DRTM needs to be able to set the locality used by kernel. Provide TPM_IOC_SET_LOCALITY operation for this purpose. It is enabled only if the kernel command-line has 'tpm.set_locality_enabled=1'. The operation is one-shot allowed only for tpm_tis for the moment.
Signed-off-by: Jarkko Sakkinen <jar...@kernel.org> --- v2: - Do not ignore the return value of tpm_ioc_set_locality(). - if (!(chip->flags & TPM_CHIP_FLAG_SET_LOCALITY_ENABLED)) - Refined kernel-parameters.txt description. - Use __u8 instead of u8 in the uapi. - Tested with https://codeberg.org/jarkko/tpm-set-locality-test/src/branch/main/src/main.rs v1: - NOTE: Only compile-tested. --- .../admin-guide/kernel-parameters.txt | 5 ++ .../userspace-api/ioctl/ioctl-number.rst | 2 + drivers/char/tpm/tpm-chip.c | 2 +- drivers/char/tpm/tpm-dev.c | 70 +++++++++++++++++++ drivers/char/tpm/tpm_tis_core.c | 2 + include/linux/tpm.h | 10 +++ include/uapi/linux/tpm.h | 11 +++ 7 files changed, 101 insertions(+), 1 deletion(-) create mode 100644 include/uapi/linux/tpm.h diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 1518343bbe22..8fd9fc94c883 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6727,6 +6727,11 @@ torture.verbose_sleep_duration= [KNL] Duration of each verbose-printk() sleep in jiffies. + tpm.set_locality_enabled= [HW,TPM] + Enable one-shot locality setting after the boot. The + operation can be performed with TPM_IOC_SET_LOCALITY + applied to /dev/tpm0. The default value is 0. + tpm_suspend_pcr=[HW,TPM] Format: integer pcr id Specify that at suspend time, the tpm driver diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst index e4be1378ba26..3eba57ab2fb1 100644 --- a/Documentation/userspace-api/ioctl/ioctl-number.rst +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst @@ -338,6 +338,8 @@ Code Seq# Include File Comments 0xA3 90-9F linux/dtlk.h 0xA4 00-1F uapi/linux/tee.h Generic TEE subsystem 0xA4 00-1F uapi/asm/sgx.h <mailto:linux-...@vger.kernel.org> +0xA4 00-1F uapi/linux/tpm.h TPM + <mailto:linux-integr...@vger.kernel.org> 0xA5 01-05 linux/surface_aggregator/cdev.h Microsoft Surface Platform System Aggregator <mailto:luzmaximil...@gmail.com> 0xA5 20-2F linux/surface_aggregator/dtx.h Microsoft Surface DTX driver diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 7df7abaf3e52..c8016342352a 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -44,7 +44,7 @@ static int tpm_request_locality(struct tpm_chip *chip) if (!chip->ops->request_locality) return 0; - rc = chip->ops->request_locality(chip, 0); + rc = chip->ops->request_locality(chip, chip->default_locality); if (rc < 0) return rc; diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c index 97c94b5e9340..d07aec98f894 100644 --- a/drivers/char/tpm/tpm-dev.c +++ b/drivers/char/tpm/tpm-dev.c @@ -13,8 +13,74 @@ * Device file system interface to the TPM */ #include <linux/slab.h> +#include <uapi/linux/tpm.h> #include "tpm-dev.h" +static bool set_locality_enabled; +module_param(set_locality_enabled, bool, 0644); + +/* + * Set a locality as a one-shot operation. A chip must declare support for it + * with %TPM_CHIP_FLAG_SET_LOCALITY_ENABLED, which will cleared after setting + * the locality. + */ +static long tpm_ioc_set_locality(struct tpm_chip *chip, u8 __user *localityp) +{ + u8 locality; + + if (!set_locality_enabled) + return -ENOIOCTLCMD; + + if (!(chip->flags & TPM_CHIP_FLAG_SET_LOCALITY_ENABLED)) + return -EOPNOTSUPP; + + if (copy_from_user(&locality, localityp, sizeof(locality))) + return -EFAULT; + + if (locality >= TPM_MAX_LOCALITY) + return -EINVAL; + + chip->default_locality = locality; + chip->flags &= ~TPM_CHIP_FLAG_SET_LOCALITY_ENABLED; + return 0; +} + +static long tpm_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct file_priv *priv = file->private_data; + void __user *argp = (void __user *)arg; + struct tpm_chip *chip = priv->chip; + int ret; + + mutex_lock(&priv->buffer_mutex); + + ret = tpm_try_get_ops(chip); + if (ret) + goto out; + + switch (cmd) { + case TPM_IOC_SET_LOCALITY: + ret = tpm_ioc_set_locality(chip, argp); + break; + default: + ret = -ENOIOCTLCMD; + break; + } + + tpm_put_ops(chip); + +out: + mutex_unlock(&priv->buffer_mutex); + return 0; +} + +#ifdef CONFIG_COMPAT +static long tpm_compat_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) +{ + return tpm_ioctl(filep, cmd, arg); +} +#endif + static int tpm_open(struct inode *inode, struct file *file) { struct tpm_chip *chip; @@ -59,6 +125,10 @@ static int tpm_release(struct inode *inode, struct file *file) const struct file_operations tpm_fops = { .owner = THIS_MODULE, + .unlocked_ioctl = tpm_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = tpm_compat_ioctl, +#endif .open = tpm_open, .read = tpm_common_read, .write = tpm_common_write, diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index fdef214b9f6b..3517db710423 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -1111,6 +1111,8 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, if (IS_ERR(chip)) return PTR_ERR(chip); + chip->flags |= TPM_CHIP_FLAG_SET_LOCALITY_ENABLED; + #ifdef CONFIG_ACPI chip->acpi_dev_handle = acpi_dev_handle; #endif diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 587b96b4418e..27071ef13b7a 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -147,6 +147,12 @@ struct tpm_chip_seqops { */ #define TPM2_MAX_CONTEXT_SIZE 4096 +/* + * The maximum locality (0 - 4) for a TPM, as defined in section 3.2 of the + * Client Platform Profile Specification. + */ +#define TPM_MAX_LOCALITY 4 + struct tpm_chip { struct device dev; struct device devs; @@ -202,6 +208,9 @@ struct tpm_chip { /* active locality */ int locality; + /* the default locality used by the kernel (default 0) */ + u8 default_locality; + #ifdef CONFIG_TCG_TPM2_HMAC /* details for communication security via sessions */ @@ -348,6 +357,7 @@ enum tpm_chip_flags { TPM_CHIP_FLAG_SUSPENDED = BIT(8), TPM_CHIP_FLAG_HWRNG_DISABLED = BIT(9), TPM_CHIP_FLAG_DISABLE = BIT(10), + TPM_CHIP_FLAG_SET_LOCALITY_ENABLED = BIT(11), }; #define to_tpm_chip(d) container_of(d, struct tpm_chip, dev) diff --git a/include/uapi/linux/tpm.h b/include/uapi/linux/tpm.h new file mode 100644 index 000000000000..73485a184f14 --- /dev/null +++ b/include/uapi/linux/tpm.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef _UAPI_TPM_H +#define _UAPI_TPM_H + +#include <linux/types.h> +#include <linux/ioctl.h> + +#define TPM_MAGIC 0xA4 +#define TPM_IOC_SET_LOCALITY _IOW(TPM_MAGIC, 0x00, __u8) + +#endif /* _UAPI_TPM_H */ -- 2.47.0 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
