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android_recovery_motorola_g.../gpt-utils/gpt-utils.cpp
Akilesh Kailash f70785956d hiphi: gpt-utils: FSync after block device writes 
When markBoolSuccessful is invoked, we update
the partition table. These writes should be
synced before merge operation is resumed post OTA.
If not, any crash before these writes are landed to
backing storage will lead to incorrect switching of
slots.

BUG: 175711601
Test: Verify slot switching correctly after crash when merge in progress
Change-Id: I2da9286490d5d063df0c9d4dc491e0fbf28f51bb
Signed-off-by: Akilesh Kailash <akailash@google.com>
Signed-off-by: sekaiacg <sekaiacg@gmail.com>
Signed-off-by: 7Soldier <reg.fm4@gmail.com>
2023-05-04 15:45:38 +03:00

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/*
* Copyright (c) 2013,2016,2020 The Linux Foundation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* * Neither the name of The Linux Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#define _LARGEFILE64_SOURCE /* enable lseek64() */
/******************************************************************************
* INCLUDE SECTION
******************************************************************************/
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <linux/fs.h>
#include <limits.h>
#include <dirent.h>
#include <linux/kernel.h>
#include <map>
#include <vector>
#include <string>
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#define LOG_TAG "gpt-utils"
#include <log/log.h>
#include <cutils/properties.h>
#include "gpt-utils.h"
#include <zlib.h>
#include <endian.h>
/******************************************************************************
* DEFINE SECTION
******************************************************************************/
#define BLK_DEV_FILE "/dev/block/mmcblk0"
/* list the names of the backed-up partitions to be swapped */
/* extension used for the backup partitions - tzbak, abootbak, etc. */
#define BAK_PTN_NAME_EXT "bak"
#define XBL_PRIMARY "/dev/block/bootdevice/by-name/xbl"
#define XBL_BACKUP "/dev/block/bootdevice/by-name/xblbak"
#define XBL_AB_PRIMARY "/dev/block/bootdevice/by-name/xbl_a"
#define XBL_AB_SECONDARY "/dev/block/bootdevice/by-name/xbl_b"
/* GPT defines */
#define MAX_LUNS 26
//This will allow us to get the root lun path from the path to the partition.
//i.e: from /dev/block/sdaXXX get /dev/block/sda. The assumption here is that
//the boot critical luns lie between sda to sdz which is acceptable because
//only user added external disks,etc would lie beyond that limit which do not
//contain partitions that interest us here.
#define PATH_TRUNCATE_LOC (sizeof("/dev/block/sda") - 1)
//From /dev/block/sda get just sda
#define LUN_NAME_START_LOC (sizeof("/dev/block/") - 1)
#define BOOT_LUN_A_ID 1
#define BOOT_LUN_B_ID 2
/******************************************************************************
* MACROS
******************************************************************************/
#define GET_4_BYTES(ptr) ((uint32_t) *((uint8_t *)(ptr)) | \
((uint32_t) *((uint8_t *)(ptr) + 1) << 8) | \
((uint32_t) *((uint8_t *)(ptr) + 2) << 16) | \
((uint32_t) *((uint8_t *)(ptr) + 3) << 24))
#define GET_8_BYTES(ptr) ((uint64_t) *((uint8_t *)(ptr)) | \
((uint64_t) *((uint8_t *)(ptr) + 1) << 8) | \
((uint64_t) *((uint8_t *)(ptr) + 2) << 16) | \
((uint64_t) *((uint8_t *)(ptr) + 3) << 24) | \
((uint64_t) *((uint8_t *)(ptr) + 4) << 32) | \
((uint64_t) *((uint8_t *)(ptr) + 5) << 40) | \
((uint64_t) *((uint8_t *)(ptr) + 6) << 48) | \
((uint64_t) *((uint8_t *)(ptr) + 7) << 56))
#define PUT_4_BYTES(ptr, y) *((uint8_t *)(ptr)) = (y) & 0xff; \
*((uint8_t *)(ptr) + 1) = ((y) >> 8) & 0xff; \
*((uint8_t *)(ptr) + 2) = ((y) >> 16) & 0xff; \
*((uint8_t *)(ptr) + 3) = ((y) >> 24) & 0xff;
/******************************************************************************
* TYPES
******************************************************************************/
using namespace std;
enum gpt_state {
GPT_OK = 0,
GPT_BAD_SIGNATURE,
GPT_BAD_CRC
};
//List of LUN's containing boot critical images.
//Required in the case of UFS devices
struct update_data {
char lun_list[MAX_LUNS][PATH_MAX];
uint32_t num_valid_entries;
};
int32_t set_boot_lun(char *sg_dev,uint8_t boot_lun_id);
/******************************************************************************
* FUNCTIONS
******************************************************************************/
/**
* ==========================================================================
*
* \brief Read/Write len bytes from/to block dev
*
* \param [in] fd block dev file descriptor (returned from open)
* \param [in] rw RW flag: 0 - read, != 0 - write
* \param [in] offset block dev offset [bytes] - RW start position
* \param [in] buf Pointer to the buffer containing the data
* \param [in] len RW size in bytes. Buf must be at least that big
*
* \return 0 on success
*
* ==========================================================================
*/
static int blk_rw(int fd, int rw, int64_t offset, uint8_t *buf, unsigned len)
{
int r;
if (lseek64(fd, offset, SEEK_SET) < 0) {
fprintf(stderr, "block dev lseek64 %" PRIi64 " failed: %s\n", offset,
strerror(errno));
return -1;
}
if (rw)
r = write(fd, buf, len);
else
r = read(fd, buf, len);
if (r < 0) {
fprintf(stderr, "block dev %s failed: %s\n", rw ? "write" : "read",
strerror(errno));
} else {
if (rw) {
r = fsync(fd);
if (r < 0)
fprintf(stderr, "fsync failed: %s\n", strerror(errno));
} else {
r = 0;
}
}
return r;
}
/**
* ==========================================================================
*
* \brief Search within GPT for partition entry with the given name
* or it's backup twin (name-bak).
*
* \param [in] ptn_name Partition name to seek
* \param [in] pentries_start Partition entries array start pointer
* \param [in] pentries_end Partition entries array end pointer
* \param [in] pentry_size Single partition entry size [bytes]
*
* \return First partition entry pointer that matches the name or NULL
*
* ==========================================================================
*/
static uint8_t *gpt_pentry_seek(const char *ptn_name,
const uint8_t *pentries_start,
const uint8_t *pentries_end,
uint32_t pentry_size)
{
char *pentry_name;
unsigned len = strlen(ptn_name);
unsigned i;
char name8[MAX_GPT_NAME_SIZE] = {0}; // initialize with null
for (pentry_name = (char *) (pentries_start + PARTITION_NAME_OFFSET);
pentry_name < (char *) pentries_end;
pentry_name += pentry_size) {
/* Partition names in GPT are UTF-16 - ignoring UTF-16 2nd byte */
for (i = 0; i < sizeof(name8) / 2; i++)
name8[i] = pentry_name[i * 2];
name8[i] = '\0';
if (!strncmp(ptn_name, name8, len)) {
if (name8[len] == 0 || !strcmp(&name8[len], BAK_PTN_NAME_EXT))
return (uint8_t *) (pentry_name - PARTITION_NAME_OFFSET);
}
}
return NULL;
}
/**
* ==========================================================================
*
* \brief Swaps boot chain in GPT partition entries array
*
* \param [in] pentries_start Partition entries array start
* \param [in] pentries_end Partition entries array end
* \param [in] pentry_size Single partition entry size
*
* \return 0 on success, 1 if no backup partitions found
*
* ==========================================================================
*/
static int gpt_boot_chain_swap(const uint8_t *pentries_start,
const uint8_t *pentries_end,
uint32_t pentry_size)
{
const char ptn_swap_list[][MAX_GPT_NAME_SIZE] = { PTN_SWAP_LIST };
int backup_not_found = 1;
unsigned i;
for (i = 0; i < ARRAY_SIZE(ptn_swap_list); i++) {
uint8_t *ptn_entry;
uint8_t *ptn_bak_entry;
uint8_t ptn_swap[PTN_ENTRY_SIZE];
//Skip the xbl, multiimgoem, multiimgqti partitions on UFS devices. That is handled
//seperately.
if ((gpt_utils_is_ufs_device() && !strncmp(ptn_swap_list[i],PTN_XBL,strlen(PTN_XBL)))
|| !strncmp(ptn_swap_list[i],PTN_MULTIIMGOEM,strlen(PTN_MULTIIMGOEM))
|| !strncmp(ptn_swap_list[i],PTN_MULTIIMGQTI,strlen(PTN_MULTIIMGQTI)))
continue;
ptn_entry = gpt_pentry_seek(ptn_swap_list[i], pentries_start,
pentries_end, pentry_size);
if (ptn_entry == NULL)
continue;
ptn_bak_entry = gpt_pentry_seek(ptn_swap_list[i],
ptn_entry + pentry_size, pentries_end, pentry_size);
if (ptn_bak_entry == NULL) {
fprintf(stderr, "'%s' partition not backup - skip safe update\n",
ptn_swap_list[i]);
continue;
}
/* swap primary <-> backup partition entries */
memcpy(ptn_swap, ptn_entry, PTN_ENTRY_SIZE);
memcpy(ptn_entry, ptn_bak_entry, PTN_ENTRY_SIZE);
memcpy(ptn_bak_entry, ptn_swap, PTN_ENTRY_SIZE);
backup_not_found = 0;
}
return backup_not_found;
}
/**
* ==========================================================================
*
* \brief Sets secondary GPT boot chain
*
* \param [in] fd block dev file descriptor
* \param [in] boot Boot chain to switch to
*
* \return 0 on success
*
* ==========================================================================
*/
static int gpt2_set_boot_chain(int fd, enum boot_chain boot)
{
int64_t gpt2_header_offset;
uint64_t pentries_start_offset;
uint32_t gpt_header_size;
uint32_t pentry_size;
uint32_t pentries_array_size;
uint8_t *gpt_header = NULL;
uint8_t *pentries = NULL;
uint32_t crc;
uint32_t crc_zero;
uint32_t blk_size = 0;
int r;
crc_zero = crc32(0L, Z_NULL, 0);
if (ioctl(fd, BLKSSZGET, &blk_size) != 0) {
fprintf(stderr, "Failed to get GPT device block size: %s\n",
strerror(errno));
r = -1;
goto EXIT;
}
gpt_header = (uint8_t*)malloc(blk_size);
if (!gpt_header) {
fprintf(stderr, "Failed to allocate memory to hold GPT block\n");
r = -1;
goto EXIT;
}
gpt2_header_offset = lseek64(fd, 0, SEEK_END) - blk_size;
if (gpt2_header_offset < 0) {
fprintf(stderr, "Getting secondary GPT header offset failed: %s\n",
strerror(errno));
r = -1;
goto EXIT;
}
/* Read primary GPT header from block dev */
r = blk_rw(fd, 0, blk_size, gpt_header, blk_size);
if (r) {
fprintf(stderr, "Failed to read primary GPT header from blk dev\n");
goto EXIT;
}
pentries_start_offset =
GET_8_BYTES(gpt_header + PENTRIES_OFFSET) * blk_size;
pentry_size = GET_4_BYTES(gpt_header + PENTRY_SIZE_OFFSET);
pentries_array_size =
GET_4_BYTES(gpt_header + PARTITION_COUNT_OFFSET) * pentry_size;
pentries = (uint8_t *) calloc(1, pentries_array_size);
if (pentries == NULL) {
fprintf(stderr,
"Failed to alloc memory for GPT partition entries array\n");
r = -1;
goto EXIT;
}
/* Read primary GPT partititon entries array from block dev */
r = blk_rw(fd, 0, pentries_start_offset, pentries, pentries_array_size);
if (r)
goto EXIT;
crc = crc32(crc_zero, pentries, pentries_array_size);
if (GET_4_BYTES(gpt_header + PARTITION_CRC_OFFSET) != crc) {
fprintf(stderr, "Primary GPT partition entries array CRC invalid\n");
r = -1;
goto EXIT;
}
/* Read secondary GPT header from block dev */
r = blk_rw(fd, 0, gpt2_header_offset, gpt_header, blk_size);
if (r)
goto EXIT;
gpt_header_size = GET_4_BYTES(gpt_header + HEADER_SIZE_OFFSET);
pentries_start_offset =
GET_8_BYTES(gpt_header + PENTRIES_OFFSET) * blk_size;
if (boot == BACKUP_BOOT) {
r = gpt_boot_chain_swap(pentries, pentries + pentries_array_size,
pentry_size);
if (r)
goto EXIT;
}
crc = crc32(crc_zero, pentries, pentries_array_size);
PUT_4_BYTES(gpt_header + PARTITION_CRC_OFFSET, crc);
/* header CRC is calculated with this field cleared */
PUT_4_BYTES(gpt_header + HEADER_CRC_OFFSET, 0);
crc = crc32(crc_zero, gpt_header, gpt_header_size);
PUT_4_BYTES(gpt_header + HEADER_CRC_OFFSET, crc);
/* Write the modified GPT header back to block dev */
r = blk_rw(fd, 1, gpt2_header_offset, gpt_header, blk_size);
if (!r)
/* Write the modified GPT partititon entries array back to block dev */
r = blk_rw(fd, 1, pentries_start_offset, pentries,
pentries_array_size);
EXIT:
if(gpt_header)
free(gpt_header);
if (pentries)
free(pentries);
return r;
}
/**
* ==========================================================================
*
* \brief Checks GPT state (header signature and CRC)
*
* \param [in] fd block dev file descriptor
* \param [in] gpt GPT header to be checked
* \param [out] state GPT header state
*
* \return 0 on success
*
* ==========================================================================
*/
static int gpt_get_state(int fd, enum gpt_instance gpt, enum gpt_state *state)
{
int64_t gpt_header_offset;
uint32_t gpt_header_size;
uint8_t *gpt_header = NULL;
uint32_t crc;
uint32_t crc_zero;
uint32_t blk_size = 0;
*state = GPT_OK;
crc_zero = crc32(0L, Z_NULL, 0);
if (ioctl(fd, BLKSSZGET, &blk_size) != 0) {
fprintf(stderr, "Failed to get GPT device block size: %s\n",
strerror(errno));
goto error;
}
gpt_header = (uint8_t*)malloc(blk_size);
if (!gpt_header) {
fprintf(stderr, "gpt_get_state:Failed to alloc memory for header\n");
goto error;
}
if (gpt == PRIMARY_GPT)
gpt_header_offset = blk_size;
else {
gpt_header_offset = lseek64(fd, 0, SEEK_END) - blk_size;
if (gpt_header_offset < 0) {
fprintf(stderr, "gpt_get_state:Seek to end of GPT part fail\n");
goto error;
}
}
if (blk_rw(fd, 0, gpt_header_offset, gpt_header, blk_size)) {
fprintf(stderr, "gpt_get_state: blk_rw failed\n");
goto error;
}
if (memcmp(gpt_header, GPT_SIGNATURE, sizeof(GPT_SIGNATURE)))
*state = GPT_BAD_SIGNATURE;
gpt_header_size = GET_4_BYTES(gpt_header + HEADER_SIZE_OFFSET);
crc = GET_4_BYTES(gpt_header + HEADER_CRC_OFFSET);
/* header CRC is calculated with this field cleared */
PUT_4_BYTES(gpt_header + HEADER_CRC_OFFSET, 0);
if (crc32(crc_zero, gpt_header, gpt_header_size) != crc)
*state = GPT_BAD_CRC;
free(gpt_header);
return 0;
error:
if (gpt_header)
free(gpt_header);
return -1;
}
/**
* ==========================================================================
*
* \brief Sets GPT header state (used to corrupt and fix GPT signature)
*
* \param [in] fd block dev file descriptor
* \param [in] gpt GPT header to be checked
* \param [in] state GPT header state to set (GPT_OK or GPT_BAD_SIGNATURE)
*
* \return 0 on success
*
* ==========================================================================
*/
static int gpt_set_state(int fd, enum gpt_instance gpt, enum gpt_state state)
{
int64_t gpt_header_offset;
uint32_t gpt_header_size;
uint8_t *gpt_header = NULL;
uint32_t crc;
uint32_t crc_zero;
uint32_t blk_size = 0;
crc_zero = crc32(0L, Z_NULL, 0);
if (ioctl(fd, BLKSSZGET, &blk_size) != 0) {
fprintf(stderr, "Failed to get GPT device block size: %s\n",
strerror(errno));
goto error;
}
gpt_header = (uint8_t*)malloc(blk_size);
if (!gpt_header) {
fprintf(stderr, "Failed to alloc memory for gpt header\n");
goto error;
}
if (gpt == PRIMARY_GPT)
gpt_header_offset = blk_size;
else {
gpt_header_offset = lseek64(fd, 0, SEEK_END) - blk_size;
if (gpt_header_offset < 0) {
fprintf(stderr, "Failed to seek to end of GPT device\n");
goto error;
}
}
if (blk_rw(fd, 0, gpt_header_offset, gpt_header, blk_size)) {
fprintf(stderr, "Failed to r/w gpt header\n");
goto error;
}
if (state == GPT_OK)
memcpy(gpt_header, GPT_SIGNATURE, sizeof(GPT_SIGNATURE));
else if (state == GPT_BAD_SIGNATURE)
*gpt_header = 0;
else {
fprintf(stderr, "gpt_set_state: Invalid state\n");
goto error;
}
gpt_header_size = GET_4_BYTES(gpt_header + HEADER_SIZE_OFFSET);
/* header CRC is calculated with this field cleared */
PUT_4_BYTES(gpt_header + HEADER_CRC_OFFSET, 0);
crc = crc32(crc_zero, gpt_header, gpt_header_size);
PUT_4_BYTES(gpt_header + HEADER_CRC_OFFSET, crc);
if (blk_rw(fd, 1, gpt_header_offset, gpt_header, blk_size)) {
fprintf(stderr, "gpt_set_state: blk write failed\n");
goto error;
}
return 0;
error:
if(gpt_header)
free(gpt_header);
return -1;
}
int get_scsi_node_from_bootdevice(const char *bootdev_path,
char *sg_node_path,
size_t buf_size)
{
char sg_dir_path[PATH_MAX] = {0};
char real_path[PATH_MAX] = {0};
DIR *scsi_dir = NULL;
struct dirent *de;
int node_found = 0;
if (!bootdev_path || !sg_node_path) {
fprintf(stderr, "%s : invalid argument\n",
__func__);
goto error;
}
if (readlink(bootdev_path, real_path, sizeof(real_path) - 1) < 0) {
fprintf(stderr, "failed to resolve link for %s(%s)\n",
bootdev_path,
strerror(errno));
goto error;
}
if(strlen(real_path) < PATH_TRUNCATE_LOC + 1){
fprintf(stderr, "Unrecognized path :%s:\n",
real_path);
goto error;
}
//For the safe side in case there are additional partitions on
//the XBL lun we truncate the name.
real_path[PATH_TRUNCATE_LOC] = '\0';
if(strlen(real_path) < LUN_NAME_START_LOC + 1){
fprintf(stderr, "Unrecognized truncated path :%s:\n",
real_path);
goto error;
}
//This will give us /dev/block/sdb/device/scsi_generic
//which contains a file sgY whose name gives us the path
//to /dev/sgY which we return
snprintf(sg_dir_path, sizeof(sg_dir_path) - 1,
"/sys/block/%s/device/scsi_generic",
&real_path[LUN_NAME_START_LOC]);
scsi_dir = opendir(sg_dir_path);
if (!scsi_dir) {
fprintf(stderr, "%s : Failed to open %s(%s)\n",
__func__,
sg_dir_path,
strerror(errno));
goto error;
}
while((de = readdir(scsi_dir))) {
if (de->d_name[0] == '.')
continue;
else if (!strncmp(de->d_name, "sg", 2)) {
snprintf(sg_node_path,
buf_size -1,
"/dev/%s",
de->d_name);
fprintf(stderr, "%s:scsi generic node is :%s:\n",
__func__,
sg_node_path);
node_found = 1;
break;
}
}
if(!node_found) {
fprintf(stderr,"%s: Unable to locate scsi generic node\n",
__func__);
goto error;
}
closedir(scsi_dir);
return 0;
error:
if (scsi_dir)
closedir(scsi_dir);
return -1;
}
//Swtich betwieen using either the primary or the backup
//boot LUN for boot. This is required since UFS boot partitions
//cannot have a backup GPT which is what we use for failsafe
//updates of the other 'critical' partitions. This function will
//not be invoked for emmc targets and on UFS targets is only required
//to be invoked for XBL.
//
//The algorithm to do this is as follows:
//- Find the real block device(eg: /dev/block/sdb) that corresponds
// to the /dev/block/bootdevice/by-name/xbl(bak) symlink
//
//- Once we have the block device 'node' name(sdb in the above example)
// use this node to to locate the scsi generic device that represents
// it by checking the file /sys/block/sdb/device/scsi_generic/sgY
//
//- Once we locate sgY we call the query ioctl on /dev/sgy to switch
//the boot lun to either LUNA or LUNB
int gpt_utils_set_xbl_boot_partition(enum boot_chain chain)
{
struct stat st;
///sys/block/sdX/device/scsi_generic/
char sg_dev_node[PATH_MAX] = {0};
uint8_t boot_lun_id = 0;
const char *boot_dev = NULL;
if (chain == BACKUP_BOOT) {
boot_lun_id = BOOT_LUN_B_ID;
if (!stat(XBL_BACKUP, &st))
boot_dev = XBL_BACKUP;
else if (!stat(XBL_AB_SECONDARY, &st))
boot_dev = XBL_AB_SECONDARY;
else {
fprintf(stderr, "%s: Failed to locate secondary xbl\n",
__func__);
goto error;
}
} else if (chain == NORMAL_BOOT) {
boot_lun_id = BOOT_LUN_A_ID;
if (!stat(XBL_PRIMARY, &st))
boot_dev = XBL_PRIMARY;
else if (!stat(XBL_AB_PRIMARY, &st))
boot_dev = XBL_AB_PRIMARY;
else {
fprintf(stderr, "%s: Failed to locate primary xbl\n",
__func__);
goto error;
}
} else {
fprintf(stderr, "%s: Invalid boot chain id\n", __func__);
goto error;
}
//We need either both xbl and xblbak or both xbl_a and xbl_b to exist at
//the same time. If not the current configuration is invalid.
if((stat(XBL_PRIMARY, &st) ||
stat(XBL_BACKUP, &st)) &&
(stat(XBL_AB_PRIMARY, &st) ||
stat(XBL_AB_SECONDARY, &st))) {
fprintf(stderr, "%s:primary/secondary XBL prt not found(%s)\n",
__func__,
strerror(errno));
goto error;
}
fprintf(stderr, "%s: setting %s lun as boot lun\n",
__func__,
boot_dev);
if (get_scsi_node_from_bootdevice(boot_dev,
sg_dev_node,
sizeof(sg_dev_node))) {
fprintf(stderr, "%s: Failed to get scsi node path for xblbak\n",
__func__);
goto error;
}
/* set boot lun using /dev/sg or /dev/ufs-bsg* */
if (set_boot_lun(sg_dev_node, boot_lun_id)) {
fprintf(stderr, "%s: Failed to set xblbak as boot partition\n",
__func__);
goto error;
}
return 0;
error:
return -1;
}
int gpt_utils_is_ufs_device()
{
char bootdevice[PROPERTY_VALUE_MAX] = {0};
property_get("ro.boot.bootdevice", bootdevice, "N/A");
if (strlen(bootdevice) < strlen(".ufshc") + 1)
return 0;
return (!strncmp(&bootdevice[strlen(bootdevice) - strlen(".ufshc")],
".ufshc",
sizeof(".ufshc")));
}
//dev_path is the path to the block device that contains the GPT image that
//needs to be updated. This would be the device which holds one or more critical
//boot partitions and their backups. In the case of EMMC this function would
//be invoked only once on /dev/block/mmcblk1 since it holds the GPT image
//containing all the partitions For UFS devices it could potentially be
//invoked multiple times, once for each LUN containing critical image(s) and
//their backups
int prepare_partitions(enum boot_update_stage stage, const char *dev_path)
{
int r = 0;
int fd = -1;
int is_ufs = gpt_utils_is_ufs_device();
enum gpt_state gpt_prim, gpt_second;
enum boot_update_stage internal_stage;
struct stat xbl_partition_stat;
if (!dev_path) {
fprintf(stderr, "%s: Invalid dev_path\n",
__func__);
r = -1;
goto EXIT;
}
fd = open(dev_path, O_RDWR);
if (fd < 0) {
fprintf(stderr, "%s: Opening '%s' failed: %s\n",
__func__,
BLK_DEV_FILE,
strerror(errno));
r = -1;
goto EXIT;
}
r = gpt_get_state(fd, PRIMARY_GPT, &gpt_prim) ||
gpt_get_state(fd, SECONDARY_GPT, &gpt_second);
if (r) {
fprintf(stderr, "%s: Getting GPT headers state failed\n",
__func__);
goto EXIT;
}
/* These 2 combinations are unexpected and unacceptable */
if (gpt_prim == GPT_BAD_CRC || gpt_second == GPT_BAD_CRC) {
fprintf(stderr, "%s: GPT headers CRC corruption detected, aborting\n",
__func__);
r = -1;
goto EXIT;
}
if (gpt_prim == GPT_BAD_SIGNATURE && gpt_second == GPT_BAD_SIGNATURE) {
fprintf(stderr, "%s: Both GPT headers corrupted, aborting\n",
__func__);
r = -1;
goto EXIT;
}
/* Check internal update stage according GPT headers' state */
if (gpt_prim == GPT_OK && gpt_second == GPT_OK)
internal_stage = UPDATE_MAIN;
else if (gpt_prim == GPT_BAD_SIGNATURE)
internal_stage = UPDATE_BACKUP;
else if (gpt_second == GPT_BAD_SIGNATURE)
internal_stage = UPDATE_FINALIZE;
else {
fprintf(stderr, "%s: Abnormal GPTs state: primary (%d), secondary (%d), "
"aborting\n", __func__, gpt_prim, gpt_second);
r = -1;
goto EXIT;
}
/* Stage already set - ready for update, exitting */
if ((int) stage == (int) internal_stage - 1)
goto EXIT;
/* Unexpected stage given */
if (stage != internal_stage) {
r = -1;
goto EXIT;
}
switch (stage) {
case UPDATE_MAIN:
if (is_ufs) {
if(stat(XBL_PRIMARY, &xbl_partition_stat)||
stat(XBL_BACKUP, &xbl_partition_stat)){
//Non fatal error. Just means this target does not
//use XBL but relies on sbl whose update is handled
//by the normal methods.
fprintf(stderr, "%s: xbl part not found(%s).Assuming sbl in use\n",
__func__,
strerror(errno));
} else {
//Switch the boot lun so that backup boot LUN is used
r = gpt_utils_set_xbl_boot_partition(BACKUP_BOOT);
if(r){
fprintf(stderr, "%s: Failed to set xbl backup partition as boot\n",
__func__);
goto EXIT;
}
}
}
//Fix up the backup GPT table so that it actually points to
//the backup copy of the boot critical images
fprintf(stderr, "%s: Preparing for primary partition update\n",
__func__);
r = gpt2_set_boot_chain(fd, BACKUP_BOOT);
if (r) {
if (r < 0)
fprintf(stderr,
"%s: Setting secondary GPT to backup boot failed\n",
__func__);
/* No backup partitions - do not corrupt GPT, do not flag error */
else
r = 0;
goto EXIT;
}
//corrupt the primary GPT so that the backup(which now points to
//the backup boot partitions is used)
r = gpt_set_state(fd, PRIMARY_GPT, GPT_BAD_SIGNATURE);
if (r) {
fprintf(stderr, "%s: Corrupting primary GPT header failed\n",
__func__);
goto EXIT;
}
break;
case UPDATE_BACKUP:
if (is_ufs) {
if(stat(XBL_PRIMARY, &xbl_partition_stat)||
stat(XBL_BACKUP, &xbl_partition_stat)){
//Non fatal error. Just means this target does not
//use XBL but relies on sbl whose update is handled
//by the normal methods.
fprintf(stderr, "%s: xbl part not found(%s).Assuming sbl in use\n",
__func__,
strerror(errno));
} else {
//Switch the boot lun so that backup boot LUN is used
r = gpt_utils_set_xbl_boot_partition(NORMAL_BOOT);
if(r) {
fprintf(stderr, "%s: Failed to set xbl backup partition as boot\n",
__func__);
goto EXIT;
}
}
}
//Fix the primary GPT header so that is used
fprintf(stderr, "%s: Preparing for backup partition update\n",
__func__);
r = gpt_set_state(fd, PRIMARY_GPT, GPT_OK);
if (r) {
fprintf(stderr, "%s: Fixing primary GPT header failed\n",
__func__);
goto EXIT;
}
//Corrupt the scondary GPT header
r = gpt_set_state(fd, SECONDARY_GPT, GPT_BAD_SIGNATURE);
if (r) {
fprintf(stderr, "%s: Corrupting secondary GPT header failed\n",
__func__);
goto EXIT;
}
break;
case UPDATE_FINALIZE:
//Undo the changes we had made in the UPDATE_MAIN stage so that the
//primary/backup GPT headers once again point to the same set of
//partitions
fprintf(stderr, "%s: Finalizing partitions\n",
__func__);
r = gpt2_set_boot_chain(fd, NORMAL_BOOT);
if (r < 0) {
fprintf(stderr, "%s: Setting secondary GPT to normal boot failed\n",
__func__);
goto EXIT;
}
r = gpt_set_state(fd, SECONDARY_GPT, GPT_OK);
if (r) {
fprintf(stderr, "%s: Fixing secondary GPT header failed\n",
__func__);
goto EXIT;
}
break;
default:;
}
EXIT:
if (fd >= 0) {
fsync(fd);
close(fd);
}
return r;
}
int add_lun_to_update_list(char *lun_path, struct update_data *dat)
{
uint32_t i = 0;
struct stat st;
if (!lun_path || !dat){
fprintf(stderr, "%s: Invalid data",
__func__);
return -1;
}
if (stat(lun_path, &st)) {
fprintf(stderr, "%s: Unable to access %s. Skipping adding to list",
__func__,
lun_path);
return -1;
}
if (dat->num_valid_entries == 0) {
fprintf(stderr, "%s: Copying %s into lun_list[%d]\n",
__func__,
lun_path,
i);
strlcpy(dat->lun_list[0], lun_path,
PATH_MAX * sizeof(char));
dat->num_valid_entries = 1;
} else {
for (i = 0; (i < dat->num_valid_entries) &&
(dat->num_valid_entries < MAX_LUNS - 1); i++) {
//Check if the current LUN is not already part
//of the lun list
if (!strncmp(lun_path,dat->lun_list[i],
strlen(dat->lun_list[i]))) {
//LUN already in list..Return
return 0;
}
}
fprintf(stderr, "%s: Copying %s into lun_list[%d]\n",
__func__,
lun_path,
dat->num_valid_entries);
//Add LUN path lun list
strlcpy(dat->lun_list[dat->num_valid_entries], lun_path,
PATH_MAX * sizeof(char));
dat->num_valid_entries++;
}
return 0;
}
int prepare_boot_update(enum boot_update_stage stage)
{
int is_ufs = gpt_utils_is_ufs_device();
struct stat ufs_dir_stat;
struct update_data data;
int rcode = 0;
uint32_t i = 0;
int is_error = 0;
const char ptn_swap_list[][MAX_GPT_NAME_SIZE] = { PTN_SWAP_LIST };
//Holds /dev/block/bootdevice/by-name/*bak entry
char buf[PATH_MAX] = {0};
//Holds the resolved path of the symlink stored in buf
char real_path[PATH_MAX] = {0};
if (!is_ufs) {
//emmc device. Just pass in path to mmcblk0
return prepare_partitions(stage, BLK_DEV_FILE);
} else {
//Now we need to find the list of LUNs over
//which the boot critical images are spread
//and set them up for failsafe updates.To do
//this we find out where the symlinks for the
//each of the paths under
///dev/block/bootdevice/by-name/PTN_SWAP_LIST
//actually point to.
fprintf(stderr, "%s: Running on a UFS device\n",
__func__);
memset(&data, '\0', sizeof(struct update_data));
for (i=0; i < ARRAY_SIZE(ptn_swap_list); i++) {
//XBL on UFS does not follow the convention
//of being loaded based on well known GUID'S.
//We take care of switching the UFS boot LUN
//explicitly later on.
if (!strncmp(ptn_swap_list[i],PTN_XBL,strlen(PTN_XBL))
|| !strncmp(ptn_swap_list[i],PTN_MULTIIMGOEM,strlen(PTN_MULTIIMGOEM))
|| !strncmp(ptn_swap_list[i],PTN_MULTIIMGQTI,strlen(PTN_MULTIIMGQTI)))
continue;
snprintf(buf, sizeof(buf),
"%s/%sbak",
BOOT_DEV_DIR,
ptn_swap_list[i]);
if (stat(buf, &ufs_dir_stat)) {
continue;
}
if (readlink(buf, real_path, sizeof(real_path) - 1) < 0)
{
fprintf(stderr, "%s: readlink error. Skipping %s",
__func__,
strerror(errno));
} else {
if(strlen(real_path) < PATH_TRUNCATE_LOC + 1){
fprintf(stderr, "Unknown path.Skipping :%s:\n",
real_path);
} else {
real_path[PATH_TRUNCATE_LOC] = '\0';
add_lun_to_update_list(real_path, &data);
}
}
memset(buf, '\0', sizeof(buf));
memset(real_path, '\0', sizeof(real_path));
}
for (i=0; i < data.num_valid_entries; i++) {
fprintf(stderr, "%s: Preparing %s for update stage %d\n",
__func__,
data.lun_list[i],
stage);
rcode = prepare_partitions(stage, data.lun_list[i]);
if (rcode != 0)
{
fprintf(stderr, "%s: Failed to prepare %s.Continuing..\n",
__func__,
data.lun_list[i]);
is_error = 1;
}
}
}
if (is_error)
return -1;
return 0;
}
//Given a parttion name(eg: rpm) get the path to the block device that
//represents the GPT disk the partition resides on. In the case of emmc it
//would be the default emmc dev(/dev/block/mmcblk0). In the case of UFS we look
//through the /dev/block/bootdevice/by-name/ tree for partname, and resolve
//the path to the LUN from there.
static int get_dev_path_from_partition_name(const char *partname,
char *buf,
size_t buflen)
{
struct stat st;
char path[PATH_MAX] = {0};
if (!partname || !buf || buflen < ((PATH_TRUNCATE_LOC) + 1)) {
ALOGE("%s: Invalid argument", __func__);
goto error;
}
if (gpt_utils_is_ufs_device()) {
//Need to find the lun that holds partition partname
snprintf(path, sizeof(path),
"%s/%s",
BOOT_DEV_DIR,
partname);
if (stat(path, &st)) {
goto error;
}
if (readlink(path, buf, buflen) < 0)
{
goto error;
} else {
buf[PATH_TRUNCATE_LOC] = '\0';
}
} else {
snprintf(buf, buflen, BLK_DEV_FILE);
}
return 0;
error:
return -1;
}
int gpt_utils_get_partition_map(vector<string>& ptn_list,
map<string, vector<string>>& partition_map) {
char devpath[PATH_MAX] = {'\0'};
map<string, vector<string>>::iterator it;
if (ptn_list.size() < 1) {
fprintf(stderr, "%s: Invalid ptn list\n", __func__);
goto error;
}
//Go through the passed in list
for (uint32_t i = 0; i < ptn_list.size(); i++)
{
//Key in the map is the path to the device that holds the
//partition
if (get_dev_path_from_partition_name(ptn_list[i].c_str(),
devpath,
sizeof(devpath))) {
//Not necessarily an error. The partition may just
//not be present.
continue;
}
string path = devpath;
it = partition_map.find(path);
if (it != partition_map.end()) {
it->second.push_back(ptn_list[i]);
} else {
vector<string> str_vec;
str_vec.push_back( ptn_list[i]);
partition_map.insert(pair<string, vector<string>>
(path, str_vec));
}
memset(devpath, '\0', sizeof(devpath));
}
return 0;
error:
return -1;
}
//Get the block size of the disk represented by decsriptor fd
static uint32_t gpt_get_block_size(int fd)
{
uint32_t block_size = 0;
if (fd < 0) {
ALOGE("%s: invalid descriptor",
__func__);
goto error;
}
if (ioctl(fd, BLKSSZGET, &block_size) != 0) {
ALOGE("%s: Failed to get GPT dev block size : %s",
__func__,
strerror(errno));
goto error;
}
return block_size;
error:
return 0;
}
//Write the GPT header present in the passed in buffer back to the
//disk represented by fd
static int gpt_set_header(uint8_t *gpt_header, int fd,
enum gpt_instance instance)
{
uint32_t block_size = 0;
off64_t gpt_header_offset = 0;
if (!gpt_header || fd < 0) {
ALOGE("%s: Invalid arguments",
__func__);
goto error;
}
block_size = gpt_get_block_size(fd);
if (block_size == 0) {
ALOGE("%s: Failed to get block size", __func__);
goto error;
}
if (instance == PRIMARY_GPT)
gpt_header_offset = block_size;
else
gpt_header_offset = lseek64(fd, 0, SEEK_END) - block_size;
if (gpt_header_offset <= 0) {
ALOGE("%s: Failed to get gpt header offset",__func__);
goto error;
}
if (blk_rw(fd, 1, gpt_header_offset, gpt_header, block_size)) {
ALOGE("%s: Failed to write back GPT header", __func__);
goto error;
}
return 0;
error:
return -1;
}
//Read out the GPT header for the disk that contains the partition partname
static uint8_t* gpt_get_header(const char *partname, enum gpt_instance instance)
{
uint8_t* hdr = NULL;
char devpath[PATH_MAX] = {0};
int64_t hdr_offset = 0;
uint32_t block_size = 0;
int fd = -1;
if (!partname) {
ALOGE("%s: Invalid partition name", __func__);
goto error;
}
if (get_dev_path_from_partition_name(partname, devpath, sizeof(devpath))
!= 0) {
ALOGE("%s: Failed to resolve path for %s",
__func__,
partname);
goto error;
}
fd = open(devpath, O_RDWR);
if (fd < 0) {
ALOGE("%s: Failed to open %s : %s",
__func__,
devpath,
strerror(errno));
goto error;
}
block_size = gpt_get_block_size(fd);
if (block_size == 0)
{
ALOGE("%s: Failed to get gpt block size for %s",
__func__,
partname);
goto error;
}
hdr = (uint8_t*)malloc(block_size);
if (!hdr) {
ALOGE("%s: Failed to allocate memory for gpt header",
__func__);
}
if (instance == PRIMARY_GPT)
hdr_offset = block_size;
else {
hdr_offset = lseek64(fd, 0, SEEK_END) - block_size;
}
if (hdr_offset < 0) {
ALOGE("%s: Failed to get gpt header offset",
__func__);
goto error;
}
if (blk_rw(fd, 0, hdr_offset, hdr, block_size)) {
ALOGE("%s: Failed to read GPT header from device",
__func__);
goto error;
}
close(fd);
return hdr;
error:
if (fd >= 0)
close(fd);
if (hdr)
free(hdr);
return NULL;
}
//Returns the partition entry array based on the
//passed in buffer which contains the gpt header.
//The fd here is the descriptor for the 'disk' which
//holds the partition
static uint8_t* gpt_get_pentry_arr(uint8_t *hdr, int fd)
{
uint64_t pentries_start = 0;
uint32_t pentry_size = 0;
uint32_t block_size = 0;
uint32_t pentries_arr_size = 0;
uint8_t *pentry_arr = NULL;
int rc = 0;
if (!hdr) {
ALOGE("%s: Invalid header", __func__);
goto error;
}
if (fd < 0) {
ALOGE("%s: Invalid fd", __func__);
goto error;
}
block_size = gpt_get_block_size(fd);
if (!block_size) {
ALOGE("%s: Failed to get gpt block size for",
__func__);
goto error;
}
pentries_start = GET_8_BYTES(hdr + PENTRIES_OFFSET) * block_size;
pentry_size = GET_4_BYTES(hdr + PENTRY_SIZE_OFFSET);
pentries_arr_size =
GET_4_BYTES(hdr + PARTITION_COUNT_OFFSET) * pentry_size;
pentry_arr = (uint8_t*)calloc(1, pentries_arr_size);
if (!pentry_arr) {
ALOGE("%s: Failed to allocate memory for partition array",
__func__);
goto error;
}
rc = blk_rw(fd, 0,
pentries_start,
pentry_arr,
pentries_arr_size);
if (rc) {
ALOGE("%s: Failed to read partition entry array",
__func__);
goto error;
}
return pentry_arr;
error:
if (pentry_arr)
free(pentry_arr);
return NULL;
}
static int gpt_set_pentry_arr(uint8_t *hdr, int fd, uint8_t* arr)
{
uint32_t block_size = 0;
uint64_t pentries_start = 0;
uint32_t pentry_size = 0;
uint32_t pentries_arr_size = 0;
int rc = 0;
if (!hdr || fd < 0 || !arr) {
ALOGE("%s: Invalid argument", __func__);
goto error;
}
block_size = gpt_get_block_size(fd);
if (!block_size) {
ALOGE("%s: Failed to get gpt block size for",
__func__);
goto error;
}
pentries_start = GET_8_BYTES(hdr + PENTRIES_OFFSET) * block_size;
pentry_size = GET_4_BYTES(hdr + PENTRY_SIZE_OFFSET);
pentries_arr_size =
GET_4_BYTES(hdr + PARTITION_COUNT_OFFSET) * pentry_size;
rc = blk_rw(fd, 1,
pentries_start,
arr,
pentries_arr_size);
if (rc) {
ALOGE("%s: Failed to read partition entry array",
__func__);
goto error;
}
return 0;
error:
return -1;
}
//Allocate a handle used by calls to the "gpt_disk" api's
struct gpt_disk * gpt_disk_alloc()
{
struct gpt_disk *disk;
disk = (struct gpt_disk *)malloc(sizeof(struct gpt_disk));
if (!disk) {
ALOGE("%s: Failed to allocate memory", __func__);
goto end;
}
memset(disk, 0, sizeof(struct gpt_disk));
end:
return disk;
}
//Free previously allocated/initialized handle
void gpt_disk_free(struct gpt_disk *disk)
{
if (!disk)
return;
if (disk->hdr)
free(disk->hdr);
if (disk->hdr_bak)
free(disk->hdr_bak);
if (disk->pentry_arr)
free(disk->pentry_arr);
if (disk->pentry_arr_bak)
free(disk->pentry_arr_bak);
free(disk);
return;
}
//fills up the passed in gpt_disk struct with information about the
//disk represented by path dev. Returns 0 on success and -1 on error.
int gpt_disk_get_disk_info(const char *dev, struct gpt_disk *dsk)
{
struct gpt_disk *disk = NULL;
int fd = -1;
uint32_t gpt_header_size = 0;
uint32_t crc_zero;
crc_zero = crc32(0L, Z_NULL, 0);
if (!dsk || !dev) {
ALOGE("%s: Invalid arguments", __func__);
goto error;
}
disk = dsk;
disk->hdr = gpt_get_header(dev, PRIMARY_GPT);
if (!disk->hdr) {
ALOGE("%s: Failed to get primary header", __func__);
goto error;
}
gpt_header_size = GET_4_BYTES(disk->hdr + HEADER_SIZE_OFFSET);
disk->hdr_crc = crc32(crc_zero, disk->hdr, gpt_header_size);
disk->hdr_bak = gpt_get_header(dev, SECONDARY_GPT);
if (!disk->hdr_bak) {
ALOGE("%s: Failed to get backup header", __func__);
goto error;
}
disk->hdr_bak_crc = crc32(crc_zero, disk->hdr_bak, gpt_header_size);
//Descriptor for the block device. We will use this for further
//modifications to the partition table
if (get_dev_path_from_partition_name(dev,
disk->devpath,
sizeof(disk->devpath)) != 0) {
ALOGE("%s: Failed to resolve path for %s",
__func__,
dev);
goto error;
}
fd = open(disk->devpath, O_RDWR);
if (fd < 0) {
ALOGE("%s: Failed to open %s: %s",
__func__,
disk->devpath,
strerror(errno));
goto error;
}
disk->pentry_arr = gpt_get_pentry_arr(disk->hdr, fd);
if (!disk->pentry_arr) {
ALOGE("%s: Failed to obtain partition entry array",
__func__);
goto error;
}
disk->pentry_arr_bak = gpt_get_pentry_arr(disk->hdr_bak, fd);
if (!disk->pentry_arr_bak) {
ALOGE("%s: Failed to obtain backup partition entry array",
__func__);
goto error;
}
disk->pentry_size = GET_4_BYTES(disk->hdr + PENTRY_SIZE_OFFSET);
disk->pentry_arr_size =
GET_4_BYTES(disk->hdr + PARTITION_COUNT_OFFSET) *
disk->pentry_size;
disk->pentry_arr_crc = GET_4_BYTES(disk->hdr + PARTITION_CRC_OFFSET);
disk->pentry_arr_bak_crc = GET_4_BYTES(disk->hdr_bak +
PARTITION_CRC_OFFSET);
disk->block_size = gpt_get_block_size(fd);
close(fd);
disk->is_initialized = GPT_DISK_INIT_MAGIC;
return 0;
error:
if (fd >= 0)
close(fd);
return -1;
}
//Get pointer to partition entry from a allocated gpt_disk structure
uint8_t* gpt_disk_get_pentry(struct gpt_disk *disk,
const char *partname,
enum gpt_instance instance)
{
uint8_t *ptn_arr = NULL;
if (!disk || !partname || disk->is_initialized != GPT_DISK_INIT_MAGIC) {
ALOGE("%s: Invalid argument",__func__);
goto error;
}
ptn_arr = (instance == PRIMARY_GPT) ?
disk->pentry_arr : disk->pentry_arr_bak;
return (gpt_pentry_seek(partname, ptn_arr,
ptn_arr + disk->pentry_arr_size ,
disk->pentry_size));
error:
return NULL;
}
//Update CRC values for the various components of the gpt_disk
//structure. This function should be called after any of the fields
//have been updated before the structure contents are written back to
//disk.
int gpt_disk_update_crc(struct gpt_disk *disk)
{
uint32_t gpt_header_size = 0;
uint32_t crc_zero;
crc_zero = crc32(0L, Z_NULL, 0);
if (!disk || (disk->is_initialized != GPT_DISK_INIT_MAGIC)) {
ALOGE("%s: invalid argument", __func__);
goto error;
}
//Recalculate the CRC of the primary partiton array
disk->pentry_arr_crc = crc32(crc_zero,
disk->pentry_arr,
disk->pentry_arr_size);
//Recalculate the CRC of the backup partition array
disk->pentry_arr_bak_crc = crc32(crc_zero,
disk->pentry_arr_bak,
disk->pentry_arr_size);
//Update the partition CRC value in the primary GPT header
PUT_4_BYTES(disk->hdr + PARTITION_CRC_OFFSET, disk->pentry_arr_crc);
//Update the partition CRC value in the backup GPT header
PUT_4_BYTES(disk->hdr_bak + PARTITION_CRC_OFFSET,
disk->pentry_arr_bak_crc);
//Update the CRC value of the primary header
gpt_header_size = GET_4_BYTES(disk->hdr + HEADER_SIZE_OFFSET);
//Header CRC is calculated with its own CRC field set to 0
PUT_4_BYTES(disk->hdr + HEADER_CRC_OFFSET, 0);
PUT_4_BYTES(disk->hdr_bak + HEADER_CRC_OFFSET, 0);
disk->hdr_crc = crc32(crc_zero, disk->hdr, gpt_header_size);
disk->hdr_bak_crc = crc32(crc_zero, disk->hdr_bak, gpt_header_size);
PUT_4_BYTES(disk->hdr + HEADER_CRC_OFFSET, disk->hdr_crc);
PUT_4_BYTES(disk->hdr_bak + HEADER_CRC_OFFSET, disk->hdr_bak_crc);
return 0;
error:
return -1;
}
//Write the contents of struct gpt_disk back to the actual disk
int gpt_disk_commit(struct gpt_disk *disk)
{
int fd = -1;
if (!disk || (disk->is_initialized != GPT_DISK_INIT_MAGIC)){
ALOGE("%s: Invalid args", __func__);
goto error;
}
fd = open(disk->devpath, O_RDWR | O_DSYNC);
if (fd < 0) {
ALOGE("%s: Failed to open %s: %s",
__func__,
disk->devpath,
strerror(errno));
goto error;
}
//Write the primary header
if(gpt_set_header(disk->hdr, fd, PRIMARY_GPT) != 0) {
ALOGE("%s: Failed to update primary GPT header",
__func__);
goto error;
}
//Write back the primary partition array
if (gpt_set_pentry_arr(disk->hdr, fd, disk->pentry_arr)) {
ALOGE("%s: Failed to write primary GPT partition arr",
__func__);
goto error;
}
//Write back the secondary header
if(gpt_set_header(disk->hdr_bak, fd, SECONDARY_GPT) != 0) {
ALOGE("%s: Failed to update secondary GPT header",
__func__);
goto error;
}
//Write back the secondary partition array
if (gpt_set_pentry_arr(disk->hdr_bak, fd, disk->pentry_arr_bak)) {
ALOGE("%s: Failed to write secondary GPT partition arr",
__func__);
goto error;
}
fsync(fd);
close(fd);
return 0;
error:
if (fd >= 0)
close(fd);
return -1;
}
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