From: James Bottomley <james.bottom...@hansenpartnership.com> Currently the Resource Manager (RM) is not exposed to userspace. Make this exposure via a separate device, which can now be opened multiple times because each read/write transaction goes separately via the RM.
Concurrency is protected by the chip->tpm_mutex for each read/write transaction separately. The TPM is cleared of all transient objects by the time the mutex is dropped, so there should be no interference between the kernel and userspace. Signed-off-by: James Bottomley <james.bottom...@hansenpartnership.com> --- drivers/char/tpm/Makefile | 2 +- drivers/char/tpm/tpm-chip.c | 54 ++++++++++++++++++++++++++++++++++--- drivers/char/tpm/tpm-interface.c | 13 +++++++-- drivers/char/tpm/tpm.h | 6 +++-- drivers/char/tpm/tpms-dev.c | 57 ++++++++++++++++++++++++++++++++++++++++ 5 files changed, 124 insertions(+), 8 deletions(-) create mode 100644 drivers/char/tpm/tpms-dev.c diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile index 13ff5da..e50d768 100644 --- a/drivers/char/tpm/Makefile +++ b/drivers/char/tpm/Makefile @@ -3,7 +3,7 @@ # obj-$(CONFIG_TCG_TPM) += tpm.o tpm-y := tpm-interface.o tpm-dev.o tpm-sysfs.o tpm-chip.o tpm2-cmd.o \ - tpm_eventlog.o tpm2-space.o tpm-dev-common.o + tpm_eventlog.o tpm2-space.o tpm-dev-common.o tpms-dev.o tpm-$(CONFIG_ACPI) += tpm_ppi.o tpm_acpi.o tpm-$(CONFIG_OF) += tpm_of.o obj-$(CONFIG_TCG_TIS_CORE) += tpm_tis_core.o diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 993b9ae..0d2be04 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -33,6 +33,7 @@ DEFINE_IDR(dev_nums_idr); static DEFINE_MUTEX(idr_lock); struct class *tpm_class; +struct class *tpm_rm_class; dev_t tpm_devt; /** @@ -168,27 +169,40 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev, chip->dev_num = rc; device_initialize(&chip->dev); + device_initialize(&chip->devrm); chip->dev.class = tpm_class; chip->dev.release = tpm_dev_release; chip->dev.parent = pdev; chip->dev.groups = chip->groups; + chip->devrm.parent = pdev; + chip->devrm.class = tpm_rm_class; + 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->devrm.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->devrm, "tpms%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->cdevrm, &tpm_rm_fops); chip->cdev.owner = THIS_MODULE; + chip->cdevrm.owner = THIS_MODULE; chip->cdev.kobj.parent = &chip->dev.kobj; + chip->cdevrm.kobj.parent = &chip->devrm.kobj; chip->work_space.context_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); if (!chip->work_space.context_buf) { @@ -200,6 +214,7 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev, out: put_device(&chip->dev); + put_device(&chip->devrm); return ERR_PTR(rc); } EXPORT_SYMBOL_GPL(tpm_chip_alloc); @@ -244,7 +259,7 @@ static int tpm_add_char_device(struct tpm_chip *chip) dev_name(&chip->dev), MAJOR(chip->dev.devt), MINOR(chip->dev.devt), rc); - return rc; + goto err_1; } rc = device_add(&chip->dev); @@ -254,16 +269,44 @@ static int tpm_add_char_device(struct tpm_chip *chip) dev_name(&chip->dev), MAJOR(chip->dev.devt), MINOR(chip->dev.devt), rc); - cdev_del(&chip->cdev); - return rc; + goto err_2; + } + + if (chip->flags & TPM_CHIP_FLAG_TPM2) + rc = cdev_add(&chip->cdevrm, chip->devrm.devt, 1); + if (rc) { + dev_err(&chip->dev, + "unable to cdev_add() %s, major %d, minor %d, err=%d\n", + dev_name(&chip->devrm), MAJOR(chip->devrm.devt), + MINOR(chip->devrm.devt), rc); + + goto err_3; } + if (chip->flags & TPM_CHIP_FLAG_TPM2) + rc = device_add(&chip->devrm); + if (rc) { + dev_err(&chip->dev, + "unable to device_register() %s, major %d, minor %d, err=%d\n", + dev_name(&chip->devrm), MAJOR(chip->devrm.devt), + MINOR(chip->devrm.devt), rc); + + goto err_4; + } /* Make the chip available. */ mutex_lock(&idr_lock); idr_replace(&dev_nums_idr, chip, chip->dev_num); mutex_unlock(&idr_lock); return rc; + err_4: + cdev_del(&chip->cdevrm); + err_3: + device_del(&chip->dev); + err_2: + cdev_del(&chip->cdev); + err_1: + return rc; } static void tpm_del_char_device(struct tpm_chip *chip) @@ -271,6 +314,11 @@ static void tpm_del_char_device(struct tpm_chip *chip) cdev_del(&chip->cdev); device_del(&chip->dev); + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + cdev_del(&chip->cdevrm); + device_del(&chip->devrm); + } + /* Make the chip unavailable. */ mutex_lock(&idr_lock); idr_replace(&dev_nums_idr, NULL, chip->dev_num); diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 65fcd04c..f5c9355 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -1197,9 +1197,17 @@ static int __init tpm_init(void) return PTR_ERR(tpm_class); } - rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm"); + tpm_rm_class = class_create(THIS_MODULE, "tpms"); + if (IS_ERR(tpm_rm_class)) { + pr_err("couldn't create tpmrm class\n"); + class_destroy(tpm_class); + return PTR_ERR(tpm_rm_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"); + class_destroy(tpm_rm_class); class_destroy(tpm_class); return rc; } @@ -1211,7 +1219,8 @@ static void __exit tpm_exit(void) { idr_destroy(&dev_nums_idr); class_destroy(tpm_class); - unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES); + class_destroy(tpm_rm_class); + unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES); } subsys_initcall(tpm_init); diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 0e93b93..61422e6 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -172,8 +172,8 @@ struct tpm_chip_seqops { }; struct tpm_chip { - struct device dev; - struct cdev cdev; + struct device dev, devrm; + struct cdev cdev, cdevrm; /* A driver callback under ops cannot be run unless ops_sem is held * (sometimes implicitly, eg for the sysfs code). ops becomes null @@ -510,8 +510,10 @@ static inline void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value) } extern struct class *tpm_class; +extern struct class *tpm_rm_class; extern dev_t tpm_devt; extern const struct file_operations tpm_fops; +extern const struct file_operations tpm_rm_fops; extern struct idr dev_nums_idr; enum tpm_transmit_flags { diff --git a/drivers/char/tpm/tpms-dev.c b/drivers/char/tpm/tpms-dev.c new file mode 100644 index 0000000..d822600 --- /dev/null +++ b/drivers/char/tpm/tpms-dev.c @@ -0,0 +1,57 @@ +/* + * Copyright (C) 2017 james.bottom...@hansenpartnership.com + * + * GPLv2 + */ +#include <linux/slab.h> +#include "tpm-dev.h" + +struct tpms_priv { + struct file_priv priv; + struct tpm_space space; +}; + +static int tpms_open(struct inode *inode, struct file *file) +{ + struct tpm_chip *chip; + struct tpms_priv *priv; + + chip = container_of(inode->i_cdev, struct tpm_chip, cdevrm); + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (priv == NULL) + return -ENOMEM; + + tpm_common_open(file, chip, &priv->priv); + + return 0; +} + +static int tpms_release(struct inode *inode, struct file *file) +{ + struct file_priv *fpriv = file->private_data; + struct tpms_priv *priv = container_of(fpriv, struct tpms_priv, priv); + + tpm_common_release(file, fpriv); + kfree(priv); + + return 0; +} + +ssize_t tpms_write(struct file *file, const char __user *buf, + size_t size, loff_t *off) +{ + struct file_priv *fpriv = file->private_data; + struct tpms_priv *priv = container_of(fpriv, struct tpms_priv, priv); + + return tpm_common_write(file, buf, size, off, &priv->space); +} + +const struct file_operations tpm_rm_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .open = tpms_open, + .read = tpm_common_read, + .write = tpms_write, + .release = tpms_release, +}; + -- 2.9.3 ------------------------------------------------------------------------------ Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. 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