ppc: kvm: use anon_inode_getfd() with O_CLOEXEC flag

KVM uses anon_inode_get() to allocate file descriptors as part
of some of its ioctls. But those ioctls are lacking a flag argument
allowing userspace to choose options for the newly opened file descriptor.

In such case it's advised to use O_CLOEXEC by default so that
userspace is allowed to choose, without race, if the file descriptor
is going to be inherited across exec().

This patch set O_CLOEXEC flag on all file descriptors created
with anon_inode_getfd() to not leak file descriptors across exec().

Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Link: http://lkml.kernel.org/r/cover.1377372576.git.ydroneaud@opteya.com
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Gleb Natapov <gleb@redhat.com>

arch/powerpc/kvm/book3s_64_mmu_hv.c

@@ -1579,7 +1579,7 @@ int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
 	ctx->first_pass = 1;
 
 	rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
-	ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag);
+	ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
 	if (ret < 0) {
 		kvm_put_kvm(kvm);
 		return ret;

arch/powerpc/kvm/book3s_64_vio.c

@@ -136,7 +136,7 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
 	mutex_unlock(&kvm->lock);
 
 	return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
-				stt, O_RDWR);
+				stt, O_RDWR | O_CLOEXEC);
 
 fail:
 	if (stt) {

arch/powerpc/kvm/book3s_hv.c

@@ -1556,7 +1556,7 @@ long kvm_vm_ioctl_allocate_rma(struct kvm *kvm, struct kvm_allocate_rma *ret)
 	if (!ri)
 		return -ENOMEM;
 
-	fd = anon_inode_getfd("kvm-rma", &kvm_rma_fops, ri, O_RDWR);
+	fd = anon_inode_getfd("kvm-rma", &kvm_rma_fops, ri, O_RDWR | O_CLOEXEC);
 	if (fd < 0)
 		kvm_release_rma(ri);