cregit-Linux how code gets into the kernel

Release 4.18 block/partitions/cmdline.c

Directory: block/partitions
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2013 HUAWEI
 * Author: Cai Zhiyong <caizhiyong@huawei.com>
 *
 * Read block device partition table from the command line.
 * Typically used for fixed block (eMMC) embedded devices.
 * It has no MBR, so saves storage space. Bootloader can be easily accessed
 * by absolute address of data on the block device.
 * Users can easily change the partition.
 *
 * The format for the command line is just like mtdparts.
 *
 * For further information, see "Documentation/block/cmdline-partition.txt"
 *
 */

#include <linux/cmdline-parser.h>

#include "check.h"
#include "cmdline.h"


static char *cmdline;

static struct cmdline_parts *bdev_parts;


static int add_part(int slot, struct cmdline_subpart *subpart, void *param) { int label_min; struct partition_meta_info *info; char tmp[sizeof(info->volname) + 4]; struct parsed_partitions *state = (struct parsed_partitions *)param; if (slot >= state->limit) return 1; put_partition(state, slot, subpart->from >> 9, subpart->size >> 9); info = &state->parts[slot].info; label_min = min_t(int, sizeof(info->volname) - 1, sizeof(subpart->name)); strncpy(info->volname, subpart->name, label_min); info->volname[label_min] = '\0'; snprintf(tmp, sizeof(tmp), "(%s)", info->volname); strlcat(state->pp_buf, tmp, PAGE_SIZE); state->parts[slot].has_info = true; return 0; }

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PersonTokensPropCommitsCommitProp
Cai Zhiyong179100.00%1100.00%
Total179100.00%1100.00%


static int __init cmdline_parts_setup(char *s) { cmdline = s; return 1; }

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PersonTokensPropCommitsCommitProp
Cai Zhiyong18100.00%1100.00%
Total18100.00%1100.00%

__setup("blkdevparts=", cmdline_parts_setup);
static bool has_overlaps(sector_t from, sector_t size, sector_t from2, sector_t size2) { sector_t end = from + size; sector_t end2 = from2 + size2; if (from >= from2 && from < end2) return true; if (end > from2 && end <= end2) return true; if (from2 >= from && from2 < end) return true; if (end2 > from && end2 <= end) return true; return false; }

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PersonTokensPropCommitsCommitProp
Wang YanQing87100.00%1100.00%
Total87100.00%1100.00%


static inline void overlaps_warns_header(void) { pr_warn("Overlapping partitions are used in command line partitions."); pr_warn("Don't use filesystems on overlapping partitions:"); }

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PersonTokensPropCommitsCommitProp
Wang YanQing19100.00%1100.00%
Total19100.00%1100.00%


static void cmdline_parts_verifier(int slot, struct parsed_partitions *state) { int i; bool header = true; for (; slot < state->limit && state->parts[slot].has_info; slot++) { for (i = slot+1; i < state->limit && state->parts[i].has_info; i++) { if (has_overlaps(state->parts[slot].from, state->parts[slot].size, state->parts[i].from, state->parts[i].size)) { if (header) { header = false; overlaps_warns_header(); } pr_warn("%s[%llu,%llu] overlaps with " "%s[%llu,%llu].", state->parts[slot].info.volname, (u64)state->parts[slot].from << 9, (u64)state->parts[slot].size << 9, state->parts[i].info.volname, (u64)state->parts[i].from << 9, (u64)state->parts[i].size << 9); } } } }

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PersonTokensPropCommitsCommitProp
Wang YanQing213100.00%1100.00%
Total213100.00%1100.00%

/* * Purpose: allocate cmdline partitions. * Returns: * -1 if unable to read the partition table * 0 if this isn't our partition table * 1 if successful */
int cmdline_partition(struct parsed_partitions *state) { sector_t disk_size; char bdev[BDEVNAME_SIZE]; struct cmdline_parts *parts; if (cmdline) { if (bdev_parts) cmdline_parts_free(&bdev_parts); if (cmdline_parts_parse(&bdev_parts, cmdline)) { cmdline = NULL; return -1; } cmdline = NULL; } if (!bdev_parts) return 0; bdevname(state->bdev, bdev); parts = cmdline_parts_find(bdev_parts, bdev); if (!parts) return 0; disk_size = get_capacity(state->bdev->bd_disk) << 9; cmdline_parts_set(parts, disk_size, 1, add_part, (void *)state); cmdline_parts_verifier(1, state); strlcat(state->pp_buf, "\n", PAGE_SIZE); return 1; }

Contributors

PersonTokensPropCommitsCommitProp
Cai Zhiyong14295.30%150.00%
Wang YanQing74.70%150.00%
Total149100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Cai Zhiyong36752.81%125.00%
Wang YanQing32646.91%125.00%
Greg Kroah-Hartman10.14%125.00%
Paul Gortmaker10.14%125.00%
Total695100.00%4100.00%
Directory: block/partitions
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