iterate_dir+0x48b/0x5d0 fs/readdir.c:51
>        __do_sys_getdents fs/readdir.c:231 [inline]
>        __se_sys_getdents fs/readdir.c:212 [inline]
>        __x64_sys_getdents+0x29f/0x510 fs/readdir.c:212
>        do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> -> #0 (&sb->s_type->i_mutex_key#9){++++}:
>        lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924
>        down_write+0x8f/0x130 kernel/locking/rwsem.c:70
>        inode_lock include/linux/fs.h:765 [inline]
>        shmem_fallocate+0x18b/0x12e0 mm/shmem.c:2602
>        ashmem_shrink_scan+0x236/0x630 drivers/staging/android/ashmem.c:455
>        ashmem_ioctl+0x3ae/0x13a0 drivers/staging/android/ashmem.c:797
>        vfs_ioctl fs/ioctl.c:46 [inline]
>        file_ioctl fs/ioctl.c:501 [inline]
>        do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
>        ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
>        __do_sys_ioctl fs/ioctl.c:709 [inline]
>        __se_sys_ioctl fs/ioctl.c:707 [inline]
>        __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
>        do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> other info that might help us debug this:
>
> Chain exists of:
>   &sb->s_type->i_mutex_key#9 --> &mm->mmap_sem --> ashmem_mutex
>
>  Possible unsafe locking scenario:
>
>        CPU0                    CPU1
>        ----                    ----
>   lock(ashmem_mutex);
>                                lock(&mm->mmap_sem);
>                                lock(ashmem_mutex);
>   lock(&sb->s_type->i_mutex_key#9);
>
>  *** DEADLOCK ***
>
> 1 lock held by syz-executor900/4483:
>  #0: 0000000025208078 (ashmem_mutex){+.+.}, at:
> ashmem_shrink_scan+0xb4/0x630 drivers/staging/android/ashmem.c:448

Link: http://lkml.kernel.org/r/20180821231835.166639-1-joel@joelfernandes.orgSigned-off-by: NJoel Fernandes (Google) <joel@joelfernandes.org>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Reviewed-by: NNeilBrown <neilb@suse.com>
Suggested-by: NNeilBrown <neilb@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b45d71fb
    • D
      fs/proc/kcore.c: fix invalid memory access in multi-page read optimization · a1b3d2f2
      由 Dominique Martinet 提交于 
      The 'm' kcore_list item could point to kclist_head, and it is incorrect to
look at m->addr / m->size in this case.

There is no choice but to run through the list of entries for every
address if we did not find any entry in the previous iteration

Reset 'm' to NULL in that case at Omar Sandoval's suggestion.

[akpm@linux-foundation.org: add comment]
Link: http://lkml.kernel.org/r/1536100702-28706-1-git-send-email-asmadeus@codewreck.org
Fixes: bf991c22 ("proc/kcore: optimize multiple page reads")
Signed-off-by: NDominique Martinet <asmadeus@codewreck.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Omar Sandoval <osandov@osandov.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: James Morse <james.morse@arm.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a1b3d2f2
    • P
      mm: disable deferred struct page for 32-bit arches · 889c695d
      由 Pasha Tatashin 提交于 
      Deferred struct page init is needed only on systems with large amount of
physical memory to improve boot performance.  32-bit systems do not
benefit from this feature.

Jiri reported a problem where deferred struct pages do not work well with
x86-32:

[    0.035162] Dentry cache hash table entries: 131072 (order: 7, 524288 bytes)
[    0.035725] Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
[    0.036269] Initializing CPU#0
[    0.036513] Initializing HighMem for node 0 (00036ffe:0007ffe0)
[    0.038459] page:f6780000 is uninitialized and poisoned
[    0.038460] raw: ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff
[    0.039509] page dumped because: VM_BUG_ON_PAGE(1 && PageCompound(page))
[    0.040038] ------------[ cut here ]------------
[    0.040399] kernel BUG at include/linux/page-flags.h:293!
[    0.040823] invalid opcode: 0000 [#1] SMP PTI
[    0.041166] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc1_pt_jiri #9
[    0.041694] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014
[    0.042496] EIP: free_highmem_page+0x64/0x80
[    0.042839] Code: 13 46 d8 c1 e8 18 5d 83 e0 03 8d 04 c0 c1 e0 06 ff 80 ec 5f 44 d8 c3 8d b4 26 00 00 00 00 ba 08 65 28 d8 89 d8 e8 fc 71 02 00 <0f> 0b 8d 76 00 8d bc 27 00 00 00 00 ba d0 b1 26 d8 89 d8 e8 e4 71
[    0.044338] EAX: 0000003c EBX: f6780000 ECX: 00000000 EDX: d856cbe8
[    0.044868] ESI: 0007ffe0 EDI: d838df20 EBP: d838df00 ESP: d838defc
[    0.045372] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00210086
[    0.045913] CR0: 80050033 CR2: 00000000 CR3: 18556000 CR4: 00040690
[    0.046413] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[    0.046913] DR6: fffe0ff0 DR7: 00000400
[    0.047220] Call Trace:
[    0.047419]  add_highpages_with_active_regions+0xbd/0x10d
[    0.047854]  set_highmem_pages_init+0x5b/0x71
[    0.048202]  mem_init+0x2b/0x1e8
[    0.048460]  start_kernel+0x1d2/0x425
[    0.048757]  i386_start_kernel+0x93/0x97
[    0.049073]  startup_32_smp+0x164/0x168
[    0.049379] Modules linked in:
[    0.049626] ---[ end trace 337949378db0abbb ]---

We free highmem pages before their struct pages are initialized:

mem_init()
 set_highmem_pages_init()
  add_highpages_with_active_regions()
   free_highmem_page()
    .. Access uninitialized struct page here..

Because there is no reason to have this feature on 32-bit systems, just
disable it.

Link: http://lkml.kernel.org/r/20180831150506.31246-1-pavel.tatashin@microsoft.com
Fixes: 2e3ca40f ("mm: relax deferred struct page requirements")
Signed-off-by: NPavel Tatashin <pavel.tatashin@microsoft.com>
Reported-by: NJiri Slaby <jslaby@suse.cz>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      889c695d
    • K
      fork: report pid exhaustion correctly · f83606f5
      由 KJ Tsanaktsidis 提交于 
      Make the clone and fork syscalls return EAGAIN when the limit on the
number of pids /proc/sys/kernel/pid_max is exceeded.

Currently, when the pid_max limit is exceeded, the kernel will return
ENOSPC from the fork and clone syscalls.  This is contrary to the
documented behaviour, which explicitly calls out the pid_max case as one
where EAGAIN should be returned.  It also leads to really confusing error
messages in userspace programs which will complain about a lack of disk
space when they fail to create processes/threads for this reason.

This error is being returned because alloc_pid() uses the idr api to find
a new pid; when there are none available, idr_alloc_cyclic() returns
-ENOSPC, and this is being propagated back to userspace.

This behaviour has been broken before, and was explicitly fixed in
commit 35f71bc0 ("fork: report pid reservation failure properly"),
so I think -EAGAIN is definitely the right thing to return in this case.
The current behaviour change dates from commit 95846ecf ("pid:
replace pid bitmap implementation with IDR AIP") and was I believe
unintentional.

This patch has no impact on the case where allocating a pid fails because
the child reaper for the namespace is dead; that case will still return
-ENOMEM.

Link: http://lkml.kernel.org/r/20180903111016.46461-1-ktsanaktsidis@zendesk.com
Fixes: 95846ecf ("pid: replace pid bitmap implementation with IDR AIP")
Signed-off-by: NKJ Tsanaktsidis <ktsanaktsidis@zendesk.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Gargi Sharma <gs051095@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f83606f5
    • R
      Revert "ubifs: xattr: Don't operate on deleted inodes" · f061c1cc
      由 Richard Weinberger 提交于 
      This reverts commit 11a6fc3d.
UBIFS wants to assert that xattr operations are only issued on files
with positive link count. The said patch made this operations return
-ENOENT for unlinked files such that the asserts will no longer trigger.
This was wrong since xattr operations are perfectly fine on unlinked
files.
Instead the assertions need to be fixed/removed.

Cc: <stable@vger.kernel.org>
Fixes: 11a6fc3d ("ubifs: xattr: Don't operate on deleted inodes")
Reported-by: NKoen Vandeputte <koen.vandeputte@ncentric.com>
Tested-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NRichard Weinberger <richard@nod.at>
      f061c1cc
    • S
      ubifs: drop false positive assertion · d3bdc016
      由 Sascha Hauer 提交于 
      The following sequence triggers

	ubifs_assert(c, c->lst.taken_empty_lebs > 0);

at the end of ubifs_remount_fs():

mount -t ubifs /dev/ubi0_0 /mnt
echo 1 > /sys/kernel/debug/ubifs/ubi0_0/ro_error
umount /mnt
mount -t ubifs -o ro /dev/ubix_y /mnt
mount -o remount,ro /mnt

The resulting

UBIFS assert failed in ubifs_remount_fs at 1878 (pid 161)

is a false positive. In the case above c->lst.taken_empty_lebs has
never been changed from its initial zero value. This will only happen
when the deferred recovery is done.

Fix this by doing the assertion only when recovery has been done
already.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NRichard Weinberger <richard@nod.at>
      d3bdc016
    • R
      ubifs: Check for name being NULL while mounting · 37f31b6c
      由 Richard Weinberger 提交于 
      The requested device name can be NULL or an empty string.
Check for that and refuse to continue. UBIFS has to do this manually
since we cannot use mount_bdev(), which checks for this condition.

Fixes: 1e51764a ("UBIFS: add new flash file system")
Reported-by: syzbot+38bd0f7865e5c6379280@syzkaller.appspotmail.com
Signed-off-by: NRichard Weinberger <richard@nod.at>
      37f31b6c
    • L
      KVM: nVMX: Fix bad cleanup on error of get/set nested state IOCTLs · 26b471c7
      由 Liran Alon 提交于 
      The handlers of IOCTLs in kvm_arch_vcpu_ioctl() are expected to set
their return value in "r" local var and break out of switch block
when they encounter some error.
This is because vcpu_load() is called before the switch block which
have a proper cleanup of vcpu_put() afterwards.

However, KVM_{GET,SET}_NESTED_STATE IOCTLs handlers just return
immediately on error without performing above mentioned cleanup.

Thus, change these handlers to behave as expected.

Fixes: 8fcc4b59 ("kvm: nVMX: Introduce KVM_CAP_NESTED_STATE")
Reviewed-by: NMark Kanda <mark.kanda@oracle.com>
Reviewed-by: NPatrick Colp <patrick.colp@oracle.com>
Signed-off-by: NLiran Alon <liran.alon@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      26b471c7
  9. 20 9月, 2018 15 次提交