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SubjectRe: [PATCH] block: cmdline-parser: perfect cmdline format checking
On Sat, 9 Nov 2013 11:45:14 +0000 Caizhiyong <caizhiyong@hisilicon.com> wrote:

> From: Cai Zhiyong <caizhiyong@huawei.com>
> Date: Sat, 9 Nov 2013 19:27:38 +0800
> Subject: [PATCH] block: cmdline-parser: perfect cmdline format checking
>
> -Fix compile warning with value and function undeclared.
> this reported by <fengguang.wu@intel.com> and
> Randy Dunlap <rdunlap@infradead.org>
>
> -perfect cmdline format checking, make the error information clear
> for understand, make this lib fully equivalent to the old parser
> in drivers/mtd/cmdlinepart.c
>
> ...
>
> +#define PARSER "cmdline-parser: "
> ...
> - pr_warn("cmdline partition size is invalid.");
> + pr_warn(PARSER "partition '%s' size '0x%llx' too small.",

You can use the standard pr_fmt() mechanism instead of this.



This was a large change from the previous version!

block/cmdline-parser.c | 86 +++++--
drivers/mtd/Kconfig | 1
drivers/mtd/cmdlinepart.c | 345 +++++++++++++++++++++++++++----
include/linux/cmdline-parser.h | 1
4 files changed, 371 insertions(+), 62 deletions(-)

diff -puN block/cmdline-parser.c~mtd-cmdlinepart-use-cmdline-partition-parser-lib-fix block/cmdline-parser.c
--- a/block/cmdline-parser.c~mtd-cmdlinepart-use-cmdline-partition-parser-lib-fix
+++ a/block/cmdline-parser.c
@@ -6,10 +6,15 @@
*/
#include <linux/export.h>
#include <linux/cmdline-parser.h>
+#include <linux/slab.h>
+
+#define PARSER "cmdline-parser: "

static int parse_subpart(struct cmdline_subpart **subpart, char *partdef)
{
int ret = 0;
+ int lastpart = 0;
+ char *partorg = partdef;
struct cmdline_subpart *new_subpart;

*subpart = NULL;
@@ -21,10 +26,12 @@ static int parse_subpart(struct cmdline_
if (*partdef == '-') {
new_subpart->size = (sector_t)(~0ULL);
partdef++;
+ lastpart = 1;
} else {
new_subpart->size = (sector_t)memparse(partdef, &partdef);
if (new_subpart->size < (sector_t)PAGE_SIZE) {
- pr_warn("cmdline partition size is invalid.");
+ pr_warn(PARSER "partition '%s' size '0x%llx' too small.",
+ partorg, new_subpart->size);
ret = -EINVAL;
goto fail;
}
@@ -42,13 +49,19 @@ static int parse_subpart(struct cmdline_
char *next = strchr(++partdef, ')');

if (!next) {
- pr_warn("cmdline partition format is invalid.");
+ pr_warn(PARSER "partition '%s' has no closing ')' "
+ "found in partition name.", partorg);
ret = -EINVAL;
goto fail;
}

- length = min_t(int, next - partdef,
- sizeof(new_subpart->name) - 1);
+ length = (int)(next - partdef);
+ if (length > sizeof(new_subpart->name) - 1) {
+ pr_warn(PARSER "partition '%s' partition name too long,"
+ " truncating.", partorg);
+ length = sizeof(new_subpart->name) - 1;
+ }
+
strncpy(new_subpart->name, partdef, length);
new_subpart->name[length] = '\0';

@@ -68,8 +81,15 @@ static int parse_subpart(struct cmdline_
partdef += 2;
}

+ if (*partdef) {
+ pr_warn(PARSER "partition '%s' has bad character '%c' after"
+ " partition.", partorg, *partdef);
+ ret = -EINVAL;
+ goto fail;
+ }
+
*subpart = new_subpart;
- return 0;
+ return lastpart;
fail:
kfree(new_subpart);
return ret;
@@ -86,14 +106,13 @@ static void free_subpart(struct cmdline_
}
}

-static int parse_parts(struct cmdline_parts **parts, const char *bdevdef)
+static int parse_parts(struct cmdline_parts **parts, char *bdevdef)
{
int ret = -EINVAL;
char *next;
int length;
struct cmdline_subpart **next_subpart;
struct cmdline_parts *newparts;
- char buf[BDEVNAME_SIZE + 32 + 4];

*parts = NULL;

@@ -102,14 +121,21 @@ static int parse_parts(struct cmdline_pa
return -ENOMEM;

next = strchr(bdevdef, ':');
- if (!next) {
- pr_warn("cmdline partition has no block device.");
+ if (!next || next == bdevdef) {
+ pr_warn(PARSER "partition '%s' has no block device.", bdevdef);
goto fail;
}

- length = min_t(int, next - bdevdef, sizeof(newparts->name) - 1);
+ length = (int)(next - bdevdef);
+ if (length > sizeof(newparts->name) - 1) {
+ pr_warn(PARSER "partition '%s' device name too long, "
+ "truncating.", bdevdef);
+ length = sizeof(newparts->name) - 1;
+ }
+
strncpy(newparts->name, bdevdef, length);
newparts->name[length] = '\0';
+
newparts->nr_subparts = 0;

next_subpart = &newparts->subpart;
@@ -117,23 +143,26 @@ static int parse_parts(struct cmdline_pa
while (next && *(++next)) {
bdevdef = next;
next = strchr(bdevdef, ',');
+ if (next)
+ *next = '\0';

- length = (!next) ? (sizeof(buf) - 1) :
- min_t(int, next - bdevdef, sizeof(buf) - 1);
-
- strncpy(buf, bdevdef, length);
- buf[length] = '\0';
-
- ret = parse_subpart(next_subpart, buf);
- if (ret)
+ ret = parse_subpart(next_subpart, bdevdef);
+ if (ret < 0) {
goto fail;
+ } else if (ret > 0 && next) {
+ pr_warn(PARSER "no partitions allowed after a "
+ "fill-up partition.");
+ ret = -EINVAL;
+ goto fail;
+ }

newparts->nr_subparts++;
next_subpart = &(*next_subpart)->next_subpart;
}

if (!newparts->subpart) {
- pr_warn("cmdline partition has no valid partition.");
+ pr_warn(PARSER "block device '%s' has no valid"
+ " partition.", newparts->name);
ret = -EINVAL;
goto fail;
}
@@ -192,7 +221,7 @@ int cmdline_parts_parse(struct cmdline_p
}

if (!*parts) {
- pr_warn("cmdline partition has no valid partition.");
+ pr_warn(PARSER "no found valid partition.");
ret = -EINVAL;
goto fail;
}
@@ -237,11 +266,24 @@ int cmdline_parts_set(struct cmdline_par
else
from = subpart->from;

- if (from >= disk_size)
+ if (subpart->name[0] == '\0')
+ snprintf(subpart->name, sizeof(subpart->name),
+ "partition%03d", slot);
+
+ if (from >= disk_size) {
+ pr_warn(PARSER "partition '%s' offset exceeds device"
+ " '%s' size '0x%llx', ignoring.",
+ subpart->name, parts->name, disk_size);
break;
+ }

- if (subpart->size > (disk_size - from))
+ if (subpart->size > (disk_size - from)) {
+ if (subpart->size != (sector_t)(~0ULL))
+ pr_warn(PARSER "partition '%s' size exceeds "
+ "device '%s' size '0x%llx', truncating.",
+ subpart->name, parts->name, disk_size);
subpart->size = disk_size - from;
+ }

from += subpart->size;

diff -puN drivers/mtd/Kconfig~mtd-cmdlinepart-use-cmdline-partition-parser-lib-fix drivers/mtd/Kconfig
--- a/drivers/mtd/Kconfig~mtd-cmdlinepart-use-cmdline-partition-parser-lib-fix
+++ a/drivers/mtd/Kconfig
@@ -75,7 +75,6 @@ endif # MTD_REDBOOT_PARTS

config MTD_CMDLINE_PARTS
tristate "Command line partition table parsing"
- select BLK_CMDLINE_PARSER
depends on MTD
---help---
Allow generic configuration of the MTD partition tables via the kernel
diff -puN drivers/mtd/cmdlinepart.c~mtd-cmdlinepart-use-cmdline-partition-parser-lib-fix drivers/mtd/cmdlinepart.c
--- a/drivers/mtd/cmdlinepart.c~mtd-cmdlinepart-use-cmdline-partition-parser-lib-fix
+++ a/drivers/mtd/cmdlinepart.c
@@ -47,79 +47,344 @@
* 1 NOR Flash with 2 partitions, 1 NAND with one
* edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home)
*/
- /*
- * Copyright © 2013 Cai Zhiyong <caizhiyong@huawei.com>
- * Rewrite the cmdline parser code, adjust it to a library-style code.
- * this module only use the cmdline parser lib.
- */

#include <linux/kernel.h>
+#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/module.h>
#include <linux/err.h>
-#include <linux/cmdline-parser.h>

+/* error message prefix */
+#define ERRP "mtd: "
+
+/* debug macro */
+#if 0
+#define dbg(x) do { printk("DEBUG-CMDLINE-PART: "); printk x; } while(0)
+#else
+#define dbg(x)
+#endif
+
+
+/* special size referring to all the remaining space in a partition */
+#define SIZE_REMAINING ULLONG_MAX
+#define OFFSET_CONTINUOUS ULLONG_MAX
+
+struct cmdline_mtd_partition {
+ struct cmdline_mtd_partition *next;
+ char *mtd_id;
+ int num_parts;
+ struct mtd_partition *parts;
+};
+
+/* mtdpart_setup() parses into here */
+static struct cmdline_mtd_partition *partitions;
+
+/* the command line passed to mtdpart_setup() */
static char *mtdparts;
-static struct cmdline_parts *mtd_cmdline_parts;
+static char *cmdline;
+static int cmdline_parsed;

-static int add_part(int slot, struct cmdline_subpart *subpart, void *param)
+/*
+ * Parse one partition definition for an MTD. Since there can be many
+ * comma separated partition definitions, this function calls itself
+ * recursively until no more partition definitions are found. Nice side
+ * effect: the memory to keep the mtd_partition structs and the names
+ * is allocated upon the last definition being found. At that point the
+ * syntax has been verified ok.
+ */
+static struct mtd_partition * newpart(char *s,
+ char **retptr,
+ int *num_parts,
+ int this_part,
+ unsigned char **extra_mem_ptr,
+ int extra_mem_size)
{
- struct mtd_partition *mtdpart = &((struct mtd_partition *)param)[slot];
+ struct mtd_partition *parts;
+ unsigned long long size, offset = OFFSET_CONTINUOUS;
+ char *name;
+ int name_len;
+ unsigned char *extra_mem;
+ char delim;
+ unsigned int mask_flags;
+
+ /* fetch the partition size */
+ if (*s == '-') {
+ /* assign all remaining space to this partition */
+ size = SIZE_REMAINING;
+ s++;
+ } else {
+ size = memparse(s, &s);
+ if (size < PAGE_SIZE) {
+ printk(KERN_ERR ERRP "partition size too small (%llx)\n",
+ size);
+ return ERR_PTR(-EINVAL);
+ }
+ }

- mtdpart->offset = subpart->from;
- mtdpart->size = subpart->size;
- mtdpart->name = subpart->name;
- mtdpart->mask_flags = 0;
+ /* fetch partition name and flags */
+ mask_flags = 0; /* this is going to be a regular partition */
+ delim = 0;
+
+ /* check for offset */
+ if (*s == '@') {
+ s++;
+ offset = memparse(s, &s);
+ }

- if (subpart->flags & PF_RDONLY)
- mtdpart->mask_flags |= MTD_WRITEABLE;
+ /* now look for name */
+ if (*s == '(')
+ delim = ')';
+
+ if (delim) {
+ char *p;
+
+ name = ++s;
+ p = strchr(name, delim);
+ if (!p) {
+ printk(KERN_ERR ERRP "no closing %c found in partition name\n", delim);
+ return ERR_PTR(-EINVAL);
+ }
+ name_len = p - name;
+ s = p + 1;
+ } else {
+ name = NULL;
+ name_len = 13; /* Partition_000 */
+ }

- if (subpart->flags & PF_POWERUP_LOCK)
- mtdpart->mask_flags |= MTD_POWERUP_LOCK;
+ /* record name length for memory allocation later */
+ extra_mem_size += name_len + 1;

- return 0;
+ /* test for options */
+ if (strncmp(s, "ro", 2) == 0) {
+ mask_flags |= MTD_WRITEABLE;
+ s += 2;
+ }
+
+ /* if lk is found do NOT unlock the MTD partition*/
+ if (strncmp(s, "lk", 2) == 0) {
+ mask_flags |= MTD_POWERUP_LOCK;
+ s += 2;
+ }
+
+ /* test if more partitions are following */
+ if (*s == ',') {
+ if (size == SIZE_REMAINING) {
+ printk(KERN_ERR ERRP "no partitions allowed after a fill-up partition\n");
+ return ERR_PTR(-EINVAL);
+ }
+ /* more partitions follow, parse them */
+ parts = newpart(s + 1, &s, num_parts, this_part + 1,
+ &extra_mem, extra_mem_size);
+ if (IS_ERR(parts))
+ return parts;
+ } else {
+ /* this is the last partition: allocate space for all */
+ int alloc_size;
+
+ *num_parts = this_part + 1;
+ alloc_size = *num_parts * sizeof(struct mtd_partition) +
+ extra_mem_size;
+
+ parts = kzalloc(alloc_size, GFP_KERNEL);
+ if (!parts)
+ return ERR_PTR(-ENOMEM);
+ extra_mem = (unsigned char *)(parts + *num_parts);
+ }
+
+ /* enter this partition (offset will be calculated later if it is zero at this point) */
+ parts[this_part].size = size;
+ parts[this_part].offset = offset;
+ parts[this_part].mask_flags = mask_flags;
+ if (name)
+ strlcpy(extra_mem, name, name_len + 1);
+ else
+ sprintf(extra_mem, "Partition_%03d", this_part);
+ parts[this_part].name = extra_mem;
+ extra_mem += name_len + 1;
+
+ dbg(("partition %d: name <%s>, offset %llx, size %llx, mask flags %x\n",
+ this_part, parts[this_part].name, parts[this_part].offset,
+ parts[this_part].size, parts[this_part].mask_flags));
+
+ /* return (updated) pointer to extra_mem memory */
+ if (extra_mem_ptr)
+ *extra_mem_ptr = extra_mem;
+
+ /* return (updated) pointer command line string */
+ *retptr = s;
+
+ /* return partition table */
+ return parts;
}

-static int __init mtdpart_setup(char *s)
+/*
+ * Parse the command line.
+ */
+static int mtdpart_setup_real(char *s)
{
- mtdparts = s;
- return 1;
+ cmdline_parsed = 1;
+
+ for( ; s != NULL; )
+ {
+ struct cmdline_mtd_partition *this_mtd;
+ struct mtd_partition *parts;
+ int mtd_id_len, num_parts;
+ char *p, *mtd_id;
+
+ mtd_id = s;
+
+ /* fetch <mtd-id> */
+ p = strchr(s, ':');
+ if (!p) {
+ printk(KERN_ERR ERRP "no mtd-id\n");
+ return -EINVAL;
+ }
+ mtd_id_len = p - mtd_id;
+
+ dbg(("parsing <%s>\n", p+1));
+
+ /*
+ * parse one mtd. have it reserve memory for the
+ * struct cmdline_mtd_partition and the mtd-id string.
+ */
+ parts = newpart(p + 1, /* cmdline */
+ &s, /* out: updated cmdline ptr */
+ &num_parts, /* out: number of parts */
+ 0, /* first partition */
+ (unsigned char**)&this_mtd, /* out: extra mem */
+ mtd_id_len + 1 + sizeof(*this_mtd) +
+ sizeof(void*)-1 /*alignment*/);
+ if (IS_ERR(parts)) {
+ /*
+ * An error occurred. We're either:
+ * a) out of memory, or
+ * b) in the middle of the partition spec
+ * Either way, this mtd is hosed and we're
+ * unlikely to succeed in parsing any more
+ */
+ return PTR_ERR(parts);
+ }
+
+ /* align this_mtd */
+ this_mtd = (struct cmdline_mtd_partition *)
+ ALIGN((unsigned long)this_mtd, sizeof(void *));
+ /* enter results */
+ this_mtd->parts = parts;
+ this_mtd->num_parts = num_parts;
+ this_mtd->mtd_id = (char*)(this_mtd + 1);
+ strlcpy(this_mtd->mtd_id, mtd_id, mtd_id_len + 1);
+
+ /* link into chain */
+ this_mtd->next = partitions;
+ partitions = this_mtd;
+
+ dbg(("mtdid=<%s> num_parts=<%d>\n",
+ this_mtd->mtd_id, this_mtd->num_parts));
+
+
+ /* EOS - we're done */
+ if (*s == 0)
+ break;
+
+ /* does another spec follow? */
+ if (*s != ';') {
+ printk(KERN_ERR ERRP "bad character after partition (%c)\n", *s);
+ return -EINVAL;
+ }
+ s++;
+ }
+
+ return 0;
}
-__setup("mtdparts=", mtdpart_setup);

+/*
+ * Main function to be called from the MTD mapping driver/device to
+ * obtain the partitioning information. At this point the command line
+ * arguments will actually be parsed and turned to struct mtd_partition
+ * information. It returns partitions for the requested mtd device, or
+ * the first one in the chain if a NULL mtd_id is passed in.
+ */
static int parse_cmdline_partitions(struct mtd_info *master,
struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
- struct cmdline_parts *parts;
-
- if (mtdparts) {
- if (mtd_cmdline_parts)
- cmdline_parts_free(&mtd_cmdline_parts);
+ unsigned long long offset;
+ int i, err;
+ struct cmdline_mtd_partition *part;
+ const char *mtd_id = master->name;
+
+ /* parse command line */
+ if (!cmdline_parsed) {
+ err = mtdpart_setup_real(cmdline);
+ if (err)
+ return err;
+ }

- if (cmdline_parts_parse(&mtd_cmdline_parts, mtdparts)) {
- mtdparts = NULL;
- return -EINVAL;
- }
- mtdparts = NULL;
+ /*
+ * Search for the partition definition matching master->name.
+ * If master->name is not set, stop at first partition definition.
+ */
+ for (part = partitions; part; part = part->next) {
+ if ((!mtd_id) || (!strcmp(part->mtd_id, mtd_id)))
+ break;
}

- if (!mtd_cmdline_parts)
+ if (!part)
return 0;

- parts = cmdline_parts_find(mtd_cmdline_parts, master->name);
- if (!parts)
- return 0;
+ for (i = 0, offset = 0; i < part->num_parts; i++) {
+ if (part->parts[i].offset == OFFSET_CONTINUOUS)
+ part->parts[i].offset = offset;
+ else
+ offset = part->parts[i].offset;
+
+ if (part->parts[i].size == SIZE_REMAINING)
+ part->parts[i].size = master->size - offset;
+
+ if (offset + part->parts[i].size > master->size) {
+ printk(KERN_WARNING ERRP
+ "%s: partitioning exceeds flash size, truncating\n",
+ part->mtd_id);
+ part->parts[i].size = master->size - offset;
+ }
+ offset += part->parts[i].size;
+
+ if (part->parts[i].size == 0) {
+ printk(KERN_WARNING ERRP
+ "%s: skipping zero sized partition\n",
+ part->mtd_id);
+ part->num_parts--;
+ memmove(&part->parts[i], &part->parts[i + 1],
+ sizeof(*part->parts) * (part->num_parts - i));
+ i--;
+ }
+ }

- *pparts = kzalloc(sizeof(**pparts) * parts->nr_subparts, GFP_KERNEL);
+ *pparts = kmemdup(part->parts, sizeof(*part->parts) * part->num_parts,
+ GFP_KERNEL);
if (!*pparts)
return -ENOMEM;

- return cmdline_parts_set(parts, master->size, 0, add_part,
- (void *)*pparts);
+ return part->num_parts;
}

+
+/*
+ * This is the handler for our kernel parameter, called from
+ * main.c::checksetup(). Note that we can not yet kmalloc() anything,
+ * so we only save the commandline for later processing.
+ *
+ * This function needs to be visible for bootloaders.
+ */
+static int __init mtdpart_setup(char *s)
+{
+ cmdline = s;
+ return 1;
+}
+
+__setup("mtdparts=", mtdpart_setup);
+
static struct mtd_part_parser cmdline_parser = {
.owner = THIS_MODULE,
.parse_fn = parse_cmdline_partitions,
@@ -128,6 +393,8 @@ static struct mtd_part_parser cmdline_pa

static int __init cmdline_parser_init(void)
{
+ if (mtdparts)
+ mtdpart_setup(mtdparts);
return register_mtd_parser(&cmdline_parser);
}

diff -puN include/linux/cmdline-parser.h~mtd-cmdlinepart-use-cmdline-partition-parser-lib-fix include/linux/cmdline-parser.h
--- a/include/linux/cmdline-parser.h~mtd-cmdlinepart-use-cmdline-partition-parser-lib-fix
+++ a/include/linux/cmdline-parser.h
@@ -9,6 +9,7 @@

#include <linux/fs.h>
#include <linux/blkdev.h>
+#include <linux/fs.h>

/* partition flags */
#define PF_RDONLY 0x01 /* Device is read only */
_
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