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| author | Miguel Ojeda <ojeda@kernel.org> | 2026-08-16 15:32:33 +0200 |
|---|---|---|
| committer | Miguel Ojeda <ojeda@kernel.org> | 2026-08-23 21:27:17 +0200 |
| commit | 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 (patch) | |
| tree | 93a1ed1d337bc53adf1e572c2586d347703b286e /crypto/jitterentropy.h | |
| download | linux-stable-5febf432df1cfa5b25d99b54c32103fafbdd0eb9.tar.gz linux-stable-5febf432df1cfa5b25d99b54c32103fafbdd0eb9.zip | |
kbuild: rust: keep Rust objects out of Clang LTO with inline helpersgrafted
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 <gary@garyguo.net>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust")
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Diffstat (limited to 'crypto/jitterentropy.h')
| -rw-r--r-- | crypto/jitterentropy.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/crypto/jitterentropy.h b/crypto/jitterentropy.h new file mode 100644 index 000000000..5bb15cb33 --- /dev/null +++ b/crypto/jitterentropy.h @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +struct sha3_ctx; +extern void *jent_kvzalloc(unsigned int len); +extern void jent_kvzfree(void *ptr, unsigned int len); +extern void *jent_zalloc(unsigned int len); +extern void jent_zfree(void *ptr); +extern void jent_get_nstime(__u64 *out); +void jent_hash_time(struct sha3_ctx *hash_state, __u64 time, u8 *addtl, + unsigned int addtl_len, __u64 hash_loop_cnt, + unsigned int stuck); +void jent_read_random_block(struct sha3_ctx *hash_state, char *dst, + unsigned int dst_len); + +struct rand_data; +extern int jent_entropy_init(unsigned int osr, unsigned int flags, + struct sha3_ctx *hash_state, + struct rand_data *p_ec); +extern int jent_read_entropy(struct rand_data *ec, unsigned char *data, + unsigned int len); + +extern struct rand_data * +jent_entropy_collector_alloc(unsigned int osr, unsigned int flags, + struct sha3_ctx *hash_state); +extern void jent_entropy_collector_free(struct rand_data *entropy_collector); + +#ifdef CONFIG_CRYPTO_JITTERENTROPY_TESTINTERFACE +int jent_raw_hires_entropy_store(__u64 value); +void jent_testing_init(void); +void jent_testing_exit(void); +#else /* CONFIG_CRYPTO_JITTERENTROPY_TESTINTERFACE */ +static inline int jent_raw_hires_entropy_store(__u64 value) { return 0; } +static inline void jent_testing_init(void) { } +static inline void jent_testing_exit(void) { } +#endif /* CONFIG_CRYPTO_JITTERENTROPY_TESTINTERFACE */ |