From 833b45de69a6016c4b0cebe6765d526a31a81580 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 30 Sep 2019 18:48:44 +0200 Subject: kvm: x86, powerpc: do not allow clearing largepages debugfs entry The largepages debugfs entry is incremented/decremented as shadow pages are created or destroyed. Clearing it will result in an underflow, which is harmless to KVM but ugly (and could be misinterpreted by tools that use debugfs information), so make this particular statistic read-only. Cc: kvm-ppc@vger.kernel.org Signed-off-by: Paolo Bonzini --- virt/kvm/kvm_main.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index e6de3159e682..fd68fbe0a75d 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -617,8 +617,9 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd) stat_data->kvm = kvm; stat_data->offset = p->offset; + stat_data->mode = p->mode ? p->mode : 0644; kvm->debugfs_stat_data[p - debugfs_entries] = stat_data; - debugfs_create_file(p->name, 0644, kvm->debugfs_dentry, + debugfs_create_file(p->name, stat_data->mode, kvm->debugfs_dentry, stat_data, stat_fops_per_vm[p->kind]); } return 0; @@ -3929,7 +3930,9 @@ static int kvm_debugfs_open(struct inode *inode, struct file *file, if (!refcount_inc_not_zero(&stat_data->kvm->users_count)) return -ENOENT; - if (simple_attr_open(inode, file, get, set, fmt)) { + if (simple_attr_open(inode, file, get, + stat_data->mode & S_IWUGO ? set : NULL, + fmt)) { kvm_put_kvm(stat_data->kvm); return -ENOMEM; } @@ -4177,7 +4180,8 @@ static void kvm_init_debug(void) kvm_debugfs_num_entries = 0; for (p = debugfs_entries; p->name; ++p, kvm_debugfs_num_entries++) { - debugfs_create_file(p->name, 0644, kvm_debugfs_dir, + int mode = p->mode ? p->mode : 0644; + debugfs_create_file(p->name, mode, kvm_debugfs_dir, (void *)(long)p->offset, stat_fops[p->kind]); } -- cgit v1.2.3-59-g8ed1b