2 * Copyright 2015-2020 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 #ifndef OSSL_CRYPTO_ASYNC_POSIX_H
11 #define OSSL_CRYPTO_ASYNC_POSIX_H
12 #include <openssl/e_os2.h>
14 #if defined(OPENSSL_SYS_UNIX) \
15 && defined(OPENSSL_THREADS) && !defined(OPENSSL_NO_ASYNC) \
16 && !defined(__ANDROID__) && !defined(__OpenBSD__)
20 # if _POSIX_VERSION >= 200112L \
21 && (_POSIX_VERSION < 200809L || defined(__GLIBC__))
28 # if defined(__CET__) || defined(__ia64__)
30 * When Intel CET is enabled, makecontext will create a different
31 * shadow stack for each context. async_fibre_swapcontext cannot
32 * use _longjmp. It must call swapcontext to swap shadow stack as
33 * well as normal stack.
34 * On IA64 the register stack engine is not saved across setjmp/longjmp. Here
35 * swapcontext() performs correctly.
37 # define USE_SWAPCONTEXT
39 # if defined(__aarch64__) && defined(__clang__) \
40 && defined(__ARM_FEATURE_BTI_DEFAULT) && __ARM_FEATURE_BTI_DEFAULT == 1
42 * setjmp/longjmp don't currently work with BTI on all libc implementations
43 * when compiled by clang. This is because clang doesn't put a BTI after the
44 * call to setjmp where it returns the second time. This then fails on libc
45 * implementations - notably glibc - which use an indirect jump to there.
46 * So use the swapcontext implementation, which does work.
47 * See https://github.com/llvm/llvm-project/issues/48888.
49 # define USE_SWAPCONTEXT
51 # include <ucontext.h>
52 # ifndef USE_SWAPCONTEXT
56 typedef struct async_fibre_st {
58 # ifndef USE_SWAPCONTEXT
64 static ossl_inline int async_fibre_swapcontext(async_fibre *o, async_fibre *n, int r)
66 # ifdef USE_SWAPCONTEXT
67 swapcontext(&o->fibre, &n->fibre);
71 if (!r || !_setjmp(o->env)) {
75 setcontext(&n->fibre);
82 # define async_fibre_init_dispatcher(d)
84 int async_fibre_makecontext(async_fibre *fibre);
85 void async_fibre_free(async_fibre *fibre);
89 #endif /* OSSL_CRYPTO_ASYNC_POSIX_H */