[PATCH 02/15] arm*: disable NEON in kernel mode

From: Tom Zanussi
Date: Thu Aug 02 2018 - 18:26:25 EST


From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

NEON in kernel mode is used by the crypto algorithms and raid6 code.
While the raid6 code looks okay, the crypto algorithms do not: NEON
is enabled on first invocation and may allocate/free/map memory before
the NEON mode is disabled again.
This needs to be changed until it can be enabled.
On ARM NEON in kernel mode can be simply disabled. on ARM64 it needs to
stay on due to possible EFI callbacks so here I disable each algorithm.

Cc: stable-rt@xxxxxxxxxxxxxxx
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Daniel Wagner <wagi@xxxxxxxxx>
(cherry picked from commit 728b41d8e7b5307b52bdbffcb492bc8345a4e38a)
Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
---
arch/arm/Kconfig | 2 +-
arch/arm64/crypto/Kconfig | 14 +++++++-------
2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index d635abf51063..12b1e7a5f103 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -2122,7 +2122,7 @@ config NEON

config KERNEL_MODE_NEON
bool "Support for NEON in kernel mode"
- depends on NEON && AEABI
+ depends on NEON && AEABI && !PREEMPT_RT_BASE
help
Say Y to include support for NEON in kernel mode.

diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig
index 5562652c5316..003fe0718117 100644
--- a/arch/arm64/crypto/Kconfig
+++ b/arch/arm64/crypto/Kconfig
@@ -10,42 +10,42 @@ if ARM64_CRYPTO

config CRYPTO_SHA1_ARM64_CE
tristate "SHA-1 digest algorithm (ARMv8 Crypto Extensions)"
- depends on ARM64 && KERNEL_MODE_NEON
+ depends on ARM64 && KERNEL_MODE_NEON && !PREEMPT_RT_BASE
select CRYPTO_HASH

config CRYPTO_SHA2_ARM64_CE
tristate "SHA-224/SHA-256 digest algorithm (ARMv8 Crypto Extensions)"
- depends on ARM64 && KERNEL_MODE_NEON
+ depends on ARM64 && KERNEL_MODE_NEON && !PREEMPT_RT_BASE
select CRYPTO_HASH

config CRYPTO_GHASH_ARM64_CE
tristate "GHASH (for GCM chaining mode) using ARMv8 Crypto Extensions"
- depends on ARM64 && KERNEL_MODE_NEON
+ depends on ARM64 && KERNEL_MODE_NEON && !PREEMPT_RT_BASE
select CRYPTO_HASH

config CRYPTO_AES_ARM64_CE
tristate "AES core cipher using ARMv8 Crypto Extensions"
- depends on ARM64 && KERNEL_MODE_NEON
+ depends on ARM64 && KERNEL_MODE_NEON && !PREEMPT_RT_BASE
select CRYPTO_ALGAPI
select CRYPTO_AES

config CRYPTO_AES_ARM64_CE_CCM
tristate "AES in CCM mode using ARMv8 Crypto Extensions"
- depends on ARM64 && KERNEL_MODE_NEON
+ depends on ARM64 && KERNEL_MODE_NEON && !PREEMPT_RT_BASE
select CRYPTO_ALGAPI
select CRYPTO_AES
select CRYPTO_AEAD

config CRYPTO_AES_ARM64_CE_BLK
tristate "AES in ECB/CBC/CTR/XTS modes using ARMv8 Crypto Extensions"
- depends on ARM64 && KERNEL_MODE_NEON
+ depends on ARM64 && KERNEL_MODE_NEON && !PREEMPT_RT_BASE
select CRYPTO_BLKCIPHER
select CRYPTO_AES
select CRYPTO_ABLK_HELPER

config CRYPTO_AES_ARM64_NEON_BLK
tristate "AES in ECB/CBC/CTR/XTS modes using NEON instructions"
- depends on ARM64 && KERNEL_MODE_NEON
+ depends on ARM64 && KERNEL_MODE_NEON && !PREEMPT_RT_BASE
select CRYPTO_BLKCIPHER
select CRYPTO_AES
select CRYPTO_ABLK_HELPER
--
2.14.1