security/vboot: Ensure firmware body size is respected again
CB:36845 simplified how coreboot finds the RW CBFS after vboot has and
eliminated a layer of caching. Unfortunately, we missed the fact that
the former cached value didn't exactly match the FMAP section... it was
in fact truncated to the data actually used by vboot. That patch
unintentionally broke this truncation which leads to performance
regressions on certain CBFS accesses.
This patch makes use of a new API function added to vboot (CL:1965920)
which we can use to retrieve the real firmware body length as before.
(Also stop making all the vb2_context pointers const. vboot generally
never marks context pointers as const in its API functions, even when
the function doesn't modify the context. Therefore constifying it inside
coreboot just makes things weird because it prevents you from calling
random API functions for no reason. If we really want const context
pointers, that's a refactoring that would have to start inside vboot
first.)
This patch brings in upstream vboot commit 4b0408d2:
2019-12-12 Julius Werner 2lib: Move firmware body size reporting to
separate function
Change-Id: I167cd40cb435dbae7f09d6069c9f1ffc1d99fe13
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37680
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Mathew King <mathewk@chromium.org>
diff --git a/src/security/vboot/vboot_logic.c b/src/security/vboot/vboot_logic.c
index 6c4f8fd..1d17a17 100644
--- a/src/security/vboot/vboot_logic.c
+++ b/src/security/vboot/vboot_logic.c
@@ -173,10 +173,10 @@
}
static vb2_error_t hash_body(struct vb2_context *ctx,
- struct region_device *fw_main)
+ struct region_device *fw_body)
{
uint64_t load_ts;
- uint32_t expected_size;
+ uint32_t remaining;
uint8_t block[TODO_BLOCK_SIZE];
uint8_t hash_digest[VBOOT_MAX_HASH_SIZE];
const size_t hash_digest_sz = sizeof(hash_digest);
@@ -197,33 +197,22 @@
load_ts = timestamp_get();
timestamp_add(TS_START_HASH_BODY, load_ts);
- expected_size = region_device_sz(fw_main);
+ remaining = region_device_sz(fw_body);
offset = 0;
/* Start the body hash */
- rv = vb2api_init_hash(ctx, VB2_HASH_TAG_FW_BODY, &expected_size);
+ rv = vb2api_init_hash(ctx, VB2_HASH_TAG_FW_BODY);
if (rv)
return rv;
- /*
- * Honor vboot's RW slot size. The expected size is pulled out of
- * the preamble and obtained through vb2api_init_hash() above. By
- * creating sub region the RW slot portion of the boot media is
- * limited.
- */
- if (rdev_chain(fw_main, fw_main, 0, expected_size)) {
- printk(BIOS_ERR, "Unable to restrict CBFS size.\n");
- return VB2_ERROR_UNKNOWN;
- }
-
/* Extend over the body */
- while (expected_size) {
+ while (remaining) {
uint64_t temp_ts;
- if (block_size > expected_size)
- block_size = expected_size;
+ if (block_size > remaining)
+ block_size = remaining;
temp_ts = timestamp_get();
- if (rdev_readat(fw_main, block, offset, block_size) < 0)
+ if (rdev_readat(fw_body, block, offset, block_size) < 0)
return VB2_ERROR_UNKNOWN;
load_ts += timestamp_get() - temp_ts;
@@ -231,7 +220,7 @@
if (rv)
return rv;
- expected_size -= block_size;
+ remaining -= block_size;
offset += block_size;
}
@@ -309,7 +298,7 @@
void verstage_main(void)
{
struct vb2_context *ctx;
- struct region_device fw_main;
+ struct region_device fw_body;
vb2_error_t rv;
timestamp_add_now(TS_START_VBOOT);
@@ -405,12 +394,12 @@
}
printk(BIOS_INFO, "Phase 4\n");
- rv = vboot_locate_firmware(ctx, &fw_main);
+ rv = vboot_locate_firmware(ctx, &fw_body);
if (rv)
die_with_post_code(POST_INVALID_ROM,
"Failed to read FMAP to locate firmware");
- rv = hash_body(ctx, &fw_main);
+ rv = hash_body(ctx, &fw_body);
vboot_save_data(ctx);
if (rv) {
printk(BIOS_INFO, "Reboot requested (%x)\n", rv);