blob: 4f1aa298da13d788f0cf94e398d9d679caf47481 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* EFI variable service via OP-TEE
*
* Copyright (C) 2019 Linaro Ltd. <sughosh.ganu@linaro.org>
* Copyright (C) 2019 Linaro Ltd. <ilias.apalodimas@linaro.org>
* Copyright 2022-2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
*
* Authors:
* Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
*/
#if CONFIG_IS_ENABLED(ARM_FFA_TRANSPORT)
#include <arm_ffa.h>
#endif
#include <cpu_func.h>
#include <dm.h>
#include <efi.h>
#include <efi_api.h>
#include <efi_loader.h>
#include <efi_variable.h>
#include <malloc.h>
#include <mapmem.h>
#include <mm_communication.h>
#include <tee.h>
#if CONFIG_IS_ENABLED(ARM_FFA_TRANSPORT)
/* MM return codes */
#define MM_SUCCESS (0)
#define MM_NOT_SUPPORTED (-1)
#define MM_INVALID_PARAMETER (-2)
#define MM_DENIED (-3)
#define MM_NO_MEMORY (-5)
static const char *mm_sp_svc_uuid = MM_SP_UUID;
static u16 mm_sp_id;
#endif
extern struct efi_var_file __efi_runtime_data *efi_var_buf;
static efi_uintn_t max_buffer_size; /* comm + var + func + data */
static efi_uintn_t max_payload_size; /* func + data */
struct mm_connection {
struct udevice *tee;
u32 session;
};
/**
* get_connection() - Retrieve OP-TEE session for a specific UUID.
*
* @conn: session buffer to fill
* Return: status code
*/
static int get_connection(struct mm_connection *conn)
{
static const struct tee_optee_ta_uuid uuid = PTA_STMM_UUID;
struct udevice *tee = NULL;
struct tee_open_session_arg arg;
int rc = -ENODEV;
tee = tee_find_device(tee, NULL, NULL, NULL);
if (!tee)
goto out;
memset(&arg, 0, sizeof(arg));
tee_optee_ta_uuid_to_octets(arg.uuid, &uuid);
rc = tee_open_session(tee, &arg, 0, NULL);
if (rc)
goto out;
/* Check the internal OP-TEE result */
if (arg.ret != TEE_SUCCESS) {
rc = -EIO;
goto out;
}
conn->tee = tee;
conn->session = arg.session;
return 0;
out:
return rc;
}
/**
* optee_mm_communicate() - Pass a buffer to StandaloneMM running in OP-TEE
*
* @comm_buf: locally allocted communcation buffer
* @dsize: buffer size
* Return: status code
*/
static efi_status_t optee_mm_communicate(void *comm_buf, ulong dsize)
{
ulong buf_size;
efi_status_t ret;
struct efi_mm_communicate_header *mm_hdr;
struct mm_connection conn = { NULL, 0 };
struct tee_invoke_arg arg;
struct tee_param param[2];
struct tee_shm *shm = NULL;
int rc;
if (!comm_buf)
return EFI_INVALID_PARAMETER;
mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
buf_size = mm_hdr->message_len + sizeof(efi_guid_t) + sizeof(size_t);
if (dsize != buf_size)
return EFI_INVALID_PARAMETER;
rc = get_connection(&conn);
if (rc) {
log_err("Unable to open OP-TEE session (err=%d)\n", rc);
return EFI_UNSUPPORTED;
}
if (tee_shm_register(conn.tee, comm_buf, buf_size, 0, &shm)) {
log_err("Unable to register shared memory\n");
tee_close_session(conn.tee, conn.session);
return EFI_UNSUPPORTED;
}
memset(&arg, 0, sizeof(arg));
arg.func = PTA_STMM_CMDID_COMMUNICATE;
arg.session = conn.session;
memset(param, 0, sizeof(param));
param[0].attr = TEE_PARAM_ATTR_TYPE_MEMREF_INOUT;
param[0].u.memref.size = buf_size;
param[0].u.memref.shm = shm;
param[1].attr = TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT;
rc = tee_invoke_func(conn.tee, &arg, 2, param);
tee_shm_free(shm);
tee_close_session(conn.tee, conn.session);
if (rc)
return EFI_DEVICE_ERROR;
if (arg.ret == TEE_ERROR_EXCESS_DATA)
log_err("Variable payload too large\n");
if (arg.ret != TEE_SUCCESS)
return EFI_DEVICE_ERROR;
switch (param[1].u.value.a) {
case ARM_SVC_SPM_RET_SUCCESS:
ret = EFI_SUCCESS;
break;
case ARM_SVC_SPM_RET_INVALID_PARAMS:
ret = EFI_INVALID_PARAMETER;
break;
case ARM_SVC_SPM_RET_DENIED:
ret = EFI_ACCESS_DENIED;
break;
case ARM_SVC_SPM_RET_NO_MEMORY:
ret = EFI_OUT_OF_RESOURCES;
break;
default:
ret = EFI_ACCESS_DENIED;
}
return ret;
}
#if CONFIG_IS_ENABLED(ARM_FFA_TRANSPORT)
/**
* ffa_notify_mm_sp() - Announce there is data in the shared buffer
*
* Notify the MM partition in the trusted world that
* data is available in the shared buffer.
* This is a blocking call during which trusted world has exclusive access
* to the MM shared buffer.
*
* Return:
*
* 0 on success
*/
static int ffa_notify_mm_sp(void)
{
struct ffa_send_direct_data msg = {0};
int ret;
int sp_event_ret;
struct udevice *dev;
ret = uclass_first_device_err(UCLASS_FFA, &dev);
if (ret) {
log_err("EFI: Cannot find FF-A bus device, notify MM SP failure\n");
return ret;
}
msg.data0 = CONFIG_FFA_SHARED_MM_BUF_OFFSET; /* x3 */
ret = ffa_sync_send_receive(dev, mm_sp_id, &msg, 1);
if (ret)
return ret;
sp_event_ret = msg.data0; /* x3 */
switch (sp_event_ret) {
case MM_SUCCESS:
ret = 0;
break;
case MM_NOT_SUPPORTED:
ret = -EINVAL;
break;
case MM_INVALID_PARAMETER:
ret = -EPERM;
break;
case MM_DENIED:
ret = -EACCES;
break;
case MM_NO_MEMORY:
ret = -EBUSY;
break;
default:
ret = -EACCES;
}
return ret;
}
/**
* ffa_discover_mm_sp_id() - Query the MM partition ID
*
* Use the FF-A driver to get the MM partition ID.
* If multiple partitions are found, use the first one.
* This is a boot time function.
*
* Return:
*
* 0 on success
*/
static int ffa_discover_mm_sp_id(void)
{
u32 count = 0;
int ret;
struct ffa_partition_desc *descs;
struct udevice *dev;
ret = uclass_first_device_err(UCLASS_FFA, &dev);
if (ret) {
log_err("EFI: Cannot find FF-A bus device, MM SP discovery failure\n");
return ret;
}
/* Ask the driver to fill the buffer with the SPs info */
ret = ffa_partition_info_get(dev, mm_sp_svc_uuid, &count, &descs);
if (ret) {
log_err("EFI: Failure in querying SPs info (%d), MM SP discovery failure\n", ret);
return ret;
}
/* MM SPs found , use the first one */
mm_sp_id = descs[0].info.id;
log_info("EFI: MM partition ID 0x%x\n", mm_sp_id);
return 0;
}
/**
* ffa_mm_communicate() - Exchange EFI services data with the MM partition using FF-A
* @comm_buf: locally allocated communication buffer used for rx/tx
* @dsize: communication buffer size
*
* Issue a door bell event to notify the MM partition (SP) running in OP-TEE
* that there is data to read from the shared buffer.
* Communication with the MM SP is performed using FF-A transport.
* On the event, MM SP can read the data from the buffer and
* update the MM shared buffer with response data.
* The response data is copied back to the communication buffer.
*
* Return:
*
* EFI status code
*/
static efi_status_t ffa_mm_communicate(void *comm_buf, ulong comm_buf_size)
{
ulong tx_data_size;
int ffa_ret;
efi_status_t efi_ret;
struct efi_mm_communicate_header *mm_hdr;
void *virt_shared_buf;
if (!comm_buf)
return EFI_INVALID_PARAMETER;
/* Discover MM partition ID at boot time */
if (!mm_sp_id && ffa_discover_mm_sp_id()) {
log_err("EFI: Failure to discover MM SP ID at boot time, FF-A MM comms failure\n");
return EFI_UNSUPPORTED;
}
mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
tx_data_size = mm_hdr->message_len + sizeof(efi_guid_t) + sizeof(size_t);
if (comm_buf_size != tx_data_size || tx_data_size > CONFIG_FFA_SHARED_MM_BUF_SIZE)
return EFI_INVALID_PARAMETER;
/* Copy the data to the shared buffer */
virt_shared_buf = map_sysmem((phys_addr_t)CONFIG_FFA_SHARED_MM_BUF_ADDR, 0);
memcpy(virt_shared_buf, comm_buf, tx_data_size);
/*
* The secure world might have cache disabled for
* the device region used for shared buffer (which is the case for Optee).
* In this case, the secure world reads the data from DRAM.
* Let's flush the cache so the DRAM is updated with the latest data.
*/
#ifdef CONFIG_ARM64
invalidate_dcache_all();
#endif
/* Announce there is data in the shared buffer */
ffa_ret = ffa_notify_mm_sp();
switch (ffa_ret) {
case 0: {
ulong rx_data_size;
/* Copy the MM SP response from the shared buffer to the communication buffer */
rx_data_size = ((struct efi_mm_communicate_header *)virt_shared_buf)->message_len +
sizeof(efi_guid_t) +
sizeof(size_t);
if (rx_data_size > comm_buf_size) {
efi_ret = EFI_OUT_OF_RESOURCES;
break;
}
memcpy(comm_buf, virt_shared_buf, rx_data_size);
efi_ret = EFI_SUCCESS;
break;
}
case -EINVAL:
efi_ret = EFI_DEVICE_ERROR;
break;
case -EPERM:
efi_ret = EFI_INVALID_PARAMETER;
break;
case -EACCES:
efi_ret = EFI_ACCESS_DENIED;
break;
case -EBUSY:
efi_ret = EFI_OUT_OF_RESOURCES;
break;
default:
efi_ret = EFI_ACCESS_DENIED;
}
unmap_sysmem(virt_shared_buf);
return efi_ret;
}
/**
* get_mm_comms() - detect the available MM transport
*
* Make sure the FF-A bus is probed successfully
* which means FF-A communication with secure world works and ready
* for use.
*
* If FF-A bus is not ready, use OPTEE comms.
*
* Return:
*
* MM_COMMS_FFA or MM_COMMS_OPTEE
*/
static enum mm_comms_select get_mm_comms(void)
{
struct udevice *dev;
int ret;
ret = uclass_first_device_err(UCLASS_FFA, &dev);
if (ret) {
log_debug("EFI: Cannot find FF-A bus device, trying Optee comms\n");
return MM_COMMS_OPTEE;
}
return MM_COMMS_FFA;
}
#endif
/**
* mm_communicate() - Adjust the communication buffer to the MM SP and send
* it to OP-TEE
*
* @comm_buf: locally allocated communication buffer
* @dsize: buffer size
*
* The SP (also called partition) can be any MM SP such as StandAlonneMM or smm-gateway.
* The comm_buf format is the same for both partitions.
* When using the u-boot OP-TEE driver, StandAlonneMM is supported.
* When using the u-boot FF-A driver, any MM SP is supported.
*
* Return: status code
*/
static efi_status_t mm_communicate(u8 *comm_buf, efi_uintn_t dsize)
{
efi_status_t ret;
struct efi_mm_communicate_header *mm_hdr;
struct smm_variable_communicate_header *var_hdr;
#if CONFIG_IS_ENABLED(ARM_FFA_TRANSPORT)
enum mm_comms_select mm_comms;
#endif
dsize += MM_COMMUNICATE_HEADER_SIZE + MM_VARIABLE_COMMUNICATE_SIZE;
mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data;
#if CONFIG_IS_ENABLED(ARM_FFA_TRANSPORT)
mm_comms = get_mm_comms();
if (mm_comms == MM_COMMS_FFA)
ret = ffa_mm_communicate(comm_buf, dsize);
else
ret = optee_mm_communicate(comm_buf, dsize);
#else
ret = optee_mm_communicate(comm_buf, dsize);
#endif
if (ret != EFI_SUCCESS) {
log_err("%s failed!\n", __func__);
return ret;
}
return var_hdr->ret_status;
}
/**
* setup_mm_hdr() - Allocate a buffer for StandAloneMM and initialize the
* header data.
*
* @dptr: pointer address of the corresponding StandAloneMM
* function
* @payload_size: buffer size
* @func: standAloneMM function number
* @ret: EFI return code
* Return: buffer or NULL
*/
static u8 *setup_mm_hdr(void **dptr, efi_uintn_t payload_size,
efi_uintn_t func, efi_status_t *ret)
{
const efi_guid_t mm_var_guid = EFI_MM_VARIABLE_GUID;
struct efi_mm_communicate_header *mm_hdr;
struct smm_variable_communicate_header *var_hdr;
u8 *comm_buf;
/* In the init function we initialize max_buffer_size with
* get_max_payload(). So skip the test if max_buffer_size is initialized
* StandAloneMM will perform similar checks and drop the buffer if it's
* too long
*/
if (max_buffer_size && max_buffer_size <
(MM_COMMUNICATE_HEADER_SIZE +
MM_VARIABLE_COMMUNICATE_SIZE +
payload_size)) {
*ret = EFI_INVALID_PARAMETER;
return NULL;
}
comm_buf = calloc(1, MM_COMMUNICATE_HEADER_SIZE +
MM_VARIABLE_COMMUNICATE_SIZE +
payload_size);
if (!comm_buf) {
*ret = EFI_OUT_OF_RESOURCES;
return NULL;
}
mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
guidcpy(&mm_hdr->header_guid, &mm_var_guid);
mm_hdr->message_len = MM_VARIABLE_COMMUNICATE_SIZE + payload_size;
var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data;
var_hdr->function = func;
if (dptr)
*dptr = var_hdr->data;
*ret = EFI_SUCCESS;
return comm_buf;
}
/**
* get_max_payload() - Get variable payload size from StandAloneMM.
*
* @size: size of the variable in storage
* Return: status code
*/
efi_status_t EFIAPI get_max_payload(efi_uintn_t *size)
{
struct smm_variable_payload_size *var_payload = NULL;
efi_uintn_t payload_size;
u8 *comm_buf = NULL;
efi_status_t ret;
if (!size) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
payload_size = sizeof(*var_payload);
comm_buf = setup_mm_hdr((void **)&var_payload, payload_size,
SMM_VARIABLE_FUNCTION_GET_PAYLOAD_SIZE, &ret);
if (!comm_buf)
goto out;
ret = mm_communicate(comm_buf, payload_size);
if (ret != EFI_SUCCESS)
goto out;
/* Make sure the buffer is big enough for storing variables */
if (var_payload->size < MM_VARIABLE_ACCESS_HEADER_SIZE + 0x20) {
ret = EFI_DEVICE_ERROR;
goto out;
}
*size = var_payload->size;
/*
* There seems to be a bug in EDK2 miscalculating the boundaries and
* size checks, so deduct 2 more bytes to fulfill this requirement. Fix
* it up here to ensure backwards compatibility with older versions
* (cf. StandaloneMmPkg/Drivers/StandaloneMmCpu/AArch64/EventHandle.c.
* sizeof (EFI_MM_COMMUNICATE_HEADER) instead the size minus the
* flexible array member).
*
* size is guaranteed to be > 2 due to checks on the beginning.
*/
*size -= 2;
out:
free(comm_buf);
return ret;
}
/*
* StMM can store internal attributes and properties for variables, i.e enabling
* R/O variables
*/
static efi_status_t set_property_int(const u16 *variable_name,
efi_uintn_t name_size,
const efi_guid_t *vendor,
struct var_check_property *var_property)
{
struct smm_variable_var_check_property *smm_property;
efi_uintn_t payload_size;
u8 *comm_buf = NULL;
efi_status_t ret;
payload_size = sizeof(*smm_property) + name_size;
if (payload_size > max_payload_size) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
comm_buf = setup_mm_hdr((void **)&smm_property, payload_size,
SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_SET,
&ret);
if (!comm_buf)
goto out;
guidcpy(&smm_property->guid, vendor);
smm_property->name_size = name_size;
memcpy(&smm_property->property, var_property,
sizeof(smm_property->property));
memcpy(smm_property->name, variable_name, name_size);
ret = mm_communicate(comm_buf, payload_size);
out:
free(comm_buf);
return ret;
}
static efi_status_t get_property_int(const u16 *variable_name,
efi_uintn_t name_size,
const efi_guid_t *vendor,
struct var_check_property *var_property)
{
struct smm_variable_var_check_property *smm_property;
efi_uintn_t payload_size;
u8 *comm_buf = NULL;
efi_status_t ret;
memset(var_property, 0, sizeof(*var_property));
payload_size = sizeof(*smm_property) + name_size;
if (payload_size > max_payload_size) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
comm_buf = setup_mm_hdr((void **)&smm_property, payload_size,
SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_GET,
&ret);
if (!comm_buf)
goto out;
guidcpy(&smm_property->guid, vendor);
smm_property->name_size = name_size;
memcpy(smm_property->name, variable_name, name_size);
ret = mm_communicate(comm_buf, payload_size);
/*
* Currently only R/O property is supported in StMM.
* Variables that are not set to R/O will not set the property in StMM
* and the call will return EFI_NOT_FOUND. We are setting the
* properties to 0x0 so checking against that is enough for the
* EFI_NOT_FOUND case.
*/
if (ret == EFI_NOT_FOUND)
ret = EFI_SUCCESS;
if (ret != EFI_SUCCESS)
goto out;
memcpy(var_property, &smm_property->property, sizeof(*var_property));
out:
free(comm_buf);
return ret;
}
efi_status_t efi_get_variable_int(const u16 *variable_name,
const efi_guid_t *vendor,
u32 *attributes, efi_uintn_t *data_size,
void *data, u64 *timep)
{
struct var_check_property var_property;
struct smm_variable_access *var_acc;
efi_uintn_t payload_size;
efi_uintn_t name_size;
efi_uintn_t tmp_dsize;
u8 *comm_buf = NULL;
efi_status_t ret, tmp;
if (!variable_name || !vendor || !data_size) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
/* Check payload size */
name_size = u16_strsize(variable_name);
if (name_size > max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
/* Trim output buffer size */
tmp_dsize = *data_size;
if (name_size + tmp_dsize >
max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE) {
tmp_dsize = max_payload_size -
MM_VARIABLE_ACCESS_HEADER_SIZE -
name_size;
}
/* Get communication buffer and initialize header */
payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + tmp_dsize;
comm_buf = setup_mm_hdr((void **)&var_acc, payload_size,
SMM_VARIABLE_FUNCTION_GET_VARIABLE, &ret);
if (!comm_buf)
goto out;
/* Fill in contents */
guidcpy(&var_acc->guid, vendor);
var_acc->data_size = tmp_dsize;
var_acc->name_size = name_size;
var_acc->attr = attributes ? *attributes : 0;
memcpy(var_acc->name, variable_name, name_size);
/* Communicate */
ret = mm_communicate(comm_buf, payload_size);
if (ret != EFI_SUCCESS && ret != EFI_BUFFER_TOO_SMALL)
goto out;
/* Update with reported data size for trimmed case */
*data_size = var_acc->data_size;
/*
* UEFI > 2.7 needs the attributes set even if the buffer is
* smaller
*/
if (attributes) {
tmp = get_property_int(variable_name, name_size, vendor,
&var_property);
if (tmp != EFI_SUCCESS) {
ret = tmp;
goto out;
}
*attributes = var_acc->attr;
if (var_property.property &
VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY)
*attributes |= EFI_VARIABLE_READ_ONLY;
}
/* return if ret is EFI_BUFFER_TOO_SMALL */
if (ret != EFI_SUCCESS)
goto out;
if (data)
memcpy(data, (u8 *)var_acc->name + var_acc->name_size,
var_acc->data_size);
else
ret = EFI_INVALID_PARAMETER;
out:
free(comm_buf);
return ret;
}
efi_status_t efi_get_next_variable_name_int(efi_uintn_t *variable_name_size,
u16 *variable_name,
efi_guid_t *guid)
{
struct smm_variable_getnext *var_getnext;
efi_uintn_t payload_size;
efi_uintn_t out_name_size;
efi_uintn_t in_name_size;
u8 *comm_buf = NULL;
efi_status_t ret;
if (!variable_name_size || !variable_name || !guid) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
out_name_size = *variable_name_size;
in_name_size = u16_strsize(variable_name);
if (out_name_size < in_name_size) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
if (in_name_size > max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
/* Trim output buffer size */
if (out_name_size > max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE)
out_name_size = max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE;
payload_size = MM_VARIABLE_GET_NEXT_HEADER_SIZE + out_name_size;
comm_buf = setup_mm_hdr((void **)&var_getnext, payload_size,
SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME,
&ret);
if (!comm_buf)
goto out;
/* Fill in contents */
guidcpy(&var_getnext->guid, guid);
var_getnext->name_size = out_name_size;
memcpy(var_getnext->name, variable_name, in_name_size);
memset((u8 *)var_getnext->name + in_name_size, 0x0,
out_name_size - in_name_size);
/* Communicate */
ret = mm_communicate(comm_buf, payload_size);
if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) {
/* Update with reported data size for trimmed case */
*variable_name_size = var_getnext->name_size;
}
if (ret != EFI_SUCCESS)
goto out;
guidcpy(guid, &var_getnext->guid);
memcpy(variable_name, var_getnext->name, var_getnext->name_size);
out:
free(comm_buf);
return ret;
}
efi_status_t efi_set_variable_int(const u16 *variable_name,
const efi_guid_t *vendor, u32 attributes,
efi_uintn_t data_size, const void *data,
bool ro_check)
{
efi_status_t ret, alt_ret = EFI_SUCCESS;
struct var_check_property var_property;
struct smm_variable_access *var_acc;
efi_uintn_t payload_size;
efi_uintn_t name_size;
u8 *comm_buf = NULL;
bool ro;
if (!variable_name || variable_name[0] == 0 || !vendor) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
if (data_size > 0 && !data) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
/* Check payload size */
name_size = u16_strsize(variable_name);
payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + data_size;
if (payload_size > max_payload_size) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
/*
* Allocate the buffer early, before switching to RW (if needed)
* so we won't need to account for any failures in reading/setting
* the properties, if the allocation fails
*/
comm_buf = setup_mm_hdr((void **)&var_acc, payload_size,
SMM_VARIABLE_FUNCTION_SET_VARIABLE, &ret);
if (!comm_buf)
goto out;
ro = !!(attributes & EFI_VARIABLE_READ_ONLY);
attributes &= EFI_VARIABLE_MASK;
/*
* The API has the ability to override RO flags. If no RO check was
* requested switch the variable to RW for the duration of this call
*/
ret = get_property_int(variable_name, name_size, vendor,
&var_property);
if (ret != EFI_SUCCESS)
goto out;
if (var_property.property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY) {
/* Bypass r/o check */
if (!ro_check) {
var_property.property &= ~VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY;
ret = set_property_int(variable_name, name_size, vendor, &var_property);
if (ret != EFI_SUCCESS)
goto out;
} else {
ret = EFI_WRITE_PROTECTED;
goto out;
}
}
/* Fill in contents */
guidcpy(&var_acc->guid, vendor);
var_acc->data_size = data_size;
var_acc->name_size = name_size;
var_acc->attr = attributes;
memcpy(var_acc->name, variable_name, name_size);
memcpy((u8 *)var_acc->name + name_size, data, data_size);
/* Communicate */
ret = mm_communicate(comm_buf, payload_size);
if (ret != EFI_SUCCESS)
alt_ret = ret;
if (ro && !(var_property.property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY)) {
var_property.revision = VAR_CHECK_VARIABLE_PROPERTY_REVISION;
var_property.property |= VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY;
var_property.attributes = attributes;
var_property.minsize = 1;
var_property.maxsize = var_acc->data_size;
ret = set_property_int(variable_name, name_size, vendor, &var_property);
}
if (alt_ret != EFI_SUCCESS)
goto out;
if (!u16_strcmp(variable_name, u"PK"))
alt_ret = efi_init_secure_state();
out:
free(comm_buf);
return alt_ret == EFI_SUCCESS ? ret : alt_ret;
}
efi_status_t efi_query_variable_info_int(u32 attributes,
u64 *max_variable_storage_size,
u64 *remain_variable_storage_size,
u64 *max_variable_size)
{
struct smm_variable_query_info *mm_query_info;
efi_uintn_t payload_size;
efi_status_t ret;
u8 *comm_buf;
payload_size = sizeof(*mm_query_info);
comm_buf = setup_mm_hdr((void **)&mm_query_info, payload_size,
SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO,
&ret);
if (!comm_buf)
goto out;
mm_query_info->attr = attributes;
ret = mm_communicate(comm_buf, payload_size);
if (ret != EFI_SUCCESS)
goto out;
*max_variable_storage_size = mm_query_info->max_variable_storage;
*remain_variable_storage_size =
mm_query_info->remaining_variable_storage;
*max_variable_size = mm_query_info->max_variable_size;
out:
free(comm_buf);
return ret;
}
/**
* efi_query_variable_info() - get information about EFI variables
*
* This function implements the QueryVariableInfo() runtime service.
*
* See the Unified Extensible Firmware Interface (UEFI) specification for
* details.
*
* @attributes: bitmask to select variables to be
* queried
* @maximum_variable_storage_size: maximum size of storage area for the
* selected variable types
* @remaining_variable_storage_size: remaining size of storage are for the
* selected variable types
* @maximum_variable_size: maximum size of a variable of the
* selected type
* Return: status code
*/
efi_status_t EFIAPI __efi_runtime
efi_query_variable_info_runtime(u32 attributes, u64 *max_variable_storage_size,
u64 *remain_variable_storage_size,
u64 *max_variable_size)
{
return EFI_UNSUPPORTED;
}
/**
* efi_set_variable_runtime() - runtime implementation of SetVariable()
*
* @variable_name: name of the variable
* @guid: vendor GUID
* @attributes: attributes of the variable
* @data_size: size of the buffer with the variable value
* @data: buffer with the variable value
* Return: status code
*/
static efi_status_t __efi_runtime EFIAPI
efi_set_variable_runtime(u16 *variable_name, const efi_guid_t *guid,
u32 attributes, efi_uintn_t data_size,
const void *data)
{
return EFI_UNSUPPORTED;
}
/**
* efi_variables_boot_exit_notify() - notify ExitBootServices() is called
*/
void efi_variables_boot_exit_notify(void)
{
efi_status_t ret;
u8 *comm_buf;
loff_t len;
struct efi_var_file *var_buf;
comm_buf = setup_mm_hdr(NULL, 0,
SMM_VARIABLE_FUNCTION_EXIT_BOOT_SERVICE, &ret);
if (comm_buf)
ret = mm_communicate(comm_buf, 0);
else
ret = EFI_NOT_FOUND;
if (ret != EFI_SUCCESS)
log_err("Unable to notify the MM partition for ExitBootServices\n");
free(comm_buf);
ret = efi_var_collect(&var_buf, &len, EFI_VARIABLE_RUNTIME_ACCESS);
if (ret != EFI_SUCCESS)
log_err("Can't populate EFI variables. No runtime variables will be available\n");
else
efi_var_buf_update(var_buf);
free(var_buf);
/* Update runtime service table */
efi_runtime_services.query_variable_info =
efi_query_variable_info_runtime;
efi_runtime_services.get_variable = efi_get_variable_runtime;
efi_runtime_services.get_next_variable_name =
efi_get_next_variable_name_runtime;
efi_runtime_services.set_variable = efi_set_variable_runtime;
efi_update_table_header_crc32(&efi_runtime_services.hdr);
}
/**
* efi_init_variables() - initialize variable services
*
* Return: status code
*/
efi_status_t efi_init_variables(void)
{
efi_status_t ret;
/* Create a cached copy of the variables that will be enabled on ExitBootServices() */
ret = efi_var_mem_init();
if (ret != EFI_SUCCESS)
return ret;
ret = get_max_payload(&max_payload_size);
if (ret != EFI_SUCCESS)
return ret;
max_buffer_size = MM_COMMUNICATE_HEADER_SIZE +
MM_VARIABLE_COMMUNICATE_SIZE +
max_payload_size;
ret = efi_init_secure_state();
if (ret != EFI_SUCCESS)
return ret;
return EFI_SUCCESS;
}