1

dm: Constify struct dm_block_validator

'struct dm_block_validator' are not modified in these drivers.

Constifying this structure moves some data to a read-only section, so
increase overall security.

On a x86_64, with allmodconfig, as an example:

Before:
======
   text	   data	    bss	    dec	    hex	filename
  32047	    920	     16	  32983	   80d7	drivers/md/dm-cache-metadata.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  32075	    896	     16	  32987	   80db	drivers/md/dm-cache-metadata.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
This commit is contained in:
Christophe JAILLET 2024-07-14 09:13:56 +02:00 committed by Mikulas Patocka
parent fb0987682c
commit 0b60be1628
12 changed files with 46 additions and 44 deletions

View File

@ -170,7 +170,7 @@ struct dm_cache_metadata {
*/
#define SUPERBLOCK_CSUM_XOR 9031977
static void sb_prepare_for_write(struct dm_block_validator *v,
static void sb_prepare_for_write(const struct dm_block_validator *v,
struct dm_block *b,
size_t sb_block_size)
{
@ -195,7 +195,7 @@ static int check_metadata_version(struct cache_disk_superblock *disk_super)
return 0;
}
static int sb_check(struct dm_block_validator *v,
static int sb_check(const struct dm_block_validator *v,
struct dm_block *b,
size_t sb_block_size)
{
@ -228,7 +228,7 @@ static int sb_check(struct dm_block_validator *v,
return check_metadata_version(disk_super);
}
static struct dm_block_validator sb_validator = {
static const struct dm_block_validator sb_validator = {
.name = "superblock",
.prepare_for_write = sb_prepare_for_write,
.check = sb_check

View File

@ -163,7 +163,7 @@ struct dm_clone_metadata {
/*
* Superblock validation.
*/
static void sb_prepare_for_write(struct dm_block_validator *v,
static void sb_prepare_for_write(const struct dm_block_validator *v,
struct dm_block *b, size_t sb_block_size)
{
struct superblock_disk *sb;
@ -177,7 +177,7 @@ static void sb_prepare_for_write(struct dm_block_validator *v,
sb->csum = cpu_to_le32(csum);
}
static int sb_check(struct dm_block_validator *v, struct dm_block *b,
static int sb_check(const struct dm_block_validator *v, struct dm_block *b,
size_t sb_block_size)
{
struct superblock_disk *sb;
@ -220,7 +220,7 @@ static int sb_check(struct dm_block_validator *v, struct dm_block *b,
return 0;
}
static struct dm_block_validator sb_validator = {
static const struct dm_block_validator sb_validator = {
.name = "superblock",
.prepare_for_write = sb_prepare_for_write,
.check = sb_check

View File

@ -196,7 +196,7 @@ struct superblock_disk {
* Superblock validation
*--------------------------------------------------------------
*/
static void sb_prepare_for_write(struct dm_block_validator *v,
static void sb_prepare_for_write(const struct dm_block_validator *v,
struct dm_block *b,
size_t sb_block_size)
{
@ -221,7 +221,7 @@ static int check_metadata_version(struct superblock_disk *disk)
return 0;
}
static int sb_check(struct dm_block_validator *v,
static int sb_check(const struct dm_block_validator *v,
struct dm_block *b,
size_t sb_block_size)
{
@ -254,7 +254,7 @@ static int sb_check(struct dm_block_validator *v,
return check_metadata_version(disk);
}
static struct dm_block_validator sb_validator = {
static const struct dm_block_validator sb_validator = {
.name = "superblock",
.prepare_for_write = sb_prepare_for_write,
.check = sb_check

View File

@ -249,7 +249,7 @@ struct dm_thin_device {
*/
#define SUPERBLOCK_CSUM_XOR 160774
static void sb_prepare_for_write(struct dm_block_validator *v,
static void sb_prepare_for_write(const struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
@ -261,7 +261,7 @@ static void sb_prepare_for_write(struct dm_block_validator *v,
SUPERBLOCK_CSUM_XOR));
}
static int sb_check(struct dm_block_validator *v,
static int sb_check(const struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
@ -294,7 +294,7 @@ static int sb_check(struct dm_block_validator *v,
return 0;
}
static struct dm_block_validator sb_validator = {
static const struct dm_block_validator sb_validator = {
.name = "superblock",
.prepare_for_write = sb_prepare_for_write,
.check = sb_check

View File

@ -38,7 +38,7 @@ struct array_block {
*/
#define CSUM_XOR 595846735
static void array_block_prepare_for_write(struct dm_block_validator *v,
static void array_block_prepare_for_write(const struct dm_block_validator *v,
struct dm_block *b,
size_t size_of_block)
{
@ -50,7 +50,7 @@ static void array_block_prepare_for_write(struct dm_block_validator *v,
CSUM_XOR));
}
static int array_block_check(struct dm_block_validator *v,
static int array_block_check(const struct dm_block_validator *v,
struct dm_block *b,
size_t size_of_block)
{
@ -77,7 +77,7 @@ static int array_block_check(struct dm_block_validator *v,
return 0;
}
static struct dm_block_validator array_validator = {
static const struct dm_block_validator array_validator = {
.name = "array",
.prepare_for_write = array_block_prepare_for_write,
.check = array_block_check

View File

@ -345,7 +345,7 @@ void *dm_block_data(struct dm_block *b)
EXPORT_SYMBOL_GPL(dm_block_data);
struct buffer_aux {
struct dm_block_validator *validator;
const struct dm_block_validator *validator;
int write_locked;
#ifdef CONFIG_DM_DEBUG_BLOCK_MANAGER_LOCKING
@ -441,7 +441,7 @@ dm_block_t dm_bm_nr_blocks(struct dm_block_manager *bm)
static int dm_bm_validate_buffer(struct dm_block_manager *bm,
struct dm_buffer *buf,
struct buffer_aux *aux,
struct dm_block_validator *v)
const struct dm_block_validator *v)
{
if (unlikely(!aux->validator)) {
int r;
@ -467,7 +467,7 @@ static int dm_bm_validate_buffer(struct dm_block_manager *bm,
return 0;
}
int dm_bm_read_lock(struct dm_block_manager *bm, dm_block_t b,
struct dm_block_validator *v,
const struct dm_block_validator *v,
struct dm_block **result)
{
struct buffer_aux *aux;
@ -500,7 +500,7 @@ int dm_bm_read_lock(struct dm_block_manager *bm, dm_block_t b,
EXPORT_SYMBOL_GPL(dm_bm_read_lock);
int dm_bm_write_lock(struct dm_block_manager *bm,
dm_block_t b, struct dm_block_validator *v,
dm_block_t b, const struct dm_block_validator *v,
struct dm_block **result)
{
struct buffer_aux *aux;
@ -536,7 +536,7 @@ int dm_bm_write_lock(struct dm_block_manager *bm,
EXPORT_SYMBOL_GPL(dm_bm_write_lock);
int dm_bm_read_try_lock(struct dm_block_manager *bm,
dm_block_t b, struct dm_block_validator *v,
dm_block_t b, const struct dm_block_validator *v,
struct dm_block **result)
{
struct buffer_aux *aux;
@ -569,7 +569,7 @@ int dm_bm_read_try_lock(struct dm_block_manager *bm,
}
int dm_bm_write_lock_zero(struct dm_block_manager *bm,
dm_block_t b, struct dm_block_validator *v,
dm_block_t b, const struct dm_block_validator *v,
struct dm_block **result)
{
int r;

View File

@ -51,12 +51,14 @@ dm_block_t dm_bm_nr_blocks(struct dm_block_manager *bm);
*/
struct dm_block_validator {
const char *name;
void (*prepare_for_write)(struct dm_block_validator *v, struct dm_block *b, size_t block_size);
void (*prepare_for_write)(const struct dm_block_validator *v,
struct dm_block *b, size_t block_size);
/*
* Return 0 if the checksum is valid or < 0 on error.
*/
int (*check)(struct dm_block_validator *v, struct dm_block *b, size_t block_size);
int (*check)(const struct dm_block_validator *v,
struct dm_block *b, size_t block_size);
};
/*----------------------------------------------------------------*/
@ -73,11 +75,11 @@ struct dm_block_validator {
* written back to the disk sometime after dm_bm_unlock is called.
*/
int dm_bm_read_lock(struct dm_block_manager *bm, dm_block_t b,
struct dm_block_validator *v,
const struct dm_block_validator *v,
struct dm_block **result);
int dm_bm_write_lock(struct dm_block_manager *bm, dm_block_t b,
struct dm_block_validator *v,
const struct dm_block_validator *v,
struct dm_block **result);
/*
@ -85,7 +87,7 @@ int dm_bm_write_lock(struct dm_block_manager *bm, dm_block_t b,
* available immediately.
*/
int dm_bm_read_try_lock(struct dm_block_manager *bm, dm_block_t b,
struct dm_block_validator *v,
const struct dm_block_validator *v,
struct dm_block **result);
/*
@ -93,7 +95,7 @@ int dm_bm_read_try_lock(struct dm_block_manager *bm, dm_block_t b,
* overwrite the block completely. It saves a disk read.
*/
int dm_bm_write_lock_zero(struct dm_block_manager *bm, dm_block_t b,
struct dm_block_validator *v,
const struct dm_block_validator *v,
struct dm_block **result);
void dm_bm_unlock(struct dm_block *b);

View File

@ -138,7 +138,7 @@ static inline uint64_t value64(struct btree_node *n, uint32_t index)
*/
int lower_bound(struct btree_node *n, uint64_t key);
extern struct dm_block_validator btree_node_validator;
extern const struct dm_block_validator btree_node_validator;
/*
* Value type for upper levels of multi-level btrees.

View File

@ -16,7 +16,7 @@
#define BTREE_CSUM_XOR 121107
static void node_prepare_for_write(struct dm_block_validator *v,
static void node_prepare_for_write(const struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
@ -29,7 +29,7 @@ static void node_prepare_for_write(struct dm_block_validator *v,
BTREE_CSUM_XOR));
}
static int node_check(struct dm_block_validator *v,
static int node_check(const struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
@ -81,7 +81,7 @@ static int node_check(struct dm_block_validator *v,
return 0;
}
struct dm_block_validator btree_node_validator = {
const struct dm_block_validator btree_node_validator = {
.name = "btree_node",
.prepare_for_write = node_prepare_for_write,
.check = node_check

View File

@ -22,7 +22,7 @@
*/
#define INDEX_CSUM_XOR 160478
static void index_prepare_for_write(struct dm_block_validator *v,
static void index_prepare_for_write(const struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
@ -34,7 +34,7 @@ static void index_prepare_for_write(struct dm_block_validator *v,
INDEX_CSUM_XOR));
}
static int index_check(struct dm_block_validator *v,
static int index_check(const struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
@ -59,7 +59,7 @@ static int index_check(struct dm_block_validator *v,
return 0;
}
static struct dm_block_validator index_validator = {
static const struct dm_block_validator index_validator = {
.name = "index",
.prepare_for_write = index_prepare_for_write,
.check = index_check
@ -72,7 +72,7 @@ static struct dm_block_validator index_validator = {
*/
#define BITMAP_CSUM_XOR 240779
static void dm_bitmap_prepare_for_write(struct dm_block_validator *v,
static void dm_bitmap_prepare_for_write(const struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
@ -84,7 +84,7 @@ static void dm_bitmap_prepare_for_write(struct dm_block_validator *v,
BITMAP_CSUM_XOR));
}
static int dm_bitmap_check(struct dm_block_validator *v,
static int dm_bitmap_check(const struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
@ -109,7 +109,7 @@ static int dm_bitmap_check(struct dm_block_validator *v,
return 0;
}
static struct dm_block_validator dm_sm_bitmap_validator = {
static const struct dm_block_validator dm_sm_bitmap_validator = {
.name = "sm_bitmap",
.prepare_for_write = dm_bitmap_prepare_for_write,
.check = dm_bitmap_check,

View File

@ -237,7 +237,7 @@ int dm_tm_commit(struct dm_transaction_manager *tm, struct dm_block *root)
EXPORT_SYMBOL_GPL(dm_tm_commit);
int dm_tm_new_block(struct dm_transaction_manager *tm,
struct dm_block_validator *v,
const struct dm_block_validator *v,
struct dm_block **result)
{
int r;
@ -266,7 +266,7 @@ int dm_tm_new_block(struct dm_transaction_manager *tm,
}
static int __shadow_block(struct dm_transaction_manager *tm, dm_block_t orig,
struct dm_block_validator *v,
const struct dm_block_validator *v,
struct dm_block **result)
{
int r;
@ -306,7 +306,7 @@ static int __shadow_block(struct dm_transaction_manager *tm, dm_block_t orig,
}
int dm_tm_shadow_block(struct dm_transaction_manager *tm, dm_block_t orig,
struct dm_block_validator *v, struct dm_block **result,
const struct dm_block_validator *v, struct dm_block **result,
int *inc_children)
{
int r;
@ -331,7 +331,7 @@ int dm_tm_shadow_block(struct dm_transaction_manager *tm, dm_block_t orig,
EXPORT_SYMBOL_GPL(dm_tm_shadow_block);
int dm_tm_read_lock(struct dm_transaction_manager *tm, dm_block_t b,
struct dm_block_validator *v,
const struct dm_block_validator *v,
struct dm_block **blk)
{
if (tm->is_clone) {

View File

@ -64,7 +64,7 @@ int dm_tm_commit(struct dm_transaction_manager *tm, struct dm_block *superblock)
* Zeroes the new block and returns with write lock held.
*/
int dm_tm_new_block(struct dm_transaction_manager *tm,
struct dm_block_validator *v,
const struct dm_block_validator *v,
struct dm_block **result);
/*
@ -84,7 +84,7 @@ int dm_tm_new_block(struct dm_transaction_manager *tm,
* it locked when you call this.
*/
int dm_tm_shadow_block(struct dm_transaction_manager *tm, dm_block_t orig,
struct dm_block_validator *v,
const struct dm_block_validator *v,
struct dm_block **result, int *inc_children);
/*
@ -92,7 +92,7 @@ int dm_tm_shadow_block(struct dm_transaction_manager *tm, dm_block_t orig,
* on it outstanding then it'll block.
*/
int dm_tm_read_lock(struct dm_transaction_manager *tm, dm_block_t b,
struct dm_block_validator *v,
const struct dm_block_validator *v,
struct dm_block **result);
void dm_tm_unlock(struct dm_transaction_manager *tm, struct dm_block *b);