diff options
Diffstat (limited to 'drivers/tee/qcomtee/user_obj.c')
| -rw-r--r-- | drivers/tee/qcomtee/user_obj.c | 692 |
1 files changed, 692 insertions, 0 deletions
diff --git a/drivers/tee/qcomtee/user_obj.c b/drivers/tee/qcomtee/user_obj.c new file mode 100644 index 000000000000..0139905f2684 --- /dev/null +++ b/drivers/tee/qcomtee/user_obj.c @@ -0,0 +1,692 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/slab.h> +#include <linux/uaccess.h> + +#include "qcomtee.h" + +/** + * DOC: User Objects aka Supplicants + * + * Any userspace process with access to the TEE device file can behave as a + * supplicant by creating a user object. Any TEE parameter of type OBJREF with + * %QCOMTEE_OBJREF_FLAG_USER flag set is considered a user object. + * + * A supplicant uses qcomtee_user_object_select() (i.e. TEE_IOC_SUPPL_RECV) to + * receive a QTEE user object request and qcomtee_user_object_submit() + * (i.e. TEE_IOC_SUPPL_SEND) to submit a response. QTEE expects to receive the + * response, including OB and OO in a specific order in the message; parameters + * submitted with qcomtee_user_object_submit() should maintain this order. + */ + +/** + * struct qcomtee_user_object - User object. + * @object: &struct qcomtee_object representing the user object. + * @ctx: context for which the user object is defined. + * @object_id: object ID in @ctx. + * @notify: notify on release. + * + * Any object managed in userspace is represented by this struct. + * If @notify is set, a notification message is sent back to userspace + * upon release. + */ +struct qcomtee_user_object { + struct qcomtee_object object; + struct tee_context *ctx; + u64 object_id; + bool notify; +}; + +#define to_qcomtee_user_object(o) \ + container_of((o), struct qcomtee_user_object, object) + +static struct qcomtee_object_operations qcomtee_user_object_ops; + +/* Is it a user object? */ +int is_qcomtee_user_object(struct qcomtee_object *object) +{ + return object != NULL_QCOMTEE_OBJECT && + typeof_qcomtee_object(object) == QCOMTEE_OBJECT_TYPE_CB && + object->ops == &qcomtee_user_object_ops; +} + +/* Set the user object's 'notify on release' flag. */ +void qcomtee_user_object_set_notify(struct qcomtee_object *object, bool notify) +{ + if (is_qcomtee_user_object(object)) + to_qcomtee_user_object(object)->notify = notify; +} + +/* Supplicant Requests: */ + +/** + * enum qcomtee_req_state - Current state of request. + * @QCOMTEE_REQ_QUEUED: Request is waiting for supplicant. + * @QCOMTEE_REQ_PROCESSING: Request has been picked by the supplicant. + * @QCOMTEE_REQ_PROCESSED: Response has been submitted for the request. + */ +enum qcomtee_req_state { + QCOMTEE_REQ_QUEUED = 1, + QCOMTEE_REQ_PROCESSING, + QCOMTEE_REQ_PROCESSED, +}; + +/* User requests sent to supplicants. */ +struct qcomtee_ureq { + enum qcomtee_req_state state; + + /* User Request: */ + int req_id; + u64 object_id; + u32 op; + struct qcomtee_arg *args; + int errno; + + struct list_head node; + struct completion c; /* Completion for whoever wait. */ +}; + +/* + * Placeholder for a PROCESSING request in qcomtee_context.reqs_idr. + * + * If the thread that calls qcomtee_object_invoke() dies and the supplicant + * is processing the request, replace the entry in qcomtee_context.reqs_idr + * with empty_ureq. This ensures that (1) the req_id remains busy and is not + * reused, and (2) the supplicant fails to submit the response and performs + * the necessary rollback. + */ +static struct qcomtee_ureq empty_ureq = { .state = QCOMTEE_REQ_PROCESSING }; + +/* Enqueue a user request for a context and assign a request ID. */ +static int ureq_enqueue(struct qcomtee_context_data *ctxdata, + struct qcomtee_ureq *ureq) +{ + int ret; + + guard(mutex)(&ctxdata->reqs_lock); + /* Supplicant is dying. */ + if (ctxdata->released) + return -ENODEV; + + /* Allocate an ID and queue the request. */ + ret = idr_alloc(&ctxdata->reqs_idr, ureq, 0, 0, GFP_KERNEL); + if (ret < 0) + return ret; + + ureq->req_id = ret; + ureq->state = QCOMTEE_REQ_QUEUED; + list_add_tail(&ureq->node, &ctxdata->reqs_list); + + return 0; +} + +/** + * ureq_dequeue() - Dequeue a user request from a context. + * @ctxdata: context data for a context to dequeue the request. + * @req_id: ID of the request to be dequeued. + * + * It dequeues a user request and releases its request ID. + * + * Context: The caller should hold &qcomtee_context_data->reqs_lock. + * Return: Returns the user request associated with this ID; otherwise, NULL. + */ +static struct qcomtee_ureq *ureq_dequeue(struct qcomtee_context_data *ctxdata, + int req_id) +{ + struct qcomtee_ureq *ureq; + + ureq = idr_remove(&ctxdata->reqs_idr, req_id); + if (ureq == &empty_ureq || !ureq) + return NULL; + + list_del(&ureq->node); + + return ureq; +} + +/** + * ureq_select() - Select the next request in a context. + * @ctxdata: context data for a context to pop a request. + * @ubuf_size: size of the available buffer for UBUF parameters. + * @num_params: number of entries for the TEE parameter array. + * + * It checks if @num_params is large enough to fit the next request arguments. + * It checks if @ubuf_size is large enough to fit IB buffer arguments. + * + * Context: The caller should hold &qcomtee_context_data->reqs_lock. + * Return: On success, returns a request; + * on failure, returns NULL and ERR_PTR. + */ +static struct qcomtee_ureq *ureq_select(struct qcomtee_context_data *ctxdata, + size_t ubuf_size, int num_params) +{ + struct qcomtee_ureq *req, *ureq = NULL; + struct qcomtee_arg *u; + int i; + + /* Find the a queued request. */ + list_for_each_entry(req, &ctxdata->reqs_list, node) { + if (req->state == QCOMTEE_REQ_QUEUED) { + ureq = req; + break; + } + } + + if (!ureq) + return NULL; + + u = ureq->args; + /* (1) Is there enough TEE parameters? */ + if (num_params < qcomtee_args_len(u)) + return ERR_PTR(-EINVAL); + /* (2) Is there enough space to pass input buffers? */ + qcomtee_arg_for_each_input_buffer(i, u) { + ubuf_size = size_sub(ubuf_size, u[i].b.size); + if (ubuf_size == SIZE_MAX) + return ERR_PTR(-EINVAL); + + ubuf_size = round_down(ubuf_size, 8); + } + + return ureq; +} + +/* Gets called when the user closes the device. */ +void qcomtee_requests_destroy(struct qcomtee_context_data *ctxdata) +{ + struct qcomtee_ureq *req, *ureq; + + guard(mutex)(&ctxdata->reqs_lock); + /* So ureq_enqueue() refuses new requests from QTEE. */ + ctxdata->released = true; + /* ureqs in reqs_list are in QUEUED or PROCESSING (!= empty_ureq) state. */ + list_for_each_entry_safe(ureq, req, &ctxdata->reqs_list, node) { + ureq_dequeue(ctxdata, ureq->req_id); + + if (ureq->op != QCOMTEE_MSG_OBJECT_OP_RELEASE) { + ureq->state = QCOMTEE_REQ_PROCESSED; + ureq->errno = -ENODEV; + + complete(&ureq->c); + } else { + kfree(ureq); + } + } +} + +/* User Object API. */ + +/* User object dispatcher. */ +static int qcomtee_user_object_dispatch(struct qcomtee_object_invoke_ctx *oic, + struct qcomtee_object *object, u32 op, + struct qcomtee_arg *args) +{ + struct qcomtee_user_object *uo = to_qcomtee_user_object(object); + struct qcomtee_context_data *ctxdata = uo->ctx->data; + struct qcomtee_ureq *ureq __free(kfree) = NULL; + int errno; + + ureq = kzalloc(sizeof(*ureq), GFP_KERNEL); + if (!ureq) + return -ENOMEM; + + init_completion(&ureq->c); + ureq->object_id = uo->object_id; + ureq->op = op; + ureq->args = args; + + /* Queue the request. */ + if (ureq_enqueue(ctxdata, ureq)) + return -ENODEV; + /* Wakeup supplicant to process it. */ + complete(&ctxdata->req_c); + + /* + * Wait for the supplicant to process the request. Wait as KILLABLE + * in case the supplicant and invoke thread are both running from the + * same process, the supplicant crashes, or the shutdown sequence + * starts with supplicant dies first; otherwise, it stuck indefinitely. + * + * If the supplicant processes long-running requests, also use + * TASK_FREEZABLE to allow the device to safely suspend if needed. + */ + if (!wait_for_completion_state(&ureq->c, + TASK_KILLABLE | TASK_FREEZABLE)) { + errno = ureq->errno; + if (!errno) + oic->data = no_free_ptr(ureq); + } else { + enum qcomtee_req_state prev_state; + + errno = -ENODEV; + + scoped_guard(mutex, &ctxdata->reqs_lock) { + prev_state = ureq->state; + /* Replace with empty_ureq to keep req_id reserved. */ + if (prev_state == QCOMTEE_REQ_PROCESSING) { + list_del(&ureq->node); + idr_replace(&ctxdata->reqs_idr, + &empty_ureq, ureq->req_id); + + /* Remove as supplicant has never seen this request. */ + } else if (prev_state == QCOMTEE_REQ_QUEUED) { + ureq_dequeue(ctxdata, ureq->req_id); + } + } + + /* Supplicant did some work, do not discard it. */ + if (prev_state == QCOMTEE_REQ_PROCESSED) { + errno = ureq->errno; + if (!errno) + oic->data = no_free_ptr(ureq); + } + } + + return errno; +} + +/* Gets called after submitting the dispatcher response. */ +static void qcomtee_user_object_notify(struct qcomtee_object_invoke_ctx *oic, + struct qcomtee_object *unused_object, + int err) +{ + struct qcomtee_ureq *ureq = oic->data; + struct qcomtee_arg *u = ureq->args; + int i; + + /* + * If err, there was a transport issue, and QTEE did not receive the + * response for the dispatcher. Release the callback object created for + * QTEE, in addition to the copies of objects kept for the drivers. + */ + qcomtee_arg_for_each_output_object(i, u) { + if (err && + (typeof_qcomtee_object(u[i].o) == QCOMTEE_OBJECT_TYPE_CB)) + qcomtee_object_put(u[i].o); + qcomtee_object_put(u[i].o); + } + + kfree(ureq); +} + +static void qcomtee_user_object_release(struct qcomtee_object *object) +{ + struct qcomtee_user_object *uo = to_qcomtee_user_object(object); + struct qcomtee_context_data *ctxdata = uo->ctx->data; + struct qcomtee_ureq *ureq; + + /* RELEASE does not require any argument. */ + static struct qcomtee_arg args[] = { { .type = QCOMTEE_ARG_TYPE_INV } }; + + if (!uo->notify) + goto out_no_notify; + + ureq = kzalloc(sizeof(*ureq), GFP_KERNEL); + if (!ureq) + goto out_no_notify; + + /* QUEUE a release request: */ + ureq->object_id = uo->object_id; + ureq->op = QCOMTEE_MSG_OBJECT_OP_RELEASE; + ureq->args = args; + if (ureq_enqueue(ctxdata, ureq)) { + kfree(ureq); + /* Ignore the notification if it cannot be queued. */ + goto out_no_notify; + } + + complete(&ctxdata->req_c); + +out_no_notify: + teedev_ctx_put(uo->ctx); + kfree(uo); +} + +static struct qcomtee_object_operations qcomtee_user_object_ops = { + .release = qcomtee_user_object_release, + .notify = qcomtee_user_object_notify, + .dispatch = qcomtee_user_object_dispatch, +}; + +/** + * qcomtee_user_param_to_object() - OBJREF parameter to &struct qcomtee_object. + * @object: object returned. + * @param: TEE parameter. + * @ctx: context in which the conversion should happen. + * + * @param is an OBJREF with %QCOMTEE_OBJREF_FLAG_USER flags. + * + * Return: On success, returns 0; on failure, returns < 0. + */ +int qcomtee_user_param_to_object(struct qcomtee_object **object, + struct tee_param *param, + struct tee_context *ctx) +{ + struct qcomtee_user_object *user_object __free(kfree) = NULL; + int err; + + user_object = kzalloc(sizeof(*user_object), GFP_KERNEL); + if (!user_object) + return -ENOMEM; + + user_object->ctx = ctx; + user_object->object_id = param->u.objref.id; + /* By default, always notify userspace upon release. */ + user_object->notify = true; + err = qcomtee_object_user_init(&user_object->object, + QCOMTEE_OBJECT_TYPE_CB, + &qcomtee_user_object_ops, "uo-%llu", + param->u.objref.id); + if (err) + return err; + /* Matching teedev_ctx_put() is in qcomtee_user_object_release(). */ + teedev_ctx_get(ctx); + + *object = &no_free_ptr(user_object)->object; + + return 0; +} + +/* Reverse what qcomtee_user_param_to_object() does. */ +int qcomtee_user_param_from_object(struct tee_param *param, + struct qcomtee_object *object, + struct tee_context *ctx) +{ + struct qcomtee_user_object *uo; + + uo = to_qcomtee_user_object(object); + /* Ensure the object is in the same context as the caller. */ + if (uo->ctx != ctx) + return -EINVAL; + + param->u.objref.id = uo->object_id; + param->u.objref.flags = QCOMTEE_OBJREF_FLAG_USER; + + /* User objects are valid in userspace; do not keep a copy. */ + qcomtee_object_put(object); + + return 0; +} + +/** + * qcomtee_cb_params_from_args() - Convert QTEE arguments to TEE parameters. + * @params: TEE parameters. + * @u: QTEE arguments. + * @num_params: number of elements in the parameter array. + * @ubuf_addr: user buffer for arguments of type %QCOMTEE_ARG_TYPE_IB. + * @ubuf_size: size of the user buffer. + * @ctx: context in which the conversion should happen. + * + * It expects @params to have enough entries for @u. Entries in @params are of + * %TEE_IOCTL_PARAM_ATTR_TYPE_NONE. + * + * Return: On success, returns the number of input parameters; + * on failure, returns < 0. + */ +static int qcomtee_cb_params_from_args(struct tee_param *params, + struct qcomtee_arg *u, int num_params, + void __user *ubuf_addr, size_t ubuf_size, + struct tee_context *ctx) +{ + int i, np; + void __user *uaddr; + + qcomtee_arg_for_each(i, u) { + switch (u[i].type) { + case QCOMTEE_ARG_TYPE_IB: + params[i].attr = TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT; + + /* Underflow already checked in ureq_select(). */ + ubuf_size = round_down(ubuf_size - u[i].b.size, 8); + uaddr = (void __user *)(ubuf_addr + ubuf_size); + + params[i].u.ubuf.uaddr = uaddr; + params[i].u.ubuf.size = u[i].b.size; + if (copy_to_user(params[i].u.ubuf.uaddr, u[i].b.addr, + u[i].b.size)) + goto out_failed; + + break; + case QCOMTEE_ARG_TYPE_OB: + params[i].attr = TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT; + /* Let the user knows the maximum size QTEE expects. */ + params[i].u.ubuf.size = u[i].b.size; + + break; + case QCOMTEE_ARG_TYPE_IO: + params[i].attr = TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT; + if (qcomtee_objref_from_arg(¶ms[i], &u[i], ctx)) + goto out_failed; + + break; + case QCOMTEE_ARG_TYPE_OO: + params[i].attr = + TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT; + + break; + default: /* Never get here! */ + goto out_failed; + } + } + + return i; + +out_failed: + /* Undo qcomtee_objref_from_arg(). */ + for (np = i; np >= 0; np--) { + if (params[np].attr == TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT) + qcomtee_context_del_qtee_object(¶ms[np], ctx); + } + + /* Release any IO objects not processed. */ + for (; u[i].type; i++) { + if (u[i].type == QCOMTEE_ARG_TYPE_IO) + qcomtee_object_put(u[i].o); + } + + return -EINVAL; +} + +/** + * qcomtee_cb_params_to_args() - Convert TEE parameters to QTEE arguments. + * @u: QTEE arguments. + * @params: TEE parameters. + * @num_params: number of elements in the parameter array. + * @ctx: context in which the conversion should happen. + * + * Return: On success, returns 0; on failure, returns < 0. + */ +static int qcomtee_cb_params_to_args(struct qcomtee_arg *u, + struct tee_param *params, int num_params, + struct tee_context *ctx) +{ + int i; + + qcomtee_arg_for_each(i, u) { + switch (u[i].type) { + case QCOMTEE_ARG_TYPE_IB: + if (params[i].attr != + TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT) + goto out_failed; + + break; + case QCOMTEE_ARG_TYPE_OB: + if (params[i].attr != + TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT) + goto out_failed; + + /* Client can not send more data than requested. */ + if (params[i].u.ubuf.size > u[i].b.size) + goto out_failed; + + if (copy_from_user(u[i].b.addr, params[i].u.ubuf.uaddr, + params[i].u.ubuf.size)) + goto out_failed; + + u[i].b.size = params[i].u.ubuf.size; + + break; + case QCOMTEE_ARG_TYPE_IO: + if (params[i].attr != + TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT) + goto out_failed; + + break; + case QCOMTEE_ARG_TYPE_OO: + if (params[i].attr != + TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT) + goto out_failed; + + if (qcomtee_objref_to_arg(&u[i], ¶ms[i], ctx)) + goto out_failed; + + break; + default: /* Never get here! */ + goto out_failed; + } + } + + return 0; + +out_failed: + /* Undo qcomtee_objref_to_arg(). */ + for (i--; i >= 0; i--) { + if (u[i].type != QCOMTEE_ARG_TYPE_OO) + continue; + + qcomtee_user_object_set_notify(u[i].o, false); + if (typeof_qcomtee_object(u[i].o) == QCOMTEE_OBJECT_TYPE_CB) + qcomtee_object_put(u[i].o); + + qcomtee_object_put(u[i].o); + } + + return -EINVAL; +} + +/** + * qcomtee_user_object_select() - Select a request for a user object. + * @ctx: context to look for a user object. + * @params: parameters for @op. + * @num_params: number of elements in the parameter array. + * @uaddr: user buffer for output UBUF parameters. + * @size: size of user buffer @uaddr. + * @data: information for the selected request. + * + * @params is filled along with @data for the selected request. + * + * Return: On success, returns 0; on failure, returns < 0. + */ +int qcomtee_user_object_select(struct tee_context *ctx, + struct tee_param *params, int num_params, + void __user *uaddr, size_t size, + struct qcomtee_user_object_request_data *data) +{ + struct qcomtee_context_data *ctxdata = ctx->data; + struct qcomtee_ureq *ureq; + int ret; + + /* + * Hold the reqs_lock not only for ureq_select() and updating the ureq + * state to PROCESSING but for the entire duration of ureq access. + * This prevents qcomtee_user_object_dispatch() from freeing + * ureq while it is still in use, if client dies. + */ + + while (1) { + scoped_guard(mutex, &ctxdata->reqs_lock) { + ureq = ureq_select(ctxdata, size, num_params); + if (!ureq) + goto wait_for_request; + + if (IS_ERR(ureq)) + return PTR_ERR(ureq); + + /* Processing the request 'QUEUED -> PROCESSING'. */ + ureq->state = QCOMTEE_REQ_PROCESSING; + /* ''Prepare user request:'' */ + data->id = ureq->req_id; + data->object_id = ureq->object_id; + data->op = ureq->op; + ret = qcomtee_cb_params_from_args(params, ureq->args, + num_params, uaddr, + size, ctx); + if (ret >= 0) + goto done_request; + + /* Something is wrong with the request: */ + ureq_dequeue(ctxdata, data->id); + /* Send error to QTEE. */ + ureq->state = QCOMTEE_REQ_PROCESSED; + ureq->errno = ret; + + complete(&ureq->c); + } + + continue; +wait_for_request: + /* Wait for a new QUEUED request. */ + if (wait_for_completion_interruptible(&ctxdata->req_c)) + return -ERESTARTSYS; + } + +done_request: + /* No one is waiting for the response. */ + if (data->op == QCOMTEE_MSG_OBJECT_OP_RELEASE) { + scoped_guard(mutex, &ctxdata->reqs_lock) + ureq_dequeue(ctxdata, data->id); + kfree(ureq); + } + + data->np = ret; + + return 0; +} + +/** + * qcomtee_user_object_submit() - Submit a response for a user object. + * @ctx: context to look for a user object. + * @params: returned parameters. + * @num_params: number of elements in the parameter array. + * @req_id: request ID for the response. + * @errno: result of user object invocation. + * + * Return: On success, returns 0; on failure, returns < 0. + */ +int qcomtee_user_object_submit(struct tee_context *ctx, + struct tee_param *params, int num_params, + int req_id, int errno) +{ + struct qcomtee_context_data *ctxdata = ctx->data; + struct qcomtee_ureq *ureq; + + /* See comments for reqs_lock in qcomtee_user_object_select(). */ + guard(mutex)(&ctxdata->reqs_lock); + + ureq = ureq_dequeue(ctxdata, req_id); + if (!ureq) + return -EINVAL; + + ureq->state = QCOMTEE_REQ_PROCESSED; + + if (!errno) + ureq->errno = qcomtee_cb_params_to_args(ureq->args, params, + num_params, ctx); + else + ureq->errno = errno; + /* Return errno if qcomtee_cb_params_to_args() failed; otherwise 0. */ + if (!errno && ureq->errno) + errno = ureq->errno; + else + errno = 0; + + /* Send result to QTEE. */ + complete(&ureq->c); + + return errno; +} |