libc/private/bionic_ifuncs.h

/*
 * Copyright (C) 2019 The Android Open Source Project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#pragma once

#include <stdint.h>
#include <sys/ifunc.h>

#if defined(__aarch64__)
#define IFUNC_ARGS (uint64_t hwcap __attribute__((unused)), \
                    __ifunc_arg_t* arg __attribute__((unused)))
#elif defined(__arm__)
#define IFUNC_ARGS (unsigned long hwcap __attribute__((unused)))
#else
#define IFUNC_ARGS ()
#endif

// We can't have HWASAN enabled in resolvers because they may be called before HWASAN is
// initialized.
#define DEFINE_IFUNC_FOR(name) \
    name##_func name __attribute__((ifunc(#name "_resolver"))); \
    __attribute__((visibility("hidden"))) \
    __attribute__((no_sanitize("hwaddress"))) \
    name##_func* name##_resolver IFUNC_ARGS

#define DECLARE_FUNC(type, name) \
    __attribute__((visibility("hidden"))) \
    type name

#define RETURN_FUNC(type, name) { \
        DECLARE_FUNC(type, name); \
        return name; \
    }