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vboot: copy data structures to CBMEM for downstream use 

For platforms that do not employ VBOOT_STARTS_IN_ROMSTAGE,
vboot verification occurs before CBMEM is brought online.
In order to make vboot data structures available downstream,
copy vb2_working_data from CAR/SRAM into CBMEM when CBMEM
comes online.  Create VBOOT_MIGRATE_WORKING_DATA config
option to toggle this functionality.

BUG=b:124141368, b:124192753
TEST=Built and deployed on eve with STARTS_IN_BOOTBLOCK
TEST=Built and deployed on eve with STARTS_IN_ROMSTAGE
TEST=util/lint/checkpatch.pl -g origin/master..HEAD
TEST=util/abuild/abuild -B -e -y -c 50 -p none -x
BRANCH=none

Change-Id: I62c11268a83927bc00ae9bd93b1b31363b38e8cf
Signed-off-by: Joel Kitching <kitching@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31329
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
This commit is contained in:
Joel Kitching 2019-02-11 15:37:49 +08:00 committed by Patrick Georgi
parent 6b8a29e8b9
commit 0bcee88298
7 changed files with 94 additions and 73 deletions
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2
src/commonlib/include/commonlib/cbmem_id.h
View File

@ -67,7 +67,7 @@
#define CBMEM_ID_TIMESTAMP 0x54494d45
#define CBMEM_ID_TPM2_TCG_LOG 0x54504d32
#define CBMEM_ID_VBOOT_HANDOFF 0x780074f0
#define CBMEM_ID_VBOOT_SEL_REG 0x780074f1
#define CBMEM_ID_VBOOT_SEL_REG 0x780074f1 /* deprecated */
#define CBMEM_ID_VBOOT_WORKBUF 0x78007343
#define CBMEM_ID_VPD 0x56504420
#define CBMEM_ID_WIFI_CALIBRATION 0x57494649

7
src/include/symbols.h
View File

@ -67,4 +67,11 @@ DECLARE_REGION(bl31)
*/
#define DECLARE_OPTIONAL_REGION(name) asm (".weak _" #name ", _e" #name)
/* Returns true when pre-RAM symbols are known to the linker.
* (Does not necessarily mean that the memory is accessible.) */
static inline int preram_symbols_available(void)
{
return !IS_ENABLED(CONFIG_CACHE_AS_RAM) || ENV_CACHE_AS_RAM;
}
#endif /* __SYMBOLS_H */

15
src/security/vboot/Kconfig
View File

@ -107,6 +107,21 @@ config VBOOT_STARTS_IN_ROMSTAGE
memory initialization). This implies that vboot working data is
allocated in CBMEM.
config VBOOT_MIGRATE_WORKING_DATA
bool
default y if CACHE_AS_RAM
depends on !VBOOT_STARTS_IN_ROMSTAGE
help
In order to make vboot data structures available downstream,
migrate verified boot working data to CBMEM after CBMEM comes
online, when VBOOT_STARTS_IN_BOOTBLOCK is employed. This should
always be enabled on x86 architectures to migrate data from CAR
before losing access in ramstage, and should almost always be
disabled in SRAM architectures, where access to SRAM is usually
retained. Any SRAM platform where the original location of the
VBOOT_WORKBUF region becomes inaccessible in later stages should
manually select this option.
config VBOOT_MOCK_SECDATA
bool "Mock secdata for firmware verification"
default n

131
src/security/vboot/common.c
View File

@ -15,8 +15,11 @@
#include <assert.h>
#include <cbmem.h>
#include <console/console.h>
#include <reset.h>
#include <stdint.h>
#include <string.h>
#include <symbols.h>
#include <vb2_api.h>
#include <security/vboot/misc.h>
#include <security/vboot/symbols.h>
@ -40,82 +43,77 @@ struct vb2_working_data {
uint32_t buffer_size;
};
static const size_t vb_work_buf_size = 16 * KiB;
static struct vb2_working_data * const vboot_get_working_data(void)
{
if (CONFIG(VBOOT_STARTS_IN_ROMSTAGE))
/* cbmem_add() does a cbmem_find() first. */
return cbmem_add(CBMEM_ID_VBOOT_WORKBUF, vb_work_buf_size);
else
return (struct vb2_working_data *)_vboot2_work;
}
/* TODO(kitching): Use VB2_FIRMWARE_WORKBUF_RECOMMENDED_SIZE instead. */
static size_t vb2_working_data_size(void)
{
if (CONFIG(VBOOT_STARTS_IN_ROMSTAGE))
return vb_work_buf_size;
else
return 12 * KiB;
else if (CONFIG(VBOOT_STARTS_IN_BOOTBLOCK) &&
preram_symbols_available())
return REGION_SIZE(vboot2_work);
die("impossible!");
}
static struct selected_region *vb2_selected_region(void)
static struct vb2_working_data * const vb2_get_working_data(void)
{
struct selected_region *sel_reg = NULL;
struct vb2_working_data *wd = NULL;
/* Ramstage and postcar always uses cbmem as a source of truth. */
if (ENV_RAMSTAGE || ENV_POSTCAR)
sel_reg = cbmem_find(CBMEM_ID_VBOOT_SEL_REG);
else if (ENV_ROMSTAGE) {
/* Try cbmem first. Fall back on working data if not found. */
sel_reg = cbmem_find(CBMEM_ID_VBOOT_SEL_REG);
if (cbmem_possibly_online())
wd = cbmem_find(CBMEM_ID_VBOOT_WORKBUF);
if (sel_reg == NULL) {
struct vb2_working_data *wd = vboot_get_working_data();
sel_reg = &wd->selected_region;
}
} else {
/* Stages such as bootblock and verstage use working data. */
struct vb2_working_data *wd = vboot_get_working_data();
sel_reg = &wd->selected_region;
}
if (wd == NULL && CONFIG(VBOOT_STARTS_IN_BOOTBLOCK) &&
preram_symbols_available())
wd = (struct vb2_working_data *)_vboot2_work;
return sel_reg;
assert(wd != NULL);
return wd;
}
void vb2_init_work_context(struct vb2_context *ctx)
{
struct vb2_working_data *wd;
size_t work_size;
/* First initialize the working data region. */
work_size = vb2_working_data_size();
wd = vboot_get_working_data();
memset(wd, 0, work_size);
/* First initialize the working data struct. */
wd = vb2_get_working_data();
memset(wd, 0, sizeof(struct vb2_working_data));
/*
* vboot prefers 16-byte alignment. This takes away 16 bytes
* from the VBOOT2_WORK region, but the vboot devs said that's okay.
*/
wd->buffer_offset = ALIGN_UP(sizeof(*wd), 16);
wd->buffer_size = work_size - wd->buffer_offset;
wd->buffer_size = vb2_working_data_size() - wd->buffer_offset;
/* Initialize the vb2_context. */
memset(ctx, 0, sizeof(*ctx));
ctx->workbuf = (void *)vb2_get_shared_data();
ctx->workbuf_size = wd->buffer_size;
}
void vb2_finalize_work_context(struct vb2_context *ctx)
{
/*
* Shrink buffer_size so that vb2_migrate_cbmem knows how much
* of vb2_working_data needs to be copied into CBMEM (if applicable),
* and so that downstream users know how much of the workbuf is
* currently used.
*/
vb2_get_working_data()->buffer_size = ctx->workbuf_used;
}
struct vb2_shared_data *vb2_get_shared_data(void)
{
struct vb2_working_data *wd = vboot_get_working_data();
struct vb2_working_data *wd = vb2_get_working_data();
return (void *)((uintptr_t)wd + wd->buffer_offset);
}
int vb2_get_selected_region(struct region *region)
{
const struct selected_region *reg = vb2_selected_region();
const struct selected_region *reg =
&vb2_get_working_data()->selected_region;
if (reg == NULL)
return -1;
@ -131,7 +129,7 @@ int vb2_get_selected_region(struct region *region)
void vb2_set_selected_region(const struct region *region)
{
struct selected_region *reg = vb2_selected_region();
struct selected_region *reg = &vb2_get_working_data()->selected_region;
assert(reg != NULL);
@ -141,40 +139,41 @@ void vb2_set_selected_region(const struct region *region)
int vb2_is_slot_selected(void)
{
const struct selected_region *reg = vb2_selected_region();
struct selected_region *reg = &vb2_get_working_data()->selected_region;
assert(reg != NULL);
return reg->size > 0;
}
void vb2_store_selected_region(void)
{
const struct vb2_working_data *wd;
struct selected_region *sel_reg;
/* Always use the working data in this path since it's the object
* which has the result.. */
wd = vboot_get_working_data();
sel_reg = cbmem_add(CBMEM_ID_VBOOT_SEL_REG, sizeof(*sel_reg));
assert(sel_reg != NULL);
sel_reg->offset = wd->selected_region.offset;
sel_reg->size = wd->selected_region.size;
}
#if CONFIG(VBOOT_MIGRATE_WORKING_DATA)
/*
* For platforms that employ VBOOT_STARTS_IN_ROMSTAGE, the vboot
* verification doesn't happen until after cbmem is brought online.
* Therefore, the selected region contents would not be initialized
* so don't automatically add results when cbmem comes online.
* For platforms that do not employ VBOOT_STARTS_IN_ROMSTAGE, vboot
* verification occurs before CBMEM is brought online, using pre-RAM.
* In order to make vboot data structures available downstream, copy
* vb2_working_data from SRAM/CAR into CBMEM on platforms where this
* memory later becomes unavailable.
*/
#if !CONFIG(VBOOT_STARTS_IN_ROMSTAGE)
static void vb2_store_selected_region_cbmem(int unused)
static void vb2_migrate_cbmem(int unused)
{
vb2_store_selected_region();
const struct vb2_working_data *wd_preram =
(struct vb2_working_data *)_vboot2_work;
size_t cbmem_size = wd_preram->buffer_offset + wd_preram->buffer_size;
struct vb2_working_data *wd_cbmem =
cbmem_add(CBMEM_ID_VBOOT_WORKBUF, cbmem_size);
printk(BIOS_DEBUG,
"VBOOT: copying vb2_working_data (%zu bytes) to CBMEM...\n",
cbmem_size);
memcpy(wd_cbmem, wd_preram, cbmem_size);
assert(wd_cbmem != NULL);
}
ROMSTAGE_CBMEM_INIT_HOOK(vb2_store_selected_region_cbmem)
ROMSTAGE_CBMEM_INIT_HOOK(vb2_migrate_cbmem)
#elif CONFIG(VBOOT_STARTS_IN_ROMSTAGE)
static void vb2_setup_cbmem(int unused)
{
struct vb2_working_data *wd_cbmem =
cbmem_add(CBMEM_ID_VBOOT_WORKBUF, vb2_working_data_size());
assert(wd_cbmem != NULL);
}
ROMSTAGE_CBMEM_INIT_HOOK(vb2_setup_cbmem)
#endif

4
src/security/vboot/misc.h
View File

@ -24,6 +24,7 @@ struct vb2_shared_data;
void vboot_fill_handoff(void);
void vb2_init_work_context(struct vb2_context *ctx);
void vb2_finalize_work_context(struct vb2_context *ctx);
struct vb2_shared_data *vb2_get_shared_data(void);
/* Returns 0 on success. < 0 on failure. */
@ -32,9 +33,6 @@ void vb2_set_selected_region(const struct region *region);
int vb2_is_slot_selected(void);
int vb2_logic_executed(void);
/* Store the selected region in cbmem for later use. */
void vb2_store_selected_region(void);
void vb2_save_recovery_reason_vbnv(void);
#endif /* __VBOOT_MISC_H__ */

7
src/security/vboot/vboot_loader.c
View File

@ -27,6 +27,9 @@
_Static_assert(CONFIG(VBOOT_STARTS_IN_BOOTBLOCK) +
CONFIG(VBOOT_STARTS_IN_ROMSTAGE) == 1,
"vboot must either start in bootblock or romstage (not both!)");
_Static_assert(CONFIG(VBOOT_STARTS_IN_BOOTBLOCK) ||
!CONFIG(VBOOT_MIGRATE_WORKING_DATA),
"no need to migrate working data after CBMEM is already up!");
_Static_assert(!CONFIG(VBOOT_SEPARATE_VERSTAGE) ||
CONFIG(VBOOT_STARTS_IN_BOOTBLOCK),
"stand-alone verstage must start in (i.e. after) bootblock");
@ -126,10 +129,8 @@ static void vboot_prepare(void)
* other platforms the vboot cbmem objects are initialized when
* cbmem comes online.
*/
if (ENV_ROMSTAGE && CONFIG(VBOOT_STARTS_IN_ROMSTAGE)) {
vb2_store_selected_region();
if (ENV_ROMSTAGE && CONFIG(VBOOT_STARTS_IN_ROMSTAGE))
vboot_fill_handoff();
}
}
static int vboot_locate(struct cbfs_props *props)

1
src/security/vboot/vboot_logic.c
View File

@ -438,5 +438,6 @@ void verstage_main(void)
printk(BIOS_INFO, "Slot %c is selected\n", is_slot_a(&ctx) ? 'A' : 'B');
vb2_set_selected_region(region_device_region(&fw_main));
vb2_finalize_work_context(&ctx);
timestamp_add_now(TS_END_VBOOT);
}