From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- crypto/mldsa.c | 201 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 201 insertions(+) create mode 100644 crypto/mldsa.c (limited to 'crypto/mldsa.c') diff --git a/crypto/mldsa.c b/crypto/mldsa.c new file mode 100644 index 000000000..d8de082cc --- /dev/null +++ b/crypto/mldsa.c @@ -0,0 +1,201 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * crypto_sig wrapper around ML-DSA library. + */ +#include +#include +#include +#include + +struct crypto_mldsa_ctx { + u8 pk[MAX(MAX(MLDSA44_PUBLIC_KEY_SIZE, + MLDSA65_PUBLIC_KEY_SIZE), + MLDSA87_PUBLIC_KEY_SIZE)]; + unsigned int pk_len; + enum mldsa_alg strength; + bool key_set; +}; + +static int crypto_mldsa_sign(struct crypto_sig *tfm, + const void *msg, unsigned int msg_len, + void *sig, unsigned int sig_len) +{ + return -EOPNOTSUPP; +} + +static int crypto_mldsa_verify(struct crypto_sig *tfm, + const void *sig, unsigned int sig_len, + const void *msg, unsigned int msg_len) +{ + const struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm); + + if (unlikely(!ctx->key_set)) + return -EINVAL; + + return mldsa_verify(ctx->strength, sig, sig_len, msg, msg_len, + ctx->pk, ctx->pk_len); +} + +static unsigned int crypto_mldsa_key_size(struct crypto_sig *tfm) +{ + struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm); + + switch (ctx->strength) { + case MLDSA44: + return MLDSA44_PUBLIC_KEY_SIZE; + case MLDSA65: + return MLDSA65_PUBLIC_KEY_SIZE; + case MLDSA87: + return MLDSA87_PUBLIC_KEY_SIZE; + default: + WARN_ON_ONCE(1); + return 0; + } +} + +static int crypto_mldsa_set_pub_key(struct crypto_sig *tfm, + const void *key, unsigned int keylen) +{ + struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm); + unsigned int expected_len = crypto_mldsa_key_size(tfm); + + if (keylen != expected_len) + return -EINVAL; + + ctx->pk_len = keylen; + memcpy(ctx->pk, key, keylen); + ctx->key_set = true; + return 0; +} + +static int crypto_mldsa_set_priv_key(struct crypto_sig *tfm, + const void *key, unsigned int keylen) +{ + return -EOPNOTSUPP; +} + +static unsigned int crypto_mldsa_max_size(struct crypto_sig *tfm) +{ + struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm); + + switch (ctx->strength) { + case MLDSA44: + return MLDSA44_SIGNATURE_SIZE; + case MLDSA65: + return MLDSA65_SIGNATURE_SIZE; + case MLDSA87: + return MLDSA87_SIGNATURE_SIZE; + default: + WARN_ON_ONCE(1); + return 0; + } +} + +static int crypto_mldsa44_alg_init(struct crypto_sig *tfm) +{ + struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm); + + ctx->strength = MLDSA44; + ctx->key_set = false; + return 0; +} + +static int crypto_mldsa65_alg_init(struct crypto_sig *tfm) +{ + struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm); + + ctx->strength = MLDSA65; + ctx->key_set = false; + return 0; +} + +static int crypto_mldsa87_alg_init(struct crypto_sig *tfm) +{ + struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm); + + ctx->strength = MLDSA87; + ctx->key_set = false; + return 0; +} + +static void crypto_mldsa_alg_exit(struct crypto_sig *tfm) +{ +} + +static struct sig_alg crypto_mldsa_algs[] = { + { + .sign = crypto_mldsa_sign, + .verify = crypto_mldsa_verify, + .set_pub_key = crypto_mldsa_set_pub_key, + .set_priv_key = crypto_mldsa_set_priv_key, + .key_size = crypto_mldsa_key_size, + .max_size = crypto_mldsa_max_size, + .init = crypto_mldsa44_alg_init, + .exit = crypto_mldsa_alg_exit, + .base.cra_name = "mldsa44", + .base.cra_driver_name = "mldsa44-lib", + .base.cra_ctxsize = sizeof(struct crypto_mldsa_ctx), + .base.cra_module = THIS_MODULE, + .base.cra_priority = 5000, + }, { + .sign = crypto_mldsa_sign, + .verify = crypto_mldsa_verify, + .set_pub_key = crypto_mldsa_set_pub_key, + .set_priv_key = crypto_mldsa_set_priv_key, + .key_size = crypto_mldsa_key_size, + .max_size = crypto_mldsa_max_size, + .init = crypto_mldsa65_alg_init, + .exit = crypto_mldsa_alg_exit, + .base.cra_name = "mldsa65", + .base.cra_driver_name = "mldsa65-lib", + .base.cra_ctxsize = sizeof(struct crypto_mldsa_ctx), + .base.cra_module = THIS_MODULE, + .base.cra_priority = 5000, + }, { + .sign = crypto_mldsa_sign, + .verify = crypto_mldsa_verify, + .set_pub_key = crypto_mldsa_set_pub_key, + .set_priv_key = crypto_mldsa_set_priv_key, + .key_size = crypto_mldsa_key_size, + .max_size = crypto_mldsa_max_size, + .init = crypto_mldsa87_alg_init, + .exit = crypto_mldsa_alg_exit, + .base.cra_name = "mldsa87", + .base.cra_driver_name = "mldsa87-lib", + .base.cra_ctxsize = sizeof(struct crypto_mldsa_ctx), + .base.cra_module = THIS_MODULE, + .base.cra_priority = 5000, + }, +}; + +static int __init mldsa_init(void) +{ + int ret, i; + + for (i = 0; i < ARRAY_SIZE(crypto_mldsa_algs); i++) { + ret = crypto_register_sig(&crypto_mldsa_algs[i]); + if (ret < 0) + goto error; + } + return 0; + +error: + pr_err("Failed to register (%d)\n", ret); + for (i--; i >= 0; i--) + crypto_unregister_sig(&crypto_mldsa_algs[i]); + return ret; +} +module_init(mldsa_init); + +static void mldsa_exit(void) +{ + for (int i = 0; i < ARRAY_SIZE(crypto_mldsa_algs); i++) + crypto_unregister_sig(&crypto_mldsa_algs[i]); +} +module_exit(mldsa_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Crypto API support for ML-DSA signature verification"); +MODULE_ALIAS_CRYPTO("mldsa44"); +MODULE_ALIAS_CRYPTO("mldsa65"); +MODULE_ALIAS_CRYPTO("mldsa87"); -- cgit v1.3.1