From 5918302b4766f0f5e17df8105c65cd5c2597b72a Mon Sep 17 00:00:00 2001
Message-Id: <5918302b4766f0f5e17df8105c65cd5c2597b72a.1594742966.git.zanussi@kernel.org>
In-Reply-To: <832f7d97d6b989a5b4860dd2dbec58ad6ad5ab81.1594742966.git.zanussi@kernel.org>
References: <832f7d97d6b989a5b4860dd2dbec58ad6ad5ab81.1594742966.git.zanussi@kernel.org>
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri, 1 Dec 2017 10:42:03 +0100
Subject: [PATCH 047/329] arm*: disable NEON in kernel mode
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.132-rt59.tar.xz

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         | 28 ++++++++++++++--------------
 arch/arm64/crypto/crc32-ce-glue.c |  3 ++-
 3 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 91ba9fe945ff..bd9d180db5c7 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -2163,7 +2163,7 @@ 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 d51944ff9f91..0d4b3f0cfba6 100644
--- a/arch/arm64/crypto/Kconfig
+++ b/arch/arm64/crypto/Kconfig
@@ -19,43 +19,43 @@ 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_SHA512_ARM64_CE
 	tristate "SHA-384/SHA-512 digest algorithm (ARMv8 Crypto Extensions)"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_HASH
 	select CRYPTO_SHA512_ARM64
 
 config CRYPTO_SHA3_ARM64
 	tristate "SHA3 digest algorithm (ARMv8.2 Crypto Extensions)"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_HASH
 	select CRYPTO_SHA3
 
 config CRYPTO_SM3_ARM64_CE
 	tristate "SM3 digest algorithm (ARMv8.2 Crypto Extensions)"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_HASH
 	select CRYPTO_SM3
 
 config CRYPTO_SM4_ARM64_CE
 	tristate "SM4 symmetric cipher (ARMv8.2 Crypto Extensions)"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_ALGAPI
 	select CRYPTO_SM4
 
 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
@@ -63,7 +63,7 @@ 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
@@ -77,13 +77,13 @@ 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
@@ -91,7 +91,7 @@ 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
@@ -99,7 +99,7 @@ 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
@@ -107,13 +107,13 @@ 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 34b4e3d46aab..ae055cdad8cf 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;
 
-- 
2.17.1

