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Revert "ANDROID: AVB error handler to invalidate vbmeta partition."

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This driver is not used and can cause problems if used on modern
devices. Remove it.

This reverts commit 6115619831.

Bug: 185178770
Signed-off-by: Alistair Delva <adelva@google.com>
Change-Id: I1d5acb96dda765a1e3ea0cf62a3bf4b2a78892ea
This commit is contained in:
Alistair Delva
2021-04-12 17:35:37 -07:00
parent d434336cff
commit d9d3fe628e
7 changed files with 1 additions and 253 deletions
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1
arch/arm64/configs/gki_defconfig
View File

@@ -283,7 +283,6 @@ CONFIG_DM_DEFAULT_KEY=y
CONFIG_DM_SNAPSHOT=y
CONFIG_DM_UEVENT=y
CONFIG_DM_VERITY=y
CONFIG_DM_VERITY_AVB=y
CONFIG_DM_VERITY_FEC=y
CONFIG_DM_BOW=y
CONFIG_NETDEVICES=y

1
arch/x86/configs/gki_defconfig
View File

@@ -260,7 +260,6 @@ CONFIG_DM_DEFAULT_KEY=y
CONFIG_DM_SNAPSHOT=y
CONFIG_DM_UEVENT=y
CONFIG_DM_VERITY=y
CONFIG_DM_VERITY_AVB=y
CONFIG_DM_VERITY_FEC=y
CONFIG_DM_BOW=y
CONFIG_NETDEVICES=y

11
drivers/md/Kconfig
View File

@@ -579,17 +579,6 @@ config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
If unsure, say N.
config DM_VERITY_AVB
tristate "Support AVB specific verity error behavior"
depends on DM_VERITY
help
Enables Android Verified Boot platform-specific error
behavior. In particular, it will modify the vbmeta partition
specified on the kernel command-line when non-transient error
occurs (followed by a panic).
If unsure, say N.
config DM_VERITY_FEC
bool "Verity forward error correction support"
depends on DM_VERITY

4
drivers/md/Makefile
View File

@@ -95,10 +95,6 @@ ifeq ($(CONFIG_DM_UEVENT),y)
dm-mod-objs += dm-uevent.o
endif
ifeq ($(CONFIG_DM_VERITY_AVB),y)
dm-verity-objs += dm-verity-avb.o
endif
ifeq ($(CONFIG_DM_VERITY_FEC),y)
dm-verity-objs += dm-verity-fec.o
endif

229
drivers/md/dm-verity-avb.c
View File

@@ -1,229 +0,0 @@
/*
* Copyright (C) 2017 Google.
*
* This file is released under the GPLv2.
*
* Based on drivers/md/dm-verity-chromeos.c
*/
#include <linux/device-mapper.h>
#include <linux/module.h>
#include <linux/mount.h>
#define DM_MSG_PREFIX "verity-avb"
/* Set via module parameters. */
static char avb_vbmeta_device[64];
static char avb_invalidate_on_error[4];
static void invalidate_vbmeta_endio(struct bio *bio)
{
if (bio->bi_status)
DMERR("invalidate_vbmeta_endio: error %d", bio->bi_status);
complete(bio->bi_private);
}
static int invalidate_vbmeta_submit(struct bio *bio,
struct block_device *bdev,
int op, int access_last_sector,
struct page *page)
{
DECLARE_COMPLETION_ONSTACK(wait);
bio->bi_private = &wait;
bio->bi_end_io = invalidate_vbmeta_endio;
bio_set_dev(bio, bdev);
bio_set_op_attrs(bio, op, REQ_SYNC);
bio->bi_iter.bi_sector = 0;
if (access_last_sector) {
sector_t last_sector;
last_sector = (i_size_read(bdev->bd_inode)>>SECTOR_SHIFT) - 1;
bio->bi_iter.bi_sector = last_sector;
}
if (!bio_add_page(bio, page, PAGE_SIZE, 0)) {
DMERR("invalidate_vbmeta_submit: bio_add_page error");
return -EIO;
}
submit_bio(bio);
/* Wait up to 2 seconds for completion or fail. */
if (!wait_for_completion_timeout(&wait, msecs_to_jiffies(2000)))
return -EIO;
return 0;
}
static int invalidate_vbmeta(dev_t vbmeta_devt)
{
int ret = 0;
struct block_device *bdev;
struct bio *bio;
struct page *page;
fmode_t dev_mode;
/* Ensure we do synchronous unblocked I/O. We may also need
* sync_bdev() on completion, but it really shouldn't.
*/
int access_last_sector = 0;
DMINFO("invalidate_vbmeta: acting on device %d:%d",
MAJOR(vbmeta_devt), MINOR(vbmeta_devt));
/* First we open the device for reading. */
dev_mode = FMODE_READ | FMODE_EXCL;
bdev = blkdev_get_by_dev(vbmeta_devt, dev_mode,
invalidate_vbmeta);
if (IS_ERR(bdev)) {
DMERR("invalidate_kernel: could not open device for reading");
dev_mode = 0;
ret = -ENOENT;
goto failed_to_read;
}
bio = bio_alloc(GFP_NOIO, 1);
if (!bio) {
ret = -ENOMEM;
goto failed_bio_alloc;
}
page = alloc_page(GFP_NOIO);
if (!page) {
ret = -ENOMEM;
goto failed_to_alloc_page;
}
access_last_sector = 0;
ret = invalidate_vbmeta_submit(bio, bdev, REQ_OP_READ,
access_last_sector, page);
if (ret) {
DMERR("invalidate_vbmeta: error reading");
goto failed_to_submit_read;
}
/* We have a page. Let's make sure it looks right. */
if (memcmp("AVB0", page_address(page), 4) == 0) {
/* Stamp it. */
memcpy(page_address(page), "AVE0", 4);
DMINFO("invalidate_vbmeta: found vbmeta partition");
} else {
/* Could be this is on a AVB footer, check. Also, since the
* AVB footer is in the last 64 bytes, adjust for the fact that
* we're dealing with 512-byte sectors.
*/
size_t offset = (1<<SECTOR_SHIFT) - 64;
access_last_sector = 1;
ret = invalidate_vbmeta_submit(bio, bdev, REQ_OP_READ,
access_last_sector, page);
if (ret) {
DMERR("invalidate_vbmeta: error reading");
goto failed_to_submit_read;
}
if (memcmp("AVBf", page_address(page) + offset, 4) != 0) {
DMERR("invalidate_vbmeta on non-vbmeta partition");
ret = -EINVAL;
goto invalid_header;
}
/* Stamp it. */
memcpy(page_address(page) + offset, "AVE0", 4);
DMINFO("invalidate_vbmeta: found vbmeta footer partition");
}
/* Now rewrite the changed page - the block dev was being
* changed on read. Let's reopen here.
*/
blkdev_put(bdev, dev_mode);
dev_mode = FMODE_WRITE | FMODE_EXCL;
bdev = blkdev_get_by_dev(vbmeta_devt, dev_mode,
invalidate_vbmeta);
if (IS_ERR(bdev)) {
DMERR("invalidate_vbmeta: could not open device for writing");
dev_mode = 0;
ret = -ENOENT;
goto failed_to_write;
}
/* We re-use the same bio to do the write after the read. Need to reset
* it to initialize bio->bi_remaining.
*/
bio_reset(bio);
ret = invalidate_vbmeta_submit(bio, bdev, REQ_OP_WRITE,
access_last_sector, page);
if (ret) {
DMERR("invalidate_vbmeta: error writing");
goto failed_to_submit_write;
}
DMERR("invalidate_vbmeta: completed.");
ret = 0;
failed_to_submit_write:
failed_to_write:
invalid_header:
__free_page(page);
failed_to_submit_read:
/* Technically, we'll leak a page with the pending bio, but
* we're about to reboot anyway.
*/
failed_to_alloc_page:
bio_put(bio);
failed_bio_alloc:
if (dev_mode)
blkdev_put(bdev, dev_mode);
failed_to_read:
return ret;
}
void dm_verity_avb_error_handler(void)
{
dev_t dev;
DMINFO("AVB error handler called for %s", avb_vbmeta_device);
if (strcmp(avb_invalidate_on_error, "yes") != 0) {
DMINFO("Not configured to invalidate");
return;
}
if (avb_vbmeta_device[0] == '\0') {
DMERR("avb_vbmeta_device parameter not set");
goto fail_no_dev;
}
dev = name_to_dev_t(avb_vbmeta_device);
if (!dev) {
DMERR("No matching partition for device: %s",
avb_vbmeta_device);
goto fail_no_dev;
}
invalidate_vbmeta(dev);
fail_no_dev:
;
}
static int __init dm_verity_avb_init(void)
{
DMINFO("AVB error handler initialized with vbmeta device: %s",
avb_vbmeta_device);
return 0;
}
static void __exit dm_verity_avb_exit(void)
{
}
module_init(dm_verity_avb_init);
module_exit(dm_verity_avb_exit);
MODULE_AUTHOR("David Zeuthen <zeuthen@google.com>");
MODULE_DESCRIPTION("AVB-specific error handler for dm-verity");
MODULE_LICENSE("GPL");
/* Declare parameter with no module prefix */
#undef MODULE_PARAM_PREFIX
#define MODULE_PARAM_PREFIX "androidboot.vbmeta."
module_param_string(device, avb_vbmeta_device, sizeof(avb_vbmeta_device), 0);
module_param_string(invalidate_on_error, avb_invalidate_on_error,
sizeof(avb_invalidate_on_error), 0);

6
drivers/md/dm-verity-target.c
View File

@@ -252,12 +252,8 @@ out:
if (v->mode == DM_VERITY_MODE_LOGGING)
return 0;
if (v->mode == DM_VERITY_MODE_RESTART) {
#ifdef CONFIG_DM_VERITY_AVB
dm_verity_avb_error_handler();
#endif
if (v->mode == DM_VERITY_MODE_RESTART)
kernel_restart("dm-verity device corrupted");
}
if (v->mode == DM_VERITY_MODE_PANIC)
panic("dm-verity device corrupted");

2
drivers/md/dm-verity.h
View File

@@ -129,6 +129,4 @@ extern int verity_hash(struct dm_verity *v, struct ahash_request *req,
extern int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io,
sector_t block, u8 *digest, bool *is_zero);
extern void dm_verity_avb_error_handler(void);
#endif /* DM_VERITY_H */