arch/arm/user_ta_entry.c

// SPDX-License-Identifier: BSD-2-Clause
/*
 * Copyright (c) 2014, STMicroelectronics International N.V.
 * Copyright (c) 2022, Linaro Limited.
 */
#include <compiler.h>
#include <link.h>
#include <malloc.h>
#include <memtag.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <sys/queue.h>
#include <tee_api.h>
#include <tee_arith_internal.h>
#include <tee_internal_api_extensions.h>
#include <tee_ta_api.h>
#include <user_ta_header.h>
#include <utee_syscalls.h>
#include "tee_api_private.h"

struct ta_session {
	uint32_t session_id;
	void *session_ctx;
	TAILQ_ENTRY(ta_session) link;
};

static TAILQ_HEAD(ta_sessions, ta_session) ta_sessions =
		TAILQ_HEAD_INITIALIZER(ta_sessions);

static bool init_done;

/* From user_ta_header.c, built within TA */
extern uint8_t ta_heap[];
extern const size_t ta_heap_size;
extern struct ta_head ta_head;

uint32_t ta_param_types;
TEE_Param ta_params[TEE_NUM_PARAMS];
struct __elf_phdr_info __elf_phdr_info;

struct phdr_info {
	struct dl_phdr_info info;
	TAILQ_ENTRY(phdr_info) link;
};

static TAILQ_HEAD(phdr_info_head, phdr_info) __phdr_info_head =
		TAILQ_HEAD_INITIALIZER(__phdr_info_head);
/*
 * Keep track of how many modules have been initialized so that subsequent
 * dlopen() calls will not run the same initializers again
 */
static size_t _num_mod_init;

static int _init_iterate_phdr_cb(struct dl_phdr_info *info,
				 size_t size __unused, void *data)
{
	struct phdr_info *qe = NULL;
	size_t *count = data;

	qe = malloc(sizeof(*qe));
	if (!qe) {
		EMSG("init/fini: out of memory");
		abort();
	}
	qe->info = *info;
	TAILQ_INSERT_TAIL(&__phdr_info_head, qe, link);
	(*count)++;
	return 0;
}

static void _get_fn_array(struct dl_phdr_info *info, Elf_Sword tag_a,
			  Elf_Sword tag_s, void (***fn)(void), size_t *num_fn)
{
	const Elf_Phdr *phdr = NULL;
	Elf_Dyn *dyn = NULL;
	size_t num_dyn = 0;
	size_t i = 0;
	size_t j = 0;

	for (i = 0; i < info->dlpi_phnum; i++) {
		phdr = info->dlpi_phdr + i;
		if (phdr->p_type != PT_DYNAMIC)
			continue;
		num_dyn = phdr->p_memsz / sizeof(Elf_Dyn);
		dyn = (Elf_Dyn *)(phdr->p_vaddr + info->dlpi_addr);
		for (j = 0; j < num_dyn; j++) {
			if (*fn && *num_fn)
				break;
			if (dyn->d_tag == DT_NULL) {
				break;
			} else if (dyn->d_tag == tag_a) {
				*fn = (void (**)(void))(dyn->d_un.d_ptr +
							info->dlpi_addr);
			} else if (dyn->d_tag == tag_s) {
				*num_fn = dyn->d_un.d_val / sizeof(Elf_Addr);
			}
			dyn++;
		}
	}
}

void __utee_call_elf_init_fn(void)
{
	void (**fn)(void) = NULL;
	size_t num_mod = 0;
	size_t num_fn = 0;
	size_t mod = 0;
	size_t i = 0;
	struct phdr_info *qe = NULL;
	struct phdr_info *qe2 = NULL;

	dl_iterate_phdr(_init_iterate_phdr_cb, &num_mod);

	/* Reverse order: dependencies first */
	TAILQ_FOREACH_REVERSE(qe, &__phdr_info_head, phdr_info_head, link) {
		if (mod == num_mod - _num_mod_init)
			break;
		_get_fn_array(&qe->info, DT_INIT_ARRAY, DT_INIT_ARRAYSZ, &fn,
			      &num_fn);
		for (i = 0; i < num_fn; i++)
			fn[i]();
		fn = NULL;
		num_fn = 0;
		mod++;
	}
	_num_mod_init += mod;

	TAILQ_FOREACH_SAFE(qe, &__phdr_info_head, link, qe2) {
		TAILQ_REMOVE(&__phdr_info_head, qe, link);
		free(qe);
	}
}

static int _fini_iterate_phdr_cb(struct dl_phdr_info *info,
				 size_t size __unused, void *data __unused)
{
	void (**fn)(void) = NULL;
	size_t num_fn = 0;
	size_t i = 0;

	_get_fn_array(info, DT_FINI_ARRAY, DT_FINI_ARRAYSZ, &fn, &num_fn);

	for (i = 1; i <= num_fn; i++)
		fn[num_fn - i]();

	return 0;
}

void __utee_call_elf_fini_fn(void)
{
	dl_iterate_phdr(_fini_iterate_phdr_cb, NULL);
}

static unsigned int get_memtag_implementation(void)
{
	const char *s = "org.trustedfirmware.optee.cpu.feat_memtag_implemented";
	uint32_t v = 0;

	if (TEE_GetPropertyAsU32(TEE_PROPSET_TEE_IMPLEMENTATION, s, &v))
		return 0;
	return v;
}

static TEE_Result init_instance(void)
{
	trace_set_level(tahead_get_trace_level());
	__utee_gprof_init();
	malloc_add_pool(ta_heap, ta_heap_size);
	memtag_init_ops(get_memtag_implementation());
	_TEE_MathAPI_Init();
	__utee_tcb_init();
	__utee_call_elf_init_fn();
	return TA_CreateEntryPoint();
}

static void uninit_instance(void)
{
	__utee_gprof_fini();
	TA_DestroyEntryPoint();
	__utee_call_elf_fini_fn();
}

static void ta_header_save_params(uint32_t param_types,
				  TEE_Param params[TEE_NUM_PARAMS])
{
	ta_param_types = param_types;

	if (params)
		memcpy(ta_params, params, sizeof(ta_params));
	else
		memset(ta_params, 0, sizeof(ta_params));
}

static struct ta_session *ta_header_get_session(uint32_t session_id)
{
	struct ta_session *itr;

	TAILQ_FOREACH(itr, &ta_sessions, link) {
		if (itr->session_id == session_id)
			return itr;
	}
	return NULL;
}

static TEE_Result ta_header_add_session(uint32_t session_id)
{
	struct ta_session *itr = ta_header_get_session(session_id);
	TEE_Result res;

	if (itr)
		return TEE_SUCCESS;

	if (!init_done) {
		init_done = true;
		res = init_instance();
		if (res)
			return res;
	}

	itr = TEE_Malloc(sizeof(struct ta_session),
			TEE_USER_MEM_HINT_NO_FILL_ZERO);
	if (!itr)
		return TEE_ERROR_OUT_OF_MEMORY;
	itr->session_id = session_id;
	itr->session_ctx = 0;
	TAILQ_INSERT_TAIL(&ta_sessions, itr, link);

	return TEE_SUCCESS;
}

static void ta_header_remove_session(uint32_t session_id)
{
	struct ta_session *itr;
	bool keep_alive;

	TAILQ_FOREACH(itr, &ta_sessions, link) {
		if (itr->session_id == session_id) {
			TAILQ_REMOVE(&ta_sessions, itr, link);
			TEE_Free(itr);

			keep_alive =
				(ta_head.flags & TA_FLAG_SINGLE_INSTANCE) &&
				(ta_head.flags & TA_FLAG_INSTANCE_KEEP_ALIVE);
			if (TAILQ_EMPTY(&ta_sessions) && !keep_alive)
				uninit_instance();

			return;
		}
	}
}

static void to_utee_params(struct utee_params *up, uint32_t param_types,
			   const TEE_Param params[TEE_NUM_PARAMS])
{
	size_t n = 0;

	up->types = param_types;
	for (n = 0; n < TEE_NUM_PARAMS; n++) {
		switch (TEE_PARAM_TYPE_GET(param_types, n)) {
		case TEE_PARAM_TYPE_VALUE_INPUT:
		case TEE_PARAM_TYPE_VALUE_OUTPUT:
		case TEE_PARAM_TYPE_VALUE_INOUT:
			up->vals[n * 2] = params[n].value.a;
			up->vals[n * 2 + 1] = params[n].value.b;
			break;
		case TEE_PARAM_TYPE_MEMREF_INPUT:
		case TEE_PARAM_TYPE_MEMREF_OUTPUT:
		case TEE_PARAM_TYPE_MEMREF_INOUT:
			up->vals[n * 2] = (uintptr_t)params[n].memref.buffer;
			up->vals[n * 2 + 1] = params[n].memref.size;
			break;
		default:
			up->vals[n * 2] = 0;
			up->vals[n * 2 + 1] = 0;
			break;
		}
	}
}

static void from_utee_params(TEE_Param params[TEE_NUM_PARAMS],
			     uint32_t *param_types,
			     const struct utee_params *up)
{
	size_t n;
	uint32_t types = up->types;

	for (n = 0; n < TEE_NUM_PARAMS; n++) {
		uintptr_t a = up->vals[n * 2];
		uintptr_t b = up->vals[n * 2 + 1];

		switch (TEE_PARAM_TYPE_GET(types, n)) {
		case TEE_PARAM_TYPE_VALUE_INPUT:
		case TEE_PARAM_TYPE_VALUE_OUTPUT:
		case TEE_PARAM_TYPE_VALUE_INOUT:
			params[n].value.a = a;
			params[n].value.b = b;
			break;
		case TEE_PARAM_TYPE_MEMREF_INPUT:
		case TEE_PARAM_TYPE_MEMREF_OUTPUT:
		case TEE_PARAM_TYPE_MEMREF_INOUT:
			params[n].memref.buffer = (void *)a;
			params[n].memref.size = b;
			break;
		default:
			break;
		}
	}

	if (param_types)
		*param_types = types;
}

static TEE_Result entry_open_session(unsigned long session_id,
			struct utee_params *up)
{
	TEE_Result res;
	struct ta_session *session;
	uint32_t param_types;
	TEE_Param params[TEE_NUM_PARAMS];

	res = ta_header_add_session(session_id);
	if (res != TEE_SUCCESS)
		return res;

	session = ta_header_get_session(session_id);
	if (!session)
		return TEE_ERROR_BAD_STATE;

	from_utee_params(params, &param_types, up);
	ta_header_save_params(param_types, params);

	res = TA_OpenSessionEntryPoint(param_types, params,
				       &session->session_ctx);

	to_utee_params(up, param_types, params);

	if (res != TEE_SUCCESS)
		ta_header_remove_session(session_id);
	return res;
}

static TEE_Result entry_close_session(unsigned long session_id)
{
	struct ta_session *session = ta_header_get_session(session_id);

	if (!session)
		return TEE_ERROR_BAD_STATE;

	TA_CloseSessionEntryPoint(session->session_ctx);

	ta_header_remove_session(session_id);
	return TEE_SUCCESS;
}

static TEE_Result entry_invoke_command(unsigned long session_id,
			struct utee_params *up, unsigned long cmd_id)
{
	TEE_Result res;
	uint32_t param_types;
	TEE_Param params[TEE_NUM_PARAMS];
	struct ta_session *session = ta_header_get_session(session_id);

	if (!session)
		return TEE_ERROR_BAD_STATE;

	from_utee_params(params, &param_types, up);
	ta_header_save_params(param_types, params);

	res = TA_InvokeCommandEntryPoint(session->session_ctx, cmd_id,
					 param_types, params);

	to_utee_params(up, param_types, params);
	return res;
}

#if defined(CFG_TA_STATS)
static TEE_Result entry_dump_memstats(unsigned long session_id __unused,
				      struct utee_params *up)
{
	uint32_t param_types = 0;
	TEE_Param params[TEE_NUM_PARAMS] = { };
	struct malloc_stats stats = { };

	from_utee_params(params, &param_types, up);
	ta_header_save_params(param_types, params);

	if (TEE_PARAM_TYPES(TEE_PARAM_TYPE_VALUE_OUTPUT,
			    TEE_PARAM_TYPE_VALUE_OUTPUT,
			    TEE_PARAM_TYPE_VALUE_OUTPUT,
			    TEE_PARAM_TYPE_NONE) != param_types)
		return TEE_ERROR_BAD_PARAMETERS;

	malloc_get_stats(&stats);
	params[0].value.a = stats.allocated;
	params[0].value.b = stats.max_allocated;
	params[1].value.a = stats.size;
	params[1].value.b = stats.num_alloc_fail;
	params[2].value.a = stats.biggest_alloc_fail;
	params[2].value.b = stats.biggest_alloc_fail_used;
	to_utee_params(up, param_types, params);

	return TEE_SUCCESS;
}
#endif

TEE_Result __utee_entry(unsigned long func, unsigned long session_id,
			struct utee_params *up, unsigned long cmd_id)
{
	TEE_Result res;

	switch (func) {
	case UTEE_ENTRY_FUNC_OPEN_SESSION:
		res = entry_open_session(session_id, up);
		break;
	case UTEE_ENTRY_FUNC_CLOSE_SESSION:
		res = entry_close_session(session_id);
		break;
	case UTEE_ENTRY_FUNC_INVOKE_COMMAND:
		res = entry_invoke_command(session_id, up, cmd_id);
		break;
#if defined(CFG_TA_STATS)
	case UTEE_ENTRY_FUNC_DUMP_MEMSTATS:
		res = entry_dump_memstats(session_id, up);
		break;
#endif
	default:
		res = TEE_ERROR_NOT_SUPPORTED;
		break;
	}
	ta_header_save_params(0, NULL);

	return res;
}