firmware: VB2_REC_OR_DIE() should not abort before vb2_check_recovery()
Unfortunately, CL:3168437 introduced a new problem when booting with a
broken TPM: secdata accessors no longer return failure but instead just
abort when booting in normal mode and continue when we're in recovery
mode. The problem is that when accessing secdata very early in
vb2api_fw_phase1(), we have not decided whether we're booting in
recovery mode yet. If vb2_secdata_firmware_init() fails, we will call
vb2api_fail() and then continue knowing that vb2_check_recovery() will
later see the recovery reason in NVRAM and decide to boot directly into
recovery from here. But if the code in-between accesses secdata, the
VB2_CONTEXT_RECOVERY_MODE flag is technically not yet set, so our
secdata accessor thinks we are booting in normal mode and something
terrible happened (because it shouldn't be possible to boot in normal
mode when secdata_init failed), so it aborts.
In order to try to solve this problem in a more general way, introduce a
new VB2_SD_STATUS_RECOVERY_DECIDED status flag that gets set once we
reach the point where we have conclusively decided whether we are
booting into recovery mode and set the appropriate context flags. Any
code using VB2_REC_OR_DIE() before that point will play it safe and
assume that we may still go into recovery mode, so we shouldn't abort.
BRANCH=none
BUG=none
TEST=none
Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: Ic3daa8dac932286257cbceebfff8712d25c3a97a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3301540
Reviewed-by: Hsuan Ting Chen <roccochen@chromium.org>
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
9 files changed
