From d0b2f91bede3bd5e3d24dd6803e56eee959c1797 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Thu, 20 Oct 2016 00:10:27 -0300 Subject: Linux-libre 4.8.2-gnu --- drivers/char/tpm/tpm-chip.c | 299 +++++++++++++++++++++++++++++++------------- 1 file changed, 213 insertions(+), 86 deletions(-) (limited to 'drivers/char/tpm/tpm-chip.c') diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 274dd0123..e5950131b 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -29,33 +29,88 @@ #include "tpm.h" #include "tpm_eventlog.h" -static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES); -static LIST_HEAD(tpm_chip_list); -static DEFINE_SPINLOCK(driver_lock); +DEFINE_IDR(dev_nums_idr); +static DEFINE_MUTEX(idr_lock); struct class *tpm_class; dev_t tpm_devt; -/* - * tpm_chip_find_get - return tpm_chip for a given chip number - * @chip_num the device number for the chip +/** + * 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. */ -struct tpm_chip *tpm_chip_find_get(int chip_num) +int tpm_try_get_ops(struct tpm_chip *chip) { - struct tpm_chip *pos, *chip = NULL; + int rc = -EIO; - rcu_read_lock(); - list_for_each_entry_rcu(pos, &tpm_chip_list, list) { - if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num) - continue; + get_device(&chip->dev); - if (try_module_get(pos->pdev->driver->owner)) { - chip = pos; - break; - } + down_read(&chip->ops_sem); + if (!chip->ops) + goto out_lock; + + 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) +{ + up_read(&chip->ops_sem); + put_device(&chip->dev); +} +EXPORT_SYMBOL_GPL(tpm_put_ops); + +/** + * tpm_chip_find_get() - return tpm_chip for a given chip number + * @chip_num: id to find + * + * The return'd chip has been tpm_try_get_ops'd and must be released via + * tpm_put_ops + */ +struct tpm_chip *tpm_chip_find_get(int chip_num) +{ + struct tpm_chip *chip, *res = NULL; + int chip_prev; + + mutex_lock(&idr_lock); + + if (chip_num == TPM_ANY_NUM) { + chip_num = 0; + do { + chip_prev = chip_num; + chip = idr_get_next(&dev_nums_idr, &chip_num); + if (chip && !tpm_try_get_ops(chip)) { + res = chip; + break; + } + } while (chip_prev != chip_num); + } else { + chip = idr_find_slowpath(&dev_nums_idr, chip_num); + if (chip && !tpm_try_get_ops(chip)) + res = chip; } - rcu_read_unlock(); - return chip; + + mutex_unlock(&idr_lock); + + return res; } /** @@ -68,24 +123,25 @@ static void tpm_dev_release(struct device *dev) { struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev); - spin_lock(&driver_lock); - clear_bit(chip->dev_num, dev_mask); - spin_unlock(&driver_lock); + mutex_lock(&idr_lock); + idr_remove(&dev_nums_idr, chip->dev_num); + mutex_unlock(&idr_lock); + kfree(chip); } /** - * tpmm_chip_alloc() - allocate a new struct tpm_chip instance - * @dev: device to which the chip is associated + * 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. Caller does not have to worry about - * freeing the allocated resources. When the devices is removed - * devres calls tpmm_chip_remove() to do the job. + * device number for it. Must be paired with put_device(&chip->dev). */ -struct tpm_chip *tpmm_chip_alloc(struct device *dev, - const struct tpm_class_ops *ops) +struct tpm_chip *tpm_chip_alloc(struct device *dev, + const struct tpm_class_ops *ops) { struct tpm_chip *chip; int rc; @@ -95,53 +151,75 @@ struct tpm_chip *tpmm_chip_alloc(struct device *dev, return ERR_PTR(-ENOMEM); mutex_init(&chip->tpm_mutex); - INIT_LIST_HEAD(&chip->list); + init_rwsem(&chip->ops_sem); chip->ops = ops; - spin_lock(&driver_lock); - chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES); - spin_unlock(&driver_lock); - - if (chip->dev_num >= TPM_NUM_DEVICES) { + 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(dev, "No available tpm device numbers\n"); kfree(chip); - return ERR_PTR(-ENOMEM); + return ERR_PTR(rc); } + chip->dev_num = rc; - set_bit(chip->dev_num, dev_mask); - - scnprintf(chip->devname, sizeof(chip->devname), "tpm%d", chip->dev_num); - - chip->pdev = dev; - - dev_set_drvdata(dev, chip); + device_initialize(&chip->dev); chip->dev.class = tpm_class; chip->dev.release = tpm_dev_release; - chip->dev.parent = chip->pdev; -#ifdef CONFIG_ACPI + chip->dev.parent = dev; chip->dev.groups = chip->groups; -#endif if (chip->dev_num == 0) chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR); else chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num); - dev_set_name(&chip->dev, "%s", chip->devname); + rc = dev_set_name(&chip->dev, "tpm%d", chip->dev_num); + if (rc) + goto out; - device_initialize(&chip->dev); + if (!dev) + chip->flags |= TPM_CHIP_FLAG_VIRTUAL; cdev_init(&chip->cdev, &tpm_fops); - chip->cdev.owner = chip->pdev->driver->owner; + chip->cdev.owner = THIS_MODULE; chip->cdev.kobj.parent = &chip->dev.kobj; - rc = devm_add_action(dev, (void (*)(void *)) put_device, &chip->dev); - if (rc) { - put_device(&chip->dev); + return chip; + +out: + 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; } @@ -155,7 +233,7 @@ static int tpm_add_char_device(struct tpm_chip *chip) if (rc) { dev_err(&chip->dev, "unable to cdev_add() %s, major %d, minor %d, err=%d\n", - chip->devname, MAJOR(chip->dev.devt), + dev_name(&chip->dev), MAJOR(chip->dev.devt), MINOR(chip->dev.devt), rc); return rc; @@ -165,13 +243,18 @@ static int tpm_add_char_device(struct tpm_chip *chip) if (rc) { dev_err(&chip->dev, "unable to device_register() %s, major %d, minor %d, err=%d\n", - chip->devname, MAJOR(chip->dev.devt), + dev_name(&chip->dev), MAJOR(chip->dev.devt), MINOR(chip->dev.devt), rc); cdev_del(&chip->cdev); 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; } @@ -179,20 +262,28 @@ static void tpm_del_char_device(struct tpm_chip *chip) { cdev_del(&chip->cdev); device_del(&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 int tpm1_chip_register(struct tpm_chip *chip) { - int rc; - if (chip->flags & TPM_CHIP_FLAG_TPM2) return 0; - rc = tpm_sysfs_add_device(chip); - if (rc) - return rc; + tpm_sysfs_add_device(chip); - chip->bios_dir = tpm_bios_log_setup(chip->devname); + chip->bios_dir = tpm_bios_log_setup(dev_name(&chip->dev)); return 0; } @@ -204,10 +295,50 @@ static void tpm1_chip_unregister(struct tpm_chip *chip) if (chip->bios_dir) tpm_bios_log_teardown(chip->bios_dir); +} + +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"); - tpm_sysfs_del_device(chip); + 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; +} /* * tpm_chip_register() - create a character device for the TPM chip * @chip: TPM chip to use. @@ -223,6 +354,15 @@ int tpm_chip_register(struct tpm_chip *chip) { int rc; + if (chip->ops->flags & TPM_OPS_AUTO_STARTUP) { + if (chip->flags & TPM_CHIP_FLAG_TPM2) + rc = tpm2_auto_startup(chip); + else + rc = tpm1_auto_startup(chip); + if (rc) + return rc; + } + rc = tpm1_chip_register(chip); if (rc) return rc; @@ -230,30 +370,20 @@ int tpm_chip_register(struct tpm_chip *chip) tpm_add_ppi(chip); rc = tpm_add_char_device(chip); - if (rc) - goto out_err; - - /* Make the chip available. */ - spin_lock(&driver_lock); - list_add_tail_rcu(&chip->list, &tpm_chip_list); - spin_unlock(&driver_lock); + if (rc) { + tpm1_chip_unregister(chip); + return rc; + } chip->flags |= TPM_CHIP_FLAG_REGISTERED; - if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { - rc = __compat_only_sysfs_link_entry_to_kobj(&chip->pdev->kobj, - &chip->dev.kobj, - "ppi"); - if (rc && rc != -ENOENT) { - tpm_chip_unregister(chip); - return rc; - } + rc = tpm_add_legacy_sysfs(chip); + if (rc) { + tpm_chip_unregister(chip); + return rc; } return 0; -out_err: - tpm1_chip_unregister(chip); - return rc; } EXPORT_SYMBOL_GPL(tpm_chip_register); @@ -264,6 +394,9 @@ EXPORT_SYMBOL_GPL(tpm_chip_register); * 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. */ @@ -272,13 +405,7 @@ void tpm_chip_unregister(struct tpm_chip *chip) if (!(chip->flags & TPM_CHIP_FLAG_REGISTERED)) return; - spin_lock(&driver_lock); - list_del_rcu(&chip->list); - spin_unlock(&driver_lock); - synchronize_rcu(); - - if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) - sysfs_remove_link(&chip->pdev->kobj, "ppi"); + tpm_del_legacy_sysfs(chip); tpm1_chip_unregister(chip); tpm_del_char_device(chip); -- cgit v1.2.3-54-g00ecf