Re: [PATCH v4 1/4] remoteproc: Add TEE support

On Fri, Mar 08, 2024 at 03:47:05PM +0100, Arnaud Pouliquen wrote:

Add a remoteproc TEE (Trusted Execution Environment) driver that will be probed by the TEE bus. If the associated Trusted application is supported on secure part this device offers a client

Device or driver? I thought I touched on that before.

interface to load a firmware in the secure part. This firmware could be authenticated by the secure trusted application.

Signed-off-by: Arnaud Pouliquen arnaud.pouliquen@foss.st.com

Updates from V3:

• rework TEE_REMOTEPROC description in Kconfig
• fix some namings
• add tee_rproc_parse_fw to support rproc_ops::parse_fw
• add proc::tee_interface;
• add rproc struct as parameter of the tee_rproc_register() function

---

drivers/remoteproc/Kconfig | 10 + drivers/remoteproc/Makefile | 1 + drivers/remoteproc/tee_remoteproc.c | 434 ++++++++++++++++++++++++++++ include/linux/remoteproc.h | 4 + include/linux/tee_remoteproc.h | 112 +++++++ 5 files changed, 561 insertions(+) create mode 100644 drivers/remoteproc/tee_remoteproc.c create mode 100644 include/linux/tee_remoteproc.h

diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig index 48845dc8fa85..2cf1431b2b59 100644 --- a/drivers/remoteproc/Kconfig +++ b/drivers/remoteproc/Kconfig @@ -365,6 +365,16 @@ config XLNX_R5_REMOTEPROC It's safe to say N if not interested in using RPU r5f cores.

+config TEE_REMOTEPROC

• tristate "remoteproc support by a TEE application"

s/remoteproc/Remoteproc

• depends on OPTEE
• help

•  Support a remote processor with a TEE application. The Trusted
  

•  Execution Context is responsible for loading the trusted firmware
  

•  image and managing the remote processor's lifecycle.
  

•  This can be either built-in or a loadable module.
  

endif # REMOTEPROC endmenu diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile index 91314a9b43ce..fa8daebce277 100644 --- a/drivers/remoteproc/Makefile +++ b/drivers/remoteproc/Makefile @@ -36,6 +36,7 @@ obj-$(CONFIG_RCAR_REMOTEPROC) += rcar_rproc.o obj-$(CONFIG_ST_REMOTEPROC) += st_remoteproc.o obj-$(CONFIG_ST_SLIM_REMOTEPROC) += st_slim_rproc.o obj-$(CONFIG_STM32_RPROC) += stm32_rproc.o +obj-$(CONFIG_TEE_REMOTEPROC) += tee_remoteproc.o obj-$(CONFIG_TI_K3_DSP_REMOTEPROC) += ti_k3_dsp_remoteproc.o obj-$(CONFIG_TI_K3_R5_REMOTEPROC) += ti_k3_r5_remoteproc.o obj-$(CONFIG_XLNX_R5_REMOTEPROC) += xlnx_r5_remoteproc.o diff --git a/drivers/remoteproc/tee_remoteproc.c b/drivers/remoteproc/tee_remoteproc.c new file mode 100644 index 000000000000..c855210e52e3 --- /dev/null +++ b/drivers/remoteproc/tee_remoteproc.c @@ -0,0 +1,434 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/*

• • Copyright (C) STMicroelectronics 2024 - All Rights Reserved
• • Author: Arnaud Pouliquen arnaud.pouliquen@foss.st.com
• */

+#include <linux/firmware.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/remoteproc.h> +#include <linux/slab.h> +#include <linux/tee_drv.h> +#include <linux/tee_remoteproc.h>

+#include "remoteproc_internal.h"

+#define MAX_TEE_PARAM_ARRY_MEMBER 4

+/*

• • Authentication of the firmware and load in the remote processor memory
• • [in] params[0].value.a: unique 32bit identifier of the remote processor
• • [in] params[1].memref: buffer containing the image of the buffer
• */

+#define TA_RPROC_FW_CMD_LOAD_FW 1

+/*

• • Start the remote processor
• • [in] params[0].value.a: unique 32bit identifier of the remote processor
• */

+#define TA_RPROC_FW_CMD_START_FW 2

+/*

• • Stop the remote processor
• • [in] params[0].value.a: unique 32bit identifier of the remote processor
• */

+#define TA_RPROC_FW_CMD_STOP_FW 3

+/*

• • Return the address of the resource table, or 0 if not found
• • No check is done to verify that the address returned is accessible by
• • the non secure context. If the resource table is loaded in a protected
• • memory the access by the non secure context will lead to a data abort.
• • [in] params[0].value.a: unique 32bit identifier of the remote processor
• • [out] params[1].value.a: 32bit LSB resource table memory address
• • [out] params[1].value.b: 32bit MSB resource table memory address
• • [out] params[2].value.a: 32bit LSB resource table memory size
• • [out] params[2].value.b: 32bit MSB resource table memory size
• */

+#define TA_RPROC_FW_CMD_GET_RSC_TABLE 4

+/*

• • Return the address of the core dump
• • [in] params[0].value.a: unique 32bit identifier of the remote processor
• • [out] params[1].memref: address of the core dump image if exist,

• • 		else return Null
    

• */

+#define TA_RPROC_FW_CMD_GET_COREDUMP 5

+struct tee_rproc_context {

• struct list_head sessions;
• struct tee_context *tee_ctx;
• struct device *dev;

+};

+static struct tee_rproc_context *tee_rproc_ctx;

+static void tee_rproc_prepare_args(struct tee_rproc *trproc, int cmd,

• 		   struct tee_ioctl_invoke_arg *arg,
  

• 		   struct tee_param *param,
  

• 		   unsigned int num_params)
  

+{

• memset(arg, 0, sizeof(*arg));
• memset(param, 0, MAX_TEE_PARAM_ARRY_MEMBER * sizeof(*param));
• arg->func = cmd;
• arg->session = trproc->session_id;
• arg->num_params = num_params + 1;
• param[0] = (struct tee_param) {

• .attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT,
  

• .u.value.a = trproc->rproc_id,
  

• };

+}

+int tee_rproc_load_fw(struct rproc *rproc, const struct firmware *fw) +{

• struct tee_ioctl_invoke_arg arg;
• struct tee_param param[MAX_TEE_PARAM_ARRY_MEMBER];
• struct tee_rproc *trproc = rproc->tee_interface;
• struct tee_shm *fw_shm;
• int ret;

Declarations in reverse ascending order here and everywhere in the driver. Sometimes it is done properly, sometimes it isn't.

• if (!trproc)

• return -EINVAL;
  

• fw_shm = tee_shm_register_kernel_buf(tee_rproc_ctx->tee_ctx, (void *)fw->data, fw->size);
• if (IS_ERR(fw_shm))

• return PTR_ERR(fw_shm);
  

• tee_rproc_prepare_args(trproc, TA_RPROC_FW_CMD_LOAD_FW, &arg, param, 1);
• /* Provide the address of the firmware image */
• param[1] = (struct tee_param) {

• .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT,
  

• .u.memref = {
  

• 	.shm = fw_shm,
  

• 	.size = fw->size,
  

• 	.shm_offs = 0,
  

• },
  

• };
• ret = tee_client_invoke_func(tee_rproc_ctx->tee_ctx, &arg, param);
• if (ret < 0 || arg.ret != 0) {

• dev_err(tee_rproc_ctx->dev,
  

• 	"TA_RPROC_FW_CMD_LOAD_FW invoke failed TEE err: %x, ret:%x\n",
  

• 	arg.ret, ret);
  

• if (!ret)
  

• 	ret = -EIO;
  

• }
• tee_shm_free(fw_shm);
• return ret;

+} +EXPORT_SYMBOL_GPL(tee_rproc_load_fw);

+struct resource_table *tee_rproc_get_loaded_rsc_table(struct rproc *rproc, size_t *table_sz) +{

• struct tee_ioctl_invoke_arg arg;
• struct tee_param param[MAX_TEE_PARAM_ARRY_MEMBER];
• struct tee_rproc *trproc = rproc->tee_interface;
• struct resource_table *rsc_table;
• int ret;
• if (!trproc)

• return ERR_PTR(-EINVAL);
  

• tee_rproc_prepare_args(trproc, TA_RPROC_FW_CMD_GET_RSC_TABLE, &arg, param, 2);
• param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT;
• param[2].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT;
• ret = tee_client_invoke_func(tee_rproc_ctx->tee_ctx, &arg, param);
• if (ret < 0 || arg.ret != 0) {

• dev_err(tee_rproc_ctx->dev,
  

• 	"TA_RPROC_FW_CMD_GET_RSC_TABLE invoke failed TEE err: %x, ret:%x\n",
  

• 	arg.ret, ret);
  

• return ERR_PTR(-EIO);
  

• }
• *table_sz = param[2].u.value.a;
• /* If the size is null no resource table defined in the image */
• if (!*table_sz)

• return NULL;
  

• /* Store the resource table address that would be updated by the remote core. */
• rsc_table = ioremap_wc(param[1].u.value.a, *table_sz);
• if (IS_ERR_OR_NULL(rsc_table)) {

• dev_err(tee_rproc_ctx->dev, "Unable to map memory region: %lld+%zx\n",
  

• 	param[1].u.value.a, *table_sz);
  

• return ERR_PTR(-ENOMEM);
  

• }
• return rsc_table;

+} +EXPORT_SYMBOL_GPL(tee_rproc_get_loaded_rsc_table);

+int tee_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw) +{

• struct tee_rproc *trproc = rproc->tee_interface;
• struct resource_table *rsc_table;
• size_t table_sz;
• int ret;
• ret = tee_rproc_load_fw(rproc, fw);
• if (ret)

• return ret;
  

• rsc_table = tee_rproc_get_loaded_rsc_table(rproc, &table_sz);
• if (IS_ERR(rsc_table))

• return PTR_ERR(rsc_table);
  

• /* Create a copy of the resource table to have same behaviour than the elf loader. */
• rproc->cached_table = kmemdup(rsc_table, table_sz, GFP_KERNEL);
• if (!rproc->cached_table)

• return -ENOMEM;
  

Why not ->table_ptr and setting ->cached_table to NULL?

• rproc->table_ptr = rproc->cached_table;
• rproc->table_sz = table_sz;
• trproc->rsc_table = rsc_table;

I really don't see why this is needed, please remove and use rproc->table_ptr instead.

• return 0;

+} +EXPORT_SYMBOL_GPL(tee_rproc_parse_fw);

+struct resource_table *tee_rproc_find_loaded_rsc_table(struct rproc *rproc,

• 				       const struct firmware *fw)
  

+{

• struct tee_rproc *trproc = rproc->tee_interface;
• struct resource_table *rsc_table;
• size_t table_sz;
• if (!trproc)

• return ERR_PTR(-EINVAL);
  

• /* Check if the resourse table has already been obtained in tee_rproc_parse_fw() */
• if (trproc->rsc_table)

• return trproc->rsc_table;
  

Again, why not simply use rproc->rsc_table? This function should only return the resource table that was set in tee_rproc_parse_fw().

• rsc_table = tee_rproc_get_loaded_rsc_table(rproc, &table_sz);
• if (IS_ERR(rsc_table))

• return rsc_table;
  

• rproc->table_sz = table_sz;
• trproc->rsc_table = rsc_table;
• return rsc_table;

+} +EXPORT_SYMBOL_GPL(tee_rproc_find_loaded_rsc_table);

+int tee_rproc_start(struct rproc *rproc) +{

• struct tee_ioctl_invoke_arg arg;
• struct tee_param param[MAX_TEE_PARAM_ARRY_MEMBER];
• struct tee_rproc *trproc = rproc->tee_interface;
• int ret;
• if (!trproc)

• return -EINVAL;
  

• tee_rproc_prepare_args(trproc, TA_RPROC_FW_CMD_START_FW, &arg, param, 0);
• ret = tee_client_invoke_func(tee_rproc_ctx->tee_ctx, &arg, param);
• if (ret < 0 || arg.ret != 0) {

• dev_err(tee_rproc_ctx->dev,
  

• 	"TA_RPROC_FW_CMD_START_FW invoke failed TEE err: %x, ret:%x\n",
  

• 	arg.ret, ret);
  

• if (!ret)
  

• 	ret = -EIO;
  

• }
• return ret;

+} +EXPORT_SYMBOL_GPL(tee_rproc_start);

+int tee_rproc_stop(struct rproc *rproc) +{

• struct tee_ioctl_invoke_arg arg;
• struct tee_param param[MAX_TEE_PARAM_ARRY_MEMBER];
• struct tee_rproc *trproc = rproc->tee_interface;
• int ret;
• if (!trproc)

• return -EINVAL;
  

• tee_rproc_prepare_args(trproc, TA_RPROC_FW_CMD_STOP_FW, &arg, param, 0);
• ret = tee_client_invoke_func(tee_rproc_ctx->tee_ctx, &arg, param);
• if (ret < 0 || arg.ret != 0) {

• dev_err(tee_rproc_ctx->dev,
  

• 	"TA_RPROC_FW_CMD_STOP_FW invoke failed TEE err: %x, ret:%x\n",
  

• 	arg.ret, ret);
  

• if (!ret)
  

• 	ret = -EIO;
  

• }
• if (!rproc->table_ptr)

• return ret;
  

• iounmap(trproc->rsc_table);
• trproc->rsc_table = NULL;
• rproc->table_ptr = NULL;
• return 0;

+} +EXPORT_SYMBOL_GPL(tee_rproc_stop);

+static const struct tee_client_device_id stm32_tee_rproc_id_table[] = {

• {UUID_INIT(0x80a4c275, 0x0a47, 0x4905,

•    0x82, 0x85, 0x14, 0x86, 0xa9, 0x77, 0x1a, 0x08)},
  

• {}

+};

+struct tee_rproc *tee_rproc_register(struct device *dev, struct rproc *rproc, unsigned int rproc_id) +{

• struct tee_client_device *tee_device;
• struct tee_ioctl_open_session_arg sess_arg;
• struct tee_param param[MAX_TEE_PARAM_ARRY_MEMBER];
• struct tee_rproc *trproc;
• int ret;
• /*

• * Test if the device has been probed by the TEE bus. In case of failure, we ignore the
  

• * reason. The bus could be not yet probed or the service not available in the secure
  

• * firmware.The assumption in such a case is that the TEE remoteproc is not probed.
  

• */
  

• if (!tee_rproc_ctx)

• return ERR_PTR(-EPROBE_DEFER);
  

• trproc = devm_kzalloc(dev, sizeof(*trproc), GFP_KERNEL);
• if (!trproc)

• return ERR_PTR(-ENOMEM);
  

• tee_device = to_tee_client_device(tee_rproc_ctx->dev);
• memset(&sess_arg, 0, sizeof(sess_arg));
• memcpy(sess_arg.uuid, tee_device->id.uuid.b, TEE_IOCTL_UUID_LEN);
• sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
• sess_arg.num_params = 1;
• param[0] = (struct tee_param) {

• .attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT,
  

• .u.value.a = rproc_id,
  

• };
• ret = tee_client_open_session(tee_rproc_ctx->tee_ctx, &sess_arg, param);
• if (ret < 0 || sess_arg.ret != 0) {

• dev_err(dev, "tee_client_open_session failed, err: %x\n", sess_arg.ret);
  

• return ERR_PTR(-EINVAL);
  

• }
• trproc->parent = dev;
• trproc->rproc_id = rproc_id;
• trproc->session_id = sess_arg.session;
• trproc->rproc = rproc;
• rproc->tee_interface = trproc;
• list_add_tail(&trproc->node, &tee_rproc_ctx->sessions);
• return trproc;

Once this function was called by a client, what prevents a user from unloading the tee_remoteproc module and breaking everything?

+} +EXPORT_SYMBOL_GPL(tee_rproc_register);

+int tee_rproc_unregister(struct tee_rproc *trproc) +{

If you pass a struct_rproc instead of a struct tee_rproc there is no need for tee_rproc::rproc, which is only ever used in this function.

• struct rproc *rproc = trproc->rproc;
• int ret;
• ret = tee_client_close_session(tee_rproc_ctx->tee_ctx, trproc->session_id);
• if (ret < 0)

• dev_err(trproc->parent,	"tee_client_close_session failed, err: %x\n", ret);
  

• list_del(&trproc->node);
• rproc->tee_interface = NULL;
• return ret;

+} +EXPORT_SYMBOL_GPL(tee_rproc_unregister);

+static int tee_rproc_ctx_match(struct tee_ioctl_version_data *ver, const void *data) +{

• /* Today we support only the OP-TEE, could be extend to other tees */
• return (ver->impl_id == TEE_IMPL_ID_OPTEE);

+}

+static int tee_rproc_probe(struct device *dev) +{

• struct tee_context *tee_ctx;
• int ret;
• /* Open context with TEE driver */
• tee_ctx = tee_client_open_context(NULL, tee_rproc_ctx_match, NULL, NULL);
• if (IS_ERR(tee_ctx))

• return PTR_ERR(tee_ctx);
  

• tee_rproc_ctx = devm_kzalloc(dev, sizeof(*tee_ctx), GFP_KERNEL);
• if (!tee_rproc_ctx) {

• ret = -ENOMEM;
  

• goto err;
  

• }
• tee_rproc_ctx->dev = dev;
• tee_rproc_ctx->tee_ctx = tee_ctx;
• INIT_LIST_HEAD(&tee_rproc_ctx->sessions);
• return 0;

+err:

• tee_client_close_context(tee_ctx);
• return ret;

+}

+static int tee_rproc_remove(struct device *dev) +{

• struct tee_rproc *entry, *tmp;
• list_for_each_entry_safe(entry, tmp, &tee_rproc_ctx->sessions, node) {

• tee_client_close_session(tee_rproc_ctx->tee_ctx, entry->session_id);
  

• list_del(&entry->node);
  

• if (entry->rsc_table)
  

• 	iounmap(entry->rsc_table);
  

• kfree(entry);
  

• }
• tee_client_close_context(tee_rproc_ctx->tee_ctx);
• return 0;

+}

+MODULE_DEVICE_TABLE(tee, stm32_tee_rproc_id_table);

+static struct tee_client_driver tee_rproc_fw_driver = {

• .id_table = stm32_tee_rproc_id_table,
• .driver = {

• .name		= KBUILD_MODNAME,
  

• .bus		= &tee_bus_type,
  

• .probe		= tee_rproc_probe,
  

• .remove		= tee_rproc_remove,
  

• },

+};

+static int __init tee_rproc_fw_mod_init(void) +{

• return driver_register(&tee_rproc_fw_driver.driver);

+}

+static void __exit tee_rproc_fw_mod_exit(void) +{

• driver_unregister(&tee_rproc_fw_driver.driver);

+}

+module_init(tee_rproc_fw_mod_init); +module_exit(tee_rproc_fw_mod_exit);

+MODULE_DESCRIPTION(" TEE remote processor control driver"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h index b4795698d8c2..8b678009e481 100644 --- a/include/linux/remoteproc.h +++ b/include/linux/remoteproc.h @@ -503,6 +503,8 @@ enum rproc_features { RPROC_MAX_FEATURES, }; +struct tee_rproc;

/**

• struct rproc - represents a physical remote processor device
• @node: list node of this rproc object

@@ -545,6 +547,7 @@ enum rproc_features {

• @cdev: character device of the rproc
• @cdev_put_on_release: flag to indicate if remoteproc should be shutdown on @char_dev release
• @features: indicate remoteproc features

• • @tee_interface: pointer to the remoteproc tee context
  */

struct rproc { struct list_head node; @@ -586,6 +589,7 @@ struct rproc { struct cdev cdev; bool cdev_put_on_release; DECLARE_BITMAP(features, RPROC_MAX_FEATURES);

• struct tee_rproc *tee_interface;

}; /** diff --git a/include/linux/tee_remoteproc.h b/include/linux/tee_remoteproc.h new file mode 100644 index 000000000000..571e47190d02 --- /dev/null +++ b/include/linux/tee_remoteproc.h @@ -0,0 +1,112 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/*

• • Copyright(c) 2024 STMicroelectronics - All Rights Reserved
• */

+#ifndef TEE_REMOTEPROC_H +#define TEE_REMOTEPROC_H

+#include <linux/tee_drv.h> +#include <linux/firmware.h> +#include <linux/remoteproc.h>

+struct rproc;

+/**

• • struct tee_rproc - TEE remoteproc structure
• • @node: Reference in list
• • @rproc: Remoteproc reference
• • @parent: Parent device
• • @rproc_id: Identifier of the target firmware
• • @session_id: TEE session identifier
• • @rsc_table: Resource table virtual address.
• */

+struct tee_rproc {

• struct list_head node;
• struct rproc *rproc;
• struct device *parent;
• u32 rproc_id;
• u32 session_id;
• struct resource_table *rsc_table;

+};

+#if IS_REACHABLE(CONFIG_TEE_REMOTEPROC)

+struct tee_rproc *tee_rproc_register(struct device *dev, struct rproc *rproc,

• 		     unsigned int rproc_id);
  

+int tee_rproc_unregister(struct tee_rproc *trproc); +int tee_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw); +int tee_rproc_load_fw(struct rproc *rproc, const struct firmware *fw); +struct resource_table *tee_rproc_get_loaded_rsc_table(struct rproc *rproc, size_t *table_sz); +struct resource_table *tee_rproc_find_loaded_rsc_table(struct rproc *rproc,

• 				       const struct firmware *fw);
  

+int tee_rproc_start(struct rproc *rproc); +int tee_rproc_stop(struct rproc *rproc);

+#else

+static inline struct tee_rproc *tee_rproc_register(struct device *dev, struct rproc *rproc,

• 				   unsigned int rproc_id)
  

+{

• return ERR_PTR(-ENODEV);

+}

+static int tee_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw) +{

• /* This shouldn't be possible */
• WARN_ON(1);
• return 0;

+}

+static inline int tee_rproc_unregister(struct tee_rproc *trproc) +{

• /* This shouldn't be possible */
• WARN_ON(1);
• return 0;

+}

+static inline int tee_rproc_load_fw(struct rproc *rproc, const struct firmware *fw) +{

• /* This shouldn't be possible */
• WARN_ON(1);
• return 0;

+}

+static inline int tee_rproc_start(struct rproc *rproc) +{

• /* This shouldn't be possible */
• WARN_ON(1);
• return 0;

+}

+static inline int tee_rproc_stop(struct rproc *rproc) +{

• /* This shouldn't be possible */
• WARN_ON(1);
• return 0;

+}

+static inline struct resource_table * +tee_rproc_get_loaded_rsc_table(struct rproc *rproc, size_t *table_sz) +{

• /* This shouldn't be possible */
• WARN_ON(1);
• return NULL;

+}

+static inline struct resource_table * +tee_rproc_find_loaded_rsc_table(struct rproc *rproc, const struct firmware *fw) +{

• /* This shouldn't be possible */
• WARN_ON(1);
• return NULL;

+} +#endif /* CONFIG_TEE_REMOTEPROC */

+#endif /* TEE_REMOTEPROC_H */

2.25.1