OSCL-LXR linux-6.0.1/​drivers/​char/​tpm/​tpm-interface.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2004 IBM Corporation
  * Copyright (C) 2014 Intel Corporation
  *
  * Authors:
  * Leendert van Doorn <leendert@watson.ibm.com>
  * Dave Safford <safford@watson.ibm.com>
  * Reiner Sailer <sailer@watson.ibm.com>
  * Kylene Hall <kjhall@us.ibm.com>
  *
  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  *
  * Device driver for TCG/TCPA TPM (trusted platform module).
  * Specifications at www.trustedcomputinggroup.org
  *
  * Note, the TPM chip is not interrupt driven (only polling)
  * and can have very long timeouts (minutes!). Hence the unusual
  * calls to msleep.
  */
 
 #include <linux/poll.h>
 #include <linux/slab.h>
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
 #include <linux/suspend.h>
 #include <linux/freezer.h>
 #include <linux/tpm_eventlog.h>
 
 #include "tpm.h"
 
 /*
  * Bug workaround - some TPM's don't flush the most
  * recently changed pcr on suspend, so force the flush
  * with an extend to the selected _unused_ non-volatile pcr.
  */
 static u32 tpm_suspend_pcr;
 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
 MODULE_PARM_DESC(suspend_pcr,
          "PCR to use for dummy writes to facilitate flush on suspend.");
 
 /**
  * tpm_calc_ordinal_duration() - calculate the maximum command duration
  * @chip:    TPM chip to use.
  * @ordinal: TPM command ordinal.
  *
  * The function returns the maximum amount of time the chip could take
  * to return the result for a particular ordinal in jiffies.
  *
  * Return: A maximal duration time for an ordinal in jiffies.
  */
 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
 {
     if (chip->flags & TPM_CHIP_FLAG_TPM2)
         return tpm2_calc_ordinal_duration(chip, ordinal);
     else
         return tpm1_calc_ordinal_duration(chip, ordinal);
 }
 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 
 static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz)
 {
     struct tpm_header *header = buf;
     int rc;
     ssize_t len = 0;
     u32 count, ordinal;
     unsigned long stop;
 
     if (bufsiz < TPM_HEADER_SIZE)
         return -EINVAL;
 
     if (bufsiz > TPM_BUFSIZE)
         bufsiz = TPM_BUFSIZE;
 
     count = be32_to_cpu(header->length);
     ordinal = be32_to_cpu(header->ordinal);
     if (count == 0)
         return -ENODATA;
     if (count > bufsiz) {
         dev_err(&chip->dev,
             "invalid count value %x %zx\n", count, bufsiz);
         return -E2BIG;
     }
 
     rc = chip->ops->send(chip, buf, count);
     if (rc < 0) {
         if (rc != -EPIPE)
             dev_err(&chip->dev,
                 "%s: send(): error %d\n", __func__, rc);
         return rc;
     }
 
     /* A sanity check. send() should just return zero on success e.g.
      * not the command length.
      */
     if (rc > 0) {
         dev_warn(&chip->dev,
              "%s: send(): invalid value %d\n", __func__, rc);
         rc = 0;
     }
 
     if (chip->flags & TPM_CHIP_FLAG_IRQ)
         goto out_recv;
 
     stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
     do {
         u8 status = chip->ops->status(chip);
         if ((status & chip->ops->req_complete_mask) ==
             chip->ops->req_complete_val)
             goto out_recv;
 
         if (chip->ops->req_canceled(chip, status)) {
             dev_err(&chip->dev, "Operation Canceled\n");
             return -ECANCELED;
         }
 
         tpm_msleep(TPM_TIMEOUT_POLL);
         rmb();
     } while (time_before(jiffies, stop));
 
     chip->ops->cancel(chip);
     dev_err(&chip->dev, "Operation Timed out\n");
     return -ETIME;
 
 out_recv:
     len = chip->ops->recv(chip, buf, bufsiz);
     if (len < 0) {
         rc = len;
         dev_err(&chip->dev, "tpm_transmit: tpm_recv: error %d\n", rc);
     } else if (len < TPM_HEADER_SIZE || len != be32_to_cpu(header->length))
         rc = -EFAULT;
 
     return rc ? rc : len;
 }
 
 /**
  * tpm_transmit - Internal kernel interface to transmit TPM commands.
  * @chip:   a TPM chip to use
  * @buf:    a TPM command buffer
  * @bufsiz: length of the TPM command buffer
  *
  * A wrapper around tpm_try_transmit() that handles TPM2_RC_RETRY returns from
  * the TPM and retransmits the command after a delay up to a maximum wait of
  * TPM2_DURATION_LONG.
  *
  * Note that TPM 1.x never returns TPM2_RC_RETRY so the retry logic is TPM 2.0
  * only.
  *
  * Return:
  * * The response length    - OK
  * * -errno         - A system error
  */
 ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz)
 {
     struct tpm_header *header = (struct tpm_header *)buf;
     /* space for header and handles */
     u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
     unsigned int delay_msec = TPM2_DURATION_SHORT;
     u32 rc = 0;
     ssize_t ret;
     const size_t save_size = min(sizeof(save), bufsiz);
     /* the command code is where the return code will be */
     u32 cc = be32_to_cpu(header->return_code);
 
     /*
      * Subtlety here: if we have a space, the handles will be
      * transformed, so when we restore the header we also have to
      * restore the handles.
      */
     memcpy(save, buf, save_size);
 
     for (;;) {
         ret = tpm_try_transmit(chip, buf, bufsiz);
         if (ret < 0)
             break;
         rc = be32_to_cpu(header->return_code);
         if (rc != TPM2_RC_RETRY && rc != TPM2_RC_TESTING)
             break;
         /*
          * return immediately if self test returns test
          * still running to shorten boot time.
          */
         if (rc == TPM2_RC_TESTING && cc == TPM2_CC_SELF_TEST)
             break;
 
         if (delay_msec > TPM2_DURATION_LONG) {
             if (rc == TPM2_RC_RETRY)
                 dev_err(&chip->dev, "in retry loop\n");
             else
                 dev_err(&chip->dev,
                     "self test is still running\n");
             break;
         }
         tpm_msleep(delay_msec);
         delay_msec *= 2;
         memcpy(buf, save, save_size);
     }
     return ret;
 }
 
 /**
  * tpm_transmit_cmd - send a tpm command to the device
  * @chip:           a TPM chip to use
  * @buf:            a TPM command buffer
  * @min_rsp_body_length:    minimum expected length of response body
  * @desc:           command description used in the error message
  *
  * Return:
  * * 0      - OK
  * * -errno - A system error
  * * TPM_RC - A TPM error
  */
 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf,
              size_t min_rsp_body_length, const char *desc)
 {
     const struct tpm_header *header = (struct tpm_header *)buf->data;
     int err;
     ssize_t len;
 
     len = tpm_transmit(chip, buf->data, PAGE_SIZE);
     if (len <  0)
         return len;
 
     err = be32_to_cpu(header->return_code);
     if (err != 0 && err != TPM_ERR_DISABLED && err != TPM_ERR_DEACTIVATED
         && err != TPM2_RC_TESTING && desc)
         dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
             desc);
     if (err)
         return err;
 
     if (len < min_rsp_body_length + TPM_HEADER_SIZE)
         return -EFAULT;
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(tpm_transmit_cmd);
 
 int tpm_get_timeouts(struct tpm_chip *chip)
 {
     if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
         return 0;
 
     if (chip->flags & TPM_CHIP_FLAG_TPM2)
         return tpm2_get_timeouts(chip);
     else
         return tpm1_get_timeouts(chip);
 }
 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 
 /**
  * tpm_is_tpm2 - do we a have a TPM2 chip?
  * @chip:   a &struct tpm_chip instance, %NULL for the default chip
  *
  * Return:
  * 1 if we have a TPM2 chip.
  * 0 if we don't have a TPM2 chip.
  * A negative number for system errors (errno).
  */
 int tpm_is_tpm2(struct tpm_chip *chip)
 {
     int rc;
 
     chip = tpm_find_get_ops(chip);
     if (!chip)
         return -ENODEV;
 
     rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 
     tpm_put_ops(chip);
 
     return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 
 /**
  * tpm_pcr_read - read a PCR value from SHA1 bank
  * @chip:   a &struct tpm_chip instance, %NULL for the default chip
  * @pcr_idx:    the PCR to be retrieved
  * @digest: the PCR bank and buffer current PCR value is written to
  *
  * Return: same as with tpm_transmit_cmd()
  */
 int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
          struct tpm_digest *digest)
 {
     int rc;
 
     chip = tpm_find_get_ops(chip);
     if (!chip)
         return -ENODEV;
 
     if (chip->flags & TPM_CHIP_FLAG_TPM2)
         rc = tpm2_pcr_read(chip, pcr_idx, digest, NULL);
     else
         rc = tpm1_pcr_read(chip, pcr_idx, digest->digest);
 
     tpm_put_ops(chip);
     return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 
 /**
  * tpm_pcr_extend - extend a PCR value in SHA1 bank.
  * @chip:   a &struct tpm_chip instance, %NULL for the default chip
  * @pcr_idx:    the PCR to be retrieved
  * @digests:    array of tpm_digest structures used to extend PCRs
  *
  * Note: callers must pass a digest for every allocated PCR bank, in the same
  * order of the banks in chip->allocated_banks.
  *
  * Return: same as with tpm_transmit_cmd()
  */
 int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
            struct tpm_digest *digests)
 {
     int rc;
     int i;
 
     chip = tpm_find_get_ops(chip);
     if (!chip)
         return -ENODEV;
 
     for (i = 0; i < chip->nr_allocated_banks; i++) {
         if (digests[i].alg_id != chip->allocated_banks[i].alg_id) {
             rc = -EINVAL;
             goto out;
         }
     }
 
     if (chip->flags & TPM_CHIP_FLAG_TPM2) {
         rc = tpm2_pcr_extend(chip, pcr_idx, digests);
         goto out;
     }
 
     rc = tpm1_pcr_extend(chip, pcr_idx, digests[0].digest,
                  "attempting extend a PCR value");
 
 out:
     tpm_put_ops(chip);
     return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 
 /**
  * tpm_send - send a TPM command
  * @chip:   a &struct tpm_chip instance, %NULL for the default chip
  * @cmd:    a TPM command buffer
  * @buflen: the length of the TPM command buffer
  *
  * Return: same as with tpm_transmit_cmd()
  */
 int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
 {
     struct tpm_buf buf;
     int rc;
 
     chip = tpm_find_get_ops(chip);
     if (!chip)
         return -ENODEV;
 
     buf.data = cmd;
     rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to a send a command");
 
     tpm_put_ops(chip);
     return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_send);
 
 int tpm_auto_startup(struct tpm_chip *chip)
 {
     int rc;
 
     if (!(chip->ops->flags & TPM_OPS_AUTO_STARTUP))
         return 0;
 
     if (chip->flags & TPM_CHIP_FLAG_TPM2)
         rc = tpm2_auto_startup(chip);
     else
         rc = tpm1_auto_startup(chip);
 
     return rc;
 }
 
 /*
  * We are about to suspend. Save the TPM state
  * so that it can be restored.
  */
 int tpm_pm_suspend(struct device *dev)
 {
     struct tpm_chip *chip = dev_get_drvdata(dev);
     int rc = 0;
 
     if (!chip)
         return -ENODEV;
 
     if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
         goto suspended;
 
     if ((chip->flags & TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED) &&
         !pm_suspend_via_firmware())
         goto suspended;
 
     if (!tpm_chip_start(chip)) {
         if (chip->flags & TPM_CHIP_FLAG_TPM2)
             tpm2_shutdown(chip, TPM2_SU_STATE);
         else
             rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
 
         tpm_chip_stop(chip);
     }
 
 suspended:
     return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
 
 /*
  * Resume from a power safe. The BIOS already restored
  * the TPM state.
  */
 int tpm_pm_resume(struct device *dev)
 {
     struct tpm_chip *chip = dev_get_drvdata(dev);
 
     if (chip == NULL)
         return -ENODEV;
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(tpm_pm_resume);
 
 /**
  * tpm_get_random() - get random bytes from the TPM's RNG
  * @chip:   a &struct tpm_chip instance, %NULL for the default chip
  * @out:    destination buffer for the random bytes
  * @max:    the max number of bytes to write to @out
  *
  * Return: number of random bytes read or a negative error value.
  */
 int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
 {
     int rc;
 
     if (!out || max > TPM_MAX_RNG_DATA)
         return -EINVAL;
 
     chip = tpm_find_get_ops(chip);
     if (!chip)
         return -ENODEV;
 
     if (chip->flags & TPM_CHIP_FLAG_TPM2)
         rc = tpm2_get_random(chip, out, max);
     else
         rc = tpm1_get_random(chip, out, max);
 
     tpm_put_ops(chip);
     return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_get_random);
 
 static int __init tpm_init(void)
 {
     int rc;
 
     tpm_class = class_create(THIS_MODULE, "tpm");
     if (IS_ERR(tpm_class)) {
         pr_err("couldn't create tpm class\n");
         return PTR_ERR(tpm_class);
     }
 
     tpmrm_class = class_create(THIS_MODULE, "tpmrm");
     if (IS_ERR(tpmrm_class)) {
         pr_err("couldn't create tpmrm class\n");
         rc = PTR_ERR(tpmrm_class);
         goto out_destroy_tpm_class;
     }
 
     rc = alloc_chrdev_region(&tpm_devt, 0, 2*TPM_NUM_DEVICES, "tpm");
     if (rc < 0) {
         pr_err("tpm: failed to allocate char dev region\n");
         goto out_destroy_tpmrm_class;
     }
 
     rc = tpm_dev_common_init();
     if (rc) {
         pr_err("tpm: failed to allocate char dev region\n");
         goto out_unreg_chrdev;
     }
 
     return 0;
 
 out_unreg_chrdev:
     unregister_chrdev_region(tpm_devt, 2 * TPM_NUM_DEVICES);
 out_destroy_tpmrm_class:
     class_destroy(tpmrm_class);
 out_destroy_tpm_class:
     class_destroy(tpm_class);
 
     return rc;
 }
 
 static void __exit tpm_exit(void)
 {
     idr_destroy(&dev_nums_idr);
     class_destroy(tpm_class);
     class_destroy(tpmrm_class);
     unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
     tpm_dev_common_exit();
 }
 
 subsys_initcall(tpm_init);
 module_exit(tpm_exit);
 
 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
 MODULE_DESCRIPTION("TPM Driver");
 MODULE_VERSION("2.0");
 MODULE_LICENSE("GPL");

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