4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ard Biesheuvel ard.biesheuvel@linaro.org
commit 019cd46984d04703a39924178f503a98436ac0d7 upstream.
Most crypto drivers involving kernel mode NEON take care to put the code that actually touches the NEON register file in a separate compilation unit, to prevent the compiler from reordering code that preserves or restores the NEON context with code that may corrupt it. This is necessary because we currently have no way to express the restrictions imposed upon use of the NEON in kernel mode in a way that the compiler understands.
However, in the case of aes-ce-cipher, it did not seem unreasonable to deviate from this rule, given how it does not seem possible for the compiler to reorder cross object function calls with asm blocks whose in- and output constraints reflect that it reads from and writes to memory.
Now that LTO is being proposed for the arm64 kernel, it is time to revisit this. The link time optimization may replace the function calls to kernel_neon_begin() and kernel_neon_end() with instantiations of the IR that make up its implementation, allowing further reordering with the asm block.
So let's clean this up, and move the asm() blocks into a separate .S file.
Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org Reviewed-By: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Cc: Matthias Kaehlcke mka@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/arm64/crypto/Makefile | 2 arch/arm64/crypto/aes-ce-cipher.c | 281 -------------------------------------- arch/arm64/crypto/aes-ce-core.S | 87 +++++++++++ arch/arm64/crypto/aes-ce-glue.c | 190 +++++++++++++++++++++++++ 4 files changed, 278 insertions(+), 282 deletions(-)
--- a/arch/arm64/crypto/Makefile +++ b/arch/arm64/crypto/Makefile @@ -24,7 +24,7 @@ obj-$(CONFIG_CRYPTO_CRC32_ARM64_CE) += c crc32-ce-y:= crc32-ce-core.o crc32-ce-glue.o
obj-$(CONFIG_CRYPTO_AES_ARM64_CE) += aes-ce-cipher.o -CFLAGS_aes-ce-cipher.o += -march=armv8-a+crypto +aes-ce-cipher-y := aes-ce-core.o aes-ce-glue.o
obj-$(CONFIG_CRYPTO_AES_ARM64_CE_CCM) += aes-ce-ccm.o aes-ce-ccm-y := aes-ce-ccm-glue.o aes-ce-ccm-core.o --- a/arch/arm64/crypto/aes-ce-cipher.c +++ /dev/null @@ -1,281 +0,0 @@ -/* - * aes-ce-cipher.c - core AES cipher using ARMv8 Crypto Extensions - * - * Copyright (C) 2013 - 2017 Linaro Ltd ard.biesheuvel@linaro.org - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ - -#include <asm/neon.h> -#include <asm/simd.h> -#include <asm/unaligned.h> -#include <crypto/aes.h> -#include <linux/cpufeature.h> -#include <linux/crypto.h> -#include <linux/module.h> - -#include "aes-ce-setkey.h" - -MODULE_DESCRIPTION("Synchronous AES cipher using ARMv8 Crypto Extensions"); -MODULE_AUTHOR("Ard Biesheuvel ard.biesheuvel@linaro.org"); -MODULE_LICENSE("GPL v2"); - -asmlinkage void __aes_arm64_encrypt(u32 *rk, u8 *out, const u8 *in, int rounds); -asmlinkage void __aes_arm64_decrypt(u32 *rk, u8 *out, const u8 *in, int rounds); - -struct aes_block { - u8 b[AES_BLOCK_SIZE]; -}; - -static int num_rounds(struct crypto_aes_ctx *ctx) -{ - /* - * # of rounds specified by AES: - * 128 bit key 10 rounds - * 192 bit key 12 rounds - * 256 bit key 14 rounds - * => n byte key => 6 + (n/4) rounds - */ - return 6 + ctx->key_length / 4; -} - -static void aes_cipher_encrypt(struct crypto_tfm *tfm, u8 dst[], u8 const src[]) -{ - struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm); - struct aes_block *out = (struct aes_block *)dst; - struct aes_block const *in = (struct aes_block *)src; - void *dummy0; - int dummy1; - - if (!may_use_simd()) { - __aes_arm64_encrypt(ctx->key_enc, dst, src, num_rounds(ctx)); - return; - } - - kernel_neon_begin(); - - __asm__(" ld1 {v0.16b}, %[in] ;" - " ld1 {v1.4s}, [%[key]], #16 ;" - " cmp %w[rounds], #10 ;" - " bmi 0f ;" - " bne 3f ;" - " mov v3.16b, v1.16b ;" - " b 2f ;" - "0: mov v2.16b, v1.16b ;" - " ld1 {v3.4s}, [%[key]], #16 ;" - "1: aese v0.16b, v2.16b ;" - " aesmc v0.16b, v0.16b ;" - "2: ld1 {v1.4s}, [%[key]], #16 ;" - " aese v0.16b, v3.16b ;" - " aesmc v0.16b, v0.16b ;" - "3: ld1 {v2.4s}, [%[key]], #16 ;" - " subs %w[rounds], %w[rounds], #3 ;" - " aese v0.16b, v1.16b ;" - " aesmc v0.16b, v0.16b ;" - " ld1 {v3.4s}, [%[key]], #16 ;" - " bpl 1b ;" - " aese v0.16b, v2.16b ;" - " eor v0.16b, v0.16b, v3.16b ;" - " st1 {v0.16b}, %[out] ;" - - : [out] "=Q"(*out), - [key] "=r"(dummy0), - [rounds] "=r"(dummy1) - : [in] "Q"(*in), - "1"(ctx->key_enc), - "2"(num_rounds(ctx) - 2) - : "cc"); - - kernel_neon_end(); -} - -static void aes_cipher_decrypt(struct crypto_tfm *tfm, u8 dst[], u8 const src[]) -{ - struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm); - struct aes_block *out = (struct aes_block *)dst; - struct aes_block const *in = (struct aes_block *)src; - void *dummy0; - int dummy1; - - if (!may_use_simd()) { - __aes_arm64_decrypt(ctx->key_dec, dst, src, num_rounds(ctx)); - return; - } - - kernel_neon_begin(); - - __asm__(" ld1 {v0.16b}, %[in] ;" - " ld1 {v1.4s}, [%[key]], #16 ;" - " cmp %w[rounds], #10 ;" - " bmi 0f ;" - " bne 3f ;" - " mov v3.16b, v1.16b ;" - " b 2f ;" - "0: mov v2.16b, v1.16b ;" - " ld1 {v3.4s}, [%[key]], #16 ;" - "1: aesd v0.16b, v2.16b ;" - " aesimc v0.16b, v0.16b ;" - "2: ld1 {v1.4s}, [%[key]], #16 ;" - " aesd v0.16b, v3.16b ;" - " aesimc v0.16b, v0.16b ;" - "3: ld1 {v2.4s}, [%[key]], #16 ;" - " subs %w[rounds], %w[rounds], #3 ;" - " aesd v0.16b, v1.16b ;" - " aesimc v0.16b, v0.16b ;" - " ld1 {v3.4s}, [%[key]], #16 ;" - " bpl 1b ;" - " aesd v0.16b, v2.16b ;" - " eor v0.16b, v0.16b, v3.16b ;" - " st1 {v0.16b}, %[out] ;" - - : [out] "=Q"(*out), - [key] "=r"(dummy0), - [rounds] "=r"(dummy1) - : [in] "Q"(*in), - "1"(ctx->key_dec), - "2"(num_rounds(ctx) - 2) - : "cc"); - - kernel_neon_end(); -} - -/* - * aes_sub() - use the aese instruction to perform the AES sbox substitution - * on each byte in 'input' - */ -static u32 aes_sub(u32 input) -{ - u32 ret; - - __asm__("dup v1.4s, %w[in] ;" - "movi v0.16b, #0 ;" - "aese v0.16b, v1.16b ;" - "umov %w[out], v0.4s[0] ;" - - : [out] "=r"(ret) - : [in] "r"(input) - : "v0","v1"); - - return ret; -} - -int ce_aes_expandkey(struct crypto_aes_ctx *ctx, const u8 *in_key, - unsigned int key_len) -{ - /* - * The AES key schedule round constants - */ - static u8 const rcon[] = { - 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, - }; - - u32 kwords = key_len / sizeof(u32); - struct aes_block *key_enc, *key_dec; - int i, j; - - if (key_len != AES_KEYSIZE_128 && - key_len != AES_KEYSIZE_192 && - key_len != AES_KEYSIZE_256) - return -EINVAL; - - ctx->key_length = key_len; - for (i = 0; i < kwords; i++) - ctx->key_enc[i] = get_unaligned_le32(in_key + i * sizeof(u32)); - - kernel_neon_begin(); - for (i = 0; i < sizeof(rcon); i++) { - u32 *rki = ctx->key_enc + (i * kwords); - u32 *rko = rki + kwords; - - rko[0] = ror32(aes_sub(rki[kwords - 1]), 8) ^ rcon[i] ^ rki[0]; - rko[1] = rko[0] ^ rki[1]; - rko[2] = rko[1] ^ rki[2]; - rko[3] = rko[2] ^ rki[3]; - - if (key_len == AES_KEYSIZE_192) { - if (i >= 7) - break; - rko[4] = rko[3] ^ rki[4]; - rko[5] = rko[4] ^ rki[5]; - } else if (key_len == AES_KEYSIZE_256) { - if (i >= 6) - break; - rko[4] = aes_sub(rko[3]) ^ rki[4]; - rko[5] = rko[4] ^ rki[5]; - rko[6] = rko[5] ^ rki[6]; - rko[7] = rko[6] ^ rki[7]; - } - } - - /* - * Generate the decryption keys for the Equivalent Inverse Cipher. - * This involves reversing the order of the round keys, and applying - * the Inverse Mix Columns transformation on all but the first and - * the last one. - */ - key_enc = (struct aes_block *)ctx->key_enc; - key_dec = (struct aes_block *)ctx->key_dec; - j = num_rounds(ctx); - - key_dec[0] = key_enc[j]; - for (i = 1, j--; j > 0; i++, j--) - __asm__("ld1 {v0.4s}, %[in] ;" - "aesimc v1.16b, v0.16b ;" - "st1 {v1.4s}, %[out] ;" - - : [out] "=Q"(key_dec[i]) - : [in] "Q"(key_enc[j]) - : "v0","v1"); - key_dec[i] = key_enc[0]; - - kernel_neon_end(); - return 0; -} -EXPORT_SYMBOL(ce_aes_expandkey); - -int ce_aes_setkey(struct crypto_tfm *tfm, const u8 *in_key, - unsigned int key_len) -{ - struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm); - int ret; - - ret = ce_aes_expandkey(ctx, in_key, key_len); - if (!ret) - return 0; - - tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; - return -EINVAL; -} -EXPORT_SYMBOL(ce_aes_setkey); - -static struct crypto_alg aes_alg = { - .cra_name = "aes", - .cra_driver_name = "aes-ce", - .cra_priority = 250, - .cra_flags = CRYPTO_ALG_TYPE_CIPHER, - .cra_blocksize = AES_BLOCK_SIZE, - .cra_ctxsize = sizeof(struct crypto_aes_ctx), - .cra_module = THIS_MODULE, - .cra_cipher = { - .cia_min_keysize = AES_MIN_KEY_SIZE, - .cia_max_keysize = AES_MAX_KEY_SIZE, - .cia_setkey = ce_aes_setkey, - .cia_encrypt = aes_cipher_encrypt, - .cia_decrypt = aes_cipher_decrypt - } -}; - -static int __init aes_mod_init(void) -{ - return crypto_register_alg(&aes_alg); -} - -static void __exit aes_mod_exit(void) -{ - crypto_unregister_alg(&aes_alg); -} - -module_cpu_feature_match(AES, aes_mod_init); -module_exit(aes_mod_exit); --- /dev/null +++ b/arch/arm64/crypto/aes-ce-core.S @@ -0,0 +1,87 @@ +/* + * Copyright (C) 2013 - 2017 Linaro Ltd ard.biesheuvel@linaro.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> + + .arch armv8-a+crypto + +ENTRY(__aes_ce_encrypt) + sub w3, w3, #2 + ld1 {v0.16b}, [x2] + ld1 {v1.4s}, [x0], #16 + cmp w3, #10 + bmi 0f + bne 3f + mov v3.16b, v1.16b + b 2f +0: mov v2.16b, v1.16b + ld1 {v3.4s}, [x0], #16 +1: aese v0.16b, v2.16b + aesmc v0.16b, v0.16b +2: ld1 {v1.4s}, [x0], #16 + aese v0.16b, v3.16b + aesmc v0.16b, v0.16b +3: ld1 {v2.4s}, [x0], #16 + subs w3, w3, #3 + aese v0.16b, v1.16b + aesmc v0.16b, v0.16b + ld1 {v3.4s}, [x0], #16 + bpl 1b + aese v0.16b, v2.16b + eor v0.16b, v0.16b, v3.16b + st1 {v0.16b}, [x1] + ret +ENDPROC(__aes_ce_encrypt) + +ENTRY(__aes_ce_decrypt) + sub w3, w3, #2 + ld1 {v0.16b}, [x2] + ld1 {v1.4s}, [x0], #16 + cmp w3, #10 + bmi 0f + bne 3f + mov v3.16b, v1.16b + b 2f +0: mov v2.16b, v1.16b + ld1 {v3.4s}, [x0], #16 +1: aesd v0.16b, v2.16b + aesimc v0.16b, v0.16b +2: ld1 {v1.4s}, [x0], #16 + aesd v0.16b, v3.16b + aesimc v0.16b, v0.16b +3: ld1 {v2.4s}, [x0], #16 + subs w3, w3, #3 + aesd v0.16b, v1.16b + aesimc v0.16b, v0.16b + ld1 {v3.4s}, [x0], #16 + bpl 1b + aesd v0.16b, v2.16b + eor v0.16b, v0.16b, v3.16b + st1 {v0.16b}, [x1] + ret +ENDPROC(__aes_ce_decrypt) + +/* + * __aes_ce_sub() - use the aese instruction to perform the AES sbox + * substitution on each byte in 'input' + */ +ENTRY(__aes_ce_sub) + dup v1.4s, w0 + movi v0.16b, #0 + aese v0.16b, v1.16b + umov w0, v0.s[0] + ret +ENDPROC(__aes_ce_sub) + +ENTRY(__aes_ce_invert) + ld1 {v0.4s}, [x1] + aesimc v1.16b, v0.16b + st1 {v1.4s}, [x0] + ret +ENDPROC(__aes_ce_invert) --- /dev/null +++ b/arch/arm64/crypto/aes-ce-glue.c @@ -0,0 +1,190 @@ +/* + * aes-ce-cipher.c - core AES cipher using ARMv8 Crypto Extensions + * + * Copyright (C) 2013 - 2017 Linaro Ltd ard.biesheuvel@linaro.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <asm/neon.h> +#include <asm/simd.h> +#include <asm/unaligned.h> +#include <crypto/aes.h> +#include <linux/cpufeature.h> +#include <linux/crypto.h> +#include <linux/module.h> + +#include "aes-ce-setkey.h" + +MODULE_DESCRIPTION("Synchronous AES cipher using ARMv8 Crypto Extensions"); +MODULE_AUTHOR("Ard Biesheuvel ard.biesheuvel@linaro.org"); +MODULE_LICENSE("GPL v2"); + +asmlinkage void __aes_arm64_encrypt(u32 *rk, u8 *out, const u8 *in, int rounds); +asmlinkage void __aes_arm64_decrypt(u32 *rk, u8 *out, const u8 *in, int rounds); + +struct aes_block { + u8 b[AES_BLOCK_SIZE]; +}; + +asmlinkage void __aes_ce_encrypt(u32 *rk, u8 *out, const u8 *in, int rounds); +asmlinkage void __aes_ce_decrypt(u32 *rk, u8 *out, const u8 *in, int rounds); + +asmlinkage u32 __aes_ce_sub(u32 l); +asmlinkage void __aes_ce_invert(struct aes_block *out, + const struct aes_block *in); + +static int num_rounds(struct crypto_aes_ctx *ctx) +{ + /* + * # of rounds specified by AES: + * 128 bit key 10 rounds + * 192 bit key 12 rounds + * 256 bit key 14 rounds + * => n byte key => 6 + (n/4) rounds + */ + return 6 + ctx->key_length / 4; +} + +static void aes_cipher_encrypt(struct crypto_tfm *tfm, u8 dst[], u8 const src[]) +{ + struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm); + + if (!may_use_simd()) { + __aes_arm64_encrypt(ctx->key_enc, dst, src, num_rounds(ctx)); + return; + } + + kernel_neon_begin(); + __aes_ce_encrypt(ctx->key_enc, dst, src, num_rounds(ctx)); + kernel_neon_end(); +} + +static void aes_cipher_decrypt(struct crypto_tfm *tfm, u8 dst[], u8 const src[]) +{ + struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm); + + if (!may_use_simd()) { + __aes_arm64_decrypt(ctx->key_dec, dst, src, num_rounds(ctx)); + return; + } + + kernel_neon_begin(); + __aes_ce_decrypt(ctx->key_dec, dst, src, num_rounds(ctx)); + kernel_neon_end(); +} + +int ce_aes_expandkey(struct crypto_aes_ctx *ctx, const u8 *in_key, + unsigned int key_len) +{ + /* + * The AES key schedule round constants + */ + static u8 const rcon[] = { + 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, + }; + + u32 kwords = key_len / sizeof(u32); + struct aes_block *key_enc, *key_dec; + int i, j; + + if (key_len != AES_KEYSIZE_128 && + key_len != AES_KEYSIZE_192 && + key_len != AES_KEYSIZE_256) + return -EINVAL; + + ctx->key_length = key_len; + for (i = 0; i < kwords; i++) + ctx->key_enc[i] = get_unaligned_le32(in_key + i * sizeof(u32)); + + kernel_neon_begin(); + for (i = 0; i < sizeof(rcon); i++) { + u32 *rki = ctx->key_enc + (i * kwords); + u32 *rko = rki + kwords; + + rko[0] = ror32(__aes_ce_sub(rki[kwords - 1]), 8) ^ rcon[i] ^ rki[0]; + rko[1] = rko[0] ^ rki[1]; + rko[2] = rko[1] ^ rki[2]; + rko[3] = rko[2] ^ rki[3]; + + if (key_len == AES_KEYSIZE_192) { + if (i >= 7) + break; + rko[4] = rko[3] ^ rki[4]; + rko[5] = rko[4] ^ rki[5]; + } else if (key_len == AES_KEYSIZE_256) { + if (i >= 6) + break; + rko[4] = __aes_ce_sub(rko[3]) ^ rki[4]; + rko[5] = rko[4] ^ rki[5]; + rko[6] = rko[5] ^ rki[6]; + rko[7] = rko[6] ^ rki[7]; + } + } + + /* + * Generate the decryption keys for the Equivalent Inverse Cipher. + * This involves reversing the order of the round keys, and applying + * the Inverse Mix Columns transformation on all but the first and + * the last one. + */ + key_enc = (struct aes_block *)ctx->key_enc; + key_dec = (struct aes_block *)ctx->key_dec; + j = num_rounds(ctx); + + key_dec[0] = key_enc[j]; + for (i = 1, j--; j > 0; i++, j--) + __aes_ce_invert(key_dec + i, key_enc + j); + key_dec[i] = key_enc[0]; + + kernel_neon_end(); + return 0; +} +EXPORT_SYMBOL(ce_aes_expandkey); + +int ce_aes_setkey(struct crypto_tfm *tfm, const u8 *in_key, + unsigned int key_len) +{ + struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm); + int ret; + + ret = ce_aes_expandkey(ctx, in_key, key_len); + if (!ret) + return 0; + + tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; + return -EINVAL; +} +EXPORT_SYMBOL(ce_aes_setkey); + +static struct crypto_alg aes_alg = { + .cra_name = "aes", + .cra_driver_name = "aes-ce", + .cra_priority = 250, + .cra_flags = CRYPTO_ALG_TYPE_CIPHER, + .cra_blocksize = AES_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct crypto_aes_ctx), + .cra_module = THIS_MODULE, + .cra_cipher = { + .cia_min_keysize = AES_MIN_KEY_SIZE, + .cia_max_keysize = AES_MAX_KEY_SIZE, + .cia_setkey = ce_aes_setkey, + .cia_encrypt = aes_cipher_encrypt, + .cia_decrypt = aes_cipher_decrypt + } +}; + +static int __init aes_mod_init(void) +{ + return crypto_register_alg(&aes_alg); +} + +static void __exit aes_mod_exit(void) +{ + crypto_unregister_alg(&aes_alg); +} + +module_cpu_feature_match(AES, aes_mod_init); +module_exit(aes_mod_exit);