1 files changed, 302 insertions, 16 deletions

diff --git a/block/partitions/cmdline.c b/block/partitions/cmdline.c
index 5141b563adf1..da3e719d8e51 100644
--- a/block/partitions/cmdline.c
+++ b/block/partitions/cmdline.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2013 HUAWEI
  * Author: Cai Zhiyong <caizhiyong@huawei.com>
@@ -10,24 +11,225 @@
  *
  * The format for the command line is just like mtdparts.
  *
- * For further information, see "Documentation/block/cmdline-partition.txt"
+ * For further information, see "Documentation/block/cmdline-partition.rst"
  *
  */
+#include <linux/blkdev.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include "check.h"
 
-#include <linux/cmdline-parser.h>
 
-#include "check.h"
-#include "cmdline.h"
+/* partition flags */
+#define PF_RDONLY                   0x01 /* Device is read only */
+#define PF_POWERUP_LOCK             0x02 /* Always locked after reset */
+
+struct cmdline_subpart {
+	char name[BDEVNAME_SIZE]; /* partition name, such as 'rootfs' */
+	sector_t from;
+	sector_t size;
+	int flags;
+	struct cmdline_subpart *next_subpart;
+};
+
+struct cmdline_parts {
+	char name[BDEVNAME_SIZE]; /* block device, such as 'mmcblk0' */
+	unsigned int nr_subparts;
+	struct cmdline_subpart *subpart;
+	struct cmdline_parts *next_parts;
+};
+
+static int parse_subpart(struct cmdline_subpart **subpart, char *partdef)
+{
+	int ret = 0;
+	struct cmdline_subpart *new_subpart;
+
+	*subpart = NULL;
+
+	new_subpart = kzalloc(sizeof(struct cmdline_subpart), GFP_KERNEL);
+	if (!new_subpart)
+		return -ENOMEM;
+
+	if (*partdef == '-') {
+		new_subpart->size = (sector_t)(~0ULL);
+		partdef++;
+	} else {
+		new_subpart->size = (sector_t)memparse(partdef, &partdef);
+		if (new_subpart->size < (sector_t)PAGE_SIZE) {
+			pr_warn("cmdline partition size is invalid.");
+			ret = -EINVAL;
+			goto fail;
+		}
+	}
+
+	if (*partdef == '@') {
+		partdef++;
+		new_subpart->from = (sector_t)memparse(partdef, &partdef);
+	} else {
+		new_subpart->from = (sector_t)(~0ULL);
+	}
+
+	if (*partdef == '(') {
+		partdef++;
+		char *next = strsep(&partdef, ")");
+
+		if (!next) {
+			pr_warn("cmdline partition format is invalid.");
+			ret = -EINVAL;
+			goto fail;
+		}
+
+		strscpy(new_subpart->name, next, sizeof(new_subpart->name));
+	} else
+		new_subpart->name[0] = '\0';
+
+	new_subpart->flags = 0;
+
+	if (!strncmp(partdef, "ro", 2)) {
+		new_subpart->flags |= PF_RDONLY;
+		partdef += 2;
+	}
+
+	if (!strncmp(partdef, "lk", 2)) {
+		new_subpart->flags |= PF_POWERUP_LOCK;
+		partdef += 2;
+	}
+
+	*subpart = new_subpart;
+	return 0;
+fail:
+	kfree(new_subpart);
+	return ret;
+}
+
+static void free_subpart(struct cmdline_parts *parts)
+{
+	struct cmdline_subpart *subpart;
+
+	while (parts->subpart) {
+		subpart = parts->subpart;
+		parts->subpart = subpart->next_subpart;
+		kfree(subpart);
+	}
+}
+
+static int parse_parts(struct cmdline_parts **parts, char *bdevdef)
+{
+	int ret = -EINVAL;
+	char *next;
+	struct cmdline_subpart **next_subpart;
+	struct cmdline_parts *newparts;
+
+	*parts = NULL;
+
+	newparts = kzalloc(sizeof(struct cmdline_parts), GFP_KERNEL);
+	if (!newparts)
+		return -ENOMEM;
+
+	next = strsep(&bdevdef, ":");
+	if (!next) {
+		pr_warn("cmdline partition has no block device.");
+		goto fail;
+	}
+
+	strscpy(newparts->name, next, sizeof(newparts->name));
+	newparts->nr_subparts = 0;
+
+	next_subpart = &newparts->subpart;
+
+	while ((next = strsep(&bdevdef, ","))) {
+		ret = parse_subpart(next_subpart, next);
+		if (ret)
+			goto fail;
+
+		newparts->nr_subparts++;
+		next_subpart = &(*next_subpart)->next_subpart;
+	}
+
+	if (!newparts->subpart) {
+		pr_warn("cmdline partition has no valid partition.");
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	*parts = newparts;
+
+	return 0;
+fail:
+	free_subpart(newparts);
+	kfree(newparts);
+	return ret;
+}
+
+static void cmdline_parts_free(struct cmdline_parts **parts)
+{
+	struct cmdline_parts *next_parts;
+
+	while (*parts) {
+		next_parts = (*parts)->next_parts;
+		free_subpart(*parts);
+		kfree(*parts);
+		*parts = next_parts;
+	}
+}
+
+static int cmdline_parts_parse(struct cmdline_parts **parts,
+		const char *cmdline)
+{
+	int ret;
+	char *buf;
+	char *pbuf;
+	char *next;
+	struct cmdline_parts **next_parts;
+
+	*parts = NULL;
+
+	pbuf = buf = kstrdup(cmdline, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	next_parts = parts;
+
+	while ((next = strsep(&pbuf, ";"))) {
+		ret = parse_parts(next_parts, next);
+		if (ret)
+			goto fail;
+
+		next_parts = &(*next_parts)->next_parts;
+	}
+
+	if (!*parts) {
+		pr_warn("cmdline partition has no valid partition.");
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	ret = 0;
+done:
+	kfree(buf);
+	return ret;
+
+fail:
+	cmdline_parts_free(parts);
+	goto done;
+}
+
+static struct cmdline_parts *cmdline_parts_find(struct cmdline_parts *parts,
+					 const char *bdev)
+{
+	while (parts && strncmp(bdev, parts->name, sizeof(parts->name)))
+		parts = parts->next_parts;
+	return parts;
+}
 
 static char *cmdline;
 static struct cmdline_parts *bdev_parts;
 
-static int add_part(int slot, struct cmdline_subpart *subpart, void *param)
+static int add_part(int slot, struct cmdline_subpart *subpart,
+		struct parsed_partitions *state)
 {
-	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;
@@ -35,12 +237,12 @@ static int add_part(int slot, struct cmdline_subpart *subpart, void *param)
 	put_partition(state, slot, subpart->from >> 9,
 		      subpart->size >> 9);
 
+	if (subpart->flags & PF_RDONLY)
+		state->parts[slot].flags |= ADDPART_FLAG_READONLY;
+
 	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';
+	strscpy(info->volname, subpart->name, sizeof(info->volname));
 
 	snprintf(tmp, sizeof(tmp), "(%s)", info->volname);
 	strlcat(state->pp_buf, tmp, PAGE_SIZE);
@@ -50,6 +252,35 @@ static int add_part(int slot, struct cmdline_subpart *subpart, void *param)
 	return 0;
 }
 
+static int cmdline_parts_set(struct cmdline_parts *parts, sector_t disk_size,
+		struct parsed_partitions *state)
+{
+	sector_t from = 0;
+	struct cmdline_subpart *subpart;
+	int slot = 1;
+
+	for (subpart = parts->subpart; subpart;
+	     subpart = subpart->next_subpart, slot++) {
+		if (subpart->from == (sector_t)(~0ULL))
+			subpart->from = from;
+		else
+			from = subpart->from;
+
+		if (from >= disk_size)
+			break;
+
+		if (subpart->size > (disk_size - from))
+			subpart->size = disk_size - from;
+
+		from += subpart->size;
+
+		if (add_part(slot, subpart, state))
+			break;
+	}
+
+	return slot;
+}
+
 static int __init cmdline_parts_setup(char *s)
 {
 	cmdline = s;
@@ -57,6 +288,62 @@ static int __init cmdline_parts_setup(char *s)
 }
 __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;
+}
+
+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:");
+}
+
+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);
+			}
+		}
+	}
+}
+
 /*
  * Purpose: allocate cmdline partitions.
  * Returns:
@@ -67,7 +354,6 @@ __setup("blkdevparts=", cmdline_parts_setup);
 int cmdline_partition(struct parsed_partitions *state)
 {
 	sector_t disk_size;
-	char bdev[BDEVNAME_SIZE];
 	struct cmdline_parts *parts;
 
 	if (cmdline) {
@@ -84,14 +370,14 @@ int cmdline_partition(struct parsed_partitions *state)
 	if (!bdev_parts)
 		return 0;
 
-	bdevname(state->bdev, bdev);
-	parts = cmdline_parts_find(bdev_parts, bdev);
+	parts = cmdline_parts_find(bdev_parts, state->disk->disk_name);
 	if (!parts)
 		return 0;
 
-	disk_size = get_capacity(state->bdev->bd_disk) << 9;
+	disk_size = get_capacity(state->disk) << 9;
 
-	cmdline_parts_set(parts, disk_size, 1, add_part, (void *)state);
+	cmdline_parts_set(parts, disk_size, state);
+	cmdline_parts_verifier(1, state);
 
 	strlcat(state->pp_buf, "\n", PAGE_SIZE);