linux/virt/kvm
Paolo Bonzini 01954dfd48 KVM: fix spin_lock_init order on x86
[ Upstream commit e9ad4ec837 ]

Moving the initialization earlier is needed in 4.6 because
kvm_arch_init_vm is now using mmu_lock, causing lockdep to
complain:

[  284.440294] INFO: trying to register non-static key.
[  284.445259] the code is fine but needs lockdep annotation.
[  284.450736] turning off the locking correctness validator.
...
[  284.528318]  [<ffffffff810aecc3>] lock_acquire+0xd3/0x240
[  284.533733]  [<ffffffffa0305aa0>] ? kvm_page_track_register_notifier+0x20/0x60 [kvm]
[  284.541467]  [<ffffffff81715581>] _raw_spin_lock+0x41/0x80
[  284.546960]  [<ffffffffa0305aa0>] ? kvm_page_track_register_notifier+0x20/0x60 [kvm]
[  284.554707]  [<ffffffffa0305aa0>] kvm_page_track_register_notifier+0x20/0x60 [kvm]
[  284.562281]  [<ffffffffa02ece70>] kvm_mmu_init_vm+0x20/0x30 [kvm]
[  284.568381]  [<ffffffffa02dbf7a>] kvm_arch_init_vm+0x1ea/0x200 [kvm]
[  284.574740]  [<ffffffffa02bff3f>] kvm_dev_ioctl+0xbf/0x4d0 [kvm]

However, it also helps fixing a preexisting problem, which is why this
patch is also good for stable kernels: kvm_create_vm was incrementing
current->mm->mm_count but not decrementing it at the out_err label (in
case kvm_init_mmu_notifier failed).  The new initialization order makes
it possible to add the required mmdrop without adding a new error label.

Cc: stable@vger.kernel.org
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
History 2016-04-18 08:51:06 -04:00
..
arm KVM: arm/arm64: vgic: Ensure bitmaps are long enough 2016-03-07 16:30:53 -05:00
async_pf.c KVM: async_pf: do not warn on page allocation failures 2016-03-07 16:35:16 -05:00
async_pf.h KVM: Halt vcpu if page it tries to access is swapped out 2011-01-12 11:21:39 +02:00
coalesced_mmio.c KVM: move iodev.h from virt/kvm/ to include/kvm 2015-03-26 21:43:12 +00:00
coalesced_mmio.h KVM: Make coalesced mmio use a device per zone 2011-09-25 19:17:57 +03:00
eventfd.c kvm: fix double free for fast mmio eventfd 2015-10-22 14:43:10 -07:00
irqchip.c KVM: fix checkpatch.pl errors in kvm/irqchip.c 2015-03-10 10:37:42 -03:00
Kconfig KVM: Disable compat ioctl for s390 2015-02-09 12:44:14 +01:00
kvm_main.c KVM: fix spin_lock_init order on x86 2016-04-18 08:51:06 -04:00
vfio.c kvm: vfio: fix unregister kvm_device_ops of vfio 2014-10-24 13:30:47 +02:00
vfio.h kvm: vfio: fix unregister kvm_device_ops of vfio 2014-10-24 13:30:47 +02:00