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| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2017-07-10 13:35:48 +0200 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2017-07-25 14:59:52 +0200 |
| commit | 4f899147424a189b0ad1fdd6f35784ed5a642e83 (patch) | |
| tree | dc45743d7b1bf973c80be610d59678a240d7ef91 /arch | |
| parent | kvm: x86: hyperv: avoid livelock in oneshot SynIC timers (diff) | |
| download | linux-4f899147424a189b0ad1fdd6f35784ed5a642e83.tar.xz linux-4f899147424a189b0ad1fdd6f35784ed5a642e83.zip | |
KVM: s390: take srcu lock when getting/setting storage keys
The following warning was triggered by missing srcu locks around
the storage key handling functions.
=============================
WARNING: suspicious RCU usage
4.12.0+ #56 Not tainted
-----------------------------
./include/linux/kvm_host.h:572 suspicious rcu_dereference_check() usage!
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by live_migration/4936:
#0: (&mm->mmap_sem){++++++}, at: [<0000000000141be0>]
kvm_arch_vm_ioctl+0x6b8/0x22d0
CPU: 8 PID: 4936 Comm: live_migration Not tainted 4.12.0+ #56
Hardware name: IBM 2964 NC9 704 (LPAR)
Call Trace:
([<000000000011378a>] show_stack+0xea/0xf0)
[<000000000055cc4c>] dump_stack+0x94/0xd8
[<000000000012ee70>] gfn_to_memslot+0x1a0/0x1b8
[<0000000000130b76>] gfn_to_hva+0x2e/0x48
[<0000000000141c3c>] kvm_arch_vm_ioctl+0x714/0x22d0
[<000000000013306c>] kvm_vm_ioctl+0x11c/0x7b8
[<000000000037e2c0>] do_vfs_ioctl+0xa8/0x6c8
[<000000000037e984>] SyS_ioctl+0xa4/0xb8
[<00000000008b20a4>] system_call+0xc4/0x27c
1 lock held by live_migration/4936:
#0: (&mm->mmap_sem){++++++}, at: [<0000000000141be0>]
kvm_arch_vm_ioctl+0x6b8/0x22d0
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Pierre Morel<pmorel@linux.vnet.ibm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 3f2884e99ed4..af09d3437631 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -1324,7 +1324,7 @@ static long kvm_s390_get_skeys(struct kvm *kvm, struct kvm_s390_skeys *args) { uint8_t *keys; uint64_t hva; - int i, r = 0; + int srcu_idx, i, r = 0; if (args->flags != 0) return -EINVAL; @@ -1342,6 +1342,7 @@ static long kvm_s390_get_skeys(struct kvm *kvm, struct kvm_s390_skeys *args) return -ENOMEM; down_read(¤t->mm->mmap_sem); + srcu_idx = srcu_read_lock(&kvm->srcu); for (i = 0; i < args->count; i++) { hva = gfn_to_hva(kvm, args->start_gfn + i); if (kvm_is_error_hva(hva)) { @@ -1353,6 +1354,7 @@ static long kvm_s390_get_skeys(struct kvm *kvm, struct kvm_s390_skeys *args) if (r) break; } + srcu_read_unlock(&kvm->srcu, srcu_idx); up_read(¤t->mm->mmap_sem); if (!r) { @@ -1370,7 +1372,7 @@ static long kvm_s390_set_skeys(struct kvm *kvm, struct kvm_s390_skeys *args) { uint8_t *keys; uint64_t hva; - int i, r = 0; + int srcu_idx, i, r = 0; if (args->flags != 0) return -EINVAL; @@ -1396,6 +1398,7 @@ static long kvm_s390_set_skeys(struct kvm *kvm, struct kvm_s390_skeys *args) goto out; down_read(¤t->mm->mmap_sem); + srcu_idx = srcu_read_lock(&kvm->srcu); for (i = 0; i < args->count; i++) { hva = gfn_to_hva(kvm, args->start_gfn + i); if (kvm_is_error_hva(hva)) { @@ -1413,6 +1416,7 @@ static long kvm_s390_set_skeys(struct kvm *kvm, struct kvm_s390_skeys *args) if (r) break; } + srcu_read_unlock(&kvm->srcu, srcu_idx); up_read(¤t->mm->mmap_sem); out: kvfree(keys); |