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 --- lib/siphash.c | 538 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 538 insertions(+) create mode 100644 lib/siphash.c (limited to 'lib/siphash.c') diff --git a/lib/siphash.c b/lib/siphash.c new file mode 100644 index 000000000..9e4e88752 --- /dev/null +++ b/lib/siphash.c @@ -0,0 +1,538 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) +/* Copyright (C) 2016-2022 Jason A. Donenfeld . All Rights Reserved. + * + * SipHash: a fast short-input PRF + * https://131002.net/siphash/ + * + * This implementation is specifically for SipHash2-4 for a secure PRF + * and HalfSipHash1-3/SipHash1-3 for an insecure PRF only suitable for + * hashtables. + */ + +#include +#include + +#if defined(CONFIG_DCACHE_WORD_ACCESS) && BITS_PER_LONG == 64 +#include +#include +#endif + +#define SIPROUND SIPHASH_PERMUTATION(v0, v1, v2, v3) + +#define PREAMBLE(len) \ + u64 v0 = SIPHASH_CONST_0; \ + u64 v1 = SIPHASH_CONST_1; \ + u64 v2 = SIPHASH_CONST_2; \ + u64 v3 = SIPHASH_CONST_3; \ + u64 b = ((u64)(len)) << 56; \ + v3 ^= key->key[1]; \ + v2 ^= key->key[0]; \ + v1 ^= key->key[1]; \ + v0 ^= key->key[0]; + +#define POSTAMBLE \ + v3 ^= b; \ + SIPROUND; \ + SIPROUND; \ + v0 ^= b; \ + v2 ^= 0xff; \ + SIPROUND; \ + SIPROUND; \ + SIPROUND; \ + SIPROUND; \ + return (v0 ^ v1) ^ (v2 ^ v3); + +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS +u64 __siphash_aligned(const void *data, size_t len, const siphash_key_t *key) +{ + const u8 *end = data + len - (len % sizeof(u64)); + const u8 left = len & (sizeof(u64) - 1); + u64 m; + PREAMBLE(len) + for (; data != end; data += sizeof(u64)) { + m = le64_to_cpup(data); + v3 ^= m; + SIPROUND; + SIPROUND; + v0 ^= m; + } +#if defined(CONFIG_DCACHE_WORD_ACCESS) && BITS_PER_LONG == 64 + if (left) + b |= le64_to_cpu((__force __le64)(load_unaligned_zeropad(data) & + bytemask_from_count(left))); +#else + switch (left) { + case 7: b |= ((u64)end[6]) << 48; fallthrough; + case 6: b |= ((u64)end[5]) << 40; fallthrough; + case 5: b |= ((u64)end[4]) << 32; fallthrough; + case 4: b |= le32_to_cpup(data); break; + case 3: b |= ((u64)end[2]) << 16; fallthrough; + case 2: b |= le16_to_cpup(data); break; + case 1: b |= end[0]; + } +#endif + POSTAMBLE +} +EXPORT_SYMBOL(__siphash_aligned); +#endif + +u64 __siphash_unaligned(const void *data, size_t len, const siphash_key_t *key) +{ + const u8 *end = data + len - (len % sizeof(u64)); + const u8 left = len & (sizeof(u64) - 1); + u64 m; + PREAMBLE(len) + for (; data != end; data += sizeof(u64)) { + m = get_unaligned_le64(data); + v3 ^= m; + SIPROUND; + SIPROUND; + v0 ^= m; + } +#if defined(CONFIG_DCACHE_WORD_ACCESS) && BITS_PER_LONG == 64 + if (left) + b |= le64_to_cpu((__force __le64)(load_unaligned_zeropad(data) & + bytemask_from_count(left))); +#else + switch (left) { + case 7: b |= ((u64)end[6]) << 48; fallthrough; + case 6: b |= ((u64)end[5]) << 40; fallthrough; + case 5: b |= ((u64)end[4]) << 32; fallthrough; + case 4: b |= get_unaligned_le32(end); break; + case 3: b |= ((u64)end[2]) << 16; fallthrough; + case 2: b |= get_unaligned_le16(end); break; + case 1: b |= end[0]; + } +#endif + POSTAMBLE +} +EXPORT_SYMBOL(__siphash_unaligned); + +/** + * siphash_1u64 - compute 64-bit siphash PRF value of a u64 + * @first: first u64 + * @key: the siphash key + */ +u64 siphash_1u64(const u64 first, const siphash_key_t *key) +{ + PREAMBLE(8) + v3 ^= first; + SIPROUND; + SIPROUND; + v0 ^= first; + POSTAMBLE +} +EXPORT_SYMBOL(siphash_1u64); + +/** + * siphash_2u64 - compute 64-bit siphash PRF value of 2 u64 + * @first: first u64 + * @second: second u64 + * @key: the siphash key + */ +u64 siphash_2u64(const u64 first, const u64 second, const siphash_key_t *key) +{ + PREAMBLE(16) + v3 ^= first; + SIPROUND; + SIPROUND; + v0 ^= first; + v3 ^= second; + SIPROUND; + SIPROUND; + v0 ^= second; + POSTAMBLE +} +EXPORT_SYMBOL(siphash_2u64); + +/** + * siphash_3u64 - compute 64-bit siphash PRF value of 3 u64 + * @first: first u64 + * @second: second u64 + * @third: third u64 + * @key: the siphash key + */ +u64 siphash_3u64(const u64 first, const u64 second, const u64 third, + const siphash_key_t *key) +{ + PREAMBLE(24) + v3 ^= first; + SIPROUND; + SIPROUND; + v0 ^= first; + v3 ^= second; + SIPROUND; + SIPROUND; + v0 ^= second; + v3 ^= third; + SIPROUND; + SIPROUND; + v0 ^= third; + POSTAMBLE +} +EXPORT_SYMBOL(siphash_3u64); + +/** + * siphash_4u64 - compute 64-bit siphash PRF value of 4 u64 + * @first: first u64 + * @second: second u64 + * @third: third u64 + * @forth: forth u64 + * @key: the siphash key + */ +u64 siphash_4u64(const u64 first, const u64 second, const u64 third, + const u64 forth, const siphash_key_t *key) +{ + PREAMBLE(32) + v3 ^= first; + SIPROUND; + SIPROUND; + v0 ^= first; + v3 ^= second; + SIPROUND; + SIPROUND; + v0 ^= second; + v3 ^= third; + SIPROUND; + SIPROUND; + v0 ^= third; + v3 ^= forth; + SIPROUND; + SIPROUND; + v0 ^= forth; + POSTAMBLE +} +EXPORT_SYMBOL(siphash_4u64); + +u64 siphash_1u32(const u32 first, const siphash_key_t *key) +{ + PREAMBLE(4) + b |= first; + POSTAMBLE +} +EXPORT_SYMBOL(siphash_1u32); + +u64 siphash_3u32(const u32 first, const u32 second, const u32 third, + const siphash_key_t *key) +{ + u64 combined = (u64)second << 32 | first; + PREAMBLE(12) + v3 ^= combined; + SIPROUND; + SIPROUND; + v0 ^= combined; + b |= third; + POSTAMBLE +} +EXPORT_SYMBOL(siphash_3u32); + +#if BITS_PER_LONG == 64 +/* Note that on 64-bit, we make HalfSipHash1-3 actually be SipHash1-3, for + * performance reasons. On 32-bit, below, we actually implement HalfSipHash1-3. + */ + +#define HSIPROUND SIPROUND +#define HPREAMBLE(len) PREAMBLE(len) +#define HPOSTAMBLE \ + v3 ^= b; \ + HSIPROUND; \ + v0 ^= b; \ + v2 ^= 0xff; \ + HSIPROUND; \ + HSIPROUND; \ + HSIPROUND; \ + return (v0 ^ v1) ^ (v2 ^ v3); + +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS +u32 __hsiphash_aligned(const void *data, size_t len, const hsiphash_key_t *key) +{ + const u8 *end = data + len - (len % sizeof(u64)); + const u8 left = len & (sizeof(u64) - 1); + u64 m; + HPREAMBLE(len) + for (; data != end; data += sizeof(u64)) { + m = le64_to_cpup(data); + v3 ^= m; + HSIPROUND; + v0 ^= m; + } +#if defined(CONFIG_DCACHE_WORD_ACCESS) && BITS_PER_LONG == 64 + if (left) + b |= le64_to_cpu((__force __le64)(load_unaligned_zeropad(data) & + bytemask_from_count(left))); +#else + switch (left) { + case 7: b |= ((u64)end[6]) << 48; fallthrough; + case 6: b |= ((u64)end[5]) << 40; fallthrough; + case 5: b |= ((u64)end[4]) << 32; fallthrough; + case 4: b |= le32_to_cpup(data); break; + case 3: b |= ((u64)end[2]) << 16; fallthrough; + case 2: b |= le16_to_cpup(data); break; + case 1: b |= end[0]; + } +#endif + HPOSTAMBLE +} +EXPORT_SYMBOL(__hsiphash_aligned); +#endif + +u32 __hsiphash_unaligned(const void *data, size_t len, + const hsiphash_key_t *key) +{ + const u8 *end = data + len - (len % sizeof(u64)); + const u8 left = len & (sizeof(u64) - 1); + u64 m; + HPREAMBLE(len) + for (; data != end; data += sizeof(u64)) { + m = get_unaligned_le64(data); + v3 ^= m; + HSIPROUND; + v0 ^= m; + } +#if defined(CONFIG_DCACHE_WORD_ACCESS) && BITS_PER_LONG == 64 + if (left) + b |= le64_to_cpu((__force __le64)(load_unaligned_zeropad(data) & + bytemask_from_count(left))); +#else + switch (left) { + case 7: b |= ((u64)end[6]) << 48; fallthrough; + case 6: b |= ((u64)end[5]) << 40; fallthrough; + case 5: b |= ((u64)end[4]) << 32; fallthrough; + case 4: b |= get_unaligned_le32(end); break; + case 3: b |= ((u64)end[2]) << 16; fallthrough; + case 2: b |= get_unaligned_le16(end); break; + case 1: b |= end[0]; + } +#endif + HPOSTAMBLE +} +EXPORT_SYMBOL(__hsiphash_unaligned); + +/** + * hsiphash_1u32 - compute 64-bit hsiphash PRF value of a u32 + * @first: first u32 + * @key: the hsiphash key + */ +u32 hsiphash_1u32(const u32 first, const hsiphash_key_t *key) +{ + HPREAMBLE(4) + b |= first; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_1u32); + +/** + * hsiphash_2u32 - compute 32-bit hsiphash PRF value of 2 u32 + * @first: first u32 + * @second: second u32 + * @key: the hsiphash key + */ +u32 hsiphash_2u32(const u32 first, const u32 second, const hsiphash_key_t *key) +{ + u64 combined = (u64)second << 32 | first; + HPREAMBLE(8) + v3 ^= combined; + HSIPROUND; + v0 ^= combined; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_2u32); + +/** + * hsiphash_3u32 - compute 32-bit hsiphash PRF value of 3 u32 + * @first: first u32 + * @second: second u32 + * @third: third u32 + * @key: the hsiphash key + */ +u32 hsiphash_3u32(const u32 first, const u32 second, const u32 third, + const hsiphash_key_t *key) +{ + u64 combined = (u64)second << 32 | first; + HPREAMBLE(12) + v3 ^= combined; + HSIPROUND; + v0 ^= combined; + b |= third; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_3u32); + +/** + * hsiphash_4u32 - compute 32-bit hsiphash PRF value of 4 u32 + * @first: first u32 + * @second: second u32 + * @third: third u32 + * @forth: forth u32 + * @key: the hsiphash key + */ +u32 hsiphash_4u32(const u32 first, const u32 second, const u32 third, + const u32 forth, const hsiphash_key_t *key) +{ + u64 combined = (u64)second << 32 | first; + HPREAMBLE(16) + v3 ^= combined; + HSIPROUND; + v0 ^= combined; + combined = (u64)forth << 32 | third; + v3 ^= combined; + HSIPROUND; + v0 ^= combined; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_4u32); +#else +#define HSIPROUND HSIPHASH_PERMUTATION(v0, v1, v2, v3) + +#define HPREAMBLE(len) \ + u32 v0 = HSIPHASH_CONST_0; \ + u32 v1 = HSIPHASH_CONST_1; \ + u32 v2 = HSIPHASH_CONST_2; \ + u32 v3 = HSIPHASH_CONST_3; \ + u32 b = ((u32)(len)) << 24; \ + v3 ^= key->key[1]; \ + v2 ^= key->key[0]; \ + v1 ^= key->key[1]; \ + v0 ^= key->key[0]; + +#define HPOSTAMBLE \ + v3 ^= b; \ + HSIPROUND; \ + v0 ^= b; \ + v2 ^= 0xff; \ + HSIPROUND; \ + HSIPROUND; \ + HSIPROUND; \ + return v1 ^ v3; + +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS +u32 __hsiphash_aligned(const void *data, size_t len, const hsiphash_key_t *key) +{ + const u8 *end = data + len - (len % sizeof(u32)); + const u8 left = len & (sizeof(u32) - 1); + u32 m; + HPREAMBLE(len) + for (; data != end; data += sizeof(u32)) { + m = le32_to_cpup(data); + v3 ^= m; + HSIPROUND; + v0 ^= m; + } + switch (left) { + case 3: b |= ((u32)end[2]) << 16; fallthrough; + case 2: b |= le16_to_cpup(data); break; + case 1: b |= end[0]; + } + HPOSTAMBLE +} +EXPORT_SYMBOL(__hsiphash_aligned); +#endif + +u32 __hsiphash_unaligned(const void *data, size_t len, + const hsiphash_key_t *key) +{ + const u8 *end = data + len - (len % sizeof(u32)); + const u8 left = len & (sizeof(u32) - 1); + u32 m; + HPREAMBLE(len) + for (; data != end; data += sizeof(u32)) { + m = get_unaligned_le32(data); + v3 ^= m; + HSIPROUND; + v0 ^= m; + } + switch (left) { + case 3: b |= ((u32)end[2]) << 16; fallthrough; + case 2: b |= get_unaligned_le16(end); break; + case 1: b |= end[0]; + } + HPOSTAMBLE +} +EXPORT_SYMBOL(__hsiphash_unaligned); + +/** + * hsiphash_1u32 - compute 32-bit hsiphash PRF value of a u32 + * @first: first u32 + * @key: the hsiphash key + */ +u32 hsiphash_1u32(const u32 first, const hsiphash_key_t *key) +{ + HPREAMBLE(4) + v3 ^= first; + HSIPROUND; + v0 ^= first; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_1u32); + +/** + * hsiphash_2u32 - compute 32-bit hsiphash PRF value of 2 u32 + * @first: first u32 + * @second: second u32 + * @key: the hsiphash key + */ +u32 hsiphash_2u32(const u32 first, const u32 second, const hsiphash_key_t *key) +{ + HPREAMBLE(8) + v3 ^= first; + HSIPROUND; + v0 ^= first; + v3 ^= second; + HSIPROUND; + v0 ^= second; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_2u32); + +/** + * hsiphash_3u32 - compute 32-bit hsiphash PRF value of 3 u32 + * @first: first u32 + * @second: second u32 + * @third: third u32 + * @key: the hsiphash key + */ +u32 hsiphash_3u32(const u32 first, const u32 second, const u32 third, + const hsiphash_key_t *key) +{ + HPREAMBLE(12) + v3 ^= first; + HSIPROUND; + v0 ^= first; + v3 ^= second; + HSIPROUND; + v0 ^= second; + v3 ^= third; + HSIPROUND; + v0 ^= third; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_3u32); + +/** + * hsiphash_4u32 - compute 32-bit hsiphash PRF value of 4 u32 + * @first: first u32 + * @second: second u32 + * @third: third u32 + * @forth: forth u32 + * @key: the hsiphash key + */ +u32 hsiphash_4u32(const u32 first, const u32 second, const u32 third, + const u32 forth, const hsiphash_key_t *key) +{ + HPREAMBLE(16) + v3 ^= first; + HSIPROUND; + v0 ^= first; + v3 ^= second; + HSIPROUND; + v0 ^= second; + v3 ^= third; + HSIPROUND; + v0 ^= third; + v3 ^= forth; + HSIPROUND; + v0 ^= forth; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_4u32); +#endif -- cgit v1.3.1