Re: [PATCH v3 3/5] optee: refactor driver with internal callbacks

On Thu, 29 Jul 2021 at 12:26, Jens Wiklander jens.wiklander@linaro.org wrote:

On Wed, Jul 28, 2021 at 03:29:33PM +0530, Sumit Garg wrote:

...

On Thu, 22 Jul 2021 at 17:48, Jens Wiklander jens.wiklander@linaro.org wrote:

...

The OP-TEE driver is refactored with three internal callbacks replacing direct calls to optee_from_msg_param(), optee_to_msg_param() and optee_do_call_with_arg().

These functions a central to communicating with OP-TEE in secure world by using the SMC Calling Convention directly.

This refactoring makes room for using other primitives to communicate with OP-TEE in secure world while being able to reuse as much as possible from the present driver.

Signed-off-by: Jens Wiklander jens.wiklander@linaro.org

drivers/tee/optee/call.c | 86 +++++++++-------- drivers/tee/optee/core.c | 148 ++++++++++++++++++++---------- drivers/tee/optee/optee_private.h | 35 +++++-- drivers/tee/optee/rpc.c | 19 ++-- 4 files changed, 182 insertions(+), 106 deletions(-)

diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c index 9d8f5a95e42f..00ecd794e59a 100644 --- a/drivers/tee/optee/call.c +++ b/drivers/tee/optee/call.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-only /*

• • Copyright (c) 2015, Linaro Limited

• • Copyright (c) 2015-2021, Linaro Limited
  */

#include <linux/arm-smccc.h> #include <linux/device.h> @@ -118,20 +118,25 @@ static struct optee_session *find_session(struct optee_context_data *ctxdata, /**

• optee_do_call_with_arg() - Do an SMC to OP-TEE in secure world
• @ctx: calling context

• • @parg: physical address of message to pass to secure world

• • @arg: shared memory holding the message to pass to secure world
  • Does and SMC to OP-TEE in secure world and handles eventual resulting
  • Remote Procedure Calls (RPC) from OP-TEE.
  • Returns return code from secure world, 0 is OK
  */

-u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg) +int optee_do_call_with_arg(struct tee_context *ctx, struct tee_shm *arg) { struct optee *optee = tee_get_drvdata(ctx->teedev); struct optee_call_waiter w; struct optee_rpc_param param = { }; struct optee_call_ctx call_ctx = { };

•   u32 ret;
  

•   phys_addr_t parg;
  

•   int rc;
  

•   rc = tee_shm_get_pa(arg, 0, &parg);
  

•   if (rc)
  

•           return rc;
  
    param.a0 = OPTEE_SMC_CALL_WITH_ARG;
    reg_pair_from_64(&param.a1, &param.a2, parg);
  

@@ -160,7 +165,7 @@ u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg) param.a3 = res.a3; optee_handle_rpc(ctx, &param, &call_ctx); } else {

•                   ret = res.a0;
  

•                   rc = res.a0;
                    break;
            }
    }
  

@@ -172,14 +177,12 @@ u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg) */ optee_cq_wait_final(&optee->call_queue, &w);

•   return ret;
  

•   return rc;
  

}

static struct tee_shm *get_msg_arg(struct tee_context *ctx, size_t num_params,

•                              struct optee_msg_arg **msg_arg,
  

•                              phys_addr_t *msg_parg)
  

•                              struct optee_msg_arg **msg_arg)
  

{

•   int rc;
    struct tee_shm *shm;
    struct optee_msg_arg *ma;
  
  

@@ -190,22 +193,13 @@ static struct tee_shm *get_msg_arg(struct tee_context *ctx, size_t num_params,

    ma = tee_shm_get_va(shm, 0);
    if (IS_ERR(ma)) {

•           rc = PTR_ERR(ma);
  

•           goto out;
  

•           tee_shm_free(shm);
  

•           return (void *)ma;
    }
  
  

•   rc = tee_shm_get_pa(shm, 0, msg_parg);
  

•   if (rc)
  

•           goto out;
  

•   memset(ma, 0, OPTEE_MSG_GET_ARG_SIZE(num_params));
    ma->num_params = num_params;
    *msg_arg = ma;
  

-out:

•   if (rc) {
  

•           tee_shm_free(shm);
  

•           return ERR_PTR(rc);
  

•   }
  
    return shm;
  

} @@ -214,16 +208,16 @@ int optee_open_session(struct tee_context *ctx, struct tee_ioctl_open_session_arg *arg, struct tee_param *param) {

•   struct optee *optee = tee_get_drvdata(ctx->teedev);
    struct optee_context_data *ctxdata = ctx->data;
    int rc;
    struct tee_shm *shm;
    struct optee_msg_arg *msg_arg;
  

•   phys_addr_t msg_parg;
    struct optee_session *sess = NULL;
    uuid_t client_uuid;
  
    /* +2 for the meta parameters added below */
  

•   shm = get_msg_arg(ctx, arg->num_params + 2, &msg_arg, &msg_parg);
  

•   shm = get_msg_arg(ctx, arg->num_params + 2, &msg_arg);
    if (IS_ERR(shm))
            return PTR_ERR(shm);
  
  

@@ -247,7 +241,8 @@ int optee_open_session(struct tee_context *ctx, goto out; export_uuid(msg_arg->params[1].u.octets, &client_uuid);

•   rc = optee_to_msg_param(msg_arg->params + 2, arg->num_params, param);
  

•   rc = optee->ops->to_msg_param(optee, msg_arg->params + 2,
  

•                                 arg->num_params, param);
    if (rc)
            goto out;
  
  

@@ -257,7 +252,7 @@ int optee_open_session(struct tee_context *ctx, goto out; }

•   if (optee_do_call_with_arg(ctx, msg_parg)) {
  

•   if (optee->ops->do_call_with_arg(ctx, shm)) {
            msg_arg->ret = TEEC_ERROR_COMMUNICATION;
            msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
    }
  

@@ -272,7 +267,8 @@ int optee_open_session(struct tee_context *ctx, kfree(sess); }

•   if (optee_from_msg_param(param, arg->num_params, msg_arg->params + 2)) {
  

•   if (optee->ops->from_msg_param(optee, param, arg->num_params,
  

•                                  msg_arg->params + 2)) {
            arg->ret = TEEC_ERROR_COMMUNICATION;
            arg->ret_origin = TEEC_ORIGIN_COMMS;
            /* Close session again to avoid leakage */
  

@@ -291,16 +287,16 @@ int optee_open_session(struct tee_context *ctx, int optee_close_session_helper(struct tee_context *ctx, u32 session) { struct tee_shm *shm;

•   struct optee *optee = tee_get_drvdata(ctx->teedev);
    struct optee_msg_arg *msg_arg;
  

•   phys_addr_t msg_parg;
  
  

•   shm = get_msg_arg(ctx, 0, &msg_arg, &msg_parg);
  

•   shm = get_msg_arg(ctx, 0, &msg_arg);
    if (IS_ERR(shm))
            return PTR_ERR(shm);
  
    msg_arg->cmd = OPTEE_MSG_CMD_CLOSE_SESSION;
    msg_arg->session = session;
  

•   optee_do_call_with_arg(ctx, msg_parg);
  

•   optee->ops->do_call_with_arg(ctx, shm);
  
    tee_shm_free(shm);
  
  

@@ -328,10 +324,10 @@ int optee_close_session(struct tee_context *ctx, u32 session) int optee_invoke_func(struct tee_context *ctx, struct tee_ioctl_invoke_arg *arg, struct tee_param *param) {

•   struct optee *optee = tee_get_drvdata(ctx->teedev);
    struct optee_context_data *ctxdata = ctx->data;
    struct tee_shm *shm;
    struct optee_msg_arg *msg_arg;
  

•   phys_addr_t msg_parg;
    struct optee_session *sess;
    int rc;
  
  

@@ -342,7 +338,7 @@ int optee_invoke_func(struct tee_context *ctx, struct tee_ioctl_invoke_arg *arg, if (!sess) return -EINVAL;

•   shm = get_msg_arg(ctx, arg->num_params, &msg_arg, &msg_parg);
  

•   shm = get_msg_arg(ctx, arg->num_params, &msg_arg);
    if (IS_ERR(shm))
            return PTR_ERR(shm);
    msg_arg->cmd = OPTEE_MSG_CMD_INVOKE_COMMAND;
  

@@ -350,16 +346,18 @@ int optee_invoke_func(struct tee_context *ctx, struct tee_ioctl_invoke_arg *arg, msg_arg->session = arg->session; msg_arg->cancel_id = arg->cancel_id;

•   rc = optee_to_msg_param(msg_arg->params, arg->num_params, param);
  

•   rc = optee->ops->to_msg_param(optee, msg_arg->params, arg->num_params,
  

•                                 param);
    if (rc)
            goto out;
  
  

•   if (optee_do_call_with_arg(ctx, msg_parg)) {
  

•   if (optee->ops->do_call_with_arg(ctx, shm)) {
            msg_arg->ret = TEEC_ERROR_COMMUNICATION;
            msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
    }
  
  

•   if (optee_from_msg_param(param, arg->num_params, msg_arg->params)) {
  

•   if (optee->ops->from_msg_param(optee, param, arg->num_params,
  

•                                  msg_arg->params)) {
            msg_arg->ret = TEEC_ERROR_COMMUNICATION;
            msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
    }
  

@@ -373,10 +371,10 @@ int optee_invoke_func(struct tee_context *ctx, struct tee_ioctl_invoke_arg *arg,

int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session) {

•   struct optee *optee = tee_get_drvdata(ctx->teedev);
    struct optee_context_data *ctxdata = ctx->data;
    struct tee_shm *shm;
    struct optee_msg_arg *msg_arg;
  

•   phys_addr_t msg_parg;
    struct optee_session *sess;
  
    /* Check that the session is valid */
  

@@ -386,14 +384,14 @@ int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session) if (!sess) return -EINVAL;

•   shm = get_msg_arg(ctx, 0, &msg_arg, &msg_parg);
  

•   shm = get_msg_arg(ctx, 0, &msg_arg);
    if (IS_ERR(shm))
            return PTR_ERR(shm);
  
    msg_arg->cmd = OPTEE_MSG_CMD_CANCEL;
    msg_arg->session = session;
    msg_arg->cancel_id = cancel_id;
  

•   optee_do_call_with_arg(ctx, msg_parg);
  

•   optee->ops->do_call_with_arg(ctx, shm);
  
    tee_shm_free(shm);
    return 0;
  

@@ -592,10 +590,10 @@ int optee_shm_register(struct tee_context *ctx, struct tee_shm *shm, struct page **pages, size_t num_pages, unsigned long start) {

•   struct tee_shm *shm_arg = NULL;
  

•   struct optee *optee = tee_get_drvdata(ctx->teedev);
    struct optee_msg_arg *msg_arg;
  

•   struct tee_shm *shm_arg;
    u64 *pages_list;
  

•   phys_addr_t msg_parg;
    int rc;
  
    if (!num_pages)
  

@@ -609,7 +607,7 @@ int optee_shm_register(struct tee_context *ctx, struct tee_shm *shm, if (!pages_list) return -ENOMEM;

•   shm_arg = get_msg_arg(ctx, 1, &msg_arg, &msg_parg);
  

•   shm_arg = get_msg_arg(ctx, 1, &msg_arg);
    if (IS_ERR(shm_arg)) {
            rc = PTR_ERR(shm_arg);
            goto out;
  

@@ -630,7 +628,7 @@ int optee_shm_register(struct tee_context *ctx, struct tee_shm *shm, msg_arg->params->u.tmem.buf_ptr = virt_to_phys(pages_list) | (tee_shm_get_page_offset(shm) & (OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));

•   if (optee_do_call_with_arg(ctx, msg_parg) ||
  

•   if (optee->ops->do_call_with_arg(ctx, shm_arg) ||
        msg_arg->ret != TEEC_SUCCESS)
            rc = -EINVAL;
  
  

@@ -642,12 +640,12 @@ int optee_shm_register(struct tee_context *ctx, struct tee_shm *shm,

int optee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm) {

•   struct tee_shm *shm_arg;
  

•   struct optee *optee = tee_get_drvdata(ctx->teedev);
    struct optee_msg_arg *msg_arg;
  

•   phys_addr_t msg_parg;
  

•   struct tee_shm *shm_arg;
    int rc = 0;
  
  

•   shm_arg = get_msg_arg(ctx, 1, &msg_arg, &msg_parg);
  

•   shm_arg = get_msg_arg(ctx, 1, &msg_arg);
    if (IS_ERR(shm_arg))
            return PTR_ERR(shm_arg);
  
  

@@ -656,7 +654,7 @@ int optee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm) msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT; msg_arg->params[0].u.rmem.shm_ref = (unsigned long)shm;

•   if (optee_do_call_with_arg(ctx, msg_parg) ||
  

•   if (optee->ops->do_call_with_arg(ctx, shm_arg) ||
        msg_arg->ret != TEEC_SUCCESS)
            rc = -EINVAL;
    tee_shm_free(shm_arg);
  

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index 949223b214c3..f689f171a794 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-only /*

• • Copyright (c) 2015, Linaro Limited

• • Copyright (c) 2015-2021, Linaro Limited
  */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt @@ -26,21 +26,87 @@

#define OPTEE_SHM_NUM_PRIV_PAGES CONFIG_OPTEE_SHM_NUM_PRIV_PAGES

+static void from_msg_param_value(struct tee_param *p, u32 attr,

•                            const struct optee_msg_param *mp)
  

+{

•   p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT +
  

•             attr - OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
  

•   p->u.value.a = mp->u.value.a;
  

•   p->u.value.b = mp->u.value.b;
  

•   p->u.value.c = mp->u.value.c;
  

+}

+static int from_msg_param_tmp_mem(struct tee_param *p, u32 attr,

•                             const struct optee_msg_param *mp)
  

+{

•   struct tee_shm *shm;
  

•   phys_addr_t pa;
  

•   int rc;
  

•   p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
  

•             attr - OPTEE_MSG_ATTR_TYPE_TMEM_INPUT;
  

•   p->u.memref.size = mp->u.tmem.size;
  

•   shm = (struct tee_shm *)(unsigned long)mp->u.tmem.shm_ref;
  

•   if (!shm) {
  

•           p->u.memref.shm_offs = 0;
  

•           p->u.memref.shm = NULL;
  

•           return 0;
  

•   }
  

•   rc = tee_shm_get_pa(shm, 0, &pa);
  

•   if (rc)
  

•           return rc;
  

•   p->u.memref.shm_offs = mp->u.tmem.buf_ptr - pa;
  

•   p->u.memref.shm = shm;
  

•   /* Check that the memref is covered by the shm object */
  

•   if (p->u.memref.size) {
  

•           size_t o = p->u.memref.shm_offs +
  

•                      p->u.memref.size - 1;
  

•           rc = tee_shm_get_pa(shm, o, NULL);
  

•           if (rc)
  

•                   return rc;
  

•   }
  

•   return 0;
  

+}

+static void from_msg_param_reg_mem(struct tee_param *p, u32 attr,

•                              const struct optee_msg_param *mp)
  

+{

•   struct tee_shm *shm;
  

•   p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
  

•             attr - OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
  

•   p->u.memref.size = mp->u.rmem.size;
  

•   shm = (struct tee_shm *)(unsigned long)mp->u.rmem.shm_ref;
  

•   if (shm) {
  

•           p->u.memref.shm_offs = mp->u.rmem.offs;
  

•           p->u.memref.shm = shm;
  

•   } else {
  

•           p->u.memref.shm_offs = 0;
  

•           p->u.memref.shm = NULL;
  

•   }
  

+}

/**

• optee_from_msg_param() - convert from OPTEE_MSG parameters to

•                     struct tee_param
  

• • @optee: main service struct

I don't see this new argument being used. Can you throw some light on the use-case for this additional argument?

This function is registered as a callback and the counter part in the FF-A ABI (optee_ffa_from_msg_param()) will need this parameter. So it's needed to have the same signature.

Okay, I see its usage.

...

...

• @params: subsystem internal parameter representation
• @num_params: number of elements in the parameter arrays
• @msg_params: OPTEE_MSG parameters
• Returns 0 on success or <0 on failure

*/ -int optee_from_msg_param(struct tee_param *params, size_t num_params,

•                    const struct optee_msg_param *msg_params)
  

+static int optee_from_msg_param(struct optee *optee, struct tee_param *params,

•                           size_t num_params,
  

•                           const struct optee_msg_param *msg_params)
  

{ int rc; size_t n;

•   struct tee_shm *shm;
  

•   phys_addr_t pa;
  
    for (n = 0; n < num_params; n++) {
            struct tee_param *p = params + n;
  

@@ -55,48 +121,19 @@ int optee_from_msg_param(struct tee_param *params, size_t num_params, case OPTEE_MSG_ATTR_TYPE_VALUE_INPUT: case OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT: case OPTEE_MSG_ATTR_TYPE_VALUE_INOUT:

•                   p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT +
  

•                             attr - OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
  

•                   p->u.value.a = mp->u.value.a;
  

•                   p->u.value.b = mp->u.value.b;
  

•                   p->u.value.c = mp->u.value.c;
  

•                   from_msg_param_value(p, attr, mp);
                    break;
            case OPTEE_MSG_ATTR_TYPE_TMEM_INPUT:
            case OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT:
            case OPTEE_MSG_ATTR_TYPE_TMEM_INOUT:
  

•                   p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
  

•                             attr - OPTEE_MSG_ATTR_TYPE_TMEM_INPUT;
  

•                   p->u.memref.size = mp->u.tmem.size;
  

•                   shm = (struct tee_shm *)(unsigned long)
  

•                           mp->u.tmem.shm_ref;
  

•                   if (!shm) {
  

•                           p->u.memref.shm_offs = 0;
  

•                           p->u.memref.shm = NULL;
  

•                           break;
  

•                   }
  

•                   rc = tee_shm_get_pa(shm, 0, &pa);
  

•                   rc = from_msg_param_tmp_mem(p, attr, mp);
                    if (rc)
                            return rc;
  

•                   p->u.memref.shm_offs = mp->u.tmem.buf_ptr - pa;
  

•                   p->u.memref.shm = shm;
                    break;
            case OPTEE_MSG_ATTR_TYPE_RMEM_INPUT:
            case OPTEE_MSG_ATTR_TYPE_RMEM_OUTPUT:
            case OPTEE_MSG_ATTR_TYPE_RMEM_INOUT:
  

•                   p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
  

•                             attr - OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
  

•                   p->u.memref.size = mp->u.rmem.size;
  

•                   shm = (struct tee_shm *)(unsigned long)
  

•                           mp->u.rmem.shm_ref;
  

•                   if (!shm) {
  

•                           p->u.memref.shm_offs = 0;
  

•                           p->u.memref.shm = NULL;
  

•                           break;
  

•                   }
  

•                   p->u.memref.shm_offs = mp->u.rmem.offs;
  

•                   p->u.memref.shm = shm;
  

•                   from_msg_param_reg_mem(p, attr, mp);
                    break;
  
            default:
  

@@ -106,6 +143,16 @@ int optee_from_msg_param(struct tee_param *params, size_t num_params, return 0; }

+static void to_msg_param_value(struct optee_msg_param *mp,

•                          const struct tee_param *p)
  

+{

•   mp->attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT + p->attr -
  

•              TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
  

•   mp->u.value.a = p->u.value.a;
  

•   mp->u.value.b = p->u.value.b;
  

•   mp->u.value.c = p->u.value.c;
  

+}

static int to_msg_param_tmp_mem(struct optee_msg_param *mp, const struct tee_param *p) { @@ -148,13 +195,15 @@ static int to_msg_param_reg_mem(struct optee_msg_param *mp,

/**

• optee_to_msg_param() - convert from struct tee_params to OPTEE_MSG parameters

• • @optee: main service struct

Same here.

This function is also registered as a callback. Here it's questionable though, but I added it to let optee->ops->to_msg_param() and optee->ops->from_msg_param() have better symmetry.

I am fine with that. FWIW:

Reviewed-by: Sumit Garg sumit.garg@linaro.org

-Sumit

Thanks, Jens