Merge tag 'tpmdd-next-v5.12-rc1-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd

Pull tpm updates from Jarkko Sakkinen:
 "New features:

   - Cr50 I2C TPM driver

   - sysfs exports of PCR registers in TPM 2.0 chips

  Bug fixes:

   - bug fixes for tpm_tis driver, which had a racy wait for hardware
     state change to be ready to send a command to the TPM chip. The bug
     has existed already since 2006, but has only made itself known in
     recent past. This is the same as the "last time" :-)

   - Otherwise there's bunch of fixes for not as alarming regressions. I
     think the list is about the same as last time, except I added fixes
     for some disjoint bugs in trusted keys that I found some time ago"

* tag 'tpmdd-next-v5.12-rc1-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd:
  KEYS: trusted: Reserve TPM for seal and unseal operations
  KEYS: trusted: Fix migratable=1 failing
  KEYS: trusted: Fix incorrect handling of tpm_get_random()
  tpm/ppi: Constify static struct attribute_group
  ABI: add sysfs description for tpm exports of PCR registers
  tpm: add sysfs exports for all banks of PCR registers
  keys: Update comment for restrict_link_by_key_or_keyring_chain
  tpm: Remove tpm_dev_wq_lock
  char: tpm: add i2c driver for cr50
  tpm: Fix fall-through warnings for Clang
  tpm_tis: Clean up locality release
  tpm_tis: Fix check_locality for correct locality acquisition

Documentation/ABI/stable/sysfs-class-tpm

@@ -194,3 +194,17 @@ Description:	The "tpm_version_major" property shows the TCG spec major version
 		Example output::
 
 		  2
+
+What:		/sys/class/tpm/tpmX/pcr-H/N
+Date:		March 2021
+KernelVersion:	5.12
+Contact:	linux-integrity@vger.kernel.org
+Description:	produces output in compact hex representation for PCR
+		number N from hash bank H.  N is the numeric value of
+		the PCR number and H is the crypto string
+		representation of the hash
+
+		Example output::
+
+		  cat /sys/class/tpm/tpm0/pcr-sha256/7
+		  2ED93F199692DC6788EFA6A1FE74514AB9760B2A6CEEAEF6C808C13E4ABB0D42

crypto/asymmetric_keys/restrict.c

@@ -244,9 +244,10 @@ int restrict_link_by_key_or_keyring(struct key *dest_keyring,
  * @payload: The payload of the new key.
  * @trusted: A key or ring of keys that can be used to vouch for the new cert.
  *
- * Check the new certificate only against the key or keys passed in the data
- * parameter. If one of those is the signing key and validates the new
- * certificate, then mark the new certificate as being ok to link.
+ * Check the new certificate against the key or keys passed in the data
+ * parameter and against the keys already linked to the destination keyring. If
+ * one of those is the signing key and validates the new certificate, then mark
+ * the new certificate as being ok to link.
  *
  * Returns 0 if the new certificate was accepted, -ENOKEY if we
  * couldn't find a matching parent certificate in the trusted list,

drivers/char/tpm/Kconfig

@@ -86,6 +86,16 @@ config TCG_TIS_SYNQUACER
 	  To compile this driver as a module, choose  M here;
 	  the module will be called tpm_tis_synquacer.
 
+config TCG_TIS_I2C_CR50
+	tristate "TPM Interface Specification 2.0 Interface (I2C - CR50)"
+	depends on I2C
+	select TCG_CR50
+	help
+	  This is a driver for the Google cr50 I2C TPM interface which is a
+	  custom microcontroller and requires a custom i2c protocol interface
+	  to handle the limitations of the hardware.  To compile this driver
+	  as a module, choose M here; the module will be called tcg_tis_i2c_cr50.
+
 config TCG_TIS_I2C_ATMEL
 	tristate "TPM Interface Specification 1.2 Interface (I2C - Atmel)"
 	depends on I2C

drivers/char/tpm/Makefile

@@ -27,6 +27,8 @@ obj-$(CONFIG_TCG_TIS_SPI) += tpm_tis_spi.o
 tpm_tis_spi-y := tpm_tis_spi_main.o
 tpm_tis_spi-$(CONFIG_TCG_TIS_SPI_CR50) += tpm_tis_spi_cr50.o
 
+obj-$(CONFIG_TCG_TIS_I2C_CR50) += tpm_tis_i2c_cr50.o
+
 obj-$(CONFIG_TCG_TIS_I2C_ATMEL) += tpm_i2c_atmel.o
 obj-$(CONFIG_TCG_TIS_I2C_INFINEON) += tpm_i2c_infineon.o
 obj-$(CONFIG_TCG_TIS_I2C_NUVOTON) += tpm_i2c_nuvoton.o

drivers/char/tpm/eventlog/tpm1.c

@@ -210,6 +210,7 @@ static int get_event_name(char *dest, struct tcpa_event *event,
 		default:
 			break;
 		}
+		break;
 	default:
 		break;
 	}

drivers/char/tpm/tpm-chip.c

@@ -278,6 +278,8 @@ static void tpm_devs_release(struct device *dev)
 {
 	struct tpm_chip *chip = container_of(dev, struct tpm_chip, devs);
 
+	dump_stack();
+
 	/* release the master device reference */
 	put_device(&chip->dev);
 }

drivers/char/tpm/tpm-dev-common.c

@@ -20,7 +20,6 @@
 #include "tpm-dev.h"
 
 static struct workqueue_struct *tpm_dev_wq;
-static DEFINE_MUTEX(tpm_dev_wq_lock);
 
 static ssize_t tpm_dev_transmit(struct tpm_chip *chip, struct tpm_space *space,
 				u8 *buf, size_t bufsiz)

drivers/char/tpm/tpm-sysfs.c

@@ -337,11 +337,190 @@ static const struct attribute_group tpm2_dev_group = {
 	.attrs = tpm2_dev_attrs,
 };
 
+struct tpm_pcr_attr {
+	int alg_id;
+	int pcr;
+	struct device_attribute attr;
+};
+
+#define to_tpm_pcr_attr(a) container_of(a, struct tpm_pcr_attr, attr)
+
+static ssize_t pcr_value_show(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	struct tpm_pcr_attr *ha = to_tpm_pcr_attr(attr);
+	struct tpm_chip *chip = to_tpm_chip(dev);
+	struct tpm_digest digest;
+	int i;
+	int digest_size = 0;
+	int rc;
+	char *str = buf;
+
+	for (i = 0; i < chip->nr_allocated_banks; i++)
+		if (ha->alg_id == chip->allocated_banks[i].alg_id)
+			digest_size = chip->allocated_banks[i].digest_size;
+	/* should never happen */
+	if (!digest_size)
+		return -EINVAL;
+
+	digest.alg_id = ha->alg_id;
+	rc = tpm_pcr_read(chip, ha->pcr, &digest);
+	if (rc)
+		return rc;
+	for (i = 0; i < digest_size; i++)
+		str += sprintf(str, "%02X", digest.digest[i]);
+	str += sprintf(str, "\n");
+
+	return str - buf;
+}
+
+/*
+ * The following set of defines represents all the magic to build
+ * the per hash attribute groups for displaying each bank of PCRs.
+ * The only slight problem with this approach is that every PCR is
+ * hard coded to be present, so you don't know if an PCR is missing
+ * until a cat of the file returns -EINVAL
+ *
+ * Also note you must ignore checkpatch warnings in this macro
+ * code. This is deep macro magic that checkpatch.pl doesn't
+ * understand.
+ */
+
+/* Note, this must match TPM2_PLATFORM_PCR which is fixed at 24. */
+#define _TPM_HELPER(_alg, _hash, F) \
+	F(_alg, _hash, 0)	    \
+	F(_alg, _hash, 1)	    \
+	F(_alg, _hash, 2)	    \
+	F(_alg, _hash, 3)	    \
+	F(_alg, _hash, 4)	    \
+	F(_alg, _hash, 5)	    \
+	F(_alg, _hash, 6)	    \
+	F(_alg, _hash, 7)	    \
+	F(_alg, _hash, 8)	    \
+	F(_alg, _hash, 9)	    \
+	F(_alg, _hash, 10)	    \
+	F(_alg, _hash, 11)	    \
+	F(_alg, _hash, 12)	    \
+	F(_alg, _hash, 13)	    \
+	F(_alg, _hash, 14)	    \
+	F(_alg, _hash, 15)	    \
+	F(_alg, _hash, 16)	    \
+	F(_alg, _hash, 17)	    \
+	F(_alg, _hash, 18)	    \
+	F(_alg, _hash, 19)	    \
+	F(_alg, _hash, 20)	    \
+	F(_alg, _hash, 21)	    \
+	F(_alg, _hash, 22)	    \
+	F(_alg, _hash, 23)
+
+/* ignore checkpatch warning about trailing ; in macro. */
+#define PCR_ATTR(_alg, _hash, _pcr)				   \
+	static struct tpm_pcr_attr dev_attr_pcr_##_hash##_##_pcr = {	\
+		.alg_id = _alg,					   \
+		.pcr = _pcr,					   \
+		.attr = {					   \
+			.attr = {				   \
+				.name = __stringify(_pcr),	   \
+				.mode = 0444			   \
+			},					   \
+			.show = pcr_value_show			   \
+		}						   \
+	};
+
+#define PCR_ATTRS(_alg, _hash)			\
+	_TPM_HELPER(_alg, _hash, PCR_ATTR)
+
+/* ignore checkpatch warning about trailing , in macro. */
+#define PCR_ATTR_VAL(_alg, _hash, _pcr)		\
+	&dev_attr_pcr_##_hash##_##_pcr.attr.attr,
+
+#define PCR_ATTR_GROUP_ARRAY(_alg, _hash)		       \
+	static struct attribute *pcr_group_attrs_##_hash[] = { \
+		_TPM_HELPER(_alg, _hash, PCR_ATTR_VAL)	       \
+		NULL					       \
+	}
+
+#define PCR_ATTR_GROUP(_alg, _hash)			    \
+	static struct attribute_group pcr_group_##_hash = { \
+		.name = "pcr-" __stringify(_hash),	    \
+		.attrs = pcr_group_attrs_##_hash	    \
+	}
+
+#define PCR_ATTR_BUILD(_alg, _hash)	   \
+	PCR_ATTRS(_alg, _hash)		   \
+	PCR_ATTR_GROUP_ARRAY(_alg, _hash); \
+	PCR_ATTR_GROUP(_alg, _hash)
+/*
+ * End of macro structure to build an attribute group containing 24
+ * PCR value files for each supported hash algorithm
+ */
+
+/*
+ * The next set of macros implements the cleverness for each hash to
+ * build a static attribute group called pcr_group_<hash> which can be
+ * added to chip->groups[].
+ *
+ * The first argument is the TPM algorithm id and the second is the
+ * hash used as both the suffix and the group name.  Note: the group
+ * name is a directory in the top level tpm class with the name
+ * pcr-<hash>, so it must not clash with any other names already
+ * in the sysfs directory.
+ */
+PCR_ATTR_BUILD(TPM_ALG_SHA1, sha1);
+PCR_ATTR_BUILD(TPM_ALG_SHA256, sha256);
+PCR_ATTR_BUILD(TPM_ALG_SHA384, sha384);
+PCR_ATTR_BUILD(TPM_ALG_SHA512, sha512);
+PCR_ATTR_BUILD(TPM_ALG_SM3_256, sm3);
+
+
 void tpm_sysfs_add_device(struct tpm_chip *chip)
 {
+	int i;
+
 	WARN_ON(chip->groups_cnt != 0);
+
 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
 		chip->groups[chip->groups_cnt++] = &tpm2_dev_group;
 	else
 		chip->groups[chip->groups_cnt++] = &tpm1_dev_group;
+
+	/* add one group for each bank hash */
+	for (i = 0; i < chip->nr_allocated_banks; i++) {
+		switch (chip->allocated_banks[i].alg_id) {
+		case TPM_ALG_SHA1:
+			chip->groups[chip->groups_cnt++] = &pcr_group_sha1;
+			break;
+		case TPM_ALG_SHA256:
+			chip->groups[chip->groups_cnt++] = &pcr_group_sha256;
+			break;
+		case TPM_ALG_SHA384:
+			chip->groups[chip->groups_cnt++] = &pcr_group_sha384;
+			break;
+		case TPM_ALG_SHA512:
+			chip->groups[chip->groups_cnt++] = &pcr_group_sha512;
+			break;
+		case TPM_ALG_SM3_256:
+			chip->groups[chip->groups_cnt++] = &pcr_group_sm3;
+			break;
+		default:
+			/*
+			 * If triggers, send a patch to add both a
+			 * PCR_ATTR_BUILD() macro above for the
+			 * missing algorithm as well as an additional
+			 * case in this switch statement.
+			 */
+			dev_err(&chip->dev,
+				"TPM with unsupported bank algorithm 0x%04x",
+				chip->allocated_banks[i].alg_id);
+			break;
+		}
+	}
+
+	/*
+	 * This will only trigger if someone has added an additional
+	 * hash to the tpm_algorithms enum without incrementing
+	 * TPM_MAX_HASHES.
+	 */
+	WARN_ON(chip->groups_cnt > TPM_MAX_HASHES + 1);
 }

drivers/char/tpm/tpm.h

@@ -164,8 +164,6 @@ extern const struct file_operations tpmrm_fops;
 extern struct idr dev_nums_idr;
 
 ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz);
-ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf,
-			 size_t min_rsp_body_length, const char *desc);
 int tpm_get_timeouts(struct tpm_chip *);
 int tpm_auto_startup(struct tpm_chip *chip);
 
@@ -194,8 +192,6 @@ static inline void tpm_msleep(unsigned int delay_msec)
 int tpm_chip_start(struct tpm_chip *chip);
 void tpm_chip_stop(struct tpm_chip *chip);
 struct tpm_chip *tpm_find_get_ops(struct tpm_chip *chip);
-__must_check int tpm_try_get_ops(struct tpm_chip *chip);
-void tpm_put_ops(struct tpm_chip *chip);
 
 struct tpm_chip *tpm_chip_alloc(struct device *dev,
 				const struct tpm_class_ops *ops);

drivers/char/tpm/tpm_ppi.c

@@ -358,7 +358,7 @@ static struct attribute *ppi_attrs[] = {
 	&dev_attr_tcg_operations.attr,
 	&dev_attr_vs_operations.attr, NULL,
 };
-static struct attribute_group ppi_attr_grp = {
+static const struct attribute_group ppi_attr_grp = {
 	.name = "ppi",
 	.attrs = ppi_attrs
 };

drivers/char/tpm/tpm_tis_core.c

@@ -125,7 +125,8 @@ static bool check_locality(struct tpm_chip *chip, int l)
 	if (rc < 0)
 		return false;
 
-	if ((access & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
+	if ((access & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID
+		       | TPM_ACCESS_REQUEST_USE)) ==
 	    (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) {
 		priv->locality = l;
 		return true;
@@ -134,58 +135,13 @@ static bool check_locality(struct tpm_chip *chip, int l)
 	return false;
 }
 
-static bool locality_inactive(struct tpm_chip *chip, int l)
-{
-	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
-	int rc;
-	u8 access;
-
-	rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
-	if (rc < 0)
-		return false;
-
-	if ((access & (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY))
-	    == TPM_ACCESS_VALID)
-		return true;
-
-	return false;
-}
-
 static int release_locality(struct tpm_chip *chip, int l)
 {
 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
-	unsigned long stop, timeout;
-	long rc;
 
 	tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
 
-	stop = jiffies + chip->timeout_a;
-
-	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
-again:
-		timeout = stop - jiffies;
-		if ((long)timeout <= 0)
-			return -1;
-
-		rc = wait_event_interruptible_timeout(priv->int_queue,
-						      (locality_inactive(chip, l)),
-						      timeout);
-
-		if (rc > 0)
-			return 0;
-
-		if (rc == -ERESTARTSYS && freezing(current)) {
-			clear_thread_flag(TIF_SIGPENDING);
-			goto again;
-		}
-	} else {
-		do {
-			if (locality_inactive(chip, l))
-				return 0;
-			tpm_msleep(TPM_TIMEOUT);
-		} while (time_before(jiffies, stop));
-	}
-	return -1;
+	return 0;
 }
 
 static int request_locality(struct tpm_chip *chip, int l)

include/linux/tpm.h

@@ -31,6 +31,7 @@ struct tpm_chip;
 struct trusted_key_payload;
 struct trusted_key_options;
 
+/* if you add a new hash to this, increment TPM_MAX_HASHES below */
 enum tpm_algorithms {
 	TPM_ALG_ERROR		= 0x0000,
 	TPM_ALG_SHA1		= 0x0004,
@@ -42,6 +43,12 @@ enum tpm_algorithms {
 	TPM_ALG_SM3_256		= 0x0012,
 };
 
+/*
+ * maximum number of hashing algorithms a TPM can have.  This is
+ * basically a count of every hash in tpm_algorithms above
+ */
+#define TPM_MAX_HASHES	5
+
 struct tpm_digest {
 	u16 alg_id;
 	u8 digest[TPM_MAX_DIGEST_SIZE];
@@ -146,7 +153,7 @@ struct tpm_chip {
 
 	struct dentry *bios_dir[TPM_NUM_EVENT_LOG_FILES];
 
-	const struct attribute_group *groups[3];
+	const struct attribute_group *groups[3 + TPM_MAX_HASHES];
 	unsigned int groups_cnt;
 
 	u32 nr_allocated_banks;
@@ -397,6 +404,10 @@ static inline u32 tpm2_rc_value(u32 rc)
 #if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE)
 
 extern int tpm_is_tpm2(struct tpm_chip *chip);
+extern __must_check int tpm_try_get_ops(struct tpm_chip *chip);
+extern void tpm_put_ops(struct tpm_chip *chip);
+extern ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf,
+				size_t min_rsp_body_length, const char *desc);
 extern int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
 			struct tpm_digest *digest);
 extern int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
@@ -410,7 +421,6 @@ static inline int tpm_is_tpm2(struct tpm_chip *chip)
 {
 	return -ENODEV;
 }
-
 static inline int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx,
 			       struct tpm_digest *digest)
 {

security/keys/trusted-keys/trusted_tpm1.c

@@ -403,9 +403,12 @@ static int osap(struct tpm_buf *tb, struct osapsess *s,
 	int ret;
 
 	ret = tpm_get_random(chip, ononce, TPM_NONCE_SIZE);
-	if (ret != TPM_NONCE_SIZE)
+	if (ret < 0)
 		return ret;
 
+	if (ret != TPM_NONCE_SIZE)
+		return -EIO;
+
 	tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP);
 	tpm_buf_append_u16(tb, type);
 	tpm_buf_append_u32(tb, handle);
@@ -496,8 +499,12 @@ static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
 		goto out;
 
 	ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE);
+	if (ret < 0)
+		return ret;
+
 	if (ret != TPM_NONCE_SIZE)
-		goto out;
+		return -EIO;
+
 	ordinal = htonl(TPM_ORD_SEAL);
 	datsize = htonl(datalen);
 	pcrsize = htonl(pcrinfosize);
@@ -601,9 +608,12 @@ static int tpm_unseal(struct tpm_buf *tb,
 
 	ordinal = htonl(TPM_ORD_UNSEAL);
 	ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE);
+	if (ret < 0)
+		return ret;
+
 	if (ret != TPM_NONCE_SIZE) {
 		pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
-		return ret;
+		return -EIO;
 	}
 	ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
 			   enonce1, nonceodd, cont, sizeof(uint32_t),
@@ -791,7 +801,7 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
 		case Opt_migratable:
 			if (*args[0].from == '0')
 				pay->migratable = 0;
-			else
+			else if (*args[0].from != '1')
 				return -EINVAL;
 			break;
 		case Opt_pcrlock:
@@ -1013,8 +1023,12 @@ static int trusted_instantiate(struct key *key,
 	case Opt_new:
 		key_len = payload->key_len;
 		ret = tpm_get_random(chip, payload->key, key_len);
+		if (ret < 0)
+			goto out;
+
 		if (ret != key_len) {
 			pr_info("trusted_key: key_create failed (%d)\n", ret);
+			ret = -EIO;
 			goto out;
 		}
 		if (tpm2)

security/keys/trusted-keys/trusted_tpm2.c

@@ -83,6 +83,12 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
 	if (rc)
 		return rc;
 
+	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
+	if (rc) {
+		tpm_put_ops(chip);
+		return rc;
+	}
+
 	tpm_buf_append_u32(&buf, options->keyhandle);
 	tpm2_buf_append_auth(&buf, TPM2_RS_PW,
 			     NULL /* nonce */, 0,
@@ -130,7 +136,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
 		goto out;
 	}
 
-	rc = tpm_send(chip, buf.data, tpm_buf_length(&buf));
+	rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data");
 	if (rc)
 		goto out;
 
@@ -157,6 +163,7 @@ out:
 			rc = -EPERM;
 	}
 
+	tpm_put_ops(chip);
 	return rc;
 }
 
@@ -211,7 +218,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
 		goto out;
 	}
 
-	rc = tpm_send(chip, buf.data, tpm_buf_length(&buf));
+	rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob");
 	if (!rc)
 		*blob_handle = be32_to_cpup(
 			(__be32 *) &buf.data[TPM_HEADER_SIZE]);
@@ -260,7 +267,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
 			     options->blobauth /* hmac */,
 			     TPM_DIGEST_SIZE);
 
-	rc = tpm_send(chip, buf.data, tpm_buf_length(&buf));
+	rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing");
 	if (rc > 0)
 		rc = -EPERM;
 
@@ -304,12 +311,19 @@ int tpm2_unseal_trusted(struct tpm_chip *chip,
 	u32 blob_handle;
 	int rc;
 
-	rc = tpm2_load_cmd(chip, payload, options, &blob_handle);
+	rc = tpm_try_get_ops(chip);
 	if (rc)
 		return rc;
 
+	rc = tpm2_load_cmd(chip, payload, options, &blob_handle);
+	if (rc)
+		goto out;
+
 	rc = tpm2_unseal_cmd(chip, payload, options, blob_handle);
 	tpm2_flush_context(chip, blob_handle);
 
+out:
+	tpm_put_ops(chip);
+
 	return rc;
 }