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linux-next/virt/kvm
Darrick J. Wong 0ea4ed8e94 KVM: Prevent kvm_init from corrupting debugfs structures
I'm seeing an oops condition when kvm-intel and kvm-amd are modprobe'd
during boot (say on an Intel system) and then rmmod'd:

   # modprobe kvm-intel
     kvm_init()
     kvm_init_debug()
     kvm_arch_init()  <-- stores debugfs dentries internally
     (success, etc)

   # modprobe kvm-amd
     kvm_init()
     kvm_init_debug() <-- second initialization clobbers kvm's
                          internal pointers to dentries
     kvm_arch_init()
     kvm_exit_debug() <-- and frees them

   # rmmod kvm-intel
     kvm_exit()
     kvm_exit_debug() <-- double free of debugfs files!

     *BOOM*

If execution gets to the end of kvm_init(), then the calling module has been
established as the kvm provider.  Move the debugfs initialization to the end of
the function, and remove the now-unnecessary call to kvm_exit_debug() from the
error path.  That way we avoid trampling on the debugfs entries and freeing
them twice.

Cc: stable@kernel.org
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-10-16 12:30:26 -03:00
..
coalesced_mmio.c KVM: make io_bus interface more robust 2009-09-10 08:33:12 +03:00
coalesced_mmio.h KVM: move coalesced_mmio locking to its own device 2009-09-10 08:32:49 +03:00
eventfd.c KVM: correct error-handling code 2009-09-10 18:11:12 +03:00
ioapic.c KVM: Fix coalesced interrupt reporting in IOAPIC 2009-09-10 10:46:59 +03:00
ioapic.h KVM: APIC: get rid of deliver_bitmask 2009-06-10 11:48:27 +03:00
iodev.h KVM: remove in_range from io devices 2009-09-10 08:33:05 +03:00
iommu.c KVM: Enable snooping control for supported hardware 2009-06-10 11:48:50 +03:00
irq_comm.c KVM: Add trace points in irqchip code 2009-09-10 08:33:11 +03:00
Kconfig KVM: Break dependency between vcpu index in vcpus array and vcpu_id. 2009-09-10 08:32:52 +03:00
kvm_main.c KVM: Prevent kvm_init from corrupting debugfs structures 2009-10-16 12:30:26 -03:00