[PATCH 1/2] ftpm: dt-binding: add dts documentation for fTPM driver

[PATCH 1/2] ftpm: dt-binding: add dts documentation for fTPM driver

[Sasha Levin]

Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../bindings/security/tpm/tpm_ftpm_tee.txt          | 13 +++++++++++++
 .../devicetree/bindings/vendor-prefixes.txt         |  1 +
 2 files changed, 14 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/security/tpm/tpm_ftpm_tee.txt

diff --git a/Documentation/devicetree/bindings/security/tpm/tpm_ftpm_tee.txt b/Documentation/devicetree/bindings/security/tpm/tpm_ftpm_tee.txt
new file mode 100644
index 000000000000..20fca67a56c4
--- /dev/null
+++ b/Documentation/devicetree/bindings/security/tpm/tpm_ftpm_tee.txt
@@ -0,0 +1,13 @@
+Required properties:
+- compatible: should be "microsoft,ftpm"
+- linux,sml-base: 64-bit base address of the reserved memory allocated
+		  for the firmware event log
+- linux,sml-size: size of the memory allocated for the firmware event log
+
+Example:
+
+tpm@0 {
+	compatible = "microsoft,ftpm";
+	linux,sml-base = <0x0 0xC0000000>;
+	linux,sml-size = <0x10000>;
+};
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 8162b0eb4b50..902798bcb9a5 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -249,6 +249,7 @@ micrel	Micrel Inc.
 microchip	Microchip Technology Inc.
 microcrystal	Micro Crystal AG
 micron	Micron Technology Inc.
+microsoft	Microsoft Corporation
 mikroe		MikroElektronika d.o.o.
 minix	MINIX Technology Ltd.
 miramems	MiraMEMS Sensing Technology Co., Ltd.
-- 
2.19.1

[PATCH 2/2] ftpm: firmware TPM running in TEE

[Sasha Levin]

This patch adds support for a software-only implementation of a TPM
running in TEE.

There is extensive documentation of the design here:
https://www.microsoft.com/en-us/research/publication/ftpm-software-implementation-tpm-chip/ .

As well as reference code for the firmware available here:
https://github.com/Microsoft/ms-tpm-20-ref/tree/master/Samples/ARM32-FirmwareTPM

Signed-off-by: Thirupathaiah Annapureddy <thiruan@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/char/tpm/Kconfig        |   5 +
 drivers/char/tpm/Makefile       |   1 +
 drivers/char/tpm/tpm_ftpm_tee.c | 353 ++++++++++++++++++++++++++++++++
 drivers/char/tpm/tpm_ftpm_tee.h |  61 ++++++
 4 files changed, 420 insertions(+)
 create mode 100644 drivers/char/tpm/tpm_ftpm_tee.c
 create mode 100644 drivers/char/tpm/tpm_ftpm_tee.h

diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index 536e55d3919f..5638726641eb 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig
@@ -164,6 +164,11 @@ config TCG_VTPM_PROXY
 	  /dev/vtpmX and a server-side file descriptor on which the vTPM
 	  can receive commands.
 
+config TCG_FTPM_TEE
+	tristate "TEE based fTPM Interface"
+	depends on TEE
+	---help---
+	  This driver proxies for fTPM running in TEE
 
 source "drivers/char/tpm/st33zp24/Kconfig"
 endif # TCG_TPM
diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index a01c4cab902a..c354cdff9c62 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -33,3 +33,4 @@ obj-$(CONFIG_TCG_TIS_ST33ZP24) += st33zp24/
 obj-$(CONFIG_TCG_XEN) += xen-tpmfront.o
 obj-$(CONFIG_TCG_CRB) += tpm_crb.o
 obj-$(CONFIG_TCG_VTPM_PROXY) += tpm_vtpm_proxy.o
+obj-$(CONFIG_TCG_FTPM_TEE) += tpm_ftpm_tee.o
diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c
new file mode 100644
index 000000000000..fdca9093a7bf
--- /dev/null
+++ b/drivers/char/tpm/tpm_ftpm_tee.c
@@ -0,0 +1,353 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) Microsoft Corporation
+ */
+
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/acpi.h>
+#include <linux/platform_device.h>
+#include <linux/tee_drv.h>
+#include <linux/uuid.h>
+#include <linux/tpm.h>
+
+#include "tpm.h"
+#include "tpm_ftpm_tee.h"
+
+#define DRIVER_NAME "ftpm-tee"
+
+/*
+ * Note: ftpm_tee_tpm_op_recv and ftpm_tee_tpm_op_send are called from the
+ * same routine tpm_try_transmit in tpm-interface.c. These calls are protected
+ * by chip->tpm_mutex => There is no need for protecting any data shared
+ * between these routines ex: struct ftpm_tee_private
+ */
+
+/*
+ * ftpm_tee_tpm_op_recv retrieve fTPM response.
+ * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h.
+ * @param: buf,	the buffer to store data.
+ * @param: count, the number of bytes to read.
+ * @return: In case of success the number of bytes received.
+ *	    In other case, a < 0 value describing the issue.
+ */
+static int ftpm_tee_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+	struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent);
+	size_t len;
+
+	len = pvt_data->resp_len;
+	dev_dbg(&chip->dev, "%s:len=%zd, resp_len=%zd\n", __func__,
+		count, len);
+	if (count < len) {
+		dev_err(&chip->dev,
+			"%s:Invalid size in recv: count=%zd, resp_len=%zd\n",
+			__func__, count, len);
+		return -EIO;
+	}
+
+	memcpy(buf, pvt_data->resp_buf, len);
+	pvt_data->resp_len = 0;
+
+	return len;
+}
+
+/*
+ * ftpm_tee_tpm_op_send send TPM commands through the TEE shared memory.
+ *
+ * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h
+ * @param: buf,	the buffer to send.
+ * @param: len, the number of bytes to send.
+ * @return: In case of success the number of bytes sent.
+ *			In other case, a < 0 value describing the issue.
+ */
+static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t len)
+{
+	struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent);
+	size_t resp_len;
+	int rc;
+	u8 *temp_buf;
+	struct tpm_header *resp_header;
+	struct tee_ioctl_invoke_arg transceive_args;
+	struct tee_param command_params[4];
+	struct tee_shm *shm = pvt_data->shm;
+
+	dev_dbg(&chip->dev, "%s:len=%zd\n", __func__, len);
+
+	if (len > MAX_COMMAND_SIZE) {
+		dev_err(&chip->dev,
+			"%s:len=%zd exceeds MAX_COMMAND_SIZE supported by fTPM TA\n",
+			__func__, len);
+		return -EIO;
+	}
+
+	memset(&transceive_args, 0, sizeof(transceive_args));
+	memset(command_params, 0, sizeof(command_params));
+	pvt_data->resp_len = 0;
+
+	/* Invoke FTPM_OPTEE_TA_SUBMIT_COMMAND function of fTPM TA */
+	transceive_args = (struct tee_ioctl_invoke_arg) {
+		.func = FTPM_OPTEE_TA_SUBMIT_COMMAND,
+		.session = pvt_data->session,
+		.num_params = 4,
+	};
+
+	/* Fill FTPM_OPTEE_TA_SUBMIT_COMMAND parameters */
+	command_params[0] = (struct tee_param) {
+		.attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT,
+		.u.memref = {
+			.shm = shm,
+			.size = len,
+			.shm_offs = 0,
+		},
+	};
+
+	temp_buf = tee_shm_get_va(shm, 0);
+	if (IS_ERR(temp_buf)) {
+		dev_err(&chip->dev, "%s:tee_shm_get_va failed for transmit\n",
+			__func__);
+		return PTR_ERR(temp_buf);
+	}
+	memset(temp_buf, 0, (MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE));
+
+	memcpy(temp_buf, buf, len);
+
+	command_params[1] = (struct tee_param) {
+		.attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT,
+		.u.memref = {
+			.shm = shm,
+			.size = MAX_RESPONSE_SIZE,
+			.shm_offs = MAX_COMMAND_SIZE,
+		},
+	};
+
+	rc = tee_client_invoke_func(pvt_data->ctx, &transceive_args,
+					command_params);
+	if ((rc < 0) || (transceive_args.ret != 0)) {
+		dev_err(&chip->dev, "%s:SUBMIT_COMMAND invoke error: 0x%x\n",
+			__func__, transceive_args.ret);
+		return (rc < 0) ? rc : transceive_args.ret;
+	}
+
+	temp_buf = tee_shm_get_va(shm, command_params[1].u.memref.shm_offs);
+	if (IS_ERR(temp_buf)) {
+		dev_err(&chip->dev, "%s:tee_shm_get_va failed for receive\n",
+			__func__);
+		return PTR_ERR(temp_buf);
+	}
+
+	resp_header = (struct tpm_header *)temp_buf;
+	resp_len = be32_to_cpu(resp_header->length);
+
+	/* sanity check resp_len */
+	if (resp_len < TPM_HEADER_SIZE) {
+		dev_err(&chip->dev, "%s:tpm response header too small\n",
+			__func__);
+		return -EIO;
+	}
+	if (resp_len > MAX_RESPONSE_SIZE) {
+		dev_err(&chip->dev,
+			"%s:resp_len=%zd exceeds MAX_RESPONSE_SIZE\n",
+			__func__, resp_len);
+		return -EIO;
+	}
+
+	/* sanity checks look good, cache the response */
+	memcpy(pvt_data->resp_buf, temp_buf, resp_len);
+	pvt_data->resp_len = resp_len;
+
+	return len;
+}
+
+static void ftpm_tee_tpm_op_cancel(struct tpm_chip *chip)
+{
+	/* not supported */
+}
+
+static u8 ftpm_tee_tpm_op_status(struct tpm_chip *chip)
+{
+	return 0;
+}
+
+static bool ftpm_tee_tpm_req_canceled(struct tpm_chip *chip, u8 status)
+{
+	return 0;
+}
+
+static const struct tpm_class_ops ftpm_tee_tpm_ops = {
+	.flags = 0,
+	.recv = ftpm_tee_tpm_op_recv,
+	.send = ftpm_tee_tpm_op_send,
+	.cancel = ftpm_tee_tpm_op_cancel,
+	.status = ftpm_tee_tpm_op_status,
+	.req_complete_mask = 0,
+	.req_complete_val = 0,
+	.req_canceled = ftpm_tee_tpm_req_canceled,
+};
+
+/*
+ * Check whether this driver supports the fTPM TA in the TEE instance
+ * represented by the params (ver/data) to this function.
+ */
+static int ftpm_tee_match(struct tee_ioctl_version_data *ver, const void *data)
+{
+	pr_debug("%s:vers->gen_caps =0x%x\n", __func__, ver->gen_caps);
+
+	/*
+	 * Currently this driver only support GP Complaint OPTEE based fTPM TA
+	 */
+	if ((ver->impl_id == TEE_IMPL_ID_OPTEE) &&
+		(ver->gen_caps & TEE_GEN_CAP_GP))
+		return 1;
+	else
+		return 0;
+}
+
+/*
+ * Undo what has been done in ftpm_tee_probe
+ */
+static void ftpm_tee_deinit(struct ftpm_tee_private *pvt_data)
+{
+	/* Release the chip */
+	if (pvt_data->state & STATE_REGISTERED_FLAG)
+		tpm_chip_unregister(pvt_data->chip);
+
+	if (pvt_data->ctx != NULL)	{
+
+		/* Free the shared memory pool */
+		if (pvt_data->state & STATE_TEE_SHMALLOC_FLAG)
+			tee_shm_free(pvt_data->shm);
+
+		/* close the existing session with fTPM TA*/
+		if (pvt_data->state & STATE_TEE_OPENED_FLAG)
+			tee_client_close_session(pvt_data->ctx,
+				pvt_data->session);
+
+		/* close the context with TEE driver */
+		tee_client_close_context(pvt_data->ctx);
+	}
+
+	/* memory allocated with devm_kzalloc() is freed automatically */
+}
+
+/*
+ * ftpm_tee_probe initialize the fTPM
+ * @param: pdev, the platform_device description.
+ * @return: 0 in case of success.
+ *	 or a negative value describing the error.
+ */
+static int ftpm_tee_probe(struct platform_device *pdev)
+{
+	int rc;
+	struct tpm_chip *chip;
+	struct device *dev = &pdev->dev;
+	struct ftpm_tee_private *pvt_data = NULL;
+	struct tee_ioctl_open_session_arg sess_arg;
+
+	dev_dbg(dev, "%s++\n", __func__);
+
+	pvt_data = devm_kzalloc(dev, sizeof(struct ftpm_tee_private),
+				GFP_KERNEL);
+	if (!pvt_data)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, pvt_data);
+
+	/* Open context with TEE driver */
+	pvt_data->ctx = tee_client_open_context(NULL, ftpm_tee_match, NULL,
+						NULL);
+	if (IS_ERR(pvt_data->ctx))	{
+		dev_err(dev, "%s:tee_client_open_context failed\n", __func__);
+		return -EPROBE_DEFER;
+	}
+
+	/* Open a session with fTPM TA*/
+	memset(&sess_arg, 0, sizeof(sess_arg));
+	memcpy(sess_arg.uuid, ftpm_ta_uuid.b, TEE_IOCTL_UUID_LEN);
+	sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
+	sess_arg.num_params = 0;
+
+	rc = tee_client_open_session(pvt_data->ctx, &sess_arg, NULL);
+	if ((rc < 0) || (sess_arg.ret != 0)) {
+		dev_err(dev, "%s:tee_client_open_session failed, err=%x\n",
+			__func__, sess_arg.ret);
+		rc = -EINVAL;
+		goto out;
+	}
+	pvt_data->session = sess_arg.session;
+	pvt_data->state |= STATE_TEE_OPENED_FLAG;
+
+	/* Allocate dynamic shared memory with fTPM TA */
+	pvt_data->shm = tee_shm_alloc(pvt_data->ctx,
+				(MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE),
+				TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
+	if (IS_ERR(pvt_data->shm)) {
+		dev_err(dev, "%s:tee_shm_alloc failed\n", __func__);
+		rc = -ENOMEM;
+		goto out;
+	}
+	pvt_data->state |= STATE_TEE_SHMALLOC_FLAG;
+
+	/* Allocate new struct tpm_chip instance */
+	chip = tpm_chip_alloc(dev, &ftpm_tee_tpm_ops);
+	if (IS_ERR(chip)) {
+		dev_err(dev, "%s:tpm_chip_alloc failed\n", __func__);
+		rc = PTR_ERR(chip);
+		goto out;
+	}
+
+	pvt_data->chip = chip;
+	pvt_data->chip->flags |= TPM_CHIP_FLAG_TPM2;
+
+	/* Create a character device for the fTPM */
+	rc = tpm_chip_register(pvt_data->chip);
+	if (rc) {
+		dev_err(dev, "%s:tpm_chip_register failed with rc=%d\n",
+			__func__, rc);
+		goto out;
+	}
+	pvt_data->state |= STATE_REGISTERED_FLAG;
+
+out:
+	if (rc)
+		ftpm_tee_deinit(pvt_data);
+
+	dev_dbg(dev, "%s-- rc = %d\n", __func__, rc);
+
+	return rc;
+}
+
+/*
+ * ftpm_tee_remove remove the TPM device
+ * @param: pdev, the platform_device description.
+ * @return: 0 in case of success.
+ */
+static int ftpm_tee_remove(struct platform_device *pdev)
+{
+	struct ftpm_tee_private *pvt_data = dev_get_drvdata(&pdev->dev);
+
+	ftpm_tee_deinit(pvt_data);
+
+	return 0;
+}
+
+static const struct of_device_id of_ftpm_tee_ids[] = {
+	{ .compatible = "microsoft,ftpm" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, of_ftpm_tee_ids);
+
+static struct platform_driver ftpm_tee_driver = {
+	.driver = {
+		.name = DRIVER_NAME,
+		.of_match_table = of_match_ptr(of_ftpm_tee_ids),
+	},
+	.probe = ftpm_tee_probe,
+	.remove = ftpm_tee_remove,
+};
+
+module_platform_driver(ftpm_tee_driver);
+
+MODULE_AUTHOR("Thirupathaiah Annapureddy <thiruan@microsoft.com>");
+MODULE_DESCRIPTION("TPM Driver for fTPM TA in TEE");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/char/tpm/tpm_ftpm_tee.h b/drivers/char/tpm/tpm_ftpm_tee.h
new file mode 100644
index 000000000000..ea1a12c183ee
--- /dev/null
+++ b/drivers/char/tpm/tpm_ftpm_tee.h
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) Microsoft Corporation
+ */
+
+#ifndef __TPM_FTPM_TEE_H__
+#define __TPM_FTPM_TEE_H__
+
+#include <linux/tee_drv.h>
+#include <linux/uuid.h>
+#include <linux/tpm.h>
+
+/* The TAFs ID implemented in this TA */
+#define FTPM_OPTEE_TA_SUBMIT_COMMAND  (0)
+#define FTPM_OPTEE_TA_EMULATE_PPI     (1)
+
+/* max. buffer size supported by fTPM  */
+#define  MAX_COMMAND_SIZE       4096
+#define  MAX_RESPONSE_SIZE      4096
+
+/* internal state flags borrowed from drivers/char/tpm/tpm_vtpm_proxy.c */
+#define STATE_OPENED_FLAG        BIT(0)
+#define STATE_WAIT_RESPONSE_FLAG BIT(1) /* waiting for emulator response */
+#define STATE_REGISTERED_FLAG    BIT(2)
+#define STATE_DRIVER_COMMAND     BIT(3) /* sending a driver specific command */
+#define STATE_TEE_OPENED_FLAG    BIT(4) /* TEE Session opened */
+#define STATE_TEE_SHMALLOC_FLAG  BIT(5) /* TEE Shared memory is allocated */
+
+/*
+ * struct ftpm_tee_private - fTPM's private data
+ * @chip:     struct tpm_chip instance registered with tpm framework.
+ * @state:    internal state
+ * @session:  fTPM TA session identifier.
+ * @resp_len: cached response buffer length.
+ * @resp_buf: cached response buffer.
+ * @ctx:      TEE context handler.
+ * @shm:      Memory pool shared with fTPM TA in TEE.
+ */
+struct ftpm_tee_private {
+	struct tpm_chip *chip;
+	long state;
+	u32 session;
+	size_t resp_len;
+	u8 resp_buf[MAX_RESPONSE_SIZE];
+	struct tee_context *ctx;
+	struct tee_shm *shm;
+};
+
+/*
+ * Note: ftpm_tee_tpm_op_recv and ftpm_tee_tpm_op_send are called from the
+ * same routine tpm_try_transmit in tpm-interface.c. These calls are protected
+ * by chip->tpm_mutex => There is no need for protecting any data shared
+ * between these routines ex: struct ftpm_tee_private
+ */
+
+/* TA_FTPM_UUID: BC50D971-D4C9-42C4-82CB-343FB7F37896 */
+static const uuid_t ftpm_ta_uuid =
+	UUID_INIT(0xBC50D971, 0xD4C9, 0x42C4,
+		  0x82, 0xCB, 0x34, 0x3F, 0xB7, 0xF3, 0x78, 0x96);
+
+#endif /* __TPM_FTPM_TEE_H__ */
-- 
2.19.1

Re: [PATCH 2/2] ftpm: firmware TPM running in TEE

[Stephen Hemminger]

On Tue, 2 Apr 2019 12:33:16 -0700
"Sasha Levin" <sashal@kernel.org> wrote:

> +/*
> + * ftpm_tee_tpm_op_recv retrieve fTPM response.
> + * @param: chip, the tpm_chip description as specified in
> driver/char/tpm/tpm.h.
> + * @param: buf,	the buffer to store data.
> + * @param: count, the number of bytes to read.
> + * @return: In case of success the number of bytes received.
> + *	    In other case, a < 0 value describing the issue.
> + */

You are using a docbook style comment but it doesn't start with
docbook prefix.

/**
 * ftpm_tee_tpm_op_recv retrieve fTPM response.
 *
 * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h.
 * @param: buf,	the buffer to store data.
 * @param: count, the number of bytes to read.
 * @return: In case of success the number of bytes received.
 *	    In other case, a < 0 value describing the issue.
 */

Re: [PATCH 2/2] ftpm: firmware TPM running in TEE

[Jarkko Sakkinen]

On Tue, Apr 02, 2019 at 01:56:43PM -0700, Stephen Hemminger wrote:
> On Tue, 2 Apr 2019 12:33:16 -0700
> "Sasha Levin" <sashal@kernel.org> wrote:
> 
> > +/*
> > + * ftpm_tee_tpm_op_recv retrieve fTPM response.
> > + * @param: chip, the tpm_chip description as specified in
> > driver/char/tpm/tpm.h.
> > + * @param: buf,	the buffer to store data.
> > + * @param: count, the number of bytes to read.
> > + * @return: In case of success the number of bytes received.
> > + *	    In other case, a < 0 value describing the issue.
> > + */
> 
> You are using a docbook style comment but it doesn't start with
> docbook prefix.
> 
> /**
>  * ftpm_tee_tpm_op_recv retrieve fTPM response.
>  *
>  * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h.
>  * @param: buf,	the buffer to store data.
>  * @param: count, the number of bytes to read.
>  * @return: In case of success the number of bytes received.
>  *	    In other case, a < 0 value describing the issue.
>  */

This is different commenting style that we use on anything else
under drivers/char/tpm.

/Jarkko

Re: [PATCH 2/2] ftpm: firmware TPM running in TEE

[Jason Gunthorpe]

On Tue, Apr 02, 2019 at 03:33:16PM -0400, Sasha Levin wrote:

> +/*
> + * Undo what has been done in ftpm_tee_probe
> + */
> +static void ftpm_tee_deinit(struct ftpm_tee_private *pvt_data)
> +{
> +	/* Release the chip */
> +	if (pvt_data->state & STATE_REGISTERED_FLAG)
> +		tpm_chip_unregister(pvt_data->chip);
> +
> +	if (pvt_data->ctx != NULL)	{
> +
> +		/* Free the shared memory pool */
> +		if (pvt_data->state & STATE_TEE_SHMALLOC_FLAG)
> +			tee_shm_free(pvt_data->shm);
> +
> +		/* close the existing session with fTPM TA*/
> +		if (pvt_data->state & STATE_TEE_OPENED_FLAG)
> +			tee_client_close_session(pvt_data->ctx,
> +				pvt_data->session);
> +
> +		/* close the context with TEE driver */
> +		tee_client_close_context(pvt_data->ctx);
> +	}

all these flags are ugly, just use a normal goto unwind during probe
please


> +
> +	/* memory allocated with devm_kzalloc() is freed automatically */
> +}
> +
> +/*
> + * ftpm_tee_probe initialize the fTPM
> + * @param: pdev, the platform_device description.
> + * @return: 0 in case of success.
> + *	 or a negative value describing the error.
> + */
> +static int ftpm_tee_probe(struct platform_device *pdev)
> +{
> +	int rc;
> +	struct tpm_chip *chip;
> +	struct device *dev = &pdev->dev;
> +	struct ftpm_tee_private *pvt_data = NULL;
> +	struct tee_ioctl_open_session_arg sess_arg;
> +
> +	dev_dbg(dev, "%s++\n", __func__);

Please don't push tracing like this to the upstream kernel, we have
ftrace and what not to do this generally :(

> +	pvt_data = devm_kzalloc(dev, sizeof(struct ftpm_tee_private),
> +				GFP_KERNEL);
> +	if (!pvt_data)
> +		return -ENOMEM;
> +
> +	dev_set_drvdata(dev, pvt_data);
> +
> +	/* Open context with TEE driver */
> +	pvt_data->ctx = tee_client_open_context(NULL, ftpm_tee_match, NULL,
> +						NULL);
> +	if (IS_ERR(pvt_data->ctx))	{
> +		dev_err(dev, "%s:tee_client_open_context failed\n", __func__);
> +		return -EPROBE_DEFER;
> +	}
> +
> +	/* Open a session with fTPM TA*/
> +	memset(&sess_arg, 0, sizeof(sess_arg));
> +	memcpy(sess_arg.uuid, ftpm_ta_uuid.b, TEE_IOCTL_UUID_LEN);
> +	sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
> +	sess_arg.num_params = 0;
> +
> +	rc = tee_client_open_session(pvt_data->ctx, &sess_arg, NULL);
> +	if ((rc < 0) || (sess_arg.ret != 0)) {
> +		dev_err(dev, "%s:tee_client_open_session failed, err=%x\n",
> +			__func__, sess_arg.ret);
> +		rc = -EINVAL;
> +		goto out;
> +	}
> +	pvt_data->session = sess_arg.session;
> +	pvt_data->state |= STATE_TEE_OPENED_FLAG;
> +
> +	/* Allocate dynamic shared memory with fTPM TA */
> +	pvt_data->shm = tee_shm_alloc(pvt_data->ctx,
> +				(MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE),
> +				TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
> +	if (IS_ERR(pvt_data->shm)) {
> +		dev_err(dev, "%s:tee_shm_alloc failed\n", __func__);
> +		rc = -ENOMEM;
> +		goto out;
> +	}
> +	pvt_data->state |= STATE_TEE_SHMALLOC_FLAG;
> +
> +	/* Allocate new struct tpm_chip instance */
> +	chip = tpm_chip_alloc(dev, &ftpm_tee_tpm_ops);

Why not tpmm_chip_alloc ? Using devm in other places

Doesn't this leak memory? I don't see a put_device cleanup for chip_alloc?

> +	if (IS_ERR(chip)) {
> +		dev_err(dev, "%s:tpm_chip_alloc failed\n", __func__);
> +		rc = PTR_ERR(chip);
> +		goto out;
> +	}
> +
> +	pvt_data->chip = chip;
> +	pvt_data->chip->flags |= TPM_CHIP_FLAG_TPM2;
> +
> +	/* Create a character device for the fTPM */
> +	rc = tpm_chip_register(pvt_data->chip);

It is a bad idea to do things after tpm_chip_register, it should be
the last thing done during probe except for error cleanup via a goto
unwind.

Jason

Re: [PATCH 2/2] ftpm: firmware TPM running in TEE

[Jarkko Sakkinen]

On Tue, Apr 02, 2019 at 03:33:16PM -0400, Sasha Levin wrote:
> This patch adds support for a software-only implementation of a TPM
> running in TEE.
> 
> There is extensive documentation of the design here:
> https://www.microsoft.com/en-us/research/publication/ftpm-software-implementation-tpm-chip/ .
> 
> As well as reference code for the firmware available here:
> https://github.com/Microsoft/ms-tpm-20-ref/tree/master/Samples/ARM32-FirmwareTPM
> 
> Signed-off-by: Thirupathaiah Annapureddy <thiruan@microsoft.com>
> Signed-off-by: Sasha Levin <sashal@kernel.org>

What is the context anyway? I mean tpm_crb already supports fTPM running
in TZ.

/Jarkko

Re: [PATCH 2/2] ftpm: firmware TPM running in TEE

[Jarkko Sakkinen]

On Wed, Apr 03, 2019 at 09:18:27PM +0300, Jarkko Sakkinen wrote:
> On Tue, Apr 02, 2019 at 03:33:16PM -0400, Sasha Levin wrote:
> > This patch adds support for a software-only implementation of a TPM
> > running in TEE.
> > 
> > There is extensive documentation of the design here:
> > https://www.microsoft.com/en-us/research/publication/ftpm-software-implementation-tpm-chip/ .
> > 
> > As well as reference code for the firmware available here:
> > https://github.com/Microsoft/ms-tpm-20-ref/tree/master/Samples/ARM32-FirmwareTPM
> > 
> > Signed-off-by: Thirupathaiah Annapureddy <thiruan@microsoft.com>
> > Signed-off-by: Sasha Levin <sashal@kernel.org>
> 
> What is the context anyway? I mean tpm_crb already supports fTPM running
> in TZ.

Might take 2-3 weeks before I have time to go through ftpm1.pdf with
full concentration. I did search through the PDF for CRB and found
zero hits.

The commit message should absolutely better explain what is going on
and preferably there should be some more broad documentation in
Documentation/security/tpm.

Now this is just a random code dump and nothing else.

Also, I have zero idea how to test this. Any recommendations on ARM
board that can be easily used to test custom TZ applications would be
nice.

/Jarkko

Re: [PATCH 2/2] ftpm: firmware TPM running in TEE

[Sasha Levin]

On Wed, Apr 03, 2019 at 09:27:28PM +0300, Jarkko Sakkinen wrote:
>On Wed, Apr 03, 2019 at 09:18:27PM +0300, Jarkko Sakkinen wrote:
>> On Tue, Apr 02, 2019 at 03:33:16PM -0400, Sasha Levin wrote:
>> > This patch adds support for a software-only implementation of a TPM
>> > running in TEE.
>> >
>> > There is extensive documentation of the design here:
>> > https://www.microsoft.com/en-us/research/publication/ftpm-software-implementation-tpm-chip/ .
>> >
>> > As well as reference code for the firmware available here:
>> > https://github.com/Microsoft/ms-tpm-20-ref/tree/master/Samples/ARM32-FirmwareTPM
>> >
>> > Signed-off-by: Thirupathaiah Annapureddy <thiruan@microsoft.com>
>> > Signed-off-by: Sasha Levin <sashal@kernel.org>
>>
>> What is the context anyway? I mean tpm_crb already supports fTPM running
>> in TZ.
>
>Might take 2-3 weeks before I have time to go through ftpm1.pdf with
>full concentration. I did search through the PDF for CRB and found
>zero hits.

The fTPM as described in that paper and implemented in practice does not
use the CRB interface, thus we can't use tpm_crb to interface with the
firmware TPM.

>The commit message should absolutely better explain what is going on
>and preferably there should be some more broad documentation in
>Documentation/security/tpm.

The code itself is just a small shim between the firmware TPM and the
kernel's TPM interface. There's really not much else to expand on in the
commit log.

I'll add some background to Documentation/security/tpm.

>Now this is just a random code dump and nothing else.

It pretty much is, but that's because this is just a "stupid" shim,
there heavy lifting is done outside of the kernel.

>Also, I have zero idea how to test this. Any recommendations on ARM
>board that can be easily used to test custom TZ applications would be
>nice.

We are testing this on a Broadcom's Stingray SST100 board, and if you
have one we can help out with setting up a test environment. Otherwise,
we haven't really tried it on other boards.

--
Thanks,
Sasha

Re: [PATCH 2/2] ftpm: firmware TPM running in TEE

[Jarkko Sakkinen]

On Sat, Apr 06, 2019 at 11:30:47AM -0400, Sasha Levin wrote:
> On Wed, Apr 03, 2019 at 09:27:28PM +0300, Jarkko Sakkinen wrote:
> > On Wed, Apr 03, 2019 at 09:18:27PM +0300, Jarkko Sakkinen wrote:
> > > On Tue, Apr 02, 2019 at 03:33:16PM -0400, Sasha Levin wrote:
> > > > This patch adds support for a software-only implementation of a TPM
> > > > running in TEE.
> > > >
> > > > There is extensive documentation of the design here:
> > > > https://www.microsoft.com/en-us/research/publication/ftpm-software-implementation-tpm-chip/ .
> > > >
> > > > As well as reference code for the firmware available here:
> > > > https://github.com/Microsoft/ms-tpm-20-ref/tree/master/Samples/ARM32-FirmwareTPM
> > > >
> > > > Signed-off-by: Thirupathaiah Annapureddy <thiruan@microsoft.com>
> > > > Signed-off-by: Sasha Levin <sashal@kernel.org>
> > > 
> > > What is the context anyway? I mean tpm_crb already supports fTPM running
> > > in TZ.
> > 
> > Might take 2-3 weeks before I have time to go through ftpm1.pdf with
> > full concentration. I did search through the PDF for CRB and found
> > zero hits.
> 
> The fTPM as described in that paper and implemented in practice does not
> use the CRB interface, thus we can't use tpm_crb to interface with the
> firmware TPM.

Obviously not but what is the reason of not implementing CRB but instead
making yet another interface? I mean CRB supports SMC call.

For me this is taking steps back as to the early days when there was
proprietary intefaces to TPM before TCG came along and stardized.

I'm sure that the TPM implementation itself could be reworked to
inteface using CRB. It would also be good for ARM as a platform as now
this new made up interface causes unwanted divergence. I thought that
throwing ad hoc intefaces everywhere is something that ARM Linux
community tries to reduce, not increase.

/Jarkko

Re: [PATCH 2/2] ftpm: firmware TPM running in TEE

[Sasha Levin]

On Wed, Apr 10, 2019 at 02:29:27PM +0300, Jarkko Sakkinen wrote:
>On Sat, Apr 06, 2019 at 11:30:47AM -0400, Sasha Levin wrote:
>> On Wed, Apr 03, 2019 at 09:27:28PM +0300, Jarkko Sakkinen wrote:
>> > On Wed, Apr 03, 2019 at 09:18:27PM +0300, Jarkko Sakkinen wrote:
>> > > On Tue, Apr 02, 2019 at 03:33:16PM -0400, Sasha Levin wrote:
>> > > > This patch adds support for a software-only implementation of a TPM
>> > > > running in TEE.
>> > > >
>> > > > There is extensive documentation of the design here:
>> > > > https://www.microsoft.com/en-us/research/publication/ftpm-software-implementation-tpm-chip/ .
>> > > >
>> > > > As well as reference code for the firmware available here:
>> > > > https://github.com/Microsoft/ms-tpm-20-ref/tree/master/Samples/ARM32-FirmwareTPM
>> > > >
>> > > > Signed-off-by: Thirupathaiah Annapureddy <thiruan@microsoft.com>
>> > > > Signed-off-by: Sasha Levin <sashal@kernel.org>
>> > >
>> > > What is the context anyway? I mean tpm_crb already supports fTPM running
>> > > in TZ.
>> >
>> > Might take 2-3 weeks before I have time to go through ftpm1.pdf with
>> > full concentration. I did search through the PDF for CRB and found
>> > zero hits.
>>
>> The fTPM as described in that paper and implemented in practice does not
>> use the CRB interface, thus we can't use tpm_crb to interface with the
>> firmware TPM.
>
>Obviously not but what is the reason of not implementing CRB but instead
>making yet another interface? I mean CRB supports SMC call.
>
>For me this is taking steps back as to the early days when there was
>proprietary intefaces to TPM before TCG came along and stardized.
>
>I'm sure that the TPM implementation itself could be reworked to
>inteface using CRB. It would also be good for ARM as a platform as now
>this new made up interface causes unwanted divergence. I thought that
>throwing ad hoc intefaces everywhere is something that ARM Linux
>community tries to reduce, not increase.

I'm not sure what the original reasons were for not using the CRB
interface. Note that the paper is from a few years ago, and
implementations of this fTPM existed before the paper, so it's very
possible that it just predates CRB.

Either way, there is existing hardware that runs this TPM and I'm trying
to get it out of Microsoft's tree and get it upstream. There's not much
I could do about existing hardware at this point.


--
Thanks,
Sasha

Re: [PATCH 2/2] ftpm: firmware TPM running in TEE

[Jarkko Sakkinen]

On Wed, Apr 10, 2019 at 12:04:32PM -0400, Sasha Levin wrote:
> On Wed, Apr 10, 2019 at 02:29:27PM +0300, Jarkko Sakkinen wrote:
> > On Sat, Apr 06, 2019 at 11:30:47AM -0400, Sasha Levin wrote:
> > > On Wed, Apr 03, 2019 at 09:27:28PM +0300, Jarkko Sakkinen wrote:
> > > > On Wed, Apr 03, 2019 at 09:18:27PM +0300, Jarkko Sakkinen wrote:
> > > > > On Tue, Apr 02, 2019 at 03:33:16PM -0400, Sasha Levin wrote:
> > > > > > This patch adds support for a software-only implementation of a TPM
> > > > > > running in TEE.
> > > > > >
> > > > > > There is extensive documentation of the design here:
> > > > > > https://www.microsoft.com/en-us/research/publication/ftpm-software-implementation-tpm-chip/ .
> > > > > >
> > > > > > As well as reference code for the firmware available here:
> > > > > > https://github.com/Microsoft/ms-tpm-20-ref/tree/master/Samples/ARM32-FirmwareTPM
> > > > > >
> > > > > > Signed-off-by: Thirupathaiah Annapureddy <thiruan@microsoft.com>
> > > > > > Signed-off-by: Sasha Levin <sashal@kernel.org>
> > > > >
> > > > > What is the context anyway? I mean tpm_crb already supports fTPM running
> > > > > in TZ.
> > > >
> > > > Might take 2-3 weeks before I have time to go through ftpm1.pdf with
> > > > full concentration. I did search through the PDF for CRB and found
> > > > zero hits.
> > > 
> > > The fTPM as described in that paper and implemented in practice does not
> > > use the CRB interface, thus we can't use tpm_crb to interface with the
> > > firmware TPM.
> > 
> > Obviously not but what is the reason of not implementing CRB but instead
> > making yet another interface? I mean CRB supports SMC call.
> > 
> > For me this is taking steps back as to the early days when there was
> > proprietary intefaces to TPM before TCG came along and stardized.
> > 
> > I'm sure that the TPM implementation itself could be reworked to
> > inteface using CRB. It would also be good for ARM as a platform as now
> > this new made up interface causes unwanted divergence. I thought that
> > throwing ad hoc intefaces everywhere is something that ARM Linux
> > community tries to reduce, not increase.
> 
> I'm not sure what the original reasons were for not using the CRB
> interface. Note that the paper is from a few years ago, and
> implementations of this fTPM existed before the paper, so it's very
> possible that it just predates CRB.
> 
> Either way, there is existing hardware that runs this TPM and I'm trying
> to get it out of Microsoft's tree and get it upstream. There's not much
> I could do about existing hardware at this point.

OK, the 2nd paragraph kind of is enough reason to pull it. Thanks for
elaborating this. Just wanted to get a clearer picture where this sits
in the universe. I'll do detailed review as soon as I have time.

I don't need to have the hardware as long as *someone* could give
tested-by for this.

/Jarkko

Re: [PATCH 1/2] ftpm: dt-binding: add dts documentation for fTPM driver

[Greg KH]

On Tue, Apr 02, 2019 at 03:33:15PM -0400, Sasha Levin wrote:
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---

I know I don't take patches without any changelog text :)

Re: [PATCH 1/2] ftpm: dt-binding: add dts documentation for fTPM driver

[Sasha Levin]

On Tue, Apr 02, 2019 at 09:37:32PM +0200, Greg KH wrote:
>On Tue, Apr 02, 2019 at 03:33:15PM -0400, Sasha Levin wrote:
>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>> ---
>
>I know I don't take patches without any changelog text :)

I honestly don't have anything meaningful to add in the changelog, and
looking at similar commits under Documentation/devicetree/bindings/ that
just add a new binding, they have a very similar changelog as well (see
204d94e63e22, 772bf73ed4dc, and b805c403c859 for example).

While I could add meaningless text which basically copies the subject
line, I don't think it will solve the concern you're pointing out here.

There is a lot of documentation for the fTPM driver which is listed in
the following patch, but it's not relevant to this patch at all.

--
Thanks,
Sasha

Re: [PATCH 1/2] ftpm: dt-binding: add dts documentation for fTPM driver

[Jarkko Sakkinen]

On Tue, Apr 02, 2019 at 03:33:15PM -0400, Sasha Levin wrote:
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---

Acked-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

/Jarkko