18c2ecf20Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0
28c2ecf20Sopenharmony_ci/*
38c2ecf20Sopenharmony_ci * Copyright (C) 2013 HUAWEI
48c2ecf20Sopenharmony_ci * Author: Cai Zhiyong <caizhiyong@huawei.com>
58c2ecf20Sopenharmony_ci *
68c2ecf20Sopenharmony_ci * Read block device partition table from the command line.
78c2ecf20Sopenharmony_ci * Typically used for fixed block (eMMC) embedded devices.
88c2ecf20Sopenharmony_ci * It has no MBR, so saves storage space. Bootloader can be easily accessed
98c2ecf20Sopenharmony_ci * by absolute address of data on the block device.
108c2ecf20Sopenharmony_ci * Users can easily change the partition.
118c2ecf20Sopenharmony_ci *
128c2ecf20Sopenharmony_ci * The format for the command line is just like mtdparts.
138c2ecf20Sopenharmony_ci *
148c2ecf20Sopenharmony_ci * For further information, see "Documentation/block/cmdline-partition.rst"
158c2ecf20Sopenharmony_ci *
168c2ecf20Sopenharmony_ci */
178c2ecf20Sopenharmony_ci
188c2ecf20Sopenharmony_ci#include <linux/cmdline-parser.h>
198c2ecf20Sopenharmony_ci
208c2ecf20Sopenharmony_ci#include "check.h"
218c2ecf20Sopenharmony_ci
228c2ecf20Sopenharmony_cistatic char *cmdline;
238c2ecf20Sopenharmony_cistatic struct cmdline_parts *bdev_parts;
248c2ecf20Sopenharmony_ci
258c2ecf20Sopenharmony_cistatic int add_part(int slot, struct cmdline_subpart *subpart, void *param)
268c2ecf20Sopenharmony_ci{
278c2ecf20Sopenharmony_ci	int label_min;
288c2ecf20Sopenharmony_ci	struct partition_meta_info *info;
298c2ecf20Sopenharmony_ci	char tmp[sizeof(info->volname) + 4];
308c2ecf20Sopenharmony_ci	struct parsed_partitions *state = (struct parsed_partitions *)param;
318c2ecf20Sopenharmony_ci
328c2ecf20Sopenharmony_ci	if (slot >= state->limit)
338c2ecf20Sopenharmony_ci		return 1;
348c2ecf20Sopenharmony_ci
358c2ecf20Sopenharmony_ci	put_partition(state, slot, subpart->from >> 9,
368c2ecf20Sopenharmony_ci		      subpart->size >> 9);
378c2ecf20Sopenharmony_ci
388c2ecf20Sopenharmony_ci	info = &state->parts[slot].info;
398c2ecf20Sopenharmony_ci
408c2ecf20Sopenharmony_ci	label_min = min_t(int, sizeof(info->volname) - 1,
418c2ecf20Sopenharmony_ci			  sizeof(subpart->name));
428c2ecf20Sopenharmony_ci	strncpy(info->volname, subpart->name, label_min);
438c2ecf20Sopenharmony_ci	info->volname[label_min] = '\0';
448c2ecf20Sopenharmony_ci
458c2ecf20Sopenharmony_ci	snprintf(tmp, sizeof(tmp), "(%s)", info->volname);
468c2ecf20Sopenharmony_ci	strlcat(state->pp_buf, tmp, PAGE_SIZE);
478c2ecf20Sopenharmony_ci
488c2ecf20Sopenharmony_ci	state->parts[slot].has_info = true;
498c2ecf20Sopenharmony_ci
508c2ecf20Sopenharmony_ci	return 0;
518c2ecf20Sopenharmony_ci}
528c2ecf20Sopenharmony_ci
538c2ecf20Sopenharmony_cistatic int __init cmdline_parts_setup(char *s)
548c2ecf20Sopenharmony_ci{
558c2ecf20Sopenharmony_ci	cmdline = s;
568c2ecf20Sopenharmony_ci	return 1;
578c2ecf20Sopenharmony_ci}
588c2ecf20Sopenharmony_ci__setup("blkdevparts=", cmdline_parts_setup);
598c2ecf20Sopenharmony_ci
608c2ecf20Sopenharmony_cistatic bool has_overlaps(sector_t from, sector_t size,
618c2ecf20Sopenharmony_ci			 sector_t from2, sector_t size2)
628c2ecf20Sopenharmony_ci{
638c2ecf20Sopenharmony_ci	sector_t end = from + size;
648c2ecf20Sopenharmony_ci	sector_t end2 = from2 + size2;
658c2ecf20Sopenharmony_ci
668c2ecf20Sopenharmony_ci	if (from >= from2 && from < end2)
678c2ecf20Sopenharmony_ci		return true;
688c2ecf20Sopenharmony_ci
698c2ecf20Sopenharmony_ci	if (end > from2 && end <= end2)
708c2ecf20Sopenharmony_ci		return true;
718c2ecf20Sopenharmony_ci
728c2ecf20Sopenharmony_ci	if (from2 >= from && from2 < end)
738c2ecf20Sopenharmony_ci		return true;
748c2ecf20Sopenharmony_ci
758c2ecf20Sopenharmony_ci	if (end2 > from && end2 <= end)
768c2ecf20Sopenharmony_ci		return true;
778c2ecf20Sopenharmony_ci
788c2ecf20Sopenharmony_ci	return false;
798c2ecf20Sopenharmony_ci}
808c2ecf20Sopenharmony_ci
818c2ecf20Sopenharmony_cistatic inline void overlaps_warns_header(void)
828c2ecf20Sopenharmony_ci{
838c2ecf20Sopenharmony_ci	pr_warn("Overlapping partitions are used in command line partitions.");
848c2ecf20Sopenharmony_ci	pr_warn("Don't use filesystems on overlapping partitions:");
858c2ecf20Sopenharmony_ci}
868c2ecf20Sopenharmony_ci
878c2ecf20Sopenharmony_cistatic void cmdline_parts_verifier(int slot, struct parsed_partitions *state)
888c2ecf20Sopenharmony_ci{
898c2ecf20Sopenharmony_ci	int i;
908c2ecf20Sopenharmony_ci	bool header = true;
918c2ecf20Sopenharmony_ci
928c2ecf20Sopenharmony_ci	for (; slot < state->limit && state->parts[slot].has_info; slot++) {
938c2ecf20Sopenharmony_ci		for (i = slot+1; i < state->limit && state->parts[i].has_info;
948c2ecf20Sopenharmony_ci		     i++) {
958c2ecf20Sopenharmony_ci			if (has_overlaps(state->parts[slot].from,
968c2ecf20Sopenharmony_ci					 state->parts[slot].size,
978c2ecf20Sopenharmony_ci					 state->parts[i].from,
988c2ecf20Sopenharmony_ci					 state->parts[i].size)) {
998c2ecf20Sopenharmony_ci				if (header) {
1008c2ecf20Sopenharmony_ci					header = false;
1018c2ecf20Sopenharmony_ci					overlaps_warns_header();
1028c2ecf20Sopenharmony_ci				}
1038c2ecf20Sopenharmony_ci				pr_warn("%s[%llu,%llu] overlaps with "
1048c2ecf20Sopenharmony_ci					"%s[%llu,%llu].",
1058c2ecf20Sopenharmony_ci					state->parts[slot].info.volname,
1068c2ecf20Sopenharmony_ci					(u64)state->parts[slot].from << 9,
1078c2ecf20Sopenharmony_ci					(u64)state->parts[slot].size << 9,
1088c2ecf20Sopenharmony_ci					state->parts[i].info.volname,
1098c2ecf20Sopenharmony_ci					(u64)state->parts[i].from << 9,
1108c2ecf20Sopenharmony_ci					(u64)state->parts[i].size << 9);
1118c2ecf20Sopenharmony_ci			}
1128c2ecf20Sopenharmony_ci		}
1138c2ecf20Sopenharmony_ci	}
1148c2ecf20Sopenharmony_ci}
1158c2ecf20Sopenharmony_ci
1168c2ecf20Sopenharmony_ci/*
1178c2ecf20Sopenharmony_ci * Purpose: allocate cmdline partitions.
1188c2ecf20Sopenharmony_ci * Returns:
1198c2ecf20Sopenharmony_ci * -1 if unable to read the partition table
1208c2ecf20Sopenharmony_ci *  0 if this isn't our partition table
1218c2ecf20Sopenharmony_ci *  1 if successful
1228c2ecf20Sopenharmony_ci */
1238c2ecf20Sopenharmony_ciint cmdline_partition(struct parsed_partitions *state)
1248c2ecf20Sopenharmony_ci{
1258c2ecf20Sopenharmony_ci	sector_t disk_size;
1268c2ecf20Sopenharmony_ci	char bdev[BDEVNAME_SIZE];
1278c2ecf20Sopenharmony_ci	struct cmdline_parts *parts;
1288c2ecf20Sopenharmony_ci
1298c2ecf20Sopenharmony_ci	if (cmdline) {
1308c2ecf20Sopenharmony_ci		if (bdev_parts)
1318c2ecf20Sopenharmony_ci			cmdline_parts_free(&bdev_parts);
1328c2ecf20Sopenharmony_ci
1338c2ecf20Sopenharmony_ci		if (cmdline_parts_parse(&bdev_parts, cmdline)) {
1348c2ecf20Sopenharmony_ci			cmdline = NULL;
1358c2ecf20Sopenharmony_ci			return -1;
1368c2ecf20Sopenharmony_ci		}
1378c2ecf20Sopenharmony_ci		cmdline = NULL;
1388c2ecf20Sopenharmony_ci	}
1398c2ecf20Sopenharmony_ci
1408c2ecf20Sopenharmony_ci	if (!bdev_parts)
1418c2ecf20Sopenharmony_ci		return 0;
1428c2ecf20Sopenharmony_ci
1438c2ecf20Sopenharmony_ci	bdevname(state->bdev, bdev);
1448c2ecf20Sopenharmony_ci	parts = cmdline_parts_find(bdev_parts, bdev);
1458c2ecf20Sopenharmony_ci	if (!parts)
1468c2ecf20Sopenharmony_ci		return 0;
1478c2ecf20Sopenharmony_ci
1488c2ecf20Sopenharmony_ci	disk_size = get_capacity(state->bdev->bd_disk) << 9;
1498c2ecf20Sopenharmony_ci
1508c2ecf20Sopenharmony_ci	cmdline_parts_set(parts, disk_size, 1, add_part, (void *)state);
1518c2ecf20Sopenharmony_ci	cmdline_parts_verifier(1, state);
1528c2ecf20Sopenharmony_ci
1538c2ecf20Sopenharmony_ci	strlcat(state->pp_buf, "\n", PAGE_SIZE);
1548c2ecf20Sopenharmony_ci
1558c2ecf20Sopenharmony_ci	return 1;
1568c2ecf20Sopenharmony_ci}
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