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| author | Sheng Yang <sheng@linux.intel.com> | 2010-07-01 15:00:50 +0800 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2010-08-01 10:47:29 +0300 |
| commit | 95c87e2b4460a488ec7ce42f273893e410ab385a (patch) | |
| tree | 4b9375cfcdd0cbfafe15a094d39057848ac748c3 | |
| parent | fef093bec0364ff5e6fd488cd81637f6bb3a2d0d (diff) | |
| download | lwn-95c87e2b4460a488ec7ce42f273893e410ab385a.tar.gz lwn-95c87e2b4460a488ec7ce42f273893e410ab385a.zip | |
KVM: Fix IOMMU memslot reference warning
This patch fixes the following warning.
===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
include/linux/kvm_host.h:259 invoked rcu_dereference_check() without
protection!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 0
no locks held by qemu-system-x86/29679.
stack backtrace:
Pid: 29679, comm: qemu-system-x86 Not tainted 2.6.35-rc3+ #200
Call Trace:
[<ffffffff810a224e>] lockdep_rcu_dereference+0xa8/0xb1
[<ffffffffa018a06f>] kvm_iommu_unmap_memslots+0xc9/0xde [kvm]
[<ffffffffa018a0c4>] kvm_iommu_unmap_guest+0x40/0x4e [kvm]
[<ffffffffa018f772>] kvm_arch_destroy_vm+0x1a/0x186 [kvm]
[<ffffffffa01800d0>] kvm_put_kvm+0x110/0x167 [kvm]
[<ffffffffa0180ecc>] kvm_vcpu_release+0x18/0x1c [kvm]
[<ffffffff81156f5d>] fput+0x22a/0x3a0
[<ffffffff81152288>] filp_close+0xb4/0xcd
[<ffffffff8106599f>] put_files_struct+0x1b7/0x36b
[<ffffffff81065830>] ? put_files_struct+0x48/0x36b
[<ffffffff8131ee59>] ? do_raw_spin_unlock+0x118/0x160
[<ffffffff81065bc0>] exit_files+0x6d/0x75
[<ffffffff81068348>] do_exit+0x47d/0xc60
[<ffffffff8177e7b5>] ? _raw_spin_unlock_irq+0x30/0x36
[<ffffffff81068bfa>] do_group_exit+0xcf/0x134
[<ffffffff81080790>] get_signal_to_deliver+0x732/0x81d
[<ffffffff81095996>] ? cpu_clock+0x4e/0x60
[<ffffffff81002082>] do_notify_resume+0x117/0xc43
[<ffffffff810a2fa3>] ? trace_hardirqs_on+0xd/0xf
[<ffffffff81080d79>] ? sys_rt_sigtimedwait+0x2b5/0x3bf
[<ffffffff8177d9f2>] ? trace_hardirqs_off_thunk+0x3a/0x3c
[<ffffffff81003221>] ? sysret_signal+0x5/0x3d
[<ffffffff8100343b>] int_signal+0x12/0x17
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
| -rw-r--r-- | virt/kvm/iommu.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c index 673c88a8efe9..779559552ce7 100644 --- a/virt/kvm/iommu.c +++ b/virt/kvm/iommu.c @@ -126,9 +126,10 @@ unmap_pages: static int kvm_iommu_map_memslots(struct kvm *kvm) { - int i, r = 0; + int i, idx, r = 0; struct kvm_memslots *slots; + idx = srcu_read_lock(&kvm->srcu); slots = kvm_memslots(kvm); for (i = 0; i < slots->nmemslots; i++) { @@ -136,6 +137,7 @@ static int kvm_iommu_map_memslots(struct kvm *kvm) if (r) break; } + srcu_read_unlock(&kvm->srcu, idx); return r; } @@ -285,15 +287,17 @@ static void kvm_iommu_put_pages(struct kvm *kvm, static int kvm_iommu_unmap_memslots(struct kvm *kvm) { - int i; + int i, idx; struct kvm_memslots *slots; + idx = srcu_read_lock(&kvm->srcu); slots = kvm_memslots(kvm); for (i = 0; i < slots->nmemslots; i++) { kvm_iommu_put_pages(kvm, slots->memslots[i].base_gfn, slots->memslots[i].npages); } + srcu_read_unlock(&kvm->srcu, idx); return 0; } |