WSL2-Linux-Kernel/drivers/char/tpm/tpm-chip.c

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12 KiB
C
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/*
* Copyright (C) 2004 IBM Corporation
* Copyright (C) 2014 Intel Corporation
*
* Authors:
* Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
* 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>
*
* TPM chip management routines.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*
*/
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/freezer.h>
#include <linux/major.h>
#include <linux/tpm_eventlog.h>
#include <linux/hw_random.h>
#include "tpm.h"
DEFINE_IDR(dev_nums_idr);
static DEFINE_MUTEX(idr_lock);
struct class *tpm_class;
struct class *tpmrm_class;
dev_t tpm_devt;
/**
* tpm_try_get_ops() - Get a ref to the tpm_chip
* @chip: Chip to ref
*
* The caller must already have some kind of locking to ensure that chip is
* valid. This function will lock the chip so that the ops member can be
* accessed safely. The locking prevents tpm_chip_unregister from
* completing, so it should not be held for long periods.
*
* Returns -ERRNO if the chip could not be got.
*/
int tpm_try_get_ops(struct tpm_chip *chip)
{
int rc = -EIO;
get_device(&chip->dev);
down_read(&chip->ops_sem);
if (!chip->ops)
goto out_lock;
mutex_lock(&chip->tpm_mutex);
return 0;
out_lock:
up_read(&chip->ops_sem);
put_device(&chip->dev);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_try_get_ops);
/**
* tpm_put_ops() - Release a ref to the tpm_chip
* @chip: Chip to put
*
* This is the opposite pair to tpm_try_get_ops(). After this returns chip may
* be kfree'd.
*/
void tpm_put_ops(struct tpm_chip *chip)
{
mutex_unlock(&chip->tpm_mutex);
up_read(&chip->ops_sem);
put_device(&chip->dev);
}
EXPORT_SYMBOL_GPL(tpm_put_ops);
/**
* tpm_default_chip() - find a TPM chip and get a reference to it
*/
struct tpm_chip *tpm_default_chip(void)
{
struct tpm_chip *chip, *res = NULL;
int chip_num = 0;
int chip_prev;
mutex_lock(&idr_lock);
do {
chip_prev = chip_num;
chip = idr_get_next(&dev_nums_idr, &chip_num);
if (chip) {
get_device(&chip->dev);
res = chip;
break;
}
} while (chip_prev != chip_num);
mutex_unlock(&idr_lock);
return res;
}
EXPORT_SYMBOL_GPL(tpm_default_chip);
/**
* tpm_find_get_ops() - find and reserve a TPM chip
* @chip: a &struct tpm_chip instance, %NULL for the default chip
*
* Finds a TPM chip and reserves its class device and operations. The chip must
* be released with tpm_put_ops() after use.
* This function is for internal use only. It supports existing TPM callers
* by accepting NULL, but those callers should be converted to pass in a chip
* directly.
*
* Return:
* A reserved &struct tpm_chip instance.
* %NULL if a chip is not found.
* %NULL if the chip is not available.
*/
struct tpm_chip *tpm_find_get_ops(struct tpm_chip *chip)
{
int rc;
if (chip) {
if (!tpm_try_get_ops(chip))
return chip;
return NULL;
}
chip = tpm_default_chip();
if (!chip)
return NULL;
rc = tpm_try_get_ops(chip);
/* release additional reference we got from tpm_default_chip() */
put_device(&chip->dev);
if (rc)
return NULL;
return chip;
}
/**
* tpm_dev_release() - free chip memory and the device number
* @dev: the character device for the TPM chip
*
* This is used as the release function for the character device.
*/
static void tpm_dev_release(struct device *dev)
{
struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
mutex_lock(&idr_lock);
idr_remove(&dev_nums_idr, chip->dev_num);
mutex_unlock(&idr_lock);
kfree(chip->log.bios_event_log);
kfree(chip->work_space.context_buf);
tpm2: add session handle context saving and restoring to the space code Sessions are different from transient objects in that their handles may not be virtualized (because they're used for some hmac calculations). Additionally when a session is context saved, a vestigial memory remains in the TPM and if it is also flushed, that will be lost and the session context will refuse to load next time, so the code is updated to flush only transient objects after a context save. Add a separate array (chip->session_tbl) to save and restore sessions by handle. Use the failure of a context save or load to signal that the session has been flushed from the TPM and we can remove its memory from chip->session_tbl. Sessions are also isolated during each instance of a tpm space. This means that spaces shouldn't be able to see each other's sessions and is enforced by ensuring that a space user may only refer to sessions handles that are present in their own chip->session_tbl. Finally when a space is closed, all the sessions belonging to it should be flushed so the handles may be re-used by other spaces. Note that if we get a session save or load error, all sessions are effectively flushed. Even though we restore the session buffer, all the old sessions will refuse to load after the flush and they'll be purged from our session memory. This means that while transient context handling is still soft in the face of errors, session handling is hard (any failure of the model means all sessions are lost). Fixes-from: Colin Ian King <colin.king@canonical.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2017-02-01 02:47:31 +03:00
kfree(chip->work_space.session_buf);
kfree(chip);
}
static void tpm_devs_release(struct device *dev)
{
struct tpm_chip *chip = container_of(dev, struct tpm_chip, devs);
/* release the master device reference */
put_device(&chip->dev);
}
/**
* tpm_class_shutdown() - prepare the TPM device for loss of power.
* @dev: device to which the chip is associated.
*
* Issues a TPM2_Shutdown command prior to loss of power, as required by the
* TPM 2.0 spec.
* Then, calls bus- and device- specific shutdown code.
*
* XXX: This codepath relies on the fact that sysfs is not enabled for
* TPM2: sysfs uses an implicit lock on chip->ops, so this could race if TPM2
* has sysfs support enabled before TPM sysfs's implicit locking is fixed.
*/
static int tpm_class_shutdown(struct device *dev)
{
struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
down_write(&chip->ops_sem);
tpm2_shutdown(chip, TPM2_SU_CLEAR);
chip->ops = NULL;
up_write(&chip->ops_sem);
}
return 0;
}
/**
* tpm_chip_alloc() - allocate a new struct tpm_chip instance
* @pdev: device to which the chip is associated
* At this point pdev mst be initialized, but does not have to
* be registered
* @ops: struct tpm_class_ops instance
*
* Allocates a new struct tpm_chip instance and assigns a free
* device number for it. Must be paired with put_device(&chip->dev).
*/
struct tpm_chip *tpm_chip_alloc(struct device *pdev,
const struct tpm_class_ops *ops)
{
struct tpm_chip *chip;
int rc;
chip = kzalloc(sizeof(*chip), GFP_KERNEL);
if (chip == NULL)
return ERR_PTR(-ENOMEM);
mutex_init(&chip->tpm_mutex);
init_rwsem(&chip->ops_sem);
chip->ops = ops;
mutex_lock(&idr_lock);
rc = idr_alloc(&dev_nums_idr, NULL, 0, TPM_NUM_DEVICES, GFP_KERNEL);
mutex_unlock(&idr_lock);
if (rc < 0) {
dev_err(pdev, "No available tpm device numbers\n");
kfree(chip);
return ERR_PTR(rc);
}
chip->dev_num = rc;
device_initialize(&chip->dev);
device_initialize(&chip->devs);
chip->dev.class = tpm_class;
chip->dev.class->shutdown_pre = tpm_class_shutdown;
chip->dev.release = tpm_dev_release;
chip->dev.parent = pdev;
chip->dev.groups = chip->groups;
chip->devs.parent = pdev;
chip->devs.class = tpmrm_class;
chip->devs.release = tpm_devs_release;
/* get extra reference on main device to hold on
* behalf of devs. This holds the chip structure
* while cdevs is in use. The corresponding put
* is in the tpm_devs_release (TPM2 only)
*/
if (chip->flags & TPM_CHIP_FLAG_TPM2)
get_device(&chip->dev);
if (chip->dev_num == 0)
chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR);
else
chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num);
chip->devs.devt =
MKDEV(MAJOR(tpm_devt), chip->dev_num + TPM_NUM_DEVICES);
rc = dev_set_name(&chip->dev, "tpm%d", chip->dev_num);
if (rc)
goto out;
rc = dev_set_name(&chip->devs, "tpmrm%d", chip->dev_num);
if (rc)
goto out;
if (!pdev)
chip->flags |= TPM_CHIP_FLAG_VIRTUAL;
cdev_init(&chip->cdev, &tpm_fops);
cdev_init(&chip->cdevs, &tpmrm_fops);
chip->cdev.owner = THIS_MODULE;
chip->cdevs.owner = THIS_MODULE;
chip->work_space.context_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
if (!chip->work_space.context_buf) {
rc = -ENOMEM;
goto out;
}
tpm2: add session handle context saving and restoring to the space code Sessions are different from transient objects in that their handles may not be virtualized (because they're used for some hmac calculations). Additionally when a session is context saved, a vestigial memory remains in the TPM and if it is also flushed, that will be lost and the session context will refuse to load next time, so the code is updated to flush only transient objects after a context save. Add a separate array (chip->session_tbl) to save and restore sessions by handle. Use the failure of a context save or load to signal that the session has been flushed from the TPM and we can remove its memory from chip->session_tbl. Sessions are also isolated during each instance of a tpm space. This means that spaces shouldn't be able to see each other's sessions and is enforced by ensuring that a space user may only refer to sessions handles that are present in their own chip->session_tbl. Finally when a space is closed, all the sessions belonging to it should be flushed so the handles may be re-used by other spaces. Note that if we get a session save or load error, all sessions are effectively flushed. Even though we restore the session buffer, all the old sessions will refuse to load after the flush and they'll be purged from our session memory. This means that while transient context handling is still soft in the face of errors, session handling is hard (any failure of the model means all sessions are lost). Fixes-from: Colin Ian King <colin.king@canonical.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2017-02-01 02:47:31 +03:00
chip->work_space.session_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
if (!chip->work_space.session_buf) {
rc = -ENOMEM;
goto out;
}
chip->locality = -1;
return chip;
out:
put_device(&chip->devs);
put_device(&chip->dev);
return ERR_PTR(rc);
}
EXPORT_SYMBOL_GPL(tpm_chip_alloc);
/**
* tpmm_chip_alloc() - allocate a new struct tpm_chip instance
* @pdev: parent device to which the chip is associated
* @ops: struct tpm_class_ops instance
*
* Same as tpm_chip_alloc except devm is used to do the put_device
*/
struct tpm_chip *tpmm_chip_alloc(struct device *pdev,
const struct tpm_class_ops *ops)
{
struct tpm_chip *chip;
int rc;
chip = tpm_chip_alloc(pdev, ops);
if (IS_ERR(chip))
return chip;
rc = devm_add_action_or_reset(pdev,
(void (*)(void *)) put_device,
&chip->dev);
if (rc)
return ERR_PTR(rc);
dev_set_drvdata(pdev, chip);
return chip;
}
EXPORT_SYMBOL_GPL(tpmm_chip_alloc);
static int tpm_add_char_device(struct tpm_chip *chip)
{
int rc;
rc = cdev_device_add(&chip->cdev, &chip->dev);
if (rc) {
dev_err(&chip->dev,
"unable to cdev_device_add() %s, major %d, minor %d, err=%d\n",
dev_name(&chip->dev), MAJOR(chip->dev.devt),
MINOR(chip->dev.devt), rc);
return rc;
}
char/misc patches for 4.12-rc1 Here is the big set of new char/misc driver drivers and features for 4.12-rc1. There's lots of new drivers added this time around, new firmware drivers from Google, more auxdisplay drivers, extcon drivers, fpga drivers, and a bunch of other driver updates. Nothing major, except if you happen to have the hardware for these drivers, and then you will be happy :) All of these have been in linux-next for a while with no reported issues. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -----BEGIN PGP SIGNATURE----- iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCWQvAgg8cZ3JlZ0Brcm9h aC5jb20ACgkQMUfUDdst+yknsACgzkAeyz16Z97J3UTaeejbR7nKUCAAoKY4WEHY 8O9f9pr9gj8GMBwxeZQa =OIfB -----END PGP SIGNATURE----- Merge tag 'char-misc-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here is the big set of new char/misc driver drivers and features for 4.12-rc1. There's lots of new drivers added this time around, new firmware drivers from Google, more auxdisplay drivers, extcon drivers, fpga drivers, and a bunch of other driver updates. Nothing major, except if you happen to have the hardware for these drivers, and then you will be happy :) All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (136 commits) firmware: google memconsole: Fix return value check in platform_memconsole_init() firmware: Google VPD: Fix return value check in vpd_platform_init() goldfish_pipe: fix build warning about using too much stack. goldfish_pipe: An implementation of more parallel pipe fpga fr br: update supported version numbers fpga: region: release FPGA region reference in error path fpga altera-hps2fpga: disable/unprepare clock on error in alt_fpga_bridge_probe() mei: drop the TODO from samples firmware: Google VPD sysfs driver firmware: Google VPD: import lib_vpd source files misc: lkdtm: Add volatile to intentional NULL pointer reference eeprom: idt_89hpesx: Add OF device ID table misc: ds1682: Add OF device ID table misc: tsl2550: Add OF device ID table w1: Remove unneeded use of assert() and remove w1_log.h w1: Use kernel common min() implementation uio_mf624: Align memory regions to page size and set correct offsets uio_mf624: Refactor memory info initialization uio: Allow handling of non page-aligned memory regions hangcheck-timer: Fix typo in comment ...
2017-05-05 05:07:10 +03:00
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
rc = cdev_device_add(&chip->cdevs, &chip->devs);
if (rc) {
dev_err(&chip->devs,
"unable to cdev_device_add() %s, major %d, minor %d, err=%d\n",
dev_name(&chip->devs), MAJOR(chip->devs.devt),
MINOR(chip->devs.devt), rc);
return rc;
}
}
/* Make the chip available. */
mutex_lock(&idr_lock);
idr_replace(&dev_nums_idr, chip, chip->dev_num);
mutex_unlock(&idr_lock);
return rc;
}
static void tpm_del_char_device(struct tpm_chip *chip)
{
cdev_device_del(&chip->cdev, &chip->dev);
/* Make the chip unavailable. */
mutex_lock(&idr_lock);
idr_replace(&dev_nums_idr, NULL, chip->dev_num);
mutex_unlock(&idr_lock);
/* Make the driver uncallable. */
down_write(&chip->ops_sem);
if (chip->flags & TPM_CHIP_FLAG_TPM2)
tpm2_shutdown(chip, TPM2_SU_CLEAR);
chip->ops = NULL;
up_write(&chip->ops_sem);
}
static void tpm_del_legacy_sysfs(struct tpm_chip *chip)
{
struct attribute **i;
if (chip->flags & (TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_VIRTUAL))
return;
sysfs_remove_link(&chip->dev.parent->kobj, "ppi");
for (i = chip->groups[0]->attrs; *i != NULL; ++i)
sysfs_remove_link(&chip->dev.parent->kobj, (*i)->name);
}
/* For compatibility with legacy sysfs paths we provide symlinks from the
* parent dev directory to selected names within the tpm chip directory. Old
* kernel versions created these files directly under the parent.
*/
static int tpm_add_legacy_sysfs(struct tpm_chip *chip)
{
struct attribute **i;
int rc;
if (chip->flags & (TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_VIRTUAL))
return 0;
rc = __compat_only_sysfs_link_entry_to_kobj(
&chip->dev.parent->kobj, &chip->dev.kobj, "ppi");
if (rc && rc != -ENOENT)
return rc;
/* All the names from tpm-sysfs */
for (i = chip->groups[0]->attrs; *i != NULL; ++i) {
rc = __compat_only_sysfs_link_entry_to_kobj(
&chip->dev.parent->kobj, &chip->dev.kobj, (*i)->name);
if (rc) {
tpm_del_legacy_sysfs(chip);
return rc;
}
}
return 0;
}
static int tpm_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait)
{
struct tpm_chip *chip = container_of(rng, struct tpm_chip, hwrng);
return tpm_get_random(chip, data, max);
}
static int tpm_add_hwrng(struct tpm_chip *chip)
{
if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM))
return 0;
snprintf(chip->hwrng_name, sizeof(chip->hwrng_name),
"tpm-rng-%d", chip->dev_num);
chip->hwrng.name = chip->hwrng_name;
chip->hwrng.read = tpm_hwrng_read;
return hwrng_register(&chip->hwrng);
}
/*
* tpm_chip_register() - create a character device for the TPM chip
* @chip: TPM chip to use.
*
* Creates a character device for the TPM chip and adds sysfs attributes for
* the device. As the last step this function adds the chip to the list of TPM
* chips available for in-kernel use.
*
* This function should be only called after the chip initialization is
* complete.
*/
int tpm_chip_register(struct tpm_chip *chip)
{
int rc;
rc = tpm_auto_startup(chip);
if (rc)
return rc;
tpm_sysfs_add_device(chip);
rc = tpm_bios_log_setup(chip);
if (rc != 0 && rc != -ENODEV)
return rc;
tpm_add_ppi(chip);
rc = tpm_add_hwrng(chip);
if (rc)
goto out_ppi;
rc = tpm_add_char_device(chip);
if (rc)
goto out_hwrng;
rc = tpm_add_legacy_sysfs(chip);
if (rc) {
tpm_chip_unregister(chip);
return rc;
}
return 0;
out_hwrng:
if (IS_ENABLED(CONFIG_HW_RANDOM_TPM))
hwrng_unregister(&chip->hwrng);
out_ppi:
tpm_bios_log_teardown(chip);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_chip_register);
/*
* tpm_chip_unregister() - release the TPM driver
* @chip: TPM chip to use.
*
* Takes the chip first away from the list of available TPM chips and then
* cleans up all the resources reserved by tpm_chip_register().
*
* Once this function returns the driver call backs in 'op's will not be
* running and will no longer start.
*
* NOTE: This function should be only called before deinitializing chip
* resources.
*/
void tpm_chip_unregister(struct tpm_chip *chip)
{
tpm_del_legacy_sysfs(chip);
if (IS_ENABLED(CONFIG_HW_RANDOM_TPM))
hwrng_unregister(&chip->hwrng);
tpm_bios_log_teardown(chip);
char/misc patches for 4.12-rc1 Here is the big set of new char/misc driver drivers and features for 4.12-rc1. There's lots of new drivers added this time around, new firmware drivers from Google, more auxdisplay drivers, extcon drivers, fpga drivers, and a bunch of other driver updates. Nothing major, except if you happen to have the hardware for these drivers, and then you will be happy :) All of these have been in linux-next for a while with no reported issues. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -----BEGIN PGP SIGNATURE----- iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCWQvAgg8cZ3JlZ0Brcm9h aC5jb20ACgkQMUfUDdst+yknsACgzkAeyz16Z97J3UTaeejbR7nKUCAAoKY4WEHY 8O9f9pr9gj8GMBwxeZQa =OIfB -----END PGP SIGNATURE----- Merge tag 'char-misc-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here is the big set of new char/misc driver drivers and features for 4.12-rc1. There's lots of new drivers added this time around, new firmware drivers from Google, more auxdisplay drivers, extcon drivers, fpga drivers, and a bunch of other driver updates. Nothing major, except if you happen to have the hardware for these drivers, and then you will be happy :) All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (136 commits) firmware: google memconsole: Fix return value check in platform_memconsole_init() firmware: Google VPD: Fix return value check in vpd_platform_init() goldfish_pipe: fix build warning about using too much stack. goldfish_pipe: An implementation of more parallel pipe fpga fr br: update supported version numbers fpga: region: release FPGA region reference in error path fpga altera-hps2fpga: disable/unprepare clock on error in alt_fpga_bridge_probe() mei: drop the TODO from samples firmware: Google VPD sysfs driver firmware: Google VPD: import lib_vpd source files misc: lkdtm: Add volatile to intentional NULL pointer reference eeprom: idt_89hpesx: Add OF device ID table misc: ds1682: Add OF device ID table misc: tsl2550: Add OF device ID table w1: Remove unneeded use of assert() and remove w1_log.h w1: Use kernel common min() implementation uio_mf624: Align memory regions to page size and set correct offsets uio_mf624: Refactor memory info initialization uio: Allow handling of non page-aligned memory regions hangcheck-timer: Fix typo in comment ...
2017-05-05 05:07:10 +03:00
if (chip->flags & TPM_CHIP_FLAG_TPM2)
cdev_device_del(&chip->cdevs, &chip->devs);
tpm_del_char_device(chip);
}
EXPORT_SYMBOL_GPL(tpm_chip_unregister);