tf-a/tf-a-stm32mp-2.2.r1/bl1/bl1_fwu.c

739 lines
21 KiB
C

/*
* Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <assert.h>
#include <errno.h>
#include <string.h>
#include <platform_def.h>
#include <arch_helpers.h>
#include <bl1/bl1.h>
#include <common/bl_common.h>
#include <common/debug.h>
#include <context.h>
#include <drivers/auth/auth_mod.h>
#include <lib/el3_runtime/context_mgmt.h>
#include <lib/utils.h>
#include <plat/common/platform.h>
#include <smccc_helpers.h>
#include "bl1_private.h"
/*
* Function declarations.
*/
static int bl1_fwu_image_copy(unsigned int image_id,
uintptr_t image_src,
unsigned int block_size,
unsigned int image_size,
unsigned int flags);
static int bl1_fwu_image_auth(unsigned int image_id,
uintptr_t image_src,
unsigned int image_size,
unsigned int flags);
static int bl1_fwu_image_execute(unsigned int image_id,
void **handle,
unsigned int flags);
static register_t bl1_fwu_image_resume(register_t image_param,
void **handle,
unsigned int flags);
static int bl1_fwu_sec_image_done(void **handle,
unsigned int flags);
static int bl1_fwu_image_reset(unsigned int image_id,
unsigned int flags);
__dead2 static void bl1_fwu_done(void *client_cookie, void *reserved);
/*
* This keeps track of last executed secure image id.
*/
static unsigned int sec_exec_image_id = INVALID_IMAGE_ID;
/*******************************************************************************
* Top level handler for servicing FWU SMCs.
******************************************************************************/
register_t bl1_fwu_smc_handler(unsigned int smc_fid,
register_t x1,
register_t x2,
register_t x3,
register_t x4,
void *cookie,
void *handle,
unsigned int flags)
{
switch (smc_fid) {
case FWU_SMC_IMAGE_COPY:
SMC_RET1(handle, bl1_fwu_image_copy(x1, x2, x3, x4, flags));
case FWU_SMC_IMAGE_AUTH:
SMC_RET1(handle, bl1_fwu_image_auth(x1, x2, x3, flags));
case FWU_SMC_IMAGE_EXECUTE:
SMC_RET1(handle, bl1_fwu_image_execute(x1, &handle, flags));
case FWU_SMC_IMAGE_RESUME:
SMC_RET1(handle, bl1_fwu_image_resume(x1, &handle, flags));
case FWU_SMC_SEC_IMAGE_DONE:
SMC_RET1(handle, bl1_fwu_sec_image_done(&handle, flags));
case FWU_SMC_IMAGE_RESET:
SMC_RET1(handle, bl1_fwu_image_reset(x1, flags));
case FWU_SMC_UPDATE_DONE:
bl1_fwu_done((void *)x1, NULL);
default:
assert(0); /* Unreachable */
break;
}
SMC_RET1(handle, SMC_UNK);
}
/*******************************************************************************
* Utility functions to keep track of the images that are loaded at any time.
******************************************************************************/
#ifdef PLAT_FWU_MAX_SIMULTANEOUS_IMAGES
#define FWU_MAX_SIMULTANEOUS_IMAGES PLAT_FWU_MAX_SIMULTANEOUS_IMAGES
#else
#define FWU_MAX_SIMULTANEOUS_IMAGES 10
#endif
static unsigned int bl1_fwu_loaded_ids[FWU_MAX_SIMULTANEOUS_IMAGES] = {
[0 ... FWU_MAX_SIMULTANEOUS_IMAGES-1] = INVALID_IMAGE_ID
};
/*
* Adds an image_id to the bl1_fwu_loaded_ids array.
* Returns 0 on success, 1 on error.
*/
static int bl1_fwu_add_loaded_id(unsigned int image_id)
{
int i;
/* Check if the ID is already in the list */
for (i = 0; i < FWU_MAX_SIMULTANEOUS_IMAGES; i++) {
if (bl1_fwu_loaded_ids[i] == image_id)
return 0;
}
/* Find an empty slot */
for (i = 0; i < FWU_MAX_SIMULTANEOUS_IMAGES; i++) {
if (bl1_fwu_loaded_ids[i] == INVALID_IMAGE_ID) {
bl1_fwu_loaded_ids[i] = image_id;
return 0;
}
}
return 1;
}
/*
* Removes an image_id from the bl1_fwu_loaded_ids array.
* Returns 0 on success, 1 on error.
*/
static int bl1_fwu_remove_loaded_id(unsigned int image_id)
{
int i;
/* Find the ID */
for (i = 0; i < FWU_MAX_SIMULTANEOUS_IMAGES; i++) {
if (bl1_fwu_loaded_ids[i] == image_id) {
bl1_fwu_loaded_ids[i] = INVALID_IMAGE_ID;
return 0;
}
}
return 1;
}
/*******************************************************************************
* This function checks if the specified image overlaps another image already
* loaded. It returns 0 if there is no overlap, a negative error code otherwise.
******************************************************************************/
static int bl1_fwu_image_check_overlaps(unsigned int image_id)
{
const image_desc_t *image_desc, *checked_image_desc;
const image_info_t *info, *checked_info;
uintptr_t image_base, image_end;
uintptr_t checked_image_base, checked_image_end;
checked_image_desc = bl1_plat_get_image_desc(image_id);
checked_info = &checked_image_desc->image_info;
/* Image being checked mustn't be empty. */
assert(checked_info->image_size != 0);
checked_image_base = checked_info->image_base;
checked_image_end = checked_image_base + checked_info->image_size - 1;
/* No need to check for overflows, it's done in bl1_fwu_image_copy(). */
for (int i = 0; i < FWU_MAX_SIMULTANEOUS_IMAGES; i++) {
/* Skip INVALID_IMAGE_IDs and don't check image against itself */
if ((bl1_fwu_loaded_ids[i] == INVALID_IMAGE_ID) ||
(bl1_fwu_loaded_ids[i] == image_id))
continue;
image_desc = bl1_plat_get_image_desc(bl1_fwu_loaded_ids[i]);
/* Only check images that are loaded or being loaded. */
assert (image_desc && image_desc->state != IMAGE_STATE_RESET);
info = &image_desc->image_info;
/* There cannot be overlaps with an empty image. */
if (info->image_size == 0)
continue;
image_base = info->image_base;
image_end = image_base + info->image_size - 1;
/*
* Overflows cannot happen. It is checked in
* bl1_fwu_image_copy() when the image goes from RESET to
* COPYING or COPIED.
*/
assert (image_end > image_base);
/* Check if there are overlaps. */
if (!(image_end < checked_image_base ||
checked_image_end < image_base)) {
VERBOSE("Image with ID %d overlaps existing image with ID %d",
checked_image_desc->image_id, image_desc->image_id);
return -EPERM;
}
}
return 0;
}
/*******************************************************************************
* This function is responsible for copying secure images in AP Secure RAM.
******************************************************************************/
static int bl1_fwu_image_copy(unsigned int image_id,
uintptr_t image_src,
unsigned int block_size,
unsigned int image_size,
unsigned int flags)
{
uintptr_t dest_addr;
unsigned int remaining;
/* Get the image descriptor. */
image_desc_t *image_desc = bl1_plat_get_image_desc(image_id);
if (!image_desc) {
WARN("BL1-FWU: Invalid image ID %u\n", image_id);
return -EPERM;
}
/*
* The request must originate from a non-secure caller and target a
* secure image. Any other scenario is invalid.
*/
if (GET_SECURITY_STATE(flags) == SECURE) {
WARN("BL1-FWU: Copy not allowed from secure world.\n");
return -EPERM;
}
if (GET_SECURITY_STATE(image_desc->ep_info.h.attr) == NON_SECURE) {
WARN("BL1-FWU: Copy not allowed for non-secure images.\n");
return -EPERM;
}
/* Check whether the FWU state machine is in the correct state. */
if ((image_desc->state != IMAGE_STATE_RESET) &&
(image_desc->state != IMAGE_STATE_COPYING)) {
WARN("BL1-FWU: Copy not allowed at this point of the FWU"
" process.\n");
return -EPERM;
}
if ((!image_src) || (!block_size) ||
check_uptr_overflow(image_src, block_size - 1)) {
WARN("BL1-FWU: Copy not allowed due to invalid image source"
" or block size\n");
return -ENOMEM;
}
if (image_desc->state == IMAGE_STATE_COPYING) {
/*
* There must have been at least 1 copy operation for this image
* previously.
*/
assert(image_desc->copied_size != 0);
/*
* The image size must have been recorded in the 1st copy
* operation.
*/
image_size = image_desc->image_info.image_size;
assert(image_size != 0);
assert(image_desc->copied_size < image_size);
INFO("BL1-FWU: Continuing image copy in blocks\n");
} else { /* image_desc->state == IMAGE_STATE_RESET */
INFO("BL1-FWU: Initial call to copy an image\n");
/*
* image_size is relevant only for the 1st copy request, it is
* then ignored for subsequent calls for this image.
*/
if (!image_size) {
WARN("BL1-FWU: Copy not allowed due to invalid image"
" size\n");
return -ENOMEM;
}
/* Check that the image size to load is within limit */
if (image_size > image_desc->image_info.image_max_size) {
WARN("BL1-FWU: Image size out of bounds\n");
return -ENOMEM;
}
/* Save the given image size. */
image_desc->image_info.image_size = image_size;
/* Make sure the image doesn't overlap other images. */
if (bl1_fwu_image_check_overlaps(image_id)) {
image_desc->image_info.image_size = 0;
WARN("BL1-FWU: This image overlaps another one\n");
return -EPERM;
}
/*
* copied_size must be explicitly initialized here because the
* FWU code doesn't necessarily do it when it resets the state
* machine.
*/
image_desc->copied_size = 0;
}
/*
* If the given block size is more than the total image size
* then clip the former to the latter.
*/
remaining = image_size - image_desc->copied_size;
if (block_size > remaining) {
WARN("BL1-FWU: Block size is too big, clipping it.\n");
block_size = remaining;
}
/* Make sure the source image is mapped in memory. */
if (bl1_plat_mem_check(image_src, block_size, flags)) {
WARN("BL1-FWU: Source image is not mapped.\n");
return -ENOMEM;
}
if (bl1_fwu_add_loaded_id(image_id)) {
WARN("BL1-FWU: Too many images loaded at the same time.\n");
return -ENOMEM;
}
/* Allow the platform to handle pre-image load before copying */
if (image_desc->state == IMAGE_STATE_RESET) {
if (bl1_plat_handle_pre_image_load(image_id) != 0) {
ERROR("BL1-FWU: Failure in pre-image load of image id %d\n",
image_id);
return -EPERM;
}
}
/* Everything looks sane. Go ahead and copy the block of data. */
dest_addr = image_desc->image_info.image_base + image_desc->copied_size;
memcpy((void *) dest_addr, (const void *) image_src, block_size);
flush_dcache_range(dest_addr, block_size);
image_desc->copied_size += block_size;
image_desc->state = (block_size == remaining) ?
IMAGE_STATE_COPIED : IMAGE_STATE_COPYING;
INFO("BL1-FWU: Copy operation successful.\n");
return 0;
}
/*******************************************************************************
* This function is responsible for authenticating Normal/Secure images.
******************************************************************************/
static int bl1_fwu_image_auth(unsigned int image_id,
uintptr_t image_src,
unsigned int image_size,
unsigned int flags)
{
int result;
uintptr_t base_addr;
unsigned int total_size;
/* Get the image descriptor. */
image_desc_t *image_desc = bl1_plat_get_image_desc(image_id);
if (!image_desc)
return -EPERM;
if (GET_SECURITY_STATE(flags) == SECURE) {
if (image_desc->state != IMAGE_STATE_RESET) {
WARN("BL1-FWU: Authentication from secure world "
"while in invalid state\n");
return -EPERM;
}
} else {
if (GET_SECURITY_STATE(image_desc->ep_info.h.attr) == SECURE) {
if (image_desc->state != IMAGE_STATE_COPIED) {
WARN("BL1-FWU: Authentication of secure image "
"from non-secure world while not in copied state\n");
return -EPERM;
}
} else {
if (image_desc->state != IMAGE_STATE_RESET) {
WARN("BL1-FWU: Authentication of non-secure image "
"from non-secure world while in invalid state\n");
return -EPERM;
}
}
}
if (image_desc->state == IMAGE_STATE_COPIED) {
/*
* Image is in COPIED state.
* Use the stored address and size.
*/
base_addr = image_desc->image_info.image_base;
total_size = image_desc->image_info.image_size;
} else {
if ((!image_src) || (!image_size) ||
check_uptr_overflow(image_src, image_size - 1)) {
WARN("BL1-FWU: Auth not allowed due to invalid"
" image source/size\n");
return -ENOMEM;
}
/*
* Image is in RESET state.
* Check the parameters and authenticate the source image in place.
*/
if (bl1_plat_mem_check(image_src, image_size, \
image_desc->ep_info.h.attr)) {
WARN("BL1-FWU: Authentication arguments source/size not mapped\n");
return -ENOMEM;
}
if (bl1_fwu_add_loaded_id(image_id)) {
WARN("BL1-FWU: Too many images loaded at the same time.\n");
return -ENOMEM;
}
base_addr = image_src;
total_size = image_size;
/* Update the image size in the descriptor. */
image_desc->image_info.image_size = total_size;
}
/*
* Authenticate the image.
*/
INFO("BL1-FWU: Authenticating image_id:%d\n", image_id);
result = auth_mod_verify_img(image_id, (void *)base_addr, total_size);
if (result != 0) {
WARN("BL1-FWU: Authentication Failed err=%d\n", result);
/*
* Authentication has failed.
* Clear the memory if the image was copied.
* This is to prevent an attack where this contains
* some malicious code that can somehow be executed later.
*/
if (image_desc->state == IMAGE_STATE_COPIED) {
/* Clear the memory.*/
zero_normalmem((void *)base_addr, total_size);
flush_dcache_range(base_addr, total_size);
/* Indicate that image can be copied again*/
image_desc->state = IMAGE_STATE_RESET;
}
/*
* Even if this fails it's ok because the ID isn't in the array.
* The image cannot be in RESET state here, it is checked at the
* beginning of the function.
*/
bl1_fwu_remove_loaded_id(image_id);
return -EAUTH;
}
/* Indicate that image is in authenticated state. */
image_desc->state = IMAGE_STATE_AUTHENTICATED;
/* Allow the platform to handle post-image load */
result = bl1_plat_handle_post_image_load(image_id);
if (result != 0) {
ERROR("BL1-FWU: Failure %d in post-image load of image id %d\n",
result, image_id);
/*
* Panic here as the platform handling of post-image load is
* not correct.
*/
plat_error_handler(result);
}
/*
* Flush image_info to memory so that other
* secure world images can see changes.
*/
flush_dcache_range((uintptr_t)&image_desc->image_info,
sizeof(image_info_t));
INFO("BL1-FWU: Authentication was successful\n");
return 0;
}
/*******************************************************************************
* This function is responsible for executing Secure images.
******************************************************************************/
static int bl1_fwu_image_execute(unsigned int image_id,
void **handle,
unsigned int flags)
{
/* Get the image descriptor. */
image_desc_t *image_desc = bl1_plat_get_image_desc(image_id);
/*
* Execution is NOT allowed if:
* image_id is invalid OR
* Caller is from Secure world OR
* Image is Non-Secure OR
* Image is Non-Executable OR
* Image is NOT in AUTHENTICATED state.
*/
if ((!image_desc) ||
(GET_SECURITY_STATE(flags) == SECURE) ||
(GET_SECURITY_STATE(image_desc->ep_info.h.attr) == NON_SECURE) ||
(EP_GET_EXE(image_desc->ep_info.h.attr) == NON_EXECUTABLE) ||
(image_desc->state != IMAGE_STATE_AUTHENTICATED)) {
WARN("BL1-FWU: Execution not allowed due to invalid state/args\n");
return -EPERM;
}
INFO("BL1-FWU: Executing Secure image\n");
#ifdef __aarch64__
/* Save NS-EL1 system registers. */
cm_el1_sysregs_context_save(NON_SECURE);
#endif
/* Prepare the image for execution. */
bl1_prepare_next_image(image_id);
/* Update the secure image id. */
sec_exec_image_id = image_id;
#ifdef __aarch64__
*handle = cm_get_context(SECURE);
#else
*handle = smc_get_ctx(SECURE);
#endif
return 0;
}
/*******************************************************************************
* This function is responsible for resuming execution in the other security
* world
******************************************************************************/
static register_t bl1_fwu_image_resume(register_t image_param,
void **handle,
unsigned int flags)
{
image_desc_t *image_desc;
unsigned int resume_sec_state;
unsigned int caller_sec_state = GET_SECURITY_STATE(flags);
/* Get the image descriptor for last executed secure image id. */
image_desc = bl1_plat_get_image_desc(sec_exec_image_id);
if (caller_sec_state == NON_SECURE) {
if (!image_desc) {
WARN("BL1-FWU: Resume not allowed due to no available"
"secure image\n");
return -EPERM;
}
} else {
/* image_desc must be valid for secure world callers */
assert(image_desc);
}
assert(GET_SECURITY_STATE(image_desc->ep_info.h.attr) == SECURE);
assert(EP_GET_EXE(image_desc->ep_info.h.attr) == EXECUTABLE);
if (caller_sec_state == SECURE) {
assert(image_desc->state == IMAGE_STATE_EXECUTED);
/* Update the flags. */
image_desc->state = IMAGE_STATE_INTERRUPTED;
resume_sec_state = NON_SECURE;
} else {
assert(image_desc->state == IMAGE_STATE_INTERRUPTED);
/* Update the flags. */
image_desc->state = IMAGE_STATE_EXECUTED;
resume_sec_state = SECURE;
}
INFO("BL1-FWU: Resuming %s world context\n",
(resume_sec_state == SECURE) ? "secure" : "normal");
#ifdef __aarch64__
/* Save the EL1 system registers of calling world. */
cm_el1_sysregs_context_save(caller_sec_state);
/* Restore the EL1 system registers of resuming world. */
cm_el1_sysregs_context_restore(resume_sec_state);
/* Update the next context. */
cm_set_next_eret_context(resume_sec_state);
*handle = cm_get_context(resume_sec_state);
#else
/* Update the next context. */
cm_set_next_context(cm_get_context(resume_sec_state));
/* Prepare the smc context for the next BL image. */
smc_set_next_ctx(resume_sec_state);
*handle = smc_get_ctx(resume_sec_state);
#endif
return image_param;
}
/*******************************************************************************
* This function is responsible for resuming normal world context.
******************************************************************************/
static int bl1_fwu_sec_image_done(void **handle, unsigned int flags)
{
image_desc_t *image_desc;
/* Make sure caller is from the secure world */
if (GET_SECURITY_STATE(flags) == NON_SECURE) {
WARN("BL1-FWU: Image done not allowed from normal world\n");
return -EPERM;
}
/* Get the image descriptor for last executed secure image id */
image_desc = bl1_plat_get_image_desc(sec_exec_image_id);
/* image_desc must correspond to a valid secure executing image */
assert(image_desc);
assert(GET_SECURITY_STATE(image_desc->ep_info.h.attr) == SECURE);
assert(EP_GET_EXE(image_desc->ep_info.h.attr) == EXECUTABLE);
assert(image_desc->state == IMAGE_STATE_EXECUTED);
#if ENABLE_ASSERTIONS
int rc = bl1_fwu_remove_loaded_id(sec_exec_image_id);
assert(rc == 0);
#else
bl1_fwu_remove_loaded_id(sec_exec_image_id);
#endif
/* Update the flags. */
image_desc->state = IMAGE_STATE_RESET;
sec_exec_image_id = INVALID_IMAGE_ID;
INFO("BL1-FWU: Resuming Normal world context\n");
#ifdef __aarch64__
/*
* Secure world is done so no need to save the context.
* Just restore the Non-Secure context.
*/
cm_el1_sysregs_context_restore(NON_SECURE);
/* Update the next context. */
cm_set_next_eret_context(NON_SECURE);
*handle = cm_get_context(NON_SECURE);
#else
/* Update the next context. */
cm_set_next_context(cm_get_context(NON_SECURE));
/* Prepare the smc context for the next BL image. */
smc_set_next_ctx(NON_SECURE);
*handle = smc_get_ctx(NON_SECURE);
#endif
return 0;
}
/*******************************************************************************
* This function provides the opportunity for users to perform any
* platform specific handling after the Firmware update is done.
******************************************************************************/
__dead2 static void bl1_fwu_done(void *client_cookie, void *reserved)
{
NOTICE("BL1-FWU: *******FWU Process Completed*******\n");
/*
* Call platform done function.
*/
bl1_plat_fwu_done(client_cookie, reserved);
assert(0);
}
/*******************************************************************************
* This function resets an image to IMAGE_STATE_RESET. It fails if the image is
* being executed.
******************************************************************************/
static int bl1_fwu_image_reset(unsigned int image_id, unsigned int flags)
{
image_desc_t *image_desc = bl1_plat_get_image_desc(image_id);
if ((!image_desc) || (GET_SECURITY_STATE(flags) == SECURE)) {
WARN("BL1-FWU: Reset not allowed due to invalid args\n");
return -EPERM;
}
switch (image_desc->state) {
case IMAGE_STATE_RESET:
/* Nothing to do. */
break;
case IMAGE_STATE_INTERRUPTED:
case IMAGE_STATE_AUTHENTICATED:
case IMAGE_STATE_COPIED:
case IMAGE_STATE_COPYING:
if (bl1_fwu_remove_loaded_id(image_id)) {
WARN("BL1-FWU: Image reset couldn't find the image ID\n");
return -EPERM;
}
if (image_desc->copied_size) {
/* Clear the memory if the image is copied */
assert(GET_SECURITY_STATE(image_desc->ep_info.h.attr) == SECURE);
zero_normalmem((void *)image_desc->image_info.image_base,
image_desc->copied_size);
flush_dcache_range(image_desc->image_info.image_base,
image_desc->copied_size);
}
/* Reset status variables */
image_desc->copied_size = 0;
image_desc->image_info.image_size = 0;
image_desc->state = IMAGE_STATE_RESET;
/* Clear authentication state */
auth_img_flags[image_id] = 0;
break;
case IMAGE_STATE_EXECUTED:
default:
assert(0); /* Unreachable */
break;
}
return 0;
}