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/akcipher.c | 252 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 252 insertions(+) create mode 100644 crypto/akcipher.c (limited to 'crypto/akcipher.c') diff --git a/crypto/akcipher.c b/crypto/akcipher.c new file mode 100644 index 000000000..630bb1973 --- /dev/null +++ b/crypto/akcipher.c @@ -0,0 +1,252 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Public Key Encryption + * + * Copyright (c) 2015, Intel Corporation + * Authors: Tadeusz Struk + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "internal.h" + +#define CRYPTO_ALG_TYPE_AHASH_MASK 0x0000000e + +struct crypto_akcipher_sync_data { + struct crypto_akcipher *tfm; + const void *src; + void *dst; + unsigned int slen; + unsigned int dlen; + + struct akcipher_request *req; + struct crypto_wait cwait; + struct scatterlist sg; + u8 *buf; +}; + +static int __maybe_unused crypto_akcipher_report( + struct sk_buff *skb, struct crypto_alg *alg) +{ + struct crypto_report_akcipher rakcipher = { + .type = "akcipher", + }; + + return nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER, + sizeof(rakcipher), &rakcipher); +} + +static void __maybe_unused crypto_akcipher_show(struct seq_file *m, + struct crypto_alg *alg) +{ + seq_puts(m, "type : akcipher\n"); +} + +static void crypto_akcipher_exit_tfm(struct crypto_tfm *tfm) +{ + struct crypto_akcipher *akcipher = __crypto_akcipher_tfm(tfm); + struct akcipher_alg *alg = crypto_akcipher_alg(akcipher); + + alg->exit(akcipher); +} + +static int crypto_akcipher_init_tfm(struct crypto_tfm *tfm) +{ + struct crypto_akcipher *akcipher = __crypto_akcipher_tfm(tfm); + struct akcipher_alg *alg = crypto_akcipher_alg(akcipher); + + if (alg->exit) + akcipher->base.exit = crypto_akcipher_exit_tfm; + + if (alg->init) + return alg->init(akcipher); + + return 0; +} + +static void crypto_akcipher_free_instance(struct crypto_instance *inst) +{ + struct akcipher_instance *akcipher = akcipher_instance(inst); + + akcipher->free(akcipher); +} + +static const struct crypto_type crypto_akcipher_type = { + .extsize = crypto_alg_extsize, + .init_tfm = crypto_akcipher_init_tfm, + .free = crypto_akcipher_free_instance, +#ifdef CONFIG_PROC_FS + .show = crypto_akcipher_show, +#endif +#if IS_ENABLED(CONFIG_CRYPTO_USER) + .report = crypto_akcipher_report, +#endif + .maskclear = ~CRYPTO_ALG_TYPE_MASK, + .maskset = CRYPTO_ALG_TYPE_AHASH_MASK, + .type = CRYPTO_ALG_TYPE_AKCIPHER, + .tfmsize = offsetof(struct crypto_akcipher, base), + .algsize = offsetof(struct akcipher_alg, base), +}; + +int crypto_grab_akcipher(struct crypto_akcipher_spawn *spawn, + struct crypto_instance *inst, + const char *name, u32 type, u32 mask) +{ + spawn->base.frontend = &crypto_akcipher_type; + return crypto_grab_spawn(&spawn->base, inst, name, type, mask); +} +EXPORT_SYMBOL_GPL(crypto_grab_akcipher); + +struct crypto_akcipher *crypto_alloc_akcipher(const char *alg_name, u32 type, + u32 mask) +{ + return crypto_alloc_tfm(alg_name, &crypto_akcipher_type, type, mask); +} +EXPORT_SYMBOL_GPL(crypto_alloc_akcipher); + +static void akcipher_prepare_alg(struct akcipher_alg *alg) +{ + struct crypto_alg *base = &alg->base; + + base->cra_type = &crypto_akcipher_type; + base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; + base->cra_flags |= CRYPTO_ALG_TYPE_AKCIPHER; +} + +static int akcipher_default_op(struct akcipher_request *req) +{ + return -ENOSYS; +} + +static int akcipher_default_set_key(struct crypto_akcipher *tfm, + const void *key, unsigned int keylen) +{ + return -ENOSYS; +} + +int crypto_register_akcipher(struct akcipher_alg *alg) +{ + struct crypto_alg *base = &alg->base; + + if (!alg->encrypt) + alg->encrypt = akcipher_default_op; + if (!alg->decrypt) + alg->decrypt = akcipher_default_op; + if (!alg->set_priv_key) + alg->set_priv_key = akcipher_default_set_key; + + akcipher_prepare_alg(alg); + return crypto_register_alg(base); +} +EXPORT_SYMBOL_GPL(crypto_register_akcipher); + +void crypto_unregister_akcipher(struct akcipher_alg *alg) +{ + crypto_unregister_alg(&alg->base); +} +EXPORT_SYMBOL_GPL(crypto_unregister_akcipher); + +int akcipher_register_instance(struct crypto_template *tmpl, + struct akcipher_instance *inst) +{ + if (WARN_ON(!inst->free)) + return -EINVAL; + akcipher_prepare_alg(&inst->alg); + return crypto_register_instance(tmpl, akcipher_crypto_instance(inst)); +} +EXPORT_SYMBOL_GPL(akcipher_register_instance); + +static int crypto_akcipher_sync_prep(struct crypto_akcipher_sync_data *data) +{ + unsigned int reqsize = crypto_akcipher_reqsize(data->tfm); + struct akcipher_request *req; + struct scatterlist *sg; + unsigned int mlen; + unsigned int len; + u8 *buf; + + mlen = max(data->slen, data->dlen); + + len = sizeof(*req) + reqsize + mlen; + if (len < mlen) + return -EOVERFLOW; + + req = kzalloc(len, GFP_KERNEL); + if (!req) + return -ENOMEM; + + data->req = req; + akcipher_request_set_tfm(req, data->tfm); + + buf = (u8 *)(req + 1) + reqsize; + data->buf = buf; + memcpy(buf, data->src, data->slen); + + sg = &data->sg; + sg_init_one(sg, buf, mlen); + akcipher_request_set_crypt(req, sg, sg, data->slen, data->dlen); + + crypto_init_wait(&data->cwait); + akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, + crypto_req_done, &data->cwait); + + return 0; +} + +static int crypto_akcipher_sync_post(struct crypto_akcipher_sync_data *data, + int err) +{ + err = crypto_wait_req(err, &data->cwait); + memcpy(data->dst, data->buf, data->dlen); + data->dlen = data->req->dst_len; + kfree_sensitive(data->req); + return err; +} + +int crypto_akcipher_sync_encrypt(struct crypto_akcipher *tfm, + const void *src, unsigned int slen, + void *dst, unsigned int dlen) +{ + struct crypto_akcipher_sync_data data = { + .tfm = tfm, + .src = src, + .dst = dst, + .slen = slen, + .dlen = dlen, + }; + + return crypto_akcipher_sync_prep(&data) ?: + crypto_akcipher_sync_post(&data, + crypto_akcipher_encrypt(data.req)); +} +EXPORT_SYMBOL_GPL(crypto_akcipher_sync_encrypt); + +int crypto_akcipher_sync_decrypt(struct crypto_akcipher *tfm, + const void *src, unsigned int slen, + void *dst, unsigned int dlen) +{ + struct crypto_akcipher_sync_data data = { + .tfm = tfm, + .src = src, + .dst = dst, + .slen = slen, + .dlen = dlen, + }; + + return crypto_akcipher_sync_prep(&data) ?: + crypto_akcipher_sync_post(&data, + crypto_akcipher_decrypt(data.req)) ?: + data.dlen; +} +EXPORT_SYMBOL_GPL(crypto_akcipher_sync_decrypt); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Generic public key cipher type"); -- cgit v1.3.1