verity: don't call page_address on unmapped highmem pages
This fixes a bug that is preventing ARM systems from booting with verity.
We were calling page_address on what could potentially have been an
unmapped highmem page. Fix is to pass the struct page to the crypto code
and let crypto handle the kmap/kunmap.
BUG=chromium-os:14089,chrome-os-partner:3287
TEST=Ran dm-verity.git unit tests. Ran platform_DMVerityCorruption on H/W.
Verified that ARM now boots.
kernel-next.git Review URL: http://codereview.chromium.org/6835032
TBRing. Code has already been reviewed and committed to kernel-next.git
There are some trivial changes here to the unittest to match the new
list of parameters.
Change-Id: Id9e025552aee323e95d50aa9798a964510710fdd
Review URL: http://codereview.chromium.org/6851023
diff --git a/dm-bht.c b/dm-bht.c
index e3da9c5..72af2a7 100644
--- a/dm-bht.c
+++ b/dm-bht.c
@@ -20,6 +20,7 @@
#include <linux/dm-bht.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/mm_types.h>
#include <linux/scatterlist.h>
#include <linux/slab.h> /* k*alloc */
#include <linux/string.h> /* memset */
@@ -95,24 +96,14 @@
/**
* dm_bht_compute_hash: hashes a page of data
*/
-static int dm_bht_compute_hash(struct dm_bht *bht, const void *block,
- u8 *digest)
+static int dm_bht_compute_hash(struct dm_bht *bht, struct page *pg,
+ unsigned int offset, u8 *digest)
{
struct hash_desc *hash_desc = &bht->hash_desc[smp_processor_id()];
struct scatterlist sg;
- /* TODO(msb): Once we supporting block_size < PAGE_SIZE, change this to:
- * offset_into_page + length < page_size
- * For now just check that block is page-aligned.
- */
- /*
- * TODO(msb): Re-enable once user-space code is modified to use
- * aligned buffers.
- * BUG_ON(!IS_ALIGNED((uintptr_t)block, PAGE_SIZE));
- */
-
sg_init_table(&sg, 1);
- sg_set_buf(&sg, block, PAGE_SIZE);
+ sg_set_page(&sg, pg, PAGE_SIZE, offset);
/* Note, this is synchronous. */
if (crypto_hash_init(hash_desc)) {
DMCRIT("failed to reinitialize crypto hash (proc:%d)",
@@ -653,7 +644,7 @@
* Verifies the path. Returns 0 on ok.
*/
static int dm_bht_verify_path(struct dm_bht *bht, unsigned int block_index,
- const void *block)
+ struct page *pg, unsigned int offset)
{
unsigned int depth = bht->depth;
struct dm_bht_entry *entry;
@@ -674,14 +665,15 @@
BUG_ON(state < DM_BHT_ENTRY_READY);
node = dm_bht_get_node(bht, entry, depth, block_index);
- if (dm_bht_compute_hash(bht, block, digest) ||
+ if (dm_bht_compute_hash(bht, pg, offset, digest) ||
dm_bht_compare_hash(bht, digest, node))
goto mismatch;
/* Keep the containing block of hashes to be verified in the
* next pass.
*/
- block = entry->nodes;
+ pg = virt_to_page(entry->nodes);
+ offset = 0;
} while (--depth > 0 && state != DM_BHT_ENTRY_VERIFIED);
/* Mark path to leaf as verified. */
@@ -776,7 +768,7 @@
return 1;
}
- dm_bht_compute_hash(bht, block_data,
+ dm_bht_compute_hash(bht, virt_to_page(block_data), 0,
dm_bht_node(bht, entry, node_index));
return 0;
}
@@ -846,10 +838,10 @@
if (count == 0)
count = bht->node_count;
for (j = 0; j < count; j++, child++) {
- u8 *block = child->nodes;
+ struct page *pg = virt_to_page(child->nodes);
u8 *digest = dm_bht_node(bht, entry, j);
- r = dm_bht_compute_hash(bht, block, digest);
+ r = dm_bht_compute_hash(bht, pg, 0, digest);
if (r) {
DMERR("Failed to update (d=%u,i=%u)",
depth, i);
@@ -1026,10 +1018,12 @@
* should return similarly.
*/
int dm_bht_verify_block(struct dm_bht *bht, unsigned int block_index,
- const void *block)
+ struct page *pg, unsigned int offset)
{
int r = 0;
+ BUG_ON(offset != 0);
+
/* Make sure that the root has been verified */
if (atomic_read(&bht->root_state) != DM_BHT_ENTRY_VERIFIED) {
r = dm_bht_verify_root(bht, dm_bht_compare_hash);
@@ -1040,7 +1034,7 @@
}
/* Now check levels in between */
- r = dm_bht_verify_path(bht, block_index, block);
+ r = dm_bht_verify_path(bht, block_index, pg, offset);
if (r)
DMERR_LIMIT("Failed to verify block: %u (%d)", block_index, r);
diff --git a/dm-bht.h b/dm-bht.h
index e7269f6..73809d2 100644
--- a/dm-bht.h
+++ b/dm-bht.h
@@ -127,7 +127,7 @@
int dm_bht_populate(struct dm_bht *bht, void *read_cb_ctx,
unsigned int block_index);
int dm_bht_verify_block(struct dm_bht *bht, unsigned int block_index,
- const void *buf);
+ struct page *pg, unsigned int offset);
/* Functions for creating struct dm_bhts on disk. A newly created dm_bht
* should not be directly used for verification. (It should be repopulated.)
diff --git a/dm-bht_unittest.cc b/dm-bht_unittest.cc
index f0c090c..d7cf61a 100644
--- a/dm-bht_unittest.cc
+++ b/dm-bht_unittest.cc
@@ -172,7 +172,8 @@
for (unsigned int blocks = 0; blocks < total_blocks; ++blocks) {
DLOG(INFO) << "verifying block: " << blocks;
- EXPECT_EQ(0, dm_bht_verify_block(bht_.get(), blocks, zero_page));
+ EXPECT_EQ(0, dm_bht_verify_block(bht_.get(), blocks,
+ virt_to_page(zero_page), 0));
}
EXPECT_EQ(0, dm_bht_destroy(bht_.get()));
@@ -195,7 +196,8 @@
for (unsigned int blocks = 0; blocks < total_blocks; ++blocks) {
DLOG(INFO) << "verifying block: " << blocks;
- EXPECT_EQ(0, dm_bht_verify_block(bht_.get(), blocks, zero_page));
+ EXPECT_EQ(0, dm_bht_verify_block(bht_.get(), blocks,
+ virt_to_page(zero_page), 0));
}
EXPECT_EQ(0, dm_bht_destroy(bht_.get()));
@@ -218,7 +220,8 @@
for (unsigned int blocks = 0; blocks < total_blocks; ++blocks) {
DLOG(INFO) << "verifying block: " << blocks;
- EXPECT_EQ(0, dm_bht_verify_block(bht_.get(), blocks, zero_page));
+ EXPECT_EQ(0, dm_bht_verify_block(bht_.get(), blocks,
+ virt_to_page(zero_page), 0));
}
EXPECT_EQ(0, dm_bht_destroy(bht_.get()));
@@ -241,7 +244,8 @@
for (unsigned int blocks = 0; blocks < total_blocks; ++blocks) {
DLOG(INFO) << "verifying block: " << blocks;
- EXPECT_EQ(0, dm_bht_verify_block(bht_.get(), blocks, zero_page));
+ EXPECT_EQ(0, dm_bht_verify_block(bht_.get(), blocks,
+ virt_to_page(zero_page), 0));
}
EXPECT_EQ(0, dm_bht_destroy(bht_.get()));
@@ -264,7 +268,8 @@
for (unsigned int blocks = 0; blocks < total_blocks; ++blocks) {
DLOG(INFO) << "verifying block: " << blocks;
- EXPECT_EQ(0, dm_bht_verify_block(bht_.get(), blocks, zero_page));
+ EXPECT_EQ(0, dm_bht_verify_block(bht_.get(), blocks,
+ virt_to_page(zero_page), 0));
}
EXPECT_EQ(0, dm_bht_destroy(bht_.get()));
@@ -295,23 +300,25 @@
EXPECT_EQ(dm_bht_store_block(bht_.get(), kBadBlock, bad_hash_block), 0);
// Attempt to verify both the bad block and all the neighbors.
- EXPECT_LT(dm_bht_verify_block(bht_.get(), kBadBlock + 1, zero_page), 0);
+ EXPECT_LT(dm_bht_verify_block(bht_.get(), kBadBlock + 1,
+ virt_to_page(zero_page), 0), 0);
- EXPECT_LT(dm_bht_verify_block(bht_.get(), kBadBlock + 2, zero_page), 0);
+ EXPECT_LT(dm_bht_verify_block(bht_.get(), kBadBlock + 2,
+ virt_to_page(zero_page), 0), 0);
EXPECT_LT(dm_bht_verify_block(bht_.get(), kBadBlock + (bht_->node_count / 2),
- zero_page),
- 0);
+ virt_to_page(zero_page), 0), 0);
- EXPECT_LT(dm_bht_verify_block(bht_.get(), kBadBlock, zero_page), 0);
+ EXPECT_LT(dm_bht_verify_block(bht_.get(), kBadBlock,
+ virt_to_page(zero_page), 0), 0);
// Verify that the prior entry is untouched and still safe
- EXPECT_EQ(dm_bht_verify_block(bht_.get(), kBadBlock - 1, zero_page), 0);
+ EXPECT_EQ(dm_bht_verify_block(bht_.get(), kBadBlock - 1,
+ virt_to_page(zero_page), 0), 0);
// Same for the next entry
EXPECT_EQ(dm_bht_verify_block(bht_.get(), kBadBlock + bht_->node_count,
- zero_page),
- 0);
+ virt_to_page(zero_page), 0), 0);
EXPECT_EQ(0, dm_bht_destroy(bht_.get()));
free(bad_hash_block);
@@ -332,12 +339,12 @@
memset(bad_page, 'A', PAGE_SIZE);
- EXPECT_LT(dm_bht_verify_block(bht_.get(), 0, bad_page), 0);
- EXPECT_LT(dm_bht_verify_block(bht_.get(), 127, bad_page), 0);
- EXPECT_LT(dm_bht_verify_block(bht_.get(), 128, bad_page), 0);
- EXPECT_LT(dm_bht_verify_block(bht_.get(), 255, bad_page), 0);
- EXPECT_LT(dm_bht_verify_block(bht_.get(), 256, bad_page), 0);
- EXPECT_LT(dm_bht_verify_block(bht_.get(), 383, bad_page), 0);
+ EXPECT_LT(dm_bht_verify_block(bht_.get(), 0, virt_to_page(bad_page), 0), 0);
+ EXPECT_LT(dm_bht_verify_block(bht_.get(), 127, virt_to_page(bad_page), 0), 0);
+ EXPECT_LT(dm_bht_verify_block(bht_.get(), 128, virt_to_page(bad_page), 0), 0);
+ EXPECT_LT(dm_bht_verify_block(bht_.get(), 255, virt_to_page(bad_page), 0), 0);
+ EXPECT_LT(dm_bht_verify_block(bht_.get(), 256, virt_to_page(bad_page), 0), 0);
+ EXPECT_LT(dm_bht_verify_block(bht_.get(), 383, virt_to_page(bad_page), 0), 0);
EXPECT_EQ(0, dm_bht_destroy(bht_.get()));
free(bad_page);
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/include/linux/mm_types.h
