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  1. 17 Jan, 2018 11 commits
    • Maciej W. Rozycki's avatar
      MIPS: Disallow outsized PTRACE_SETREGSET NT_PRFPREG regset accesses · f2c131d0
      Maciej W. Rozycki authored 
      commit c8c5a3a2 upstream.

Complement commit c23b3d1a ("MIPS: ptrace: Change GP regset to use
correct core dump register layout") and also reject outsized
PTRACE_SETREGSET requests to the NT_PRFPREG regset, like with the
NT_PRSTATUS regset.
Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
Fixes: c23b3d1a ("MIPS: ptrace: Change GP regset to use correct core dump register layout")
Cc: James Hogan <james.hogan@mips.com>
Cc: Paul Burton <Paul.Burton@mips.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17930/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f2c131d0
    • Maciej W. Rozycki's avatar
      MIPS: Also verify sizeof `elf_fpreg_t' with PTRACE_SETREGSET · 725679dc
      Maciej W. Rozycki authored 
      commit 006501e0 upstream.

Complement commit d614fd58 ("mips/ptrace: Preserve previous
registers for short regset write") and like with the PTRACE_GETREGSET
ptrace(2) request also apply a BUILD_BUG_ON check for the size of the
`elf_fpreg_t' type in the PTRACE_SETREGSET request handler.
Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
Fixes: d614fd58 ("mips/ptrace: Preserve previous registers for short regset write")
Cc: James Hogan <james.hogan@mips.com>
Cc: Paul Burton <Paul.Burton@mips.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17929/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      725679dc
    • Maciej W. Rozycki's avatar
      MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA · 9584ae52
      Maciej W. Rozycki authored 
      commit be07a6a1 upstream.

Fix a commit 72b22bba ("MIPS: Don't assume 64-bit FP registers for
FP regset") public API regression, then activated by commit 1db1af84
("MIPS: Basic MSA context switching support"), that caused the FCSR
register not to be read or written for CONFIG_CPU_HAS_MSA kernel
configurations (regardless of actual presence or absence of the MSA
feature in a given processor) with ptrace(2) PTRACE_GETREGSET and
PTRACE_SETREGSET requests nor recorded in core dumps.

This is because with !CONFIG_CPU_HAS_MSA configurations the whole of
`elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR
in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA
configurations array elements are copied individually, and then only the
leading 32 FGR slots while the remaining slot is ignored.

Correct the code then such that only FGR slots are copied in the
respective !MSA and MSA helpers an then the FCSR slot is handled
separately in common code.  Use `ptrace_setfcr31' to update the FCSR
too, so that the read-only mask is respected.

Retrieving a correct value of FCSR is important in debugging not only
for the human to be able to get the right interpretation of the
situation, but for correct operation of GDB as well.  This is because
the condition code bits in FSCR are used by GDB to determine the
location to place a breakpoint at when single-stepping through an FPU
branch instruction.  If such a breakpoint is placed incorrectly (i.e.
with the condition reversed), then it will be missed, likely causing the
debuggee to run away from the control of GDB and consequently breaking
the process of investigation.

Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2)
request which is unaffected, so the regression only really hits with
post-mortem debug sessions using a core dump file, in which case
execution, and consequently single-stepping through branches is not
possible.  Of course core files created by buggy kernels out there will
have the value of FCSR recorded clobbered, but such core files cannot be
corrected and the person using them simply will have to be aware that
the value of FCSR retrieved is not reliable.

Which also means we can likely get away without defining a replacement
API which would ensure a correct value of FSCR to be retrieved, or none
at all.

This is based on previous work by Alex Smith, extensively rewritten.
Signed-off-by: default avatarAlex Smith <alex@alex-smith.me.uk>
Signed-off-by: default avatarJames Hogan <james.hogan@mips.com>
Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
Fixes: 72b22bba ("MIPS: Don't assume 64-bit FP registers for FP regset")
Cc: Paul Burton <Paul.Burton@mips.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17928/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9584ae52
    • Maciej W. Rozycki's avatar
      MIPS: Consistently handle buffer counter with PTRACE_SETREGSET · a6972f8b
      Maciej W. Rozycki authored 
      commit 80b3ffce upstream.

Update commit d614fd58 ("mips/ptrace: Preserve previous registers
for short regset write") bug and consistently consume all data supplied
to `fpr_set_msa' with the ptrace(2) PTRACE_SETREGSET request, such that
a zero data buffer counter is returned where insufficient data has been
given to fill a whole number of FP general registers.

In reality this is not going to happen, as the caller is supposed to
only supply data covering a whole number of registers and it is verified
in `ptrace_regset' and again asserted in `fpr_set', however structuring
code such that the presence of trailing partial FP general register data
causes `fpr_set_msa' to return with a non-zero data buffer counter makes
it appear that this trailing data will be used if there are subsequent
writes made to FP registers, which is going to be the case with the FCSR
once the missing write to that register has been fixed.

Fixes: d614fd58 ("mips/ptrace: Preserve previous registers for short regset write")
Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
Cc: James Hogan <james.hogan@mips.com>
Cc: Paul Burton <Paul.Burton@mips.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17927/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a6972f8b
    • Maciej W. Rozycki's avatar
      MIPS: Guard against any partial write attempt with PTRACE_SETREGSET · e68049f6
      Maciej W. Rozycki authored 
      commit dc24d0ed upstream.

Complement commit d614fd58 ("mips/ptrace: Preserve previous
registers for short regset write") and ensure that no partial register
write attempt is made with PTRACE_SETREGSET, as we do not preinitialize
any temporaries used to hold incoming register data and consequently
random data could be written.

It is the responsibility of the caller, such as `ptrace_regset', to
arrange for writes to span whole registers only, so here we only assert
that it has indeed happened.
Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
Fixes: 72b22bba ("MIPS: Don't assume 64-bit FP registers for FP regset")
Cc: James Hogan <james.hogan@mips.com>
Cc: Paul Burton <Paul.Burton@mips.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17926/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e68049f6
    • Maciej W. Rozycki's avatar
      MIPS: Factor out NT_PRFPREG regset access helpers · b1e808b9
      Maciej W. Rozycki authored 
      commit a03fe725 upstream.

In preparation to fix a commit 72b22bba ("MIPS: Don't assume 64-bit
FP registers for FP regset") FCSR access regression factor out
NT_PRFPREG regset access helpers for the non-MSA and the MSA variants
respectively, to avoid having to deal with excessive indentation in the
actual fix.

No functional change, however use `target->thread.fpu.fpr[0]' rather
than `target->thread.fpu.fpr[i]' for FGR holding type size determination
as there's no `i' variable to refer to anymore, and for the factored out
`i' variable declaration use `unsigned int' rather than `unsigned' as
its type, following the common style.
Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
Fixes: 72b22bba ("MIPS: Don't assume 64-bit FP registers for FP regset")
Cc: James Hogan <james.hogan@mips.com>
Cc: Paul Burton <Paul.Burton@mips.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17925/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b1e808b9
    • Maciej W. Rozycki's avatar
      MIPS: Validate PR_SET_FP_MODE prctl(2) requests against the ABI of the task · 1e918a43
      Maciej W. Rozycki authored 
      commit b67336ee upstream.

Fix an API loophole introduced with commit 9791554b ("MIPS,prctl:
add PR_[GS]ET_FP_MODE prctl options for MIPS"), where the caller of
prctl(2) is incorrectly allowed to make a change to CP0.Status.FR or
CP0.Config5.FRE register bits even if CONFIG_MIPS_O32_FP64_SUPPORT has
not been enabled, despite that an executable requesting the mode
requested via ELF file annotation would not be allowed to run in the
first place, or for n64 and n64 ABI tasks which do not have non-default
modes defined at all.  Add suitable checks to `mips_set_process_fp_mode'
and bail out if an invalid mode change has been requested for the ABI in
effect, even if the FPU hardware or emulation would otherwise allow it.

Always succeed however without taking any further action if the mode
requested is the same as one already in effect, regardless of whether
any mode change, should it be requested, would actually be allowed for
the task concerned.
Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
Fixes: 9791554b ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS")
Reviewed-by: default avatarPaul Burton <paul.burton@mips.com>
Cc: James Hogan <james.hogan@mips.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17800/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1e918a43
    • Bart Van Assche's avatar
      IB/srpt: Disable RDMA access by the initiator · 6c2c83eb
      Bart Van Assche authored 
      commit bec40c26 upstream.

With the SRP protocol all RDMA operations are initiated by the target.
Since no RDMA operations are initiated by the initiator, do not grant
the initiator permission to submit RDMA reads or writes to the target.
Signed-off-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6c2c83eb
    • Wolfgang Grandegger's avatar
      can: gs_usb: fix return value of the "set_bittiming" callback · a71d6de9
      Wolfgang Grandegger authored 
      commit d5b42e66 upstream.

The "set_bittiming" callback treats a positive return value as error!
For that reason "can_changelink()" will quit silently after setting
the bittiming values without processing ctrlmode, restart-ms, etc.
Signed-off-by: default avatarWolfgang Grandegger <wg@grandegger.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a71d6de9
    • Wanpeng Li's avatar
      KVM: Fix stack-out-of-bounds read in write_mmio · eb91461d
      Wanpeng Li authored 
      commit e39d200f upstream.

Reported by syzkaller:

  BUG: KASAN: stack-out-of-bounds in write_mmio+0x11e/0x270 [kvm]
  Read of size 8 at addr ffff8803259df7f8 by task syz-executor/32298

  CPU: 6 PID: 32298 Comm: syz-executor Tainted: G           OE    4.15.0-rc2+ #18
  Hardware name: LENOVO ThinkCentre M8500t-N000/SHARKBAY, BIOS FBKTC1AUS 02/16/2016
  Call Trace:
   dump_stack+0xab/0xe1
   print_address_description+0x6b/0x290
   kasan_report+0x28a/0x370
   write_mmio+0x11e/0x270 [kvm]
   emulator_read_write_onepage+0x311/0x600 [kvm]
   emulator_read_write+0xef/0x240 [kvm]
   emulator_fix_hypercall+0x105/0x150 [kvm]
   em_hypercall+0x2b/0x80 [kvm]
   x86_emulate_insn+0x2b1/0x1640 [kvm]
   x86_emulate_instruction+0x39a/0xb90 [kvm]
   handle_exception+0x1b4/0x4d0 [kvm_intel]
   vcpu_enter_guest+0x15a0/0x2640 [kvm]
   kvm_arch_vcpu_ioctl_run+0x549/0x7d0 [kvm]
   kvm_vcpu_ioctl+0x479/0x880 [kvm]
   do_vfs_ioctl+0x142/0x9a0
   SyS_ioctl+0x74/0x80
   entry_SYSCALL_64_fastpath+0x23/0x9a

The path of patched vmmcall will patch 3 bytes opcode 0F 01 C1(vmcall)
to the guest memory, however, write_mmio tracepoint always prints 8 bytes
through *(u64 *)val since kvm splits the mmio access into 8 bytes. This
leaks 5 bytes from the kernel stack (CVE-2017-17741).  This patch fixes
it by just accessing the bytes which we operate on.

Before patch:

syz-executor-5567  [007] .... 51370.561696: kvm_mmio: mmio write len 3 gpa 0x10 val 0x1ffff10077c1010f

After patch:

syz-executor-13416 [002] .... 51302.299573: kvm_mmio: mmio write len 3 gpa 0x10 val 0xc1010f
Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
Reviewed-by: default avatarDarren Kenny <darren.kenny@oracle.com>
Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Tested-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarWanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      eb91461d
    • Suren Baghdasaryan's avatar
      dm bufio: fix shrinker scans when (nr_to_scan < retain_target) · cbb1cc72
      Suren Baghdasaryan authored 
      commit fbc7c07e upstream.

When system is under memory pressure it is observed that dm bufio
shrinker often reclaims only one buffer per scan. This change fixes
the following two issues in dm bufio shrinker that cause this behavior:

1. ((nr_to_scan - freed) <= retain_target) condition is used to
terminate slab scan process. This assumes that nr_to_scan is equal
to the LRU size, which might not be correct because do_shrink_slab()
in vmscan.c calculates nr_to_scan using multiple inputs.
As a result when nr_to_scan is less than retain_target (64) the scan
will terminate after the first iteration, effectively reclaiming one
buffer per scan and making scans very inefficient. This hurts vmscan
performance especially because mutex is acquired/released every time
dm_bufio_shrink_scan() is called.
New implementation uses ((LRU size - freed) <= retain_target)
condition for scan termination. LRU size can be safely determined
inside __scan() because this function is called after dm_bufio_lock().

2. do_shrink_slab() uses value returned by dm_bufio_shrink_count() to
determine number of freeable objects in the slab. However dm_bufio
always retains retain_target buffers in its LRU and will terminate
a scan when this mark is reached. Therefore returning the entire LRU size
from dm_bufio_shrink_count() is misleading because that does not
represent the number of freeable objects that slab will reclaim during
a scan. Returning (LRU size - retain_target) better represents the
number of freeable objects in the slab. This way do_shrink_slab()
returns 0 when (LRU size < retain_target) and vmscan will not try to
scan this shrinker avoiding scans that will not reclaim any memory.

Test: tested using Android device running
<AOSP>/system/extras/alloc-stress that generates memory pressure
and causes intensive shrinker scans
Signed-off-by: default avatarSuren Baghdasaryan <surenb@google.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      cbb1cc72
  3. 10 Jan, 2018 23 commits
  5. 05 Jan, 2018 6 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.4.110 · b3e3db15
      Greg Kroah-Hartman authored
      b3e3db15
    • Guenter Roeck's avatar
      kaiser: Set _PAGE_NX only if supported · b33c3c64
      Guenter Roeck authored 
      This resolves a crash if loaded under qemu + haxm under windows.
See https://www.spinics.net/lists/kernel/msg2689835.html for details.
Here is a boot log (the log is from chromeos-4.4, but Tao Wu says that
the same log is also seen with vanilla v4.4.110-rc1).

[    0.712750] Freeing unused kernel memory: 552K
[    0.721821] init: Corrupted page table at address 57b029b332e0
[    0.722761] PGD 80000000bb238067 PUD bc36a067 PMD bc369067 PTE 45d2067
[    0.722761] Bad pagetable: 000b [#1] PREEMPT SMP 
[    0.722761] Modules linked in:
[    0.722761] CPU: 1 PID: 1 Comm: init Not tainted 4.4.96 #31
[    0.722761] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014
[    0.722761] task: ffff8800bc290000 ti: ffff8800bc28c000 task.ti: ffff8800bc28c000
[    0.722761] RIP: 0010:[<ffffffff83f4129e>]  [<ffffffff83f4129e>] __clear_user+0x42/0x67
[    0.722761] RSP: 0000:ffff8800bc28fcf8  EFLAGS: 00010202
[    0.722761] RAX: 0000000000000000 RBX: 00000000000001a4 RCX: 00000000000001a4
[    0.722761] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000057b029b332e0
[    0.722761] RBP: ffff8800bc28fd08 R08: ffff8800bc290000 R09: ffff8800bb2f4000
[    0.722761] R10: ffff8800bc290000 R11: ffff8800bb2f4000 R12: 000057b029b332e0
[    0.722761] R13: 0000000000000000 R14: 000057b029b33340 R15: ffff8800bb1e2a00
[    0.722761] FS:  0000000000000000(0000) GS:ffff8800bfb00000(0000) knlGS:0000000000000000
[    0.722761] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[    0.722761] CR2: 000057b029b332e0 CR3: 00000000bb2f8000 CR4: 00000000000006e0
[    0.722761] Stack:
[    0.722761]  000057b029b332e0 ffff8800bb95fa80 ffff8800bc28fd18 ffffffff83f4120c
[    0.722761]  ffff8800bc28fe18 ffffffff83e9e7a1 ffff8800bc28fd68 0000000000000000
[    0.722761]  ffff8800bc290000 ffff8800bc290000 ffff8800bc290000 ffff8800bc290000
[    0.722761] Call Trace:
[    0.722761]  [<ffffffff83f4120c>] clear_user+0x2e/0x30
[    0.722761]  [<ffffffff83e9e7a1>] load_elf_binary+0xa7f/0x18f7
[    0.722761]  [<ffffffff83de2088>] search_binary_handler+0x86/0x19c
[    0.722761]  [<ffffffff83de389e>] do_execveat_common.isra.26+0x909/0xf98
[    0.722761]  [<ffffffff844febe0>] ? rest_init+0x87/0x87
[    0.722761]  [<ffffffff83de40be>] do_execve+0x23/0x25
[    0.722761]  [<ffffffff83c002e3>] run_init_process+0x2b/0x2d
[    0.722761]  [<ffffffff844fec4d>] kernel_init+0x6d/0xda
[    0.722761]  [<ffffffff84505b2f>] ret_from_fork+0x3f/0x70
[    0.722761]  [<ffffffff844febe0>] ? rest_init+0x87/0x87
[    0.722761] Code: 86 84 be 12 00 00 00 e8 87 0d e8 ff 66 66 90 48 89 d8 48 c1
eb 03 4c 89 e7 83 e0 07 48 89 d9 be 08 00 00 00 31 d2 48 85 c9 74 0a <48> 89 17
48 01 f7 ff c9 75 f6 48 89 c1 85 c9 74 09 88 17 48 ff 
[    0.722761] RIP  [<ffffffff83f4129e>] __clear_user+0x42/0x67
[    0.722761]  RSP <ffff8800bc28fcf8>
[    0.722761] ---[ end trace def703879b4ff090 ]---
[    0.722761] BUG: sleeping function called from invalid context at /mnt/host/source/src/third_party/kernel/v4.4/kernel/locking/rwsem.c:21
[    0.722761] in_atomic(): 0, irqs_disabled(): 1, pid: 1, name: init
[    0.722761] CPU: 1 PID: 1 Comm: init Tainted: G      D         4.4.96 #31
[    0.722761] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014
[    0.722761]  0000000000000086 dcb5d76098c89836 ffff8800bc28fa30 ffffffff83f34004
[    0.722761]  ffffffff84839dc2 0000000000000015 ffff8800bc28fa40 ffffffff83d57dc9
[    0.722761]  ffff8800bc28fa68 ffffffff83d57e6a ffffffff84a53640 0000000000000000
[    0.722761] Call Trace:
[    0.722761]  [<ffffffff83f34004>] dump_stack+0x4d/0x63
[    0.722761]  [<ffffffff83d57dc9>] ___might_sleep+0x13a/0x13c
[    0.722761]  [<ffffffff83d57e6a>] __might_sleep+0x9f/0xa6
[    0.722761]  [<ffffffff84502788>] down_read+0x20/0x31
[    0.722761]  [<ffffffff83cc5d9b>] __blocking_notifier_call_chain+0x35/0x63
[    0.722761]  [<ffffffff83cc5ddd>] blocking_notifier_call_chain+0x14/0x16
[    0.800374] usb 1-1: new full-speed USB device number 2 using uhci_hcd
[    0.722761]  [<ffffffff83cefe97>] profile_task_exit+0x1a/0x1c
[    0.802309]  [<ffffffff83cac84e>] do_exit+0x39/0xe7f
[    0.802309]  [<ffffffff83ce5938>] ? vprintk_default+0x1d/0x1f
[    0.802309]  [<ffffffff83d7bb95>] ? printk+0x57/0x73
[    0.802309]  [<ffffffff83c46e25>] oops_end+0x80/0x85
[    0.802309]  [<ffffffff83c7b747>] pgtable_bad+0x8a/0x95
[    0.802309]  [<ffffffff83ca7f4a>] __do_page_fault+0x8c/0x352
[    0.802309]  [<ffffffff83eefba5>] ? file_has_perm+0xc4/0xe5
[    0.802309]  [<ffffffff83ca821c>] do_page_fault+0xc/0xe
[    0.802309]  [<ffffffff84507682>] page_fault+0x22/0x30
[    0.802309]  [<ffffffff83f4129e>] ? __clear_user+0x42/0x67
[    0.802309]  [<ffffffff83f4127f>] ? __clear_user+0x23/0x67
[    0.802309]  [<ffffffff83f4120c>] clear_user+0x2e/0x30
[    0.802309]  [<ffffffff83e9e7a1>] load_elf_binary+0xa7f/0x18f7
[    0.802309]  [<ffffffff83de2088>] search_binary_handler+0x86/0x19c
[    0.802309]  [<ffffffff83de389e>] do_execveat_common.isra.26+0x909/0xf98
[    0.802309]  [<ffffffff844febe0>] ? rest_init+0x87/0x87
[    0.802309]  [<ffffffff83de40be>] do_execve+0x23/0x25
[    0.802309]  [<ffffffff83c002e3>] run_init_process+0x2b/0x2d
[    0.802309]  [<ffffffff844fec4d>] kernel_init+0x6d/0xda
[    0.802309]  [<ffffffff84505b2f>] ret_from_fork+0x3f/0x70
[    0.802309]  [<ffffffff844febe0>] ? rest_init+0x87/0x87
[    0.830559] Kernel panic - not syncing: Attempted to kill init!  exitcode=0x00000009
[    0.830559] 
[    0.831305] Kernel Offset: 0x2c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[    0.831305] ---[ end Kernel panic - not syncing: Attempted to kill init!  exitcode=0x00000009

The crash part of this problem may be solved with the following patch
(thanks to Hugh for the hint). There is still another problem, though -
with this patch applied, the qemu session aborts with "VCPU Shutdown
request", whatever that means.

Cc: lepton <ytht.net@gmail.com>
Signed-off-by: default avatarGuenter Roeck <groeck@chromium.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b33c3c64
    • Andrey Ryabinin's avatar
      x86/kasan: Clear kasan_zero_page after TLB flush · 2b24fe5c
      Andrey Ryabinin authored 
      commit 69e0210f upstream.

Currently we clear kasan_zero_page before __flush_tlb_all(). This
works with current implementation of native_flush_tlb[_global]()
because it doesn't cause do any writes to kasan shadow memory.
But any subtle change made in native_flush_tlb*() could break this.
Also current code seems doesn't work for paravirt guests (lguest).

Only after the TLB flush we can be sure that kasan_zero_page is not
used as early shadow anymore (instrumented code will not write to it).
So it should cleared it only after the TLB flush.
Signed-off-by: default avatarAndrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1452516679-32040-2-git-send-email-aryabinin@virtuozzo.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Jamie Iles <jamie.iles@oracle.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2b24fe5c
    • Andy Lutomirski's avatar
      x86/vdso: Get pvclock data from the vvar VMA instead of the fixmap · 755bd549
      Andy Lutomirski authored 
      commit dac16fba upstream.
Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/9d37826fdc7e2d2809efe31d5345f97186859284.1449702533.git.luto@kernel.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Jamie Iles <jamie.iles@oracle.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      755bd549
    • Andy Lutomirski's avatar
      x86, vdso, pvclock: Simplify and speed up the vdso pvclock reader · 64e23980
      Andy Lutomirski authored 
      commit 6b078f5d upstream.

The pvclock vdso code was too abstracted to understand easily
and excessively paranoid.  Simplify it for a huge speedup.

This opens the door for additional simplifications, as the vdso
no longer accesses the pvti for any vcpu other than vcpu 0.

Before, vclock_gettime using kvm-clock took about 45ns on my
machine. With this change, it takes 29ns, which is almost as
fast as the pure TSC implementation.
Signed-off-by: default avatarAndy Lutomirski <luto@amacapital.net>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/6b51dcc41f1b101f963945c5ec7093d72bdac429.1449702533.git.luto@kernel.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Jamie Iles <jamie.iles@oracle.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      64e23980
    • Kees Cook's avatar
      KPTI: Report when enabled · bfd51a4d
      Kees Cook authored 
      Make sure dmesg reports when KPTI is enabled.
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bfd51a4d
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