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SubjectRe: [PATCH v2 2/4] tee: optee: add TEE bus device enumeration support
On Thu, Jan 10, 2019 at 05:54:55PM +0530, Sumit Garg wrote:
> OP-TEE provides a pseudo TA to enumerate TAs which can act as devices/
> services for TEE bus. So implement device enumeration using invoke
> function: PTA_CMD_GET_DEVICES provided by pseudo TA to fetch array of
> device UUIDs. Also register these enumerated devices with TEE bus as
> "optee-clntX" device.
>
> Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
> ---
> drivers/tee/optee/Makefile | 1 +
> drivers/tee/optee/core.c | 4 +
> drivers/tee/optee/device.c | 150 ++++++++++++++++++++++++++++++++++++++
> drivers/tee/optee/optee_private.h | 3 +
> 4 files changed, 158 insertions(+)
> create mode 100644 drivers/tee/optee/device.c
>
> diff --git a/drivers/tee/optee/Makefile b/drivers/tee/optee/Makefile
> index 48d262a..56263ae 100644
> --- a/drivers/tee/optee/Makefile
> +++ b/drivers/tee/optee/Makefile
> @@ -5,3 +5,4 @@ optee-objs += call.o
> optee-objs += rpc.o
> optee-objs += supp.o
> optee-objs += shm_pool.o
> +optee-objs += device.o
> diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> index e5efce3..ac59c77 100644
> --- a/drivers/tee/optee/core.c
> +++ b/drivers/tee/optee/core.c
> @@ -634,6 +634,10 @@ static struct optee *optee_probe(struct device_node *np)
> if (optee->sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
> pr_info("dynamic shared memory is enabled\n");
>
> + rc = optee_enumerate_devices();
> + if (rc)
> + goto err;
> +
> pr_info("initialized driver\n");
> return optee;
> err:
> diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c
> new file mode 100644
> index 0000000..b38d24b
> --- /dev/null
> +++ b/drivers/tee/optee/device.c
> @@ -0,0 +1,150 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2019 Linaro Ltd.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/tee_drv.h>
> +#include <linux/uuid.h>
> +#include "optee_private.h"
> +
> +/*
> + * Get device UUIDs
> + *
> + * [out] memref[0] Array of device UUIDs
> + *
> + * Return codes:
> + * TEE_SUCCESS - Invoke command success
> + * TEE_ERROR_BAD_PARAMETERS - Incorrect input param
> + * TEE_ERROR_SHORT_BUFFER - Output buffer size less than required
> + */
> +#define PTA_CMD_GET_DEVICES 0x0
> +
> +static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
> +{
> + if (ver->impl_id == TEE_IMPL_ID_OPTEE)
> + return 1;
> + else
> + return 0;
> +}
> +
> +static int get_devices(struct tee_context *ctx, u32 session,
> + struct tee_shm *device_uuid, u32 *shm_size)

Missing const on device_uuid?


> +{
> + u32 ret = 0;
> + struct tee_ioctl_invoke_arg inv_arg = {0};
> + struct tee_param param[4] = {0};
> +
> + /* Invoke PTA_CMD_GET_DEVICES function */
> + inv_arg.func = PTA_CMD_GET_DEVICES;
> + inv_arg.session = session;
> + inv_arg.num_params = 4;
> +
> + /* Fill invoke cmd params */
> + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
> + param[0].u.memref.shm = device_uuid;
> + param[0].u.memref.size = *shm_size;
> + param[0].u.memref.shm_offs = 0;
> +
> + ret = tee_client_invoke_func(ctx, &inv_arg, param);
> + if ((ret < 0) || ((inv_arg.ret != TEEC_SUCCESS) &&
> + (inv_arg.ret != TEEC_ERROR_SHORT_BUFFER))) {
> + pr_err("PTA_CMD_GET_DEVICES invoke function err: %x\n",
> + inv_arg.ret);
> + return -EINVAL;
> + }
> +
> + *shm_size = param[0].u.memref.size;
> +
> + return 0;
> +}
> +
> +static int optee_register_device(uuid_t *device_uuid, u32 device_id)

const?


> +{
> + struct tee_client_device *optee_device = NULL;
> + int rc;
> +
> + optee_device = kzalloc(sizeof(*optee_device), GFP_KERNEL);
> + if (!optee_device)
> + return -ENOMEM;
> +
> + optee_device->dev.bus = &tee_bus_type;
> + dev_set_name(&optee_device->dev, "optee-clnt%u", device_id);
> + uuid_copy(&optee_device->id.uuid, device_uuid);
> +
> + rc = device_register(&optee_device->dev);
> + if (rc)
> + pr_err("device registration failed, err: %d\n", rc);

Leak optee_device?


> +
> + return rc;
> +}
> +
> +int optee_enumerate_devices(void)
> +{
> + uuid_t pta_uuid =
> + UUID_INIT(0x7011a688, 0xddde, 0x4053,
> + 0xa5, 0xa9, 0x7b, 0x3c, 0x4d, 0xdf, 0x13, 0xb8);

I think this could/should be const too.


> + struct tee_ioctl_open_session_arg sess_arg = {0};
> + struct tee_shm *device_shm = NULL;
> + uuid_t *device_uuid = NULL;
> + struct tee_context *ctx = NULL;
> + u32 shm_size = 0, idx = 0;
> + int rc;
> +
> + /* Open context with OP-TEE driver */
> + ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL);
> + if (IS_ERR(ctx))
> + return -ENODEV;
> +
> + /* Open session with device enumeration pseudo TA */
> + memcpy(sess_arg.uuid, pta_uuid.b, TEE_IOCTL_UUID_LEN);
> + sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
> + sess_arg.num_params = 0;
> +
> + rc = tee_client_open_session(ctx, &sess_arg, NULL);
> + if ((rc < 0) || (sess_arg.ret != TEEC_SUCCESS)) {
> + /* Device enumeration pseudo TA not found */
> + rc = 0;
> + goto out_ctx;
> + }
> +
> + rc = get_devices(ctx, sess_arg.session, device_shm, &shm_size);

Use NULL and 0 directly here instead of relying on initialized values.
This makes it clear we are fetching the size of a buffer and are doing
something different to the next call to get_devices().


> + if (rc < 0)
> + goto out_sess;
> +
> + device_shm = tee_shm_alloc(ctx, shm_size,
> + TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
> + if (IS_ERR(device_shm)) {
> + pr_err("tee_shm_alloc failed\n");
> + rc = PTR_ERR(device_shm);
> + goto out_sess;
> + }
> +
> + rc = get_devices(ctx, sess_arg.session, device_shm, &shm_size);
> + if (rc < 0)
> + goto out_shm;
> +
> + device_uuid = tee_shm_get_va(device_shm, 0);
> + if (IS_ERR(device_uuid)) {
> + pr_err("tee_shm_get_va failed\n");
> + rc = PTR_ERR(device_uuid);
> + goto out_shm;
> + }
> +
> + while (idx < shm_size / sizeof(uuid_t)) {

This is a very uncommon way to write a for loop ;-).


> + rc = optee_register_device(&device_uuid[idx], idx);
> + if (rc)
> + goto out_shm;
> + idx++;
> + }
> +
> +out_shm:
> + tee_shm_free(device_shm);
> +out_sess:
> + tee_client_close_session(ctx, sess_arg.session);
> +out_ctx:
> + tee_client_close_context(ctx);
> +
> + return rc;
> +}
> diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> index 35e7938..a5e84af 100644
> --- a/drivers/tee/optee/optee_private.h
> +++ b/drivers/tee/optee/optee_private.h
> @@ -28,6 +28,7 @@
> #define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006
> #define TEEC_ERROR_COMMUNICATION 0xFFFF000E
> #define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C
> +#define TEEC_ERROR_SHORT_BUFFER 0xFFFF0010
>
> #define TEEC_ORIGIN_COMMS 0x00000002
>
> @@ -181,6 +182,8 @@ void optee_free_pages_list(void *array, size_t num_entries);
> void optee_fill_pages_list(u64 *dst, struct page **pages, int num_pages,
> size_t page_offset);
>
> +int optee_enumerate_devices(void);
> +
> /*
> * Small helpers
> */
> --
> 2.7.4
>

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