No need to keep a separate loadable module infrastructure for a tiny
amount of cryptoapi glue, especially as unloading of the cryptoloop
module leads to nasty interactions with the loop device state machine
through loop_unregister_transfer.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/block/Kconfig | 6 +-
drivers/block/Makefile | 1 -
drivers/block/cryptoloop.c | 190 -----------------------------------
drivers/block/loop.c | 200 +++++++++++++++++++++++++++----------
drivers/block/loop.h | 5 -
5 files changed, 151 insertions(+), 251 deletions(-)
delete mode 100644 drivers/block/cryptoloop.c
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 63056cfd4b62..c63386576ef6 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -156,6 +156,8 @@ config BLK_DEV_COW_COMMON
config BLK_DEV_LOOP
tristate "Loopback device support"
+ select CRYPTO if CRYPTOLOOP
+ select CRYPTO_CBC if CRYPTOLOOP
help
Saying Y here will allow you to use a regular file as a block
device; you can then create a file system on that block device and
@@ -213,9 +215,7 @@ config BLK_DEV_LOOP_MIN_COUNT
dynamically allocated with the /dev/loop-control interface.
config BLK_DEV_CRYPTOLOOP
- tristate "Cryptoloop Support"
- select CRYPTO
- select CRYPTO_CBC
+ bool "Cryptoloop Support"
depends on BLK_DEV_LOOP
help
Say Y here if you want to be able to use the ciphers that are
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index bc68817ef496..11a74f17c9ad 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -24,7 +24,6 @@ obj-$(CONFIG_CDROM_PKTCDVD) += pktcdvd.o
obj-$(CONFIG_SUNVDC) += sunvdc.o
obj-$(CONFIG_BLK_DEV_NBD) += nbd.o
-obj-$(CONFIG_BLK_DEV_CRYPTOLOOP) += cryptoloop.o
obj-$(CONFIG_VIRTIO_BLK) += virtio_blk.o
obj-$(CONFIG_BLK_DEV_SX8) += sx8.o
diff --git a/drivers/block/cryptoloop.c b/drivers/block/cryptoloop.c
deleted file mode 100644
index c2392ce2a819..000000000000
--- a/drivers/block/cryptoloop.c
+++ /dev/null
@@ -1,190 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- Linux loop encryption enabling module
-
- Copyright (C) 2002 Herbert Valerio Riedel <hvr@xxxxxxx>
- Copyright (C) 2003 Fruhwirth Clemens <clemens@xxxxxxxxxxxxx>
-
- */
-
-#include <linux/module.h>
-
-#include <crypto/skcipher.h>
-#include <linux/init.h>
-#include <linux/string.h>
-#include <linux/blkdev.h>
-#include <linux/scatterlist.h>
-#include <linux/uaccess.h>
-#include "loop.h"
-
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("loop blockdevice transferfunction adaptor / CryptoAPI");
-MODULE_AUTHOR("Herbert Valerio Riedel <hvr@xxxxxxx>");
-
-#define LOOP_IV_SECTOR_BITS 9
-#define LOOP_IV_SECTOR_SIZE (1 << LOOP_IV_SECTOR_BITS)
-
-static int
-cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info)
-{
- int err = -EINVAL;
- int cipher_len;
- int mode_len;
- char cms[LO_NAME_SIZE]; /* cipher-mode string */
- char *mode;
- char *cmsp = cms; /* c-m string pointer */
- struct crypto_sync_skcipher *tfm;
-
- /* encryption breaks for non sector aligned offsets */
-
- if (info->lo_offset % LOOP_IV_SECTOR_SIZE)
- goto out;
-
- strncpy(cms, info->lo_crypt_name, LO_NAME_SIZE);
- cms[LO_NAME_SIZE - 1] = 0;
-
- cipher_len = strcspn(cmsp, "-");
-
- mode = cmsp + cipher_len;
- mode_len = 0;
- if (*mode) {
- mode++;
- mode_len = strcspn(mode, "-");
- }
-
- if (!mode_len) {
- mode = "cbc";
- mode_len = 3;
- }
-
- if (cipher_len + mode_len + 3 > LO_NAME_SIZE)
- return -EINVAL;
-
- memmove(cms, mode, mode_len);
- cmsp = cms + mode_len;
- *cmsp++ = '(';
- memcpy(cmsp, info->lo_crypt_name, cipher_len);
- cmsp += cipher_len;
- *cmsp++ = ')';
- *cmsp = 0;
-
- tfm = crypto_alloc_sync_skcipher(cms, 0, 0);
- if (IS_ERR(tfm))
- return PTR_ERR(tfm);
-
- err = crypto_sync_skcipher_setkey(tfm, info->lo_encrypt_key,
- info->lo_encrypt_key_size);
-
- if (err != 0)
- goto out_free_tfm;
-
- lo->key_data = tfm;
- return 0;
-
- out_free_tfm:
- crypto_free_sync_skcipher(tfm);
-
- out:
- return err;
-}
-
-
-typedef int (*encdec_cbc_t)(struct skcipher_request *req);
-
-static int
-cryptoloop_transfer(struct loop_device *lo, int cmd,
- struct page *raw_page, unsigned raw_off,
- struct page *loop_page, unsigned loop_off,
- int size, sector_t IV)
-{
- struct crypto_sync_skcipher *tfm = lo->key_data;
- SYNC_SKCIPHER_REQUEST_ON_STACK(req, tfm);
- struct scatterlist sg_out;
- struct scatterlist sg_in;
-
- encdec_cbc_t encdecfunc;
- struct page *in_page, *out_page;
- unsigned in_offs, out_offs;
- int err;
-
- skcipher_request_set_sync_tfm(req, tfm);
- skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
- NULL, NULL);
-
- sg_init_table(&sg_out, 1);
- sg_init_table(&sg_in, 1);
-
- if (cmd == READ) {
- in_page = raw_page;
- in_offs = raw_off;
- out_page = loop_page;
- out_offs = loop_off;
- encdecfunc = crypto_skcipher_decrypt;
- } else {
- in_page = loop_page;
- in_offs = loop_off;
- out_page = raw_page;
- out_offs = raw_off;
- encdecfunc = crypto_skcipher_encrypt;
- }
-
- while (size > 0) {
- const int sz = min(size, LOOP_IV_SECTOR_SIZE);
- __le32 iv[4] = { cpu_to_le32(IV & 0xffffffff), };
-
- sg_set_page(&sg_in, in_page, sz, in_offs);
- sg_set_page(&sg_out, out_page, sz, out_offs);
-
- skcipher_request_set_crypt(req, &sg_in, &sg_out, sz, iv);
- err = encdecfunc(req);
- if (err)
- goto out;
-
- IV++;
- size -= sz;
- in_offs += sz;
- out_offs += sz;
- }
-
- err = 0;
-
-out:
- skcipher_request_zero(req);
- return err;
-}
-
-static void
-cryptoloop_release(struct loop_device *lo)
-{
- crypto_free_sync_skcipher(lo->key_data);
- lo->key_data = NULL;
-}
-
-static struct loop_func_table cryptoloop_funcs = {
- .number = LO_CRYPT_CRYPTOAPI,
- .init = cryptoloop_init,
- .transfer = cryptoloop_transfer,
- .release = cryptoloop_release,
- .owner = THIS_MODULE
-};
-
-static int __init
-init_cryptoloop(void)
-{
- int rc = loop_register_transfer(&cryptoloop_funcs);
-
- if (rc)
- printk(KERN_ERR "cryptoloop: loop_register_transfer failed\n");
- return rc;
-}
-
-static void __exit
-cleanup_cryptoloop(void)
-{
- if (loop_unregister_transfer(LO_CRYPT_CRYPTOAPI))
- printk(KERN_ERR
- "cryptoloop: loop_unregister_transfer failed\n");
-}
-
-module_init(init_cryptoloop);
-module_exit(cleanup_cryptoloop);
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 680974601161..45c7e88b0aff 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -39,6 +39,10 @@
* Support up to 256 loop devices
* Heinz Mauelshagen <mge@xxxxxxxxxxx>, Feb 2002
*
+ * Cryptoloop support:
+ * Copyright (C) 2002 Herbert Valerio Riedel <hvr@xxxxxxx>
+ * Copyright (C) 2003 Fruhwirth Clemens <clemens@xxxxxxxxxxxxx>
+ *
* Support for falling back on the write file operation when the address space
* operations write_begin is not available on the backing filesystem.
* Anton Altaparmakov, 16 Feb 2005
@@ -79,13 +83,16 @@
#include <linux/ioprio.h>
#include <linux/blk-cgroup.h>
#include <linux/sched/mm.h>
-
+#include <crypto/skcipher.h>
#include "loop.h"
#include <linux/uaccess.h>
#define LOOP_IDLE_WORKER_TIMEOUT (60 * HZ)
+#define LOOP_IV_SECTOR_BITS 9
+#define LOOP_IV_SECTOR_SIZE (1 << LOOP_IV_SECTOR_BITS)
+
static DEFINE_IDR(loop_index_idr);
static DEFINE_MUTEX(loop_ctl_mutex);
static DEFINE_MUTEX(loop_validate_mutex);
@@ -179,10 +186,144 @@ static struct loop_func_table xor_funcs = {
.init = xor_init
};
+#ifdef CONFIG_BLK_DEV_CRYPTOLOOP
+static int cryptoloop_init(struct loop_device *lo,
+ const struct loop_info64 *info)
+{
+ int err = -EINVAL;
+ int cipher_len;
+ int mode_len;
+ char cms[LO_NAME_SIZE]; /* cipher-mode string */
+ char *mode;
+ char *cmsp = cms; /* c-m string pointer */
+ struct crypto_sync_skcipher *tfm;
+
+ /* encryption breaks for non sector aligned offsets */
+ if (info->lo_offset % LOOP_IV_SECTOR_SIZE)
+ return -EINVAL;
+
+ strncpy(cms, info->lo_crypt_name, LO_NAME_SIZE);
+ cms[LO_NAME_SIZE - 1] = 0;
+
+ cipher_len = strcspn(cmsp, "-");
+ mode = cmsp + cipher_len;
+ mode_len = 0;
+ if (*mode) {
+ mode++;
+ mode_len = strcspn(mode, "-");
+ }
+ if (!mode_len) {
+ mode = "cbc";
+ mode_len = 3;
+ }
+ if (cipher_len + mode_len + 3 > LO_NAME_SIZE)
+ return -EINVAL;
+
+ memmove(cms, mode, mode_len);
+ cmsp = cms + mode_len;
+ *cmsp++ = '(';
+ memcpy(cmsp, info->lo_crypt_name, cipher_len);
+ cmsp += cipher_len;
+ *cmsp++ = ')';
+ *cmsp = 0;
+
+ tfm = crypto_alloc_sync_skcipher(cms, 0, 0);
+ if (IS_ERR(tfm))
+ return PTR_ERR(tfm);
+
+ err = crypto_sync_skcipher_setkey(tfm, info->lo_encrypt_key,
+ info->lo_encrypt_key_size);
+ if (err != 0)
+ goto out_free_tfm;
+ lo->key_data = tfm;
+ return 0;
+
+ out_free_tfm:
+ crypto_free_sync_skcipher(tfm);
+ return err;
+}
+
+typedef int (*encdec_cbc_t)(struct skcipher_request *req);
+
+static int cryptoloop_transfer(struct loop_device *lo, int cmd,
+ struct page *raw_page, unsigned raw_off, struct page *loop_page,
+ unsigned loop_off, int size, sector_t IV)
+{
+ struct crypto_sync_skcipher *tfm = lo->key_data;
+ SYNC_SKCIPHER_REQUEST_ON_STACK(req, tfm);
+ struct scatterlist sg_out;
+ struct scatterlist sg_in;
+ encdec_cbc_t encdecfunc;
+ struct page *in_page, *out_page;
+ unsigned in_offs, out_offs;
+ int err;
+
+ skcipher_request_set_sync_tfm(req, tfm);
+ skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
+ NULL, NULL);
+
+ sg_init_table(&sg_out, 1);
+ sg_init_table(&sg_in, 1);
+
+ if (cmd == READ) {
+ in_page = raw_page;
+ in_offs = raw_off;
+ out_page = loop_page;
+ out_offs = loop_off;
+ encdecfunc = crypto_skcipher_decrypt;
+ } else {
+ in_page = loop_page;
+ in_offs = loop_off;
+ out_page = raw_page;
+ out_offs = raw_off;
+ encdecfunc = crypto_skcipher_encrypt;
+ }
+
+ while (size > 0) {
+ const int sz = min(size, LOOP_IV_SECTOR_SIZE);
+ __le32 iv[4] = { cpu_to_le32(IV & 0xffffffff), };
+
+ sg_set_page(&sg_in, in_page, sz, in_offs);
+ sg_set_page(&sg_out, out_page, sz, out_offs);
+
+ skcipher_request_set_crypt(req, &sg_in, &sg_out, sz, iv);
+ err = encdecfunc(req);
+ if (err)
+ goto out;
+
+ IV++;
+ size -= sz;
+ in_offs += sz;
+ out_offs += sz;
+ }
+
+ err = 0;
+out:
+ skcipher_request_zero(req);
+ return err;
+}
+
+static void cryptoloop_release(struct loop_device *lo)
+{
+ crypto_free_sync_skcipher(lo->key_data);
+ lo->key_data = NULL;
+}
+
+static struct loop_func_table cryptoloop_funcs = {
+ .number = LO_CRYPT_CRYPTOAPI,
+ .init = cryptoloop_init,
+ .transfer = cryptoloop_transfer,
+ .release = cryptoloop_release,
+};
+#endif /* CONFIG_BLK_DEV_CRYPTOLOOP */
+
/* xfer_funcs[0] is special - its release function is never called */
static struct loop_func_table *xfer_funcs[MAX_LO_CRYPT] = {
- &none_funcs,
- &xor_funcs
+ [LO_CRYPT_NONE] = &none_funcs,
+ [LO_CRYPT_XOR] = &xor_funcs,
+#ifdef CONFIG_BLK_DEV_CRYPTOLOOP
+ [LO_CRYPT_CRYPTOAPI] = &cryptoloop_funcs,
+#endif
};
static loff_t get_size(loff_t offset, loff_t sizelimit, struct file *file)
@@ -1094,7 +1235,6 @@ loop_release_xfer(struct loop_device *lo)
xfer->release(lo);
lo->transfer = NULL;
lo->lo_encryption = NULL;
- module_put(xfer->owner);
}
}
@@ -1104,16 +1244,9 @@ loop_init_xfer(struct loop_device *lo, struct loop_func_table *xfer,
{
int err = 0;
- if (xfer) {
- struct module *owner = xfer->owner;
-
- if (!try_module_get(owner))
- return -EINVAL;
- if (xfer->init)
- err = xfer->init(lo, i);
- if (err)
- module_put(owner);
- else
+ if (xfer && xfer->init) {
+ err = xfer->init(lo, i);
+ if (!err)
lo->lo_encryption = xfer;
}
return err;
@@ -2094,44 +2227,7 @@ module_param(max_part, int, 0444);
MODULE_PARM_DESC(max_part, "Maximum number of partitions per loop device");
MODULE_LICENSE("GPL");
MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR);
-
-int loop_register_transfer(struct loop_func_table *funcs)
-{
- unsigned int n = funcs->number;
-
- if (n >= MAX_LO_CRYPT || xfer_funcs[n])
- return -EINVAL;
- xfer_funcs[n] = funcs;
- return 0;
-}
-
-static int unregister_transfer_cb(int id, void *ptr, void *data)
-{
- struct loop_device *lo = ptr;
- struct loop_func_table *xfer = data;
-
- mutex_lock(&lo->lo_mutex);
- if (lo->lo_encryption == xfer)
- loop_release_xfer(lo);
- mutex_unlock(&lo->lo_mutex);
- return 0;
-}
-
-int loop_unregister_transfer(int number)
-{
- unsigned int n = number;
- struct loop_func_table *xfer;
-
- if (n == 0 || n >= MAX_LO_CRYPT || (xfer = xfer_funcs[n]) == NULL)
- return -EINVAL;
-
- xfer_funcs[n] = NULL;
- idr_for_each(&loop_index_idr, &unregister_transfer_cb, xfer);
- return 0;
-}
-
-EXPORT_SYMBOL(loop_register_transfer);
-EXPORT_SYMBOL(loop_unregister_transfer);
+MODULE_ALIAS("cryptoloop");
static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx,
const struct blk_mq_queue_data *bd)
diff --git a/drivers/block/loop.h b/drivers/block/loop.h
index 7b84ef724de1..dd12d7f1ce30 100644
--- a/drivers/block/loop.h
+++ b/drivers/block/loop.h
@@ -87,12 +87,7 @@ struct loop_func_table {
struct page *loop_page, unsigned loop_off,
int size, sector_t real_block);
int (*init)(struct loop_device *, const struct loop_info64 *);
- /* release is called from loop_unregister_transfer or clr_fd */
void (*release)(struct loop_device *);
- struct module *owner;
};
-int loop_register_transfer(struct loop_func_table *funcs);
-int loop_unregister_transfer(int number);
-
#endif
--
2.30.2
