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  3. Nov 03, 2014
  4. Nov 02, 2014
    • Paolo Bonzini's avatar
      KVM: vmx: defer load of APIC access page address during reset · a73896cb
      Paolo Bonzini authored
      
      
      Most call paths to vmx_vcpu_reset do not hold the SRCU lock.  Defer loading
      the APIC access page to the next vmentry.
      
      This avoids the following lockdep splat:
      
      [ INFO: suspicious RCU usage. ]
      3.18.0-rc2-test2+ #70 Not tainted
      -------------------------------
      include/linux/kvm_host.h:474 suspicious rcu_dereference_check() usage!
      
      other info that might help us debug this:
      
      rcu_scheduler_active = 1, debug_locks = 0
      1 lock held by qemu-system-x86/2371:
       #0:  (&vcpu->mutex){+.+...}, at: [<ffffffffa037d800>] vcpu_load+0x20/0xd0 [kvm]
      
      stack backtrace:
      CPU: 4 PID: 2371 Comm: qemu-system-x86 Not tainted 3.18.0-rc2-test2+ #70
      Hardware name: Dell Inc. OptiPlex 9010/0M9KCM, BIOS A12 01/10/2013
       0000000000000001 ffff880209983ca8 ffffffff816f514f 0000000000000000
       ffff8802099b8990 ffff880209983cd8 ffffffff810bd687 00000000000fee00
       ffff880208a2c000 ffff880208a10000 ffff88020ef50040 ffff880209983d08
      Call Trace:
       [<ffffffff816f514f>] dump_stack+0x4e/0x71
       [<ffffffff810bd687>] lockdep_rcu_suspicious+0xe7/0x120
       [<ffffffffa037d055>] gfn_to_memslot+0xd5/0xe0 [kvm]
       [<ffffffffa03807d3>] __gfn_to_pfn+0x33/0x60 [kvm]
       [<ffffffffa0380885>] gfn_to_page+0x25/0x90 [kvm]
       [<ffffffffa038aeec>] kvm_vcpu_reload_apic_access_page+0x3c/0x80 [kvm]
       [<ffffffffa08f0a9c>] vmx_vcpu_reset+0x20c/0x460 [kvm_intel]
       [<ffffffffa039ab8e>] kvm_vcpu_reset+0x15e/0x1b0 [kvm]
       [<ffffffffa039ac0c>] kvm_arch_vcpu_setup+0x2c/0x50 [kvm]
       [<ffffffffa037f7e0>] kvm_vm_ioctl+0x1d0/0x780 [kvm]
       [<ffffffff810bc664>] ? __lock_is_held+0x54/0x80
       [<ffffffff812231f0>] do_vfs_ioctl+0x300/0x520
       [<ffffffff8122ee45>] ? __fget+0x5/0x250
       [<ffffffff8122f0fa>] ? __fget_light+0x2a/0xe0
       [<ffffffff81223491>] SyS_ioctl+0x81/0xa0
       [<ffffffff816fed6d>] system_call_fastpath+0x16/0x1b
      
      Reported-by: default avatarTakashi Iwai <tiwai@suse.de>
      Reported-by: default avatarAlexei Starovoitov <alexei.starovoitov@gmail.com>
      Reviewed-by: default avatarWanpeng Li <wanpeng.li@linux.intel.com>
      Tested-by: default avatarWanpeng Li <wanpeng.li@linux.intel.com>
      Fixes: 38b99173
      
      
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      a73896cb
    • Jan Kiszka's avatar
      KVM: nVMX: Disable preemption while reading from shadow VMCS · 282da870
      Jan Kiszka authored
      
      
      In order to access the shadow VMCS, we need to load it. At this point,
      vmx->loaded_vmcs->vmcs and the actually loaded one start to differ. If
      we now get preempted by Linux, vmx_vcpu_put and, on return, the
      vmx_vcpu_load will work against the wrong vmcs. That can cause
      copy_shadow_to_vmcs12 to corrupt the vmcs12 state.
      
      Fix the issue by disabling preemption during the copy operation.
      copy_vmcs12_to_shadow is safe from this issue as it is executed by
      vmx_vcpu_run when preemption is already disabled before vmentry.
      
      This bug is exposed by running Jailhouse within KVM on CPUs with
      shadow VMCS support.  Jailhouse never expects an interrupt pending
      vmexit, but the bug can cause it if, after copy_shadow_to_vmcs12
      is preempted, the active VMCS happens to have the virtual interrupt
      pending flag set in the CPU-based execution controls.
      
      Signed-off-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      282da870
    • Nadav Amit's avatar
      KVM: x86: Fix far-jump to non-canonical check · 7e46dddd
      Nadav Amit authored
      Commit d1442d85 ("KVM: x86: Handle errors when RIP is set during far
      jumps") introduced a bug that caused the fix to be incomplete.  Due to
      incorrect evaluation, far jump to segment with L bit cleared (i.e., 32-bit
      segment) and RIP with any of the high bits set (i.e, RIP[63:32] != 0) set may
      not trigger #GP.  As we know, this imposes a security problem.
      
      In addition, the condition for two warnings was incorrect.
      
      Fixes: d1442d85
      
      
      Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Signed-off-by: default avatarNadav Amit <namit@cs.technion.ac.il>
      [Add #ifdef CONFIG_X86_64 to avoid complaints of undefined behavior. - Paolo]
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      7e46dddd
    • Dave Airlie's avatar
      Merge branch 'vmwgfx-fixes-3.18' of git://people.freedesktop.org/~thomash/linux · 10a8fce8
      Dave Airlie authored
      A critical 3.18 regression fix from Rob, (thanks!)
      A fix to avoid advertizing modes we can't support from Sinclair
        (welcome Sinclair!)
      and a fix for an incorrect  hash key computation from me that is
        completely harmless, but can wait 'til the next merge window if necessary.
        (I can't really bother stable with this one).
      
      * 'vmwgfx-fixes-3.18' of git://people.freedesktop.org/~thomash/linux:
        drm/vmwgfx: Filter out modes those cannot be supported by the current VRAM size.
        drm/vmwgfx: Fix hash key computation
        drm/vmwgfx: fix lock breakage
      10a8fce8
    • Linus Torvalds's avatar
      Merge tag 'staging-3.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging · 12d7aaca
      Linus Torvalds authored
      Pull staging fixes from Greg KH:
       "Here are some staging driver fixes for 3.18-rc3.  Mostly iio and
        comedi driver fixes for issues reported by people.
      
        All of these have been in linux-next for a while with no reported
        issues"
      
      * tag 'staging-3.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
        staging: comedi: fix memory leak / bad pointer freeing for chanlist
        staging: comedi: Kconfig: fix config COMEDI_ADDI_APCI_3120 dependants
        staging: comedi: widen subdevice number argument in ioctl handlers
        staging: rtl8723au: Fix alignment of mac_addr for ether_addr_copy() usage
        drivers/staging/comedi/Kconfig: Let COMEDI_II_PCI20KC depend on HAS_IOMEM
        staging: comedi: (regression) channel list must be set for COMEDI_CMD ioctl
        iio: adc: mxs-lradc: Disable the clock on probe failure
        iio: st_sensors: Fix buffer copy
        staging:iio:ad5933: Drop "raw" from channel names
        staging:iio:ad5933: Fix NULL pointer deref when enabling buffer
      12d7aaca