u-boot/arch/arm/cpu/armv8/sec_firmware.c
Simon Glass c5819701a3 image: Adjust the workings of fit_check_format()
At present this function does not accept a size for the FIT. This means
that it must be read from the FIT itself, introducing potential security
risk. Update the function to include a size parameter, which can be
invalid, in which case fit_check_format() calculates it.

For now no callers pass the size, but this can be updated later.

Also adjust the return value to an error code so that all the different
types of problems can be distinguished by the user.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reported-by: Bruce Monroe <bruce.monroe@intel.com>
Reported-by: Arie Haenel <arie.haenel@intel.com>
Reported-by: Julien Lenoir <julien.lenoir@intel.com>
2021-02-15 22:31:52 -05:00

504 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2016 NXP Semiconductor, Inc.
*/
#include <common.h>
#include <cpu_func.h>
#include <errno.h>
#include <fdt_support.h>
#include <image.h>
#include <log.h>
#include <asm/cache.h>
#include <asm/global_data.h>
#include <asm/ptrace.h>
#include <linux/kernel.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/types.h>
#include <asm/macro.h>
#include <asm/armv8/sec_firmware.h>
DECLARE_GLOBAL_DATA_PTR;
extern void c_runtime_cpu_setup(void);
#define SEC_FIRMWARE_LOADED 0x1
#define SEC_FIRMWARE_RUNNING 0x2
#define SEC_FIRMWARE_ADDR_MASK (~0x3)
/*
* Secure firmware load addr
* Flags used: 0x1 secure firmware has been loaded to secure memory
* 0x2 secure firmware is running
*/
phys_addr_t sec_firmware_addr;
#ifndef SEC_FIRMWARE_FIT_IMAGE
#define SEC_FIRMWARE_FIT_IMAGE "firmware"
#endif
#ifndef SEC_FIRMWARE_FIT_CNF_NAME
#define SEC_FIRMWARE_FIT_CNF_NAME "config-1"
#endif
#ifndef SEC_FIRMWARE_TARGET_EL
#define SEC_FIRMWARE_TARGET_EL 2
#endif
static int sec_firmware_get_data(const void *sec_firmware_img,
const void **data, size_t *size)
{
int conf_node_off, fw_node_off;
char *conf_node_name = NULL;
char *desc;
int ret;
conf_node_name = SEC_FIRMWARE_FIT_CNF_NAME;
conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
if (conf_node_off < 0) {
printf("SEC Firmware: %s: no such config\n", conf_node_name);
return -ENOENT;
}
fw_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
SEC_FIRMWARE_FIT_IMAGE);
if (fw_node_off < 0) {
printf("SEC Firmware: No '%s' in config\n",
SEC_FIRMWARE_FIT_IMAGE);
return -ENOLINK;
}
/* Verify secure firmware image */
if (!(fit_image_verify(sec_firmware_img, fw_node_off))) {
printf("SEC Firmware: Bad firmware image (bad CRC)\n");
return -EINVAL;
}
if (fit_image_get_data(sec_firmware_img, fw_node_off, data, size)) {
printf("SEC Firmware: Can't get %s subimage data/size",
SEC_FIRMWARE_FIT_IMAGE);
return -ENOENT;
}
ret = fit_get_desc(sec_firmware_img, fw_node_off, &desc);
if (ret)
printf("SEC Firmware: Can't get description\n");
else
printf("%s\n", desc);
return ret;
}
/*
* SEC Firmware FIT image parser checks if the image is in FIT
* format, verifies integrity of the image and calculates raw
* image address and size values.
*
* Returns 0 on success and a negative errno on error task fail.
*/
static int sec_firmware_parse_image(const void *sec_firmware_img,
const void **raw_image_addr,
size_t *raw_image_size)
{
int ret;
ret = sec_firmware_get_data(sec_firmware_img, raw_image_addr,
raw_image_size);
if (ret)
return ret;
debug("SEC Firmware: raw_image_addr = 0x%p, raw_image_size = 0x%lx\n",
*raw_image_addr, *raw_image_size);
return 0;
}
/*
* SEC Firmware FIT image parser to check if any loadable is
* present. If present, verify integrity of the loadable and
* copy loadable to address provided in (loadable_h, loadable_l).
*
* Returns 0 on success and a negative errno on error task fail.
*/
static int sec_firmware_check_copy_loadable(const void *sec_firmware_img,
u32 *loadable_l, u32 *loadable_h)
{
phys_addr_t sec_firmware_loadable_addr = 0;
int conf_node_off, ld_node_off, images;
char *conf_node_name = NULL;
const void *data;
size_t size;
ulong load;
const char *name, *str, *type;
int len;
conf_node_name = SEC_FIRMWARE_FIT_CNF_NAME;
conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
if (conf_node_off < 0) {
printf("SEC Firmware: %s: no such config\n", conf_node_name);
return -ENOENT;
}
/* find the node holding the images information */
images = fdt_path_offset(sec_firmware_img, FIT_IMAGES_PATH);
if (images < 0) {
printf("%s: Cannot find /images node: %d\n", __func__, images);
return -1;
}
type = FIT_LOADABLE_PROP;
name = fdt_getprop(sec_firmware_img, conf_node_off, type, &len);
if (!name) {
/* Loadables not present */
return 0;
}
printf("SEC Firmware: '%s' present in config\n", type);
for (str = name; str && ((str - name) < len);
str = strchr(str, '\0') + 1) {
printf("%s: '%s'\n", type, str);
ld_node_off = fdt_subnode_offset(sec_firmware_img, images, str);
if (ld_node_off < 0) {
printf("cannot find image node '%s': %d\n", str,
ld_node_off);
return -EINVAL;
}
/* Verify secure firmware image */
if (!(fit_image_verify(sec_firmware_img, ld_node_off))) {
printf("SEC Loadable: Bad loadable image (bad CRC)\n");
return -EINVAL;
}
if (fit_image_get_data(sec_firmware_img, ld_node_off,
&data, &size)) {
printf("SEC Loadable: Can't get subimage data/size");
return -ENOENT;
}
/* Get load address, treated as load offset to secure memory */
if (fit_image_get_load(sec_firmware_img, ld_node_off, &load)) {
printf("SEC Loadable: Can't get subimage load");
return -ENOENT;
}
/* Compute load address for loadable in secure memory */
sec_firmware_loadable_addr = (sec_firmware_addr -
gd->arch.tlb_size) + load;
/* Copy loadable to secure memory and flush dcache */
debug("%s copied to address 0x%p\n",
FIT_LOADABLE_PROP, (void *)sec_firmware_loadable_addr);
memcpy((void *)sec_firmware_loadable_addr, data, size);
flush_dcache_range(sec_firmware_loadable_addr,
sec_firmware_loadable_addr + size);
/* Populate loadable address only for Trusted OS */
if (!strcmp(str, "trustedOS@1")) {
/*
* Populate address ptrs for loadable image with
* loadbale addr
*/
out_le32(loadable_l, (sec_firmware_loadable_addr &
WORD_MASK));
out_le32(loadable_h, (sec_firmware_loadable_addr >>
WORD_SHIFT));
}
}
return 0;
}
static int sec_firmware_copy_image(const char *title,
u64 image_addr, u32 image_size, u64 sec_firmware)
{
debug("%s copied to address 0x%p\n", title, (void *)sec_firmware);
memcpy((void *)sec_firmware, (void *)image_addr, image_size);
flush_dcache_range(sec_firmware, sec_firmware + image_size);
return 0;
}
/*
* This function will parse the SEC Firmware image, and then load it
* to secure memory. Also load any loadable if present along with SEC
* Firmware image.
*/
static int sec_firmware_load_image(const void *sec_firmware_img,
u32 *loadable_l, u32 *loadable_h)
{
const void *raw_image_addr;
size_t raw_image_size = 0;
int ret;
/*
* The Excetpion Level must be EL3 to load and initialize
* the SEC Firmware.
*/
if (current_el() != 3) {
ret = -EACCES;
goto out;
}
#ifdef CONFIG_SYS_MEM_RESERVE_SECURE
/*
* The SEC Firmware must be stored in secure memory.
* Append SEC Firmware to secure mmu table.
*/
if (!(gd->arch.secure_ram & MEM_RESERVE_SECURE_MAINTAINED)) {
ret = -ENXIO;
goto out;
}
sec_firmware_addr = (gd->arch.secure_ram & MEM_RESERVE_SECURE_ADDR_MASK) +
gd->arch.tlb_size;
#else
#error "The CONFIG_SYS_MEM_RESERVE_SECURE must be defined when enabled SEC Firmware support"
#endif
/* Align SEC Firmware base address to 4K */
sec_firmware_addr = (sec_firmware_addr + 0xfff) & ~0xfff;
debug("SEC Firmware: Load address: 0x%llx\n",
sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
ret = sec_firmware_parse_image(sec_firmware_img, &raw_image_addr,
&raw_image_size);
if (ret)
goto out;
/* TODO:
* Check if the end addr of SEC Firmware has been extend the secure
* memory.
*/
/* Copy the secure firmware to secure memory */
ret = sec_firmware_copy_image("SEC Firmware", (u64)raw_image_addr,
raw_image_size, sec_firmware_addr &
SEC_FIRMWARE_ADDR_MASK);
if (ret)
goto out;
/*
* Check if any loadable are present along with firmware image, if
* present load them.
*/
ret = sec_firmware_check_copy_loadable(sec_firmware_img, loadable_l,
loadable_h);
if (ret)
goto out;
sec_firmware_addr |= SEC_FIRMWARE_LOADED;
debug("SEC Firmware: Entry point: 0x%llx\n",
sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
return 0;
out:
printf("SEC Firmware: error (%d)\n", ret);
sec_firmware_addr = 0;
return ret;
}
static int sec_firmware_entry(u32 *eret_hold_l, u32 *eret_hold_h)
{
const void *entry = (void *)(sec_firmware_addr &
SEC_FIRMWARE_ADDR_MASK);
return _sec_firmware_entry(entry, eret_hold_l, eret_hold_h);
}
/* Check the secure firmware FIT image */
__weak bool sec_firmware_is_valid(const void *sec_firmware_img)
{
if (fdt_check_header(sec_firmware_img)) {
printf("SEC Firmware: Bad firmware image (not a FIT image)\n");
return false;
}
if (fit_check_format(sec_firmware_img, IMAGE_SIZE_INVAL)) {
printf("SEC Firmware: Bad firmware image (bad FIT header)\n");
return false;
}
return true;
}
#ifdef CONFIG_SEC_FIRMWARE_ARMV8_PSCI
/*
* The PSCI_VERSION function is added from PSCI v0.2. When the PSCI
* v0.1 received this function, the NOT_SUPPORTED (0xffff_ffff) error
* number will be returned according to SMC Calling Conventions. But
* when getting the NOT_SUPPORTED error number, we cannot ensure if
* the PSCI version is v0.1 or other error occurred. So, PSCI v0.1
* won't be supported by this framework.
* And if the secure firmware isn't running, return NOT_SUPPORTED.
*
* The return value on success is PSCI version in format
* major[31:16]:minor[15:0].
*/
unsigned int sec_firmware_support_psci_version(void)
{
if (current_el() == SEC_FIRMWARE_TARGET_EL)
return _sec_firmware_support_psci_version();
return PSCI_INVALID_VER;
}
#endif
/*
* Check with sec_firmware if it supports random number generation
* via HW RNG
*
* The return value will be true if it is supported
*/
bool sec_firmware_support_hwrng(void)
{
#ifdef CONFIG_TFABOOT
/* return true as TFA has one job ring reserved */
return true;
#endif
if (sec_firmware_addr & SEC_FIRMWARE_RUNNING) {
return true;
}
return false;
}
/*
* sec_firmware_get_random - Get a random number from SEC Firmware
* @rand: random number buffer to be filled
* @bytes: Number of bytes of random number to be supported
* @eret: -1 in case of error, 0 for success
*/
int sec_firmware_get_random(uint8_t *rand, int bytes)
{
unsigned long long num;
struct pt_regs regs;
int param1;
if (!bytes || bytes > 8) {
printf("Max Random bytes genration supported is 8\n");
return -1;
}
#define SIP_RNG_64 0xC200FF11
regs.regs[0] = SIP_RNG_64;
if (bytes <= 4)
param1 = 0;
else
param1 = 1;
regs.regs[1] = param1;
smc_call(&regs);
if (regs.regs[0])
return -1;
num = regs.regs[1];
memcpy(rand, &num, bytes);
return 0;
}
/*
* sec_firmware_init - Initialize the SEC Firmware
* @sec_firmware_img: the SEC Firmware image address
* @eret_hold_l: the address to hold exception return address low
* @eret_hold_h: the address to hold exception return address high
* @loadable_l: the address to hold loadable address low
* @loadable_h: the address to hold loadable address high
*/
int sec_firmware_init(const void *sec_firmware_img,
u32 *eret_hold_l,
u32 *eret_hold_h,
u32 *loadable_l,
u32 *loadable_h)
{
int ret;
if (!sec_firmware_is_valid(sec_firmware_img))
return -EINVAL;
ret = sec_firmware_load_image(sec_firmware_img, loadable_l,
loadable_h);
if (ret) {
printf("SEC Firmware: Failed to load image\n");
return ret;
} else if (sec_firmware_addr & SEC_FIRMWARE_LOADED) {
ret = sec_firmware_entry(eret_hold_l, eret_hold_h);
if (ret) {
printf("SEC Firmware: Failed to initialize\n");
return ret;
}
}
debug("SEC Firmware: Return from SEC Firmware: current_el = %d\n",
current_el());
/*
* The PE will be turned into target EL when returned from
* SEC Firmware.
*/
if (current_el() != SEC_FIRMWARE_TARGET_EL)
return -EACCES;
sec_firmware_addr |= SEC_FIRMWARE_RUNNING;
/* Set exception table and enable caches if it isn't EL3 */
if (current_el() != 3) {
c_runtime_cpu_setup();
enable_caches();
}
return 0;
}
/*
* fdt_fix_kaslr - Add kalsr-seed node in Device tree
* @fdt: Device tree
* @eret: 0 in case of error, 1 for success
*/
int fdt_fixup_kaslr(void *fdt)
{
int nodeoffset;
int err, ret = 0;
u8 rand[8];
#if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT)
/* Check if random seed generation is supported */
if (sec_firmware_support_hwrng() == false) {
printf("WARNING: SEC firmware not running, no kaslr-seed\n");
return 0;
}
ret = sec_firmware_get_random(rand, 8);
if (ret < 0) {
printf("WARNING: No random number to set kaslr-seed\n");
return 0;
}
err = fdt_check_header(fdt);
if (err < 0) {
printf("fdt_chosen: %s\n", fdt_strerror(err));
return 0;
}
/* find or create "/chosen" node. */
nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen");
if (nodeoffset < 0)
return 0;
err = fdt_setprop(fdt, nodeoffset, "kaslr-seed", rand,
sizeof(rand));
if (err < 0) {
printf("WARNING: can't set kaslr-seed %s.\n",
fdt_strerror(err));
return 0;
}
ret = 1;
#endif
return ret;
}