2sha256_arm: Fix data abort issue
Fix the following CPU exception when enabling ARMV8_CRYPTO_EXT.
[DEBUG] exception _sync_sp_el0
[DEBUG] ELR = 0x000000000025f390 ESR = 0x96000010
[DEBUG] FAR = 0x000000000c000000 SPSR = 0x2000000c
[DEBUG] X00 = 0x000000000026cf20 X01 = 0x000000000bffffe0
[DEBUG] X02 = 0x00000000ffd042de X03 = 0xffffffffffffffff
[DEBUG] X04 = 0x000000000026cf88 X05 = 0x0000000000054ff8
[DEBUG] X06 = 0x0000000000000002 X07 = 0x000000000000000a
[DEBUG] X08 = 0x000000000025f5f0 X09 = 0x000000000026cf30
[DEBUG] X10 = 0x000000000010b4ee X11 = 0x00000000000001fc
[DEBUG] X12 = 0x0000000000000080 X13 = 0x0000000000125110
[DEBUG] X14 = 0x0000000000124f10 X15 = 0x0000000000125310
[DEBUG] X16 = 0x0000000000267580 X17 = 0x749ffa8d9d5f02ca
[DEBUG] X18 = 0x0000000000125110 X19 = 0x0000000000000000
[DEBUG] X20 = 0x000000000026cf20 X21 = 0x000000000010b760
[DEBUG] X22 = 0x000000000026cf48 X23 = 0x0000000000000000
[DEBUG] X24 = 0x0000000000000000 X25 = 0x00000000000a3800
[DEBUG] X26 = 0x000000000026c970 X27 = 0x000000000026c802
[DEBUG] X28 = 0x0000000000000000 X29 = 0x0000000000000000
[DEBUG] X30 = 0x000000000025f1e0 SP = 0x000000000010b650
The issue happens when the buffer size processed by
`vb2ex_hwcrypto_digest_extend` is equal to VB2_SHA256_BLOCK_SIZE.
`vb2_sha256_transform_hwcrypto` is called twice in
`vb2ex_hwcrypto_digest_extend`. The first call processes the whole
buffer. The second call still processes the buffer even if
`remaining_blocks` is equal to 0. This causes `block_nb`(see X02)
underflow in the assembly code. Then ld1 instruction accesses an
unexpected memory address(see X01) and raises CPU exception.
Fix the issue by checking `block_nb` value before calling to
`sha256_ce_transform`.
BRANCH=corsola
BUG=b:263514393
TEST=flash image-geralt*.bin and no CPU exception raised
Change-Id: I9b74d60413b3cc571950e15c0d2b901bc4063385
Signed-off-by: Yidi Lin <yidilin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/4242678
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
(cherry picked from commit 5b8596cefd1a61252501943f2534323708338732)
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/4269955
Tested-by: Yu-Ping Wu <yupingso@chromium.org>
Auto-Submit: Yu-Ping Wu <yupingso@chromium.org>
2 files changed
