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authorChristian Borntraeger <borntraeger@de.ibm.com>2017-07-10 13:35:48 +0200
committerChristian Borntraeger <borntraeger@de.ibm.com>2017-07-25 14:59:52 +0200
commit4f899147424a189b0ad1fdd6f35784ed5a642e83 (patch)
treedc45743d7b1bf973c80be610d59678a240d7ef91 /arch
parentf1ff89ec4447c4e39d275a1ca3de43eed2a92745 (diff)
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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.c8
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(&current->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(&current->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(&current->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(&current->mm->mmap_sem);
out:
kvfree(keys);