drivers/tee/optee/supp.c - linux - Git at Google

 /*
  * Copyright (c) 2015, Linaro Limited
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  */
 #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 busy;
 	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) {
 		req->busy = false;
 		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->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 = kzalloc(sizeof(*req), GFP_KERNEL);
 	bool interruptable;
 	u32 ret;

 	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);
 	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.
 			 */
 			interruptable = !req->busy;
 			if (!req->busy)
 				list_del(&req->link);
 		}
 		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->busy = true;

 	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);

 	req->busy = false;
 	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;
 }
	/*
	* Copyright (c) 2015, Linaro Limited
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	*/
	#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 busy;
	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) {
	req->busy = false;
	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->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 = kzalloc(sizeof(req), GFP_KERNEL);
	bool interruptable;
	u32 ret;

	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);
	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.
	*/
	interruptable = !req->busy;
	if (!req->busy)
	list_del(&req->link);
	}
	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->busy = true;

	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);

	req->busy = false;
	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;
	}