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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/tee/optee/supp.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/tee/optee/supp.c')
-rw-r--r-- | drivers/tee/optee/supp.c | 382 |
1 files changed, 382 insertions, 0 deletions
diff --git a/drivers/tee/optee/supp.c b/drivers/tee/optee/supp.c new file mode 100644 index 000000000..322a543b8 --- /dev/null +++ b/drivers/tee/optee/supp.c @@ -0,0 +1,382 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2015, Linaro Limited + */ +#include <linux/device.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include "optee_private.h" + +struct optee_supp_req { + struct list_head link; + + bool in_queue; + u32 func; + u32 ret; + size_t num_params; + struct tee_param *param; + + struct completion c; +}; + +void optee_supp_init(struct optee_supp *supp) +{ + memset(supp, 0, sizeof(*supp)); + mutex_init(&supp->mutex); + init_completion(&supp->reqs_c); + idr_init(&supp->idr); + INIT_LIST_HEAD(&supp->reqs); + supp->req_id = -1; +} + +void optee_supp_uninit(struct optee_supp *supp) +{ + mutex_destroy(&supp->mutex); + idr_destroy(&supp->idr); +} + +void optee_supp_release(struct optee_supp *supp) +{ + int id; + struct optee_supp_req *req; + struct optee_supp_req *req_tmp; + + mutex_lock(&supp->mutex); + + /* Abort all request retrieved by supplicant */ + idr_for_each_entry(&supp->idr, req, id) { + idr_remove(&supp->idr, id); + req->ret = TEEC_ERROR_COMMUNICATION; + complete(&req->c); + } + + /* Abort all queued requests */ + list_for_each_entry_safe(req, req_tmp, &supp->reqs, link) { + list_del(&req->link); + req->in_queue = false; + req->ret = TEEC_ERROR_COMMUNICATION; + complete(&req->c); + } + + supp->ctx = NULL; + supp->req_id = -1; + + mutex_unlock(&supp->mutex); +} + +/** + * optee_supp_thrd_req() - request service from supplicant + * @ctx: context doing the request + * @func: function requested + * @num_params: number of elements in @param array + * @param: parameters for function + * + * Returns result of operation to be passed to secure world + */ +u32 optee_supp_thrd_req(struct tee_context *ctx, u32 func, size_t num_params, + struct tee_param *param) + +{ + struct optee *optee = tee_get_drvdata(ctx->teedev); + struct optee_supp *supp = &optee->supp; + struct optee_supp_req *req; + bool interruptable; + u32 ret; + + /* + * Return in case there is no supplicant available and + * non-blocking request. + */ + if (!supp->ctx && ctx->supp_nowait) + return TEEC_ERROR_COMMUNICATION; + + req = kzalloc(sizeof(*req), GFP_KERNEL); + if (!req) + return TEEC_ERROR_OUT_OF_MEMORY; + + init_completion(&req->c); + req->func = func; + req->num_params = num_params; + req->param = param; + + /* Insert the request in the request list */ + mutex_lock(&supp->mutex); + list_add_tail(&req->link, &supp->reqs); + req->in_queue = true; + mutex_unlock(&supp->mutex); + + /* Tell an eventual waiter there's a new request */ + complete(&supp->reqs_c); + + /* + * Wait for supplicant to process and return result, once we've + * returned from wait_for_completion(&req->c) successfully we have + * exclusive access again. + */ + while (wait_for_completion_interruptible(&req->c)) { + mutex_lock(&supp->mutex); + interruptable = !supp->ctx; + if (interruptable) { + /* + * There's no supplicant available and since the + * supp->mutex currently is held none can + * become available until the mutex released + * again. + * + * Interrupting an RPC to supplicant is only + * allowed as a way of slightly improving the user + * experience in case the supplicant hasn't been + * started yet. During normal operation the supplicant + * will serve all requests in a timely manner and + * interrupting then wouldn't make sense. + */ + if (req->in_queue) { + list_del(&req->link); + req->in_queue = false; + } + } + mutex_unlock(&supp->mutex); + + if (interruptable) { + req->ret = TEEC_ERROR_COMMUNICATION; + break; + } + } + + ret = req->ret; + kfree(req); + + return ret; +} + +static struct optee_supp_req *supp_pop_entry(struct optee_supp *supp, + int num_params, int *id) +{ + struct optee_supp_req *req; + + if (supp->req_id != -1) { + /* + * Supplicant should not mix synchronous and asnynchronous + * requests. + */ + return ERR_PTR(-EINVAL); + } + + if (list_empty(&supp->reqs)) + return NULL; + + req = list_first_entry(&supp->reqs, struct optee_supp_req, link); + + if (num_params < req->num_params) { + /* Not enough room for parameters */ + return ERR_PTR(-EINVAL); + } + + *id = idr_alloc(&supp->idr, req, 1, 0, GFP_KERNEL); + if (*id < 0) + return ERR_PTR(-ENOMEM); + + list_del(&req->link); + req->in_queue = false; + + return req; +} + +static int supp_check_recv_params(size_t num_params, struct tee_param *params, + size_t *num_meta) +{ + size_t n; + + if (!num_params) + return -EINVAL; + + /* + * If there's memrefs we need to decrease those as they where + * increased earlier and we'll even refuse to accept any below. + */ + for (n = 0; n < num_params; n++) + if (tee_param_is_memref(params + n) && params[n].u.memref.shm) + tee_shm_put(params[n].u.memref.shm); + + /* + * We only expect parameters as TEE_IOCTL_PARAM_ATTR_TYPE_NONE with + * or without the TEE_IOCTL_PARAM_ATTR_META bit set. + */ + for (n = 0; n < num_params; n++) + if (params[n].attr && + params[n].attr != TEE_IOCTL_PARAM_ATTR_META) + return -EINVAL; + + /* At most we'll need one meta parameter so no need to check for more */ + if (params->attr == TEE_IOCTL_PARAM_ATTR_META) + *num_meta = 1; + else + *num_meta = 0; + + return 0; +} + +/** + * optee_supp_recv() - receive request for supplicant + * @ctx: context receiving the request + * @func: requested function in supplicant + * @num_params: number of elements allocated in @param, updated with number + * used elements + * @param: space for parameters for @func + * + * Returns 0 on success or <0 on failure + */ +int optee_supp_recv(struct tee_context *ctx, u32 *func, u32 *num_params, + struct tee_param *param) +{ + struct tee_device *teedev = ctx->teedev; + struct optee *optee = tee_get_drvdata(teedev); + struct optee_supp *supp = &optee->supp; + struct optee_supp_req *req = NULL; + int id; + size_t num_meta; + int rc; + + rc = supp_check_recv_params(*num_params, param, &num_meta); + if (rc) + return rc; + + while (true) { + mutex_lock(&supp->mutex); + req = supp_pop_entry(supp, *num_params - num_meta, &id); + mutex_unlock(&supp->mutex); + + if (req) { + if (IS_ERR(req)) + return PTR_ERR(req); + break; + } + + /* + * If we didn't get a request we'll block in + * wait_for_completion() to avoid needless spinning. + * + * This is where supplicant will be hanging most of + * the time, let's make this interruptable so we + * can easily restart supplicant if needed. + */ + if (wait_for_completion_interruptible(&supp->reqs_c)) + return -ERESTARTSYS; + } + + if (num_meta) { + /* + * tee-supplicant support meta parameters -> requsts can be + * processed asynchronously. + */ + param->attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT | + TEE_IOCTL_PARAM_ATTR_META; + param->u.value.a = id; + param->u.value.b = 0; + param->u.value.c = 0; + } else { + mutex_lock(&supp->mutex); + supp->req_id = id; + mutex_unlock(&supp->mutex); + } + + *func = req->func; + *num_params = req->num_params + num_meta; + memcpy(param + num_meta, req->param, + sizeof(struct tee_param) * req->num_params); + + return 0; +} + +static struct optee_supp_req *supp_pop_req(struct optee_supp *supp, + size_t num_params, + struct tee_param *param, + size_t *num_meta) +{ + struct optee_supp_req *req; + int id; + size_t nm; + const u32 attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT | + TEE_IOCTL_PARAM_ATTR_META; + + if (!num_params) + return ERR_PTR(-EINVAL); + + if (supp->req_id == -1) { + if (param->attr != attr) + return ERR_PTR(-EINVAL); + id = param->u.value.a; + nm = 1; + } else { + id = supp->req_id; + nm = 0; + } + + req = idr_find(&supp->idr, id); + if (!req) + return ERR_PTR(-ENOENT); + + if ((num_params - nm) != req->num_params) + return ERR_PTR(-EINVAL); + + idr_remove(&supp->idr, id); + supp->req_id = -1; + *num_meta = nm; + + return req; +} + +/** + * optee_supp_send() - send result of request from supplicant + * @ctx: context sending result + * @ret: return value of request + * @num_params: number of parameters returned + * @param: returned parameters + * + * Returns 0 on success or <0 on failure. + */ +int optee_supp_send(struct tee_context *ctx, u32 ret, u32 num_params, + struct tee_param *param) +{ + struct tee_device *teedev = ctx->teedev; + struct optee *optee = tee_get_drvdata(teedev); + struct optee_supp *supp = &optee->supp; + struct optee_supp_req *req; + size_t n; + size_t num_meta; + + mutex_lock(&supp->mutex); + req = supp_pop_req(supp, num_params, param, &num_meta); + mutex_unlock(&supp->mutex); + + if (IS_ERR(req)) { + /* Something is wrong, let supplicant restart. */ + return PTR_ERR(req); + } + + /* Update out and in/out parameters */ + for (n = 0; n < req->num_params; n++) { + struct tee_param *p = req->param + n; + + switch (p->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) { + case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT: + case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT: + p->u.value.a = param[n + num_meta].u.value.a; + p->u.value.b = param[n + num_meta].u.value.b; + p->u.value.c = param[n + num_meta].u.value.c; + break; + case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT: + case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT: + p->u.memref.size = param[n + num_meta].u.memref.size; + break; + default: + break; + } + } + req->ret = ret; + + /* Let the requesting thread continue */ + complete(&req->c); + + return 0; +} |