linux/virt/kvm
Lai Jiangshan eda2beda83 KVM: Add missing srcu_read_lock() for kvm_mmu_notifier_release()
I got this dmesg due to srcu_read_lock() is missing in
kvm_mmu_notifier_release().

===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
arch/x86/kvm/x86.h:72 invoked rcu_dereference_check() without protection!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
2 locks held by qemu-system-x86/3100:
 #0:  (rcu_read_lock){.+.+..}, at: [<ffffffff810d73dc>] __mmu_notifier_release+0x38/0xdf
 #1:  (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa0130a6a>] kvm_mmu_zap_all+0x21/0x5e [kvm]

stack backtrace:
Pid: 3100, comm: qemu-system-x86 Not tainted 2.6.34-rc3-22949-gbc8a97a-dirty #2
Call Trace:
 [<ffffffff8106afd9>] lockdep_rcu_dereference+0xaa/0xb3
 [<ffffffffa0123a89>] unalias_gfn+0x56/0xab [kvm]
 [<ffffffffa0119600>] gfn_to_memslot+0x16/0x25 [kvm]
 [<ffffffffa012ffca>] gfn_to_rmap+0x17/0x6e [kvm]
 [<ffffffffa01300c1>] rmap_remove+0xa0/0x19d [kvm]
 [<ffffffffa0130649>] kvm_mmu_zap_page+0x109/0x34d [kvm]
 [<ffffffffa0130a7e>] kvm_mmu_zap_all+0x35/0x5e [kvm]
 [<ffffffffa0122870>] kvm_arch_flush_shadow+0x16/0x22 [kvm]
 [<ffffffffa01189e0>] kvm_mmu_notifier_release+0x15/0x17 [kvm]
 [<ffffffff810d742c>] __mmu_notifier_release+0x88/0xdf
 [<ffffffff810d73dc>] ? __mmu_notifier_release+0x38/0xdf
 [<ffffffff81040848>] ? exit_mm+0xe0/0x115
 [<ffffffff810c2cb0>] exit_mmap+0x2c/0x17e
 [<ffffffff8103c472>] mmput+0x2d/0xd4
 [<ffffffff81040870>] exit_mm+0x108/0x115
[...]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-21 11:17:43 +03:00
..
assigned-dev.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
coalesced_mmio.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
coalesced_mmio.h KVM: Simplify coalesced mmio initialization 2010-03-01 12:35:41 -03:00
eventfd.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
ioapic.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
ioapic.h KVM: cleanup the failure path of KVM_CREATE_IRQCHIP ioctrl 2010-03-01 12:36:10 -03:00
iodev.h
iommu.c KVM: enable PCI multiple-segments for pass-through device 2010-03-01 12:36:06 -03:00
irq_comm.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
Kconfig KVM: Add KVM_MMIO kconfig item 2010-03-01 12:35:41 -03:00
kvm_main.c KVM: Add missing srcu_read_lock() for kvm_mmu_notifier_release() 2010-04-21 11:17:43 +03:00