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-rw-r--r--virt/kvm/kvm_main.c18
1 files changed, 16 insertions, 2 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d20fba0fc290..b50dbe269f4b 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -892,6 +892,8 @@ static void kvm_destroy_vm_debugfs(struct kvm *kvm)
static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
{
+ static DEFINE_MUTEX(kvm_debugfs_lock);
+ struct dentry *dent;
char dir_name[ITOA_MAX_LEN * 2];
struct kvm_stat_data *stat_data;
const struct _kvm_stats_desc *pdesc;
@@ -903,8 +905,20 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
return 0;
snprintf(dir_name, sizeof(dir_name), "%d-%d", task_pid_nr(current), fd);
- kvm->debugfs_dentry = debugfs_create_dir(dir_name, kvm_debugfs_dir);
+ mutex_lock(&kvm_debugfs_lock);
+ dent = debugfs_lookup(dir_name, kvm_debugfs_dir);
+ if (dent) {
+ pr_warn_ratelimited("KVM: debugfs: duplicate directory %s\n", dir_name);
+ dput(dent);
+ mutex_unlock(&kvm_debugfs_lock);
+ return 0;
+ }
+ dent = debugfs_create_dir(dir_name, kvm_debugfs_dir);
+ mutex_unlock(&kvm_debugfs_lock);
+ if (IS_ERR(dent))
+ return 0;
+ kvm->debugfs_dentry = dent;
kvm->debugfs_stat_data = kcalloc(kvm_debugfs_num_entries,
sizeof(*kvm->debugfs_stat_data),
GFP_KERNEL_ACCOUNT);
@@ -5201,7 +5215,7 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
}
add_uevent_var(env, "PID=%d", kvm->userspace_pid);
- if (!IS_ERR_OR_NULL(kvm->debugfs_dentry)) {
+ if (kvm->debugfs_dentry) {
char *tmp, *p = kmalloc(PATH_MAX, GFP_KERNEL_ACCOUNT);
if (p) {