From 64cc0df68cd46029f7cd2d2bcccdb0b6f91dc520 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri, 1 Dec 2017 10:42:03 +0100
Subject: [PATCH 349/518] arm*: disable NEON in kernel mode

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@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 arch/arm/Kconfig                  |  2 +-
 arch/arm64/crypto/Kconfig         | 20 ++++++++++----------
 arch/arm64/crypto/crc32-ce-glue.c |  3 ++-
 3 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 3fc4912b54a68..c06381c678d77 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -2162,7 +2162,7 @@ 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 70c517aa45016..2a5f05b5a19ad 100644
--- a/arch/arm64/crypto/Kconfig
+++ b/arch/arm64/crypto/Kconfig
@@ -19,19 +19,19 @@ config CRYPTO_SHA512_ARM64
 
 config CRYPTO_SHA1_ARM64_CE
 	tristate "SHA-1 digest algorithm (ARMv8 Crypto Extensions)"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_HASH
 	select CRYPTO_SHA1
 
 config CRYPTO_SHA2_ARM64_CE
 	tristate "SHA-224/SHA-256 digest algorithm (ARMv8 Crypto Extensions)"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_HASH
 	select CRYPTO_SHA256_ARM64
 
 config CRYPTO_GHASH_ARM64_CE
 	tristate "GHASH/AES-GCM using ARMv8 Crypto Extensions"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_HASH
 	select CRYPTO_GF128MUL
 	select CRYPTO_AES
@@ -39,7 +39,7 @@ config CRYPTO_GHASH_ARM64_CE
 
 config CRYPTO_CRCT10DIF_ARM64_CE
 	tristate "CRCT10DIF digest algorithm using PMULL instructions"
-	depends on KERNEL_MODE_NEON && CRC_T10DIF
+	depends on KERNEL_MODE_NEON && CRC_T10DIF && !PREEMPT_RT_BASE
 	select CRYPTO_HASH
 
 config CRYPTO_CRC32_ARM64_CE
@@ -53,13 +53,13 @@ config CRYPTO_AES_ARM64
 
 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_ARM64
 
 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_ARM64_CE
 	select CRYPTO_AES_ARM64
@@ -67,7 +67,7 @@ config CRYPTO_AES_ARM64_CE_CCM
 
 config CRYPTO_AES_ARM64_CE_BLK
 	tristate "AES in ECB/CBC/CTR/XTS modes using ARMv8 Crypto Extensions"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_BLKCIPHER
 	select CRYPTO_AES_ARM64_CE
 	select CRYPTO_AES_ARM64
@@ -75,7 +75,7 @@ config CRYPTO_AES_ARM64_CE_BLK
 
 config CRYPTO_AES_ARM64_NEON_BLK
 	tristate "AES in ECB/CBC/CTR/XTS modes using NEON instructions"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_BLKCIPHER
 	select CRYPTO_AES_ARM64
 	select CRYPTO_AES
@@ -83,13 +83,13 @@ config CRYPTO_AES_ARM64_NEON_BLK
 
 config CRYPTO_CHACHA20_NEON
 	tristate "NEON accelerated ChaCha20 symmetric cipher"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_BLKCIPHER
 	select CRYPTO_CHACHA20
 
 config CRYPTO_AES_ARM64_BS
 	tristate "AES in ECB/CBC/CTR/XTS modes using bit-sliced NEON algorithm"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_BLKCIPHER
 	select CRYPTO_AES_ARM64_NEON_BLK
 	select CRYPTO_AES_ARM64
diff --git a/arch/arm64/crypto/crc32-ce-glue.c b/arch/arm64/crypto/crc32-ce-glue.c
index 34b4e3d46aab4..ae055cdad8cf9 100644
--- a/arch/arm64/crypto/crc32-ce-glue.c
+++ b/arch/arm64/crypto/crc32-ce-glue.c
@@ -208,7 +208,8 @@ static struct shash_alg crc32_pmull_algs[] = { {
 
 static int __init crc32_pmull_mod_init(void)
 {
-	if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_PMULL)) {
+	if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
+	    !IS_ENABLED(CONFIG_PREEMPT_RT_BASE) && (elf_hwcap & HWCAP_PMULL)) {
 		crc32_pmull_algs[0].update = crc32_pmull_update;
 		crc32_pmull_algs[1].update = crc32c_pmull_update;
 
-- 
2.41.0

