Re: [Tee-dev] [PATCH v2 2/4] tee: optee: add TEE bus device enumeration support

On Thu, 10 Jan 2019 at 19:49, Daniel Thompson daniel.thompson@linaro.org wrote:

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?

I don't think we should have a const for device_uuid here as this is shared memory struct pointer which is dynamically allocated and used to fetch device UUIDs.

...

+{

• 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?

Will add const here.

...

+{

• 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?

Will fix.

...

• 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.

Agree, will add const here 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().

Ok, will directly pass NULL here.

...

• 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 ;-).

Ok, will add "num_devices" variable.

-Sumit

...

•         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