This patch is a CE-optimized assembly implementation for CCM mode. Benchmark on T-Head Yitian-710 2.75 GHz, the data comes from the 223 and 225 modes of tcrypt, and compared the performance before and after this patch (the driver used before this patch is ccm_base(ctr-sm4-ce,cbcmac-sm4-ce)). The abscissas are blocks of different lengths. The data is tabulated and the unit is Mb/s: Before (rfc4309(ccm_base(ctr-sm4-ce,cbcmac-sm4-ce))): ccm(sm4) | 16 64 256 512 1024 1420 4096 8192 -------------+--------------------------------------------------------------- CCM enc | 35.07 125.40 336.47 468.17 581.97 619.18 712.56 736.01 CCM dec | 34.87 124.40 335.08 466.75 581.04 618.81 712.25 735.89 CCM mb enc | 34.71 123.96 333.92 465.39 579.91 617.49 711.45 734.92 CCM mb dec | 34.42 122.80 331.02 462.81 578.28 616.42 709.88 734.19 After (rfc4309(ccm-sm4-ce)): ccm-sm4-ce | 16 64 256 512 1024 1420 4096 8192 -------------+--------------------------------------------------------------- CCM enc | 77.12 249.82 569.94 725.17 839.27 867.71 952.87 969.89 CCM dec | 75.90 247.26 566.29 722.12 836.90 865.95 951.74 968.57 CCM mb enc | 75.98 245.25 562.91 718.99 834.76 864.70 950.17 967.90 CCM mb dec | 75.06 243.78 560.58 717.13 833.68 862.70 949.35 967.11 Signed-off-by: Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx> --- arch/arm64/crypto/Kconfig | 16 ++ arch/arm64/crypto/Makefile | 3 + arch/arm64/crypto/sm4-ce-ccm-core.S | 328 ++++++++++++++++++++++++++++ arch/arm64/crypto/sm4-ce-ccm-glue.c | 303 +++++++++++++++++++++++++ 4 files changed, 650 insertions(+) create mode 100644 arch/arm64/crypto/sm4-ce-ccm-core.S create mode 100644 arch/arm64/crypto/sm4-ce-ccm-glue.c diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig index 8939f5ae9214..2611036a3e3f 100644 --- a/arch/arm64/crypto/Kconfig +++ b/arch/arm64/crypto/Kconfig @@ -281,6 +281,22 @@ config CRYPTO_AES_ARM64_CE_CCM - ARMv8 Crypto Extensions - NEON (Advanced SIMD) extensions +config CRYPTO_SM4_ARM64_CE_CCM + tristate "AEAD cipher: SM4 in CCM mode (ARMv8 Crypto Extensions)" + depends on KERNEL_MODE_NEON + select CRYPTO_ALGAPI + select CRYPTO_AEAD + select CRYPTO_SM4 + select CRYPTO_SM4_ARM64_CE_BLK + help + AEAD cipher: SM4 cipher algorithms (OSCCA GB/T 32907-2016) with + CCM (Counter with Cipher Block Chaining-Message Authentication Code) + authenticated encryption mode (NIST SP800-38C) + + Architecture: arm64 using: + - ARMv8 Crypto Extensions + - NEON (Advanced SIMD) extensions + config CRYPTO_CRCT10DIF_ARM64_CE tristate "CRCT10DIF (PMULL)" depends on KERNEL_MODE_NEON && CRC_T10DIF diff --git a/arch/arm64/crypto/Makefile b/arch/arm64/crypto/Makefile index 087f1625e775..843ea5266965 100644 --- a/arch/arm64/crypto/Makefile +++ b/arch/arm64/crypto/Makefile @@ -29,6 +29,9 @@ sm4-ce-cipher-y := sm4-ce-cipher-glue.o sm4-ce-cipher-core.o obj-$(CONFIG_CRYPTO_SM4_ARM64_CE_BLK) += sm4-ce.o sm4-ce-y := sm4-ce-glue.o sm4-ce-core.o +obj-$(CONFIG_CRYPTO_SM4_ARM64_CE_CCM) += sm4-ce-ccm.o +sm4-ce-ccm-y := sm4-ce-ccm-glue.o sm4-ce-ccm-core.o + obj-$(CONFIG_CRYPTO_SM4_ARM64_NEON_BLK) += sm4-neon.o sm4-neon-y := sm4-neon-glue.o sm4-neon-core.o diff --git a/arch/arm64/crypto/sm4-ce-ccm-core.S b/arch/arm64/crypto/sm4-ce-ccm-core.S new file mode 100644 index 000000000000..028207c4afd0 --- /dev/null +++ b/arch/arm64/crypto/sm4-ce-ccm-core.S @@ -0,0 +1,328 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * SM4-CCM AEAD Algorithm using ARMv8 Crypto Extensions + * as specified in rfc8998 + * https://datatracker.ietf.org/doc/html/rfc8998 + * + * Copyright (C) 2022 Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx> + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> +#include "sm4-ce-asm.h" + +.arch armv8-a+crypto + +.irp b, 0, 1, 8, 9, 10, 11, 12, 13, 14, 15, 16, 24, 25, 26, 27, 28, 29, 30, 31 + .set .Lv\b\().4s, \b +.endr + +.macro sm4e, vd, vn + .inst 0xcec08400 | (.L\vn << 5) | .L\vd +.endm + +/* Register macros */ + +#define RMAC v16 + +/* Helper macros. */ + +#define inc_le128(vctr) \ + mov vctr.d[1], x8; \ + mov vctr.d[0], x7; \ + adds x8, x8, #1; \ + rev64 vctr.16b, vctr.16b; \ + adc x7, x7, xzr; + + +.align 3 +SYM_FUNC_START(sm4_ce_cbcmac_update) + /* input: + * x0: round key array, CTX + * x1: mac + * x2: src + * w3: nblocks + */ + SM4_PREPARE(x0) + + ld1 {RMAC.16b}, [x1] + +.Lcbcmac_loop_4x: + cmp w3, #4 + blt .Lcbcmac_loop_1x + + sub w3, w3, #4 + + ld1 {v0.16b-v3.16b}, [x2], #64 + + SM4_CRYPT_BLK(RMAC) + eor RMAC.16b, RMAC.16b, v0.16b + SM4_CRYPT_BLK(RMAC) + eor RMAC.16b, RMAC.16b, v1.16b + SM4_CRYPT_BLK(RMAC) + eor RMAC.16b, RMAC.16b, v2.16b + SM4_CRYPT_BLK(RMAC) + eor RMAC.16b, RMAC.16b, v3.16b + + cbz w3, .Lcbcmac_end + b .Lcbcmac_loop_4x + +.Lcbcmac_loop_1x: + sub w3, w3, #1 + + ld1 {v0.16b}, [x2], #16 + + SM4_CRYPT_BLK(RMAC) + eor RMAC.16b, RMAC.16b, v0.16b + + cbnz w3, .Lcbcmac_loop_1x + +.Lcbcmac_end: + st1 {RMAC.16b}, [x1] + ret +SYM_FUNC_END(sm4_ce_cbcmac_update) + +.align 3 +SYM_FUNC_START(sm4_ce_ccm_final) + /* input: + * x0: round key array, CTX + * x1: ctr0 (big endian, 128 bit) + * x2: mac + */ + SM4_PREPARE(x0) + + ld1 {RMAC.16b}, [x2] + ld1 {v0.16b}, [x1] + + SM4_CRYPT_BLK2(RMAC, v0) + + /* en-/decrypt the mac with ctr0 */ + eor RMAC.16b, RMAC.16b, v0.16b + st1 {RMAC.16b}, [x2] + + ret +SYM_FUNC_END(sm4_ce_ccm_final) + +.align 3 +SYM_FUNC_START(sm4_ce_ccm_enc) + /* input: + * x0: round key array, CTX + * x1: dst + * x2: src + * x3: ctr (big endian, 128 bit) + * w4: nbytes + * x5: mac + */ + SM4_PREPARE(x0) + + ldp x7, x8, [x3] + rev x7, x7 + rev x8, x8 + + ld1 {RMAC.16b}, [x5] + +.Lccm_enc_loop_4x: + cmp w4, #(4 * 16) + blt .Lccm_enc_loop_1x + + sub w4, w4, #(4 * 16) + + /* construct CTRs */ + inc_le128(v8) /* +0 */ + inc_le128(v9) /* +1 */ + inc_le128(v10) /* +2 */ + inc_le128(v11) /* +3 */ + + ld1 {v0.16b-v3.16b}, [x2], #64 + + SM4_CRYPT_BLK2(v8, RMAC) + eor v8.16b, v8.16b, v0.16b + eor RMAC.16b, RMAC.16b, v0.16b + SM4_CRYPT_BLK2(v9, RMAC) + eor v9.16b, v9.16b, v1.16b + eor RMAC.16b, RMAC.16b, v1.16b + SM4_CRYPT_BLK2(v10, RMAC) + eor v10.16b, v10.16b, v2.16b + eor RMAC.16b, RMAC.16b, v2.16b + SM4_CRYPT_BLK2(v11, RMAC) + eor v11.16b, v11.16b, v3.16b + eor RMAC.16b, RMAC.16b, v3.16b + + st1 {v8.16b-v11.16b}, [x1], #64 + + cbz w4, .Lccm_enc_end + b .Lccm_enc_loop_4x + +.Lccm_enc_loop_1x: + cmp w4, #16 + blt .Lccm_enc_tail + + sub w4, w4, #16 + + /* construct CTRs */ + inc_le128(v8) + + ld1 {v0.16b}, [x2], #16 + + SM4_CRYPT_BLK2(v8, RMAC) + eor v8.16b, v8.16b, v0.16b + eor RMAC.16b, RMAC.16b, v0.16b + + st1 {v8.16b}, [x1], #16 + + cbz w4, .Lccm_enc_end + b .Lccm_enc_loop_1x + +.Lccm_enc_tail: + /* construct CTRs */ + inc_le128(v8) + + SM4_CRYPT_BLK2(RMAC, v8) + + /* store new MAC */ + st1 {RMAC.16b}, [x5] + +.Lccm_enc_tail_loop: + ldrb w0, [x2], #1 /* get 1 byte from input */ + umov w9, v8.b[0] /* get top crypted CTR byte */ + umov w6, RMAC.b[0] /* get top MAC byte */ + + eor w9, w9, w0 /* w9 = CTR ^ input */ + eor w6, w6, w0 /* w6 = MAC ^ input */ + + strb w9, [x1], #1 /* store out byte */ + strb w6, [x5], #1 /* store MAC byte */ + + subs w4, w4, #1 + beq .Lccm_enc_ret + + /* shift out one byte */ + ext RMAC.16b, RMAC.16b, RMAC.16b, #1 + ext v8.16b, v8.16b, v8.16b, #1 + + b .Lccm_enc_tail_loop + +.Lccm_enc_end: + /* store new MAC */ + st1 {RMAC.16b}, [x5] + + /* store new CTR */ + rev x7, x7 + rev x8, x8 + stp x7, x8, [x3] + +.Lccm_enc_ret: + ret +SYM_FUNC_END(sm4_ce_ccm_enc) + +.align 3 +SYM_FUNC_START(sm4_ce_ccm_dec) + /* input: + * x0: round key array, CTX + * x1: dst + * x2: src + * x3: ctr (big endian, 128 bit) + * w4: nbytes + * x5: mac + */ + SM4_PREPARE(x0) + + ldp x7, x8, [x3] + rev x7, x7 + rev x8, x8 + + ld1 {RMAC.16b}, [x5] + +.Lccm_dec_loop_4x: + cmp w4, #(4 * 16) + blt .Lccm_dec_loop_1x + + sub w4, w4, #(4 * 16) + + /* construct CTRs */ + inc_le128(v8) /* +0 */ + inc_le128(v9) /* +1 */ + inc_le128(v10) /* +2 */ + inc_le128(v11) /* +3 */ + + ld1 {v0.16b-v3.16b}, [x2], #64 + + SM4_CRYPT_BLK2(v8, RMAC) + eor v8.16b, v8.16b, v0.16b + eor RMAC.16b, RMAC.16b, v8.16b + SM4_CRYPT_BLK2(v9, RMAC) + eor v9.16b, v9.16b, v1.16b + eor RMAC.16b, RMAC.16b, v9.16b + SM4_CRYPT_BLK2(v10, RMAC) + eor v10.16b, v10.16b, v2.16b + eor RMAC.16b, RMAC.16b, v10.16b + SM4_CRYPT_BLK2(v11, RMAC) + eor v11.16b, v11.16b, v3.16b + eor RMAC.16b, RMAC.16b, v11.16b + + st1 {v8.16b-v11.16b}, [x1], #64 + + cbz w4, .Lccm_dec_end + b .Lccm_dec_loop_4x + +.Lccm_dec_loop_1x: + cmp w4, #16 + blt .Lccm_dec_tail + + sub w4, w4, #16 + + /* construct CTRs */ + inc_le128(v8) + + ld1 {v0.16b}, [x2], #16 + + SM4_CRYPT_BLK2(v8, RMAC) + eor v8.16b, v8.16b, v0.16b + eor RMAC.16b, RMAC.16b, v8.16b + + st1 {v8.16b}, [x1], #16 + + cbz w4, .Lccm_dec_end + b .Lccm_dec_loop_1x + +.Lccm_dec_tail: + /* construct CTRs */ + inc_le128(v8) + + SM4_CRYPT_BLK2(RMAC, v8) + + /* store new MAC */ + st1 {RMAC.16b}, [x5] + +.Lccm_dec_tail_loop: + ldrb w0, [x2], #1 /* get 1 byte from input */ + umov w9, v8.b[0] /* get top crypted CTR byte */ + umov w6, RMAC.b[0] /* get top MAC byte */ + + eor w9, w9, w0 /* w9 = CTR ^ input */ + eor w6, w6, w9 /* w6 = MAC ^ output */ + + strb w9, [x1], #1 /* store out byte */ + strb w6, [x5], #1 /* store MAC byte */ + + subs w4, w4, #1 + beq .Lccm_dec_ret + + /* shift out one byte */ + ext RMAC.16b, RMAC.16b, RMAC.16b, #1 + ext v8.16b, v8.16b, v8.16b, #1 + + b .Lccm_dec_tail_loop + +.Lccm_dec_end: + /* store new MAC */ + st1 {RMAC.16b}, [x5] + + /* store new CTR */ + rev x7, x7 + rev x8, x8 + stp x7, x8, [x3] + +.Lccm_dec_ret: + ret +SYM_FUNC_END(sm4_ce_ccm_dec) diff --git a/arch/arm64/crypto/sm4-ce-ccm-glue.c b/arch/arm64/crypto/sm4-ce-ccm-glue.c new file mode 100644 index 000000000000..f2cec7b52efc --- /dev/null +++ b/arch/arm64/crypto/sm4-ce-ccm-glue.c @@ -0,0 +1,303 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * SM4-CCM AEAD Algorithm using ARMv8 Crypto Extensions + * as specified in rfc8998 + * https://datatracker.ietf.org/doc/html/rfc8998 + * + * Copyright (C) 2022 Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx> + */ + +#include <linux/module.h> +#include <linux/crypto.h> +#include <linux/kernel.h> +#include <linux/cpufeature.h> +#include <asm/neon.h> +#include <crypto/scatterwalk.h> +#include <crypto/internal/aead.h> +#include <crypto/internal/skcipher.h> +#include <crypto/sm4.h> +#include "sm4-ce.h" + +asmlinkage void sm4_ce_cbcmac_update(const u32 *rkey_enc, u8 *mac, + const u8 *src, unsigned int nblocks); +asmlinkage void sm4_ce_ccm_enc(const u32 *rkey_enc, u8 *dst, const u8 *src, + u8 *iv, unsigned int nbytes, u8 *mac); +asmlinkage void sm4_ce_ccm_dec(const u32 *rkey_enc, u8 *dst, const u8 *src, + u8 *iv, unsigned int nbytes, u8 *mac); +asmlinkage void sm4_ce_ccm_final(const u32 *rkey_enc, u8 *iv, u8 *mac); + + +static int ccm_setkey(struct crypto_aead *tfm, const u8 *key, + unsigned int key_len) +{ + struct sm4_ctx *ctx = crypto_aead_ctx(tfm); + + if (key_len != SM4_KEY_SIZE) + return -EINVAL; + + kernel_neon_begin(); + sm4_ce_expand_key(key, ctx->rkey_enc, ctx->rkey_dec, + crypto_sm4_fk, crypto_sm4_ck); + kernel_neon_end(); + + return 0; +} + +static int ccm_setauthsize(struct crypto_aead *tfm, unsigned int authsize) +{ + if ((authsize & 1) || authsize < 4) + return -EINVAL; + return 0; +} + +static int ccm_format_input(u8 info[], struct aead_request *req, + unsigned int msglen) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + unsigned int l = req->iv[0] + 1; + unsigned int m; + __be32 len; + + /* verify that CCM dimension 'L': 2 <= L <= 8 */ + if (l < 2 || l > 8) + return -EINVAL; + if (l < 4 && msglen >> (8 * l)) + return -EOVERFLOW; + + memset(&req->iv[SM4_BLOCK_SIZE - l], 0, l); + + memcpy(info, req->iv, SM4_BLOCK_SIZE); + + m = crypto_aead_authsize(aead); + + /* format flags field per RFC 3610/NIST 800-38C */ + *info |= ((m - 2) / 2) << 3; + if (req->assoclen) + *info |= (1 << 6); + + /* + * format message length field, + * Linux uses a u32 type to represent msglen + */ + if (l >= 4) + l = 4; + + len = cpu_to_be32(msglen); + memcpy(&info[SM4_BLOCK_SIZE - l], (u8 *)&len + 4 - l, l); + + return 0; +} + +static void ccm_calculate_auth_mac(struct aead_request *req, u8 mac[]) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct sm4_ctx *ctx = crypto_aead_ctx(aead); + struct __packed { __be16 l; __be32 h; } aadlen; + u32 assoclen = req->assoclen; + struct scatter_walk walk; + unsigned int len; + + if (assoclen < 0xff00) { + aadlen.l = cpu_to_be16(assoclen); + len = 2; + } else { + aadlen.l = cpu_to_be16(0xfffe); + put_unaligned_be32(assoclen, &aadlen.h); + len = 6; + } + + sm4_ce_crypt_block(ctx->rkey_enc, mac, mac); + crypto_xor(mac, (const u8 *)&aadlen, len); + + scatterwalk_start(&walk, req->src); + + do { + u32 n = scatterwalk_clamp(&walk, assoclen); + u8 *p, *ptr; + + if (!n) { + scatterwalk_start(&walk, sg_next(walk.sg)); + n = scatterwalk_clamp(&walk, assoclen); + } + + p = ptr = scatterwalk_map(&walk); + assoclen -= n; + scatterwalk_advance(&walk, n); + + while (n > 0) { + unsigned int l, nblocks; + + if (len == SM4_BLOCK_SIZE) { + if (n < SM4_BLOCK_SIZE) { + sm4_ce_crypt_block(ctx->rkey_enc, + mac, mac); + + len = 0; + } else { + nblocks = n / SM4_BLOCK_SIZE; + sm4_ce_cbcmac_update(ctx->rkey_enc, + mac, ptr, nblocks); + + ptr += nblocks * SM4_BLOCK_SIZE; + n %= SM4_BLOCK_SIZE; + + continue; + } + } + + l = min(n, SM4_BLOCK_SIZE - len); + if (l) { + crypto_xor(mac + len, ptr, l); + len += l; + ptr += l; + n -= l; + } + } + + scatterwalk_unmap(p); + scatterwalk_done(&walk, 0, assoclen); + } while (assoclen); +} + +static int ccm_crypt(struct aead_request *req, struct skcipher_walk *walk, + u32 *rkey_enc, u8 mac[], + void (*sm4_ce_ccm_crypt)(const u32 *rkey_enc, u8 *dst, + const u8 *src, u8 *iv, + unsigned int nbytes, u8 *mac)) +{ + u8 __aligned(8) ctr0[SM4_BLOCK_SIZE]; + int err; + + /* preserve the initial ctr0 for the TAG */ + memcpy(ctr0, walk->iv, SM4_BLOCK_SIZE); + crypto_inc(walk->iv, SM4_BLOCK_SIZE); + + kernel_neon_begin(); + + if (req->assoclen) + ccm_calculate_auth_mac(req, mac); + + do { + unsigned int tail = walk->nbytes % SM4_BLOCK_SIZE; + const u8 *src = walk->src.virt.addr; + u8 *dst = walk->dst.virt.addr; + + if (walk->nbytes == walk->total) + tail = 0; + + if (walk->nbytes - tail) + sm4_ce_ccm_crypt(rkey_enc, dst, src, walk->iv, + walk->nbytes - tail, mac); + + if (walk->nbytes == walk->total) + sm4_ce_ccm_final(rkey_enc, ctr0, mac); + + kernel_neon_end(); + + if (walk->nbytes) { + err = skcipher_walk_done(walk, tail); + if (err) + return err; + if (walk->nbytes) + kernel_neon_begin(); + } + } while (walk->nbytes > 0); + + return 0; +} + +static int ccm_encrypt(struct aead_request *req) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + struct sm4_ctx *ctx = crypto_aead_ctx(aead); + u8 __aligned(8) mac[SM4_BLOCK_SIZE]; + struct skcipher_walk walk; + int err; + + err = ccm_format_input(mac, req, req->cryptlen); + if (err) + return err; + + err = skcipher_walk_aead_encrypt(&walk, req, false); + if (err) + return err; + + err = ccm_crypt(req, &walk, ctx->rkey_enc, mac, sm4_ce_ccm_enc); + if (err) + return err; + + /* copy authtag to end of dst */ + scatterwalk_map_and_copy(mac, req->dst, req->assoclen + req->cryptlen, + crypto_aead_authsize(aead), 1); + + return 0; +} + +static int ccm_decrypt(struct aead_request *req) +{ + struct crypto_aead *aead = crypto_aead_reqtfm(req); + unsigned int authsize = crypto_aead_authsize(aead); + struct sm4_ctx *ctx = crypto_aead_ctx(aead); + u8 __aligned(8) mac[SM4_BLOCK_SIZE]; + u8 authtag[SM4_BLOCK_SIZE]; + struct skcipher_walk walk; + int err; + + err = ccm_format_input(mac, req, req->cryptlen - authsize); + if (err) + return err; + + err = skcipher_walk_aead_decrypt(&walk, req, false); + if (err) + return err; + + err = ccm_crypt(req, &walk, ctx->rkey_enc, mac, sm4_ce_ccm_dec); + if (err) + return err; + + /* compare calculated auth tag with the stored one */ + scatterwalk_map_and_copy(authtag, req->src, + req->assoclen + req->cryptlen - authsize, + authsize, 0); + + if (crypto_memneq(authtag, mac, authsize)) + return -EBADMSG; + + return 0; +} + +static struct aead_alg sm4_ccm_alg = { + .base = { + .cra_name = "ccm(sm4)", + .cra_driver_name = "ccm-sm4-ce", + .cra_priority = 400, + .cra_blocksize = 1, + .cra_ctxsize = sizeof(struct sm4_ctx), + .cra_module = THIS_MODULE, + }, + .ivsize = SM4_BLOCK_SIZE, + .chunksize = SM4_BLOCK_SIZE, + .maxauthsize = SM4_BLOCK_SIZE, + .setkey = ccm_setkey, + .setauthsize = ccm_setauthsize, + .encrypt = ccm_encrypt, + .decrypt = ccm_decrypt, +}; + +static int __init sm4_ce_ccm_init(void) +{ + return crypto_register_aead(&sm4_ccm_alg); +} + +static void __exit sm4_ce_ccm_exit(void) +{ + crypto_unregister_aead(&sm4_ccm_alg); +} + +module_cpu_feature_match(SM4, sm4_ce_ccm_init); +module_exit(sm4_ce_ccm_exit); + +MODULE_DESCRIPTION("Synchronous SM4 in CCM mode using ARMv8 Crypto Extensions"); +MODULE_ALIAS_CRYPTO("ccm(sm4)"); +MODULE_AUTHOR("Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx>"); +MODULE_LICENSE("GPL v2"); -- 2.24.3 (Apple Git-128)
