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  1. 03 Aug, 2015 33 commits
  3. 10 Jul, 2015 7 commits
    • Greg Kroah-Hartman's avatar
      Linux 3.10.84 · f1178e99
      Greg Kroah-Hartman authored
      f1178e99
    • Jan Kara's avatar
      fs: Fix S_NOSEC handling · 9b9724dc
      Jan Kara authored 
      commit 2426f391 upstream.

file_remove_suid() could mistakenly set S_NOSEC inode bit when root was
modifying the file. As a result following writes to the file by ordinary
user would avoid clearing suid or sgid bits.

Fix the bug by checking actual mode bits before setting S_NOSEC.
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9b9724dc
    • Radim Krčmář's avatar
      KVM: x86: make vapics_in_nmi_mode atomic · 455aa7c4
      Radim Krčmář authored 
      commit 42720138 upstream.

Writes were a bit racy, but hard to turn into a bug at the same time.
(Particularly because modern Linux doesn't use this feature anymore.)
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
[Actually the next patch makes it much, much easier to trigger the race
 so I'm including this one for stable@ as well. - Paolo]
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      455aa7c4
    • James Hogan's avatar
      MIPS: Fix KVM guest fixmap address · ce2eb12c
      James Hogan authored 
      commit 8e748c8d upstream.

KVM guest kernels for trap & emulate run in user mode, with a modified
set of kernel memory segments. However the fixmap address is still in
the normal KSeg3 region at 0xfffe0000 regardless, causing problems when
cache alias handling makes use of them when handling copy on write.

Therefore define FIXADDR_TOP as 0x7ffe0000 in the guest kernel mapped
region when CONFIG_KVM_GUEST is defined.
Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9887/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ce2eb12c
    • Bjorn Helgaas's avatar
      x86/PCI: Use host bridge _CRS info on Foxconn K8M890-8237A · dc86cafe
      Bjorn Helgaas authored 
      commit 1dace011 upstream.

The Foxconn K8M890-8237A has two PCI host bridges, and we can't assign
resources correctly without the information from _CRS that tells us which
address ranges are claimed by which bridge.  In the bugs mentioned below,
we incorrectly assign a sound card address (this example is from 1033299):

  bus: 00 index 2 [mem 0x80000000-0xfcffffffff]
  ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-7f])
  pci_root PNP0A08:00: host bridge window [mem 0x80000000-0xbfefffff] (ignored)
  pci_root PNP0A08:00: host bridge window [mem 0xc0000000-0xdfffffff] (ignored)
  pci_root PNP0A08:00: host bridge window [mem 0xf0000000-0xfebfffff] (ignored)
  ACPI: PCI Root Bridge [PCI1] (domain 0000 [bus 80-ff])
  pci_root PNP0A08:01: host bridge window [mem 0xbff00000-0xbfffffff] (ignored)
  pci 0000:80:01.0: [1106:3288] type 0 class 0x000403
  pci 0000:80:01.0: reg 10: [mem 0xbfffc000-0xbfffffff 64bit]
  pci 0000:80:01.0: address space collision: [mem 0xbfffc000-0xbfffffff 64bit] conflicts with PCI Bus #00 [mem 0x80000000-0xfcffffffff]
  pci 0000:80:01.0: BAR 0: assigned [mem 0xfd00000000-0xfd00003fff 64bit]
  BUG: unable to handle kernel paging request at ffffc90000378000
  IP: [<ffffffffa0345f63>] azx_create+0x37c/0x822 [snd_hda_intel]

We assigned 0xfd_0000_0000, but that is not in any of the host bridge
windows, and the sound card doesn't work.

Turn on pci=use_crs automatically for this system.

Link: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/931368
Link: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1033299Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      dc86cafe
    • Anton Blanchard's avatar
      powerpc/perf: Fix book3s kernel to userspace backtraces · aa517b18
      Anton Blanchard authored 
      commit 72e349f1 upstream.

When we take a PMU exception or a software event we call
perf_read_regs(). This overloads regs->result with a boolean that
describes if we should use the sampled instruction address register
(SIAR) or the regs.

If the exception is in kernel, we start with the kernel regs and
backtrace through the kernel stack. At this point we switch to the
userspace regs and backtrace the user stack with perf_callchain_user().

Unfortunately these regs have not got the perf_read_regs() treatment,
so regs->result could be anything. If it is non zero,
perf_instruction_pointer() decides to use the SIAR, and we get issues
like this:

0.11%  qemu-system-ppc  [kernel.kallsyms]        [k] _raw_spin_lock_irqsave
       |
       ---_raw_spin_lock_irqsave
          |
          |--52.35%-- 0
          |          |
          |          |--46.39%-- __hrtimer_start_range_ns
          |          |          kvmppc_run_core
          |          |          kvmppc_vcpu_run_hv
          |          |          kvmppc_vcpu_run
          |          |          kvm_arch_vcpu_ioctl_run
          |          |          kvm_vcpu_ioctl
          |          |          do_vfs_ioctl
          |          |          sys_ioctl
          |          |          system_call
          |          |          |
          |          |          |--67.08%-- _raw_spin_lock_irqsave <--- hi mum
          |          |          |          |
          |          |          |           --100.00%-- 0x7e714
          |          |          |                     0x7e714

Notice the bogus _raw_spin_irqsave when we transition from kernel
(system_call) to userspace (0x7e714). We inserted what was in the SIAR.

Add a check in regs_use_siar() to check that the regs in question
are from a PMU exception. With this fix the backtrace makes sense:

     0.47%  qemu-system-ppc  [kernel.vmlinux]         [k] _raw_spin_lock_irqsave
            |
            ---_raw_spin_lock_irqsave
               |
               |--53.83%-- 0
               |          |
               |          |--44.73%-- hrtimer_try_to_cancel
               |          |          kvmppc_start_thread
               |          |          kvmppc_run_core
               |          |          kvmppc_vcpu_run_hv
               |          |          kvmppc_vcpu_run
               |          |          kvm_arch_vcpu_ioctl_run
               |          |          kvm_vcpu_ioctl
               |          |          do_vfs_ioctl
               |          |          sys_ioctl
               |          |          system_call
               |          |          __ioctl
               |          |          0x7e714
               |          |          0x7e714
Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      aa517b18
    • Marc Zyngier's avatar
      arm: KVM: force execution of HCPTR access on VM exit · 06efcc86
      Marc Zyngier authored 
      commit 85e84ba3 upstream.

On VM entry, we disable access to the VFP registers in order to
perform a lazy save/restore of these registers.

On VM exit, we restore access, test if we did enable them before,
and save/restore the guest/host registers if necessary. In this
sequence, the FPEXC register is always accessed, irrespective
of the trapping configuration.

If the guest didn't touch the VFP registers, then the HCPTR access
has now enabled such access, but we're missing a barrier to ensure
architectural execution of the new HCPTR configuration. If the HCPTR
access has been delayed/reordered, the subsequent access to FPEXC
will cause a trap, which we aren't prepared to handle at all.

The same condition exists when trapping to enable VFP for the guest.

The fix is to introduce a barrier after enabling VFP access. In the
vmexit case, it can be relaxed to only takes place if the guest hasn't
accessed its view of the VFP registers, making the access to FPEXC safe.

The set_hcptr macro is modified to deal with both vmenter/vmexit and
vmtrap operations, and now takes an optional label that is branched to
when the guest hasn't touched the VFP registers.
Reported-by: default avatarVikram Sethi <vikrams@codeaurora.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      06efcc86
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