Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 473 insertions, 0 deletions

diff --git a/drivers/s390/char/uvdevice.c b/drivers/s390/char/uvdevice.c
new file mode 100644
index 0000000000..144cd2e035
--- /dev/null
+++ b/drivers/s390/char/uvdevice.c
@@ -0,0 +1,473 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright IBM Corp. 2022
+ *  Author(s): Steffen Eiden <seiden@linux.ibm.com>
+ *
+ *  This file provides a Linux misc device to give userspace access to some
+ *  Ultravisor (UV) functions. The device only accepts IOCTLs and will only
+ *  be present if the Ultravisor facility (158) is present.
+ *
+ *  When userspace sends a valid IOCTL uvdevice will copy the input data to
+ *  kernel space, do some basic validity checks to avoid kernel/system
+ *  corruption. Any other check that the Ultravisor does will not be done by
+ *  the uvdevice to keep changes minimal when adding new functionalities
+ *  to existing UV-calls.
+ *  After the checks uvdevice builds a corresponding
+ *  Ultravisor Call Control Block, and sends the request to the Ultravisor.
+ *  Then, it copies the response, including the return codes, back to userspace.
+ *  It is the responsibility of the userspace to check for any error issued
+ *  by UV and to interpret the UV response. The uvdevice acts as a communication
+ *  channel for userspace to the Ultravisor.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/types.h>
+#include <linux/stddef.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/cpufeature.h>
+
+#include <asm/uvdevice.h>
+#include <asm/uv.h>
+
+#define BIT_UVIO_INTERNAL U32_MAX
+/* Mapping from IOCTL-nr to UVC-bit */
+static const u32 ioctl_nr_to_uvc_bit[] __initconst = {
+	[UVIO_IOCTL_UVDEV_INFO_NR] = BIT_UVIO_INTERNAL,
+	[UVIO_IOCTL_ATT_NR] = BIT_UVC_CMD_RETR_ATTEST,
+	[UVIO_IOCTL_ADD_SECRET_NR] = BIT_UVC_CMD_ADD_SECRET,
+	[UVIO_IOCTL_LIST_SECRETS_NR] = BIT_UVC_CMD_LIST_SECRETS,
+	[UVIO_IOCTL_LOCK_SECRETS_NR] = BIT_UVC_CMD_LOCK_SECRETS,
+};
+
+static_assert(ARRAY_SIZE(ioctl_nr_to_uvc_bit) == UVIO_IOCTL_NUM_IOCTLS);
+
+static struct uvio_uvdev_info uvdev_info = {
+	.supp_uvio_cmds = GENMASK_ULL(UVIO_IOCTL_NUM_IOCTLS - 1, 0),
+};
+
+static void __init set_supp_uv_cmds(unsigned long *supp_uv_cmds)
+{
+	int i;
+
+	for (i = 0; i < UVIO_IOCTL_NUM_IOCTLS; i++) {
+		if (ioctl_nr_to_uvc_bit[i] == BIT_UVIO_INTERNAL)
+			continue;
+		if (!test_bit_inv(ioctl_nr_to_uvc_bit[i], uv_info.inst_calls_list))
+			continue;
+		__set_bit(i, supp_uv_cmds);
+	}
+}
+
+/**
+ * uvio_uvdev_info() - get information about the uvdevice
+ *
+ * @uv_ioctl: ioctl control block
+ *
+ * Lists all IOCTLs that are supported by this uvdevice
+ */
+static int uvio_uvdev_info(struct uvio_ioctl_cb *uv_ioctl)
+{
+	void __user *user_buf_arg = (void __user *)uv_ioctl->argument_addr;
+
+	if (uv_ioctl->argument_len < sizeof(uvdev_info))
+		return -EINVAL;
+	if (copy_to_user(user_buf_arg, &uvdev_info, sizeof(uvdev_info)))
+		return -EFAULT;
+
+	uv_ioctl->uv_rc = UVC_RC_EXECUTED;
+	return 0;
+}
+
+static int uvio_build_uvcb_attest(struct uv_cb_attest *uvcb_attest, u8 *arcb,
+				  u8 *meas, u8 *add_data, struct uvio_attest *uvio_attest)
+{
+	void __user *user_buf_arcb = (void __user *)uvio_attest->arcb_addr;
+
+	if (copy_from_user(arcb, user_buf_arcb, uvio_attest->arcb_len))
+		return -EFAULT;
+
+	uvcb_attest->header.len = sizeof(*uvcb_attest);
+	uvcb_attest->header.cmd = UVC_CMD_RETR_ATTEST;
+	uvcb_attest->arcb_addr = (u64)arcb;
+	uvcb_attest->cont_token = 0;
+	uvcb_attest->user_data_len = uvio_attest->user_data_len;
+	memcpy(uvcb_attest->user_data, uvio_attest->user_data, sizeof(uvcb_attest->user_data));
+	uvcb_attest->meas_len = uvio_attest->meas_len;
+	uvcb_attest->meas_addr = (u64)meas;
+	uvcb_attest->add_data_len = uvio_attest->add_data_len;
+	uvcb_attest->add_data_addr = (u64)add_data;
+
+	return 0;
+}
+
+static int uvio_copy_attest_result_to_user(struct uv_cb_attest *uvcb_attest,
+					   struct uvio_ioctl_cb *uv_ioctl,
+					   u8 *measurement, u8 *add_data,
+					   struct uvio_attest *uvio_attest)
+{
+	struct uvio_attest __user *user_uvio_attest = (void __user *)uv_ioctl->argument_addr;
+	void __user *user_buf_add = (void __user *)uvio_attest->add_data_addr;
+	void __user *user_buf_meas = (void __user *)uvio_attest->meas_addr;
+	void __user *user_buf_uid = &user_uvio_attest->config_uid;
+
+	if (copy_to_user(user_buf_meas, measurement, uvio_attest->meas_len))
+		return -EFAULT;
+	if (add_data && copy_to_user(user_buf_add, add_data, uvio_attest->add_data_len))
+		return -EFAULT;
+	if (copy_to_user(user_buf_uid, uvcb_attest->config_uid, sizeof(uvcb_attest->config_uid)))
+		return -EFAULT;
+	return 0;
+}
+
+static int get_uvio_attest(struct uvio_ioctl_cb *uv_ioctl, struct uvio_attest *uvio_attest)
+{
+	u8 __user *user_arg_buf = (u8 __user *)uv_ioctl->argument_addr;
+
+	if (copy_from_user(uvio_attest, user_arg_buf, sizeof(*uvio_attest)))
+		return -EFAULT;
+
+	if (uvio_attest->arcb_len > UVIO_ATT_ARCB_MAX_LEN)
+		return -EINVAL;
+	if (uvio_attest->arcb_len == 0)
+		return -EINVAL;
+	if (uvio_attest->meas_len > UVIO_ATT_MEASUREMENT_MAX_LEN)
+		return -EINVAL;
+	if (uvio_attest->meas_len == 0)
+		return -EINVAL;
+	if (uvio_attest->add_data_len > UVIO_ATT_ADDITIONAL_MAX_LEN)
+		return -EINVAL;
+	if (uvio_attest->reserved136)
+		return -EINVAL;
+	return 0;
+}
+
+/**
+ * uvio_attestation() - Perform a Retrieve Attestation Measurement UVC.
+ *
+ * @uv_ioctl: ioctl control block
+ *
+ * uvio_attestation() does a Retrieve Attestation Measurement Ultravisor Call.
+ * It verifies that the given userspace addresses are valid and request sizes
+ * are sane. Every other check is made by the Ultravisor (UV) and won't result
+ * in a negative return value. It copies the input to kernelspace, builds the
+ * request, sends the UV-call, and copies the result to userspace.
+ *
+ * The Attestation Request has two input and two outputs.
+ * ARCB and User Data are inputs for the UV generated by userspace.
+ * Measurement and Additional Data are outputs for userspace generated by UV.
+ *
+ * The Attestation Request Control Block (ARCB) is a cryptographically verified
+ * and secured request to UV and User Data is some plaintext data which is
+ * going to be included in the Attestation Measurement calculation.
+ *
+ * Measurement is a cryptographic measurement of the callers properties,
+ * optional data configured by the ARCB and the user data. If specified by the
+ * ARCB, UV will add some Additional Data to the measurement calculation.
+ * This Additional Data is then returned as well.
+ *
+ * If the Retrieve Attestation Measurement UV facility is not present,
+ * UV will return invalid command rc. This won't be fenced in the driver
+ * and does not result in a negative return value.
+ *
+ * Context: might sleep
+ *
+ * Return: 0 on success or a negative error code on error.
+ */
+static int uvio_attestation(struct uvio_ioctl_cb *uv_ioctl)
+{
+	struct uv_cb_attest *uvcb_attest = NULL;
+	struct uvio_attest *uvio_attest = NULL;
+	u8 *measurement = NULL;
+	u8 *add_data = NULL;
+	u8 *arcb = NULL;
+	int ret;
+
+	ret = -EINVAL;
+	if (uv_ioctl->argument_len != sizeof(*uvio_attest))
+		goto out;
+
+	ret = -ENOMEM;
+	uvio_attest = kzalloc(sizeof(*uvio_attest), GFP_KERNEL);
+	if (!uvio_attest)
+		goto out;
+
+	ret = get_uvio_attest(uv_ioctl, uvio_attest);
+	if (ret)
+		goto out;
+
+	ret = -ENOMEM;
+	arcb = kvzalloc(uvio_attest->arcb_len, GFP_KERNEL);
+	measurement = kvzalloc(uvio_attest->meas_len, GFP_KERNEL);
+	if (!arcb || !measurement)
+		goto out;
+
+	if (uvio_attest->add_data_len) {
+		add_data = kvzalloc(uvio_attest->add_data_len, GFP_KERNEL);
+		if (!add_data)
+			goto out;
+	}
+
+	uvcb_attest = kzalloc(sizeof(*uvcb_attest), GFP_KERNEL);
+	if (!uvcb_attest)
+		goto out;
+
+	ret = uvio_build_uvcb_attest(uvcb_attest, arcb,  measurement, add_data, uvio_attest);
+	if (ret)
+		goto out;
+
+	uv_call_sched(0, (u64)uvcb_attest);
+
+	uv_ioctl->uv_rc = uvcb_attest->header.rc;
+	uv_ioctl->uv_rrc = uvcb_attest->header.rrc;
+
+	ret = uvio_copy_attest_result_to_user(uvcb_attest, uv_ioctl, measurement, add_data,
+					      uvio_attest);
+out:
+	kvfree(arcb);
+	kvfree(measurement);
+	kvfree(add_data);
+	kfree(uvio_attest);
+	kfree(uvcb_attest);
+	return ret;
+}
+
+/** uvio_add_secret() - perform an Add Secret UVC
+ *
+ * @uv_ioctl: ioctl control block
+ *
+ * uvio_add_secret() performs the Add Secret Ultravisor Call.
+ *
+ * The given userspace argument address and size are verified to be
+ * valid but every other check is made by the Ultravisor
+ * (UV). Therefore UV errors won't result in a negative return
+ * value. The request is then copied to kernelspace, the UV-call is
+ * performed and the results are copied back to userspace.
+ *
+ * The argument has to point to an Add Secret Request Control Block
+ * which is an encrypted and cryptographically verified request that
+ * inserts a protected guest's secrets into the Ultravisor for later
+ * use.
+ *
+ * If the Add Secret UV facility is not present, UV will return
+ * invalid command rc. This won't be fenced in the driver and does not
+ * result in a negative return value.
+ *
+ * Context: might sleep
+ *
+ * Return: 0 on success or a negative error code on error.
+ */
+static int uvio_add_secret(struct uvio_ioctl_cb *uv_ioctl)
+{
+	void __user *user_buf_arg = (void __user *)uv_ioctl->argument_addr;
+	struct uv_cb_guest_addr uvcb = {
+		.header.len = sizeof(uvcb),
+		.header.cmd = UVC_CMD_ADD_SECRET,
+	};
+	void *asrcb = NULL;
+	int ret;
+
+	if (uv_ioctl->argument_len > UVIO_ADD_SECRET_MAX_LEN)
+		return -EINVAL;
+	if (uv_ioctl->argument_len == 0)
+		return -EINVAL;
+
+	asrcb = kvzalloc(uv_ioctl->argument_len, GFP_KERNEL);
+	if (!asrcb)
+		return -ENOMEM;
+
+	ret = -EFAULT;
+	if (copy_from_user(asrcb, user_buf_arg, uv_ioctl->argument_len))
+		goto out;
+
+	ret = 0;
+	uvcb.addr = (u64)asrcb;
+	uv_call_sched(0, (u64)&uvcb);
+	uv_ioctl->uv_rc = uvcb.header.rc;
+	uv_ioctl->uv_rrc = uvcb.header.rrc;
+
+out:
+	kvfree(asrcb);
+	return ret;
+}
+
+/** uvio_list_secrets() - perform a List Secret UVC
+ * @uv_ioctl: ioctl control block
+ *
+ * uvio_list_secrets() performs the List Secret Ultravisor Call. It verifies
+ * that the given userspace argument address is valid and its size is sane.
+ * Every other check is made by the Ultravisor (UV) and won't result in a
+ * negative return value. It builds the request, performs the UV-call, and
+ * copies the result to userspace.
+ *
+ * The argument specifies the location for the result of the UV-Call.
+ *
+ * If the List Secrets UV facility is not present, UV will return invalid
+ * command rc. This won't be fenced in the driver and does not result in a
+ * negative return value.
+ *
+ * Context: might sleep
+ *
+ * Return: 0 on success or a negative error code on error.
+ */
+static int uvio_list_secrets(struct uvio_ioctl_cb *uv_ioctl)
+{
+	void __user *user_buf_arg = (void __user *)uv_ioctl->argument_addr;
+	struct uv_cb_guest_addr uvcb = {
+		.header.len = sizeof(uvcb),
+		.header.cmd = UVC_CMD_LIST_SECRETS,
+	};
+	void *secrets = NULL;
+	int ret = 0;
+
+	if (uv_ioctl->argument_len != UVIO_LIST_SECRETS_LEN)
+		return -EINVAL;
+
+	secrets = kvzalloc(UVIO_LIST_SECRETS_LEN, GFP_KERNEL);
+	if (!secrets)
+		return -ENOMEM;
+
+	uvcb.addr = (u64)secrets;
+	uv_call_sched(0, (u64)&uvcb);
+	uv_ioctl->uv_rc = uvcb.header.rc;
+	uv_ioctl->uv_rrc = uvcb.header.rrc;
+
+	if (copy_to_user(user_buf_arg, secrets, UVIO_LIST_SECRETS_LEN))
+		ret = -EFAULT;
+
+	kvfree(secrets);
+	return ret;
+}
+
+/** uvio_lock_secrets() - perform a Lock Secret Store UVC
+ * @uv_ioctl: ioctl control block
+ *
+ * uvio_lock_secrets() performs the Lock Secret Store Ultravisor Call. It
+ * performs the UV-call and copies the return codes to the ioctl control block.
+ * After this call was dispatched successfully every following Add Secret UVC
+ * and Lock Secrets UVC will fail with return code 0x102.
+ *
+ * The argument address and size must be 0.
+ *
+ * If the Lock Secrets UV facility is not present, UV will return invalid
+ * command rc. This won't be fenced in the driver and does not result in a
+ * negative return value.
+ *
+ * Context: might sleep
+ *
+ * Return: 0 on success or a negative error code on error.
+ */
+static int uvio_lock_secrets(struct uvio_ioctl_cb *ioctl)
+{
+	struct uv_cb_nodata uvcb = {
+		.header.len = sizeof(uvcb),
+		.header.cmd = UVC_CMD_LOCK_SECRETS,
+	};
+
+	if (ioctl->argument_addr || ioctl->argument_len)
+		return -EINVAL;
+
+	uv_call(0, (u64)&uvcb);
+	ioctl->uv_rc = uvcb.header.rc;
+	ioctl->uv_rrc = uvcb.header.rrc;
+
+	return 0;
+}
+
+static int uvio_copy_and_check_ioctl(struct uvio_ioctl_cb *ioctl, void __user *argp,
+				     unsigned long cmd)
+{
+	u8 nr = _IOC_NR(cmd);
+
+	if (_IOC_DIR(cmd) != (_IOC_READ | _IOC_WRITE))
+		return -ENOIOCTLCMD;
+	if (_IOC_TYPE(cmd) != UVIO_TYPE_UVC)
+		return -ENOIOCTLCMD;
+	if (nr >= UVIO_IOCTL_NUM_IOCTLS)
+		return -ENOIOCTLCMD;
+	if (_IOC_SIZE(cmd) != sizeof(*ioctl))
+		return -ENOIOCTLCMD;
+	if (copy_from_user(ioctl, argp, sizeof(*ioctl)))
+		return -EFAULT;
+	if (ioctl->flags != 0)
+		return -EINVAL;
+	if (memchr_inv(ioctl->reserved14, 0, sizeof(ioctl->reserved14)))
+		return -EINVAL;
+
+	return nr;
+}
+
+/*
+ * IOCTL entry point for the Ultravisor device.
+ */
+static long uvio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+	struct uvio_ioctl_cb uv_ioctl = { };
+	long ret;
+	int nr;
+
+	nr = uvio_copy_and_check_ioctl(&uv_ioctl, argp, cmd);
+	if (nr < 0)
+		return nr;
+
+	switch (nr) {
+	case UVIO_IOCTL_UVDEV_INFO_NR:
+		ret = uvio_uvdev_info(&uv_ioctl);
+		break;
+	case UVIO_IOCTL_ATT_NR:
+		ret = uvio_attestation(&uv_ioctl);
+		break;
+	case UVIO_IOCTL_ADD_SECRET_NR:
+		ret = uvio_add_secret(&uv_ioctl);
+		break;
+	case UVIO_IOCTL_LIST_SECRETS_NR:
+		ret = uvio_list_secrets(&uv_ioctl);
+		break;
+	case UVIO_IOCTL_LOCK_SECRETS_NR:
+		ret = uvio_lock_secrets(&uv_ioctl);
+		break;
+	default:
+		ret = -ENOIOCTLCMD;
+		break;
+	}
+	if (ret)
+		return ret;
+
+	if (copy_to_user(argp, &uv_ioctl, sizeof(uv_ioctl)))
+		ret = -EFAULT;
+
+	return ret;
+}
+
+static const struct file_operations uvio_dev_fops = {
+	.owner = THIS_MODULE,
+	.unlocked_ioctl = uvio_ioctl,
+	.llseek = no_llseek,
+};
+
+static struct miscdevice uvio_dev_miscdev = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = UVIO_DEVICE_NAME,
+	.fops = &uvio_dev_fops,
+};
+
+static void __exit uvio_dev_exit(void)
+{
+	misc_deregister(&uvio_dev_miscdev);
+}
+
+static int __init uvio_dev_init(void)
+{
+	set_supp_uv_cmds((unsigned long *)&uvdev_info.supp_uv_cmds);
+	return misc_register(&uvio_dev_miscdev);
+}
+
+module_cpu_feature_match(S390_CPU_FEATURE_UV, uvio_dev_init);
+module_exit(uvio_dev_exit);
+
+MODULE_AUTHOR("IBM Corporation");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Ultravisor UAPI driver");