freebsd-skq/sys/x86/include/ifunc.h
Konstantin Belousov d5effb01f1 Add helper macros to hide some boring repeatable ceremonies to define
ifuncs on x86.

Also keep helpers to define 'pseudo-ifuncs' which are emulated by the
indirect jmp.

Reviewed by:	jhb (previous version, as part of the larger patch)
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D13838
2018-05-03 21:45:59 +00:00

59 lines
2.4 KiB
C

/*-
* Copyright (c) 2015, 2017 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Konstantin Belousov <kib@FreeBSD.org>
* under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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 AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#ifndef __X86_IFUNC_H
#define __X86_IFUNC_H
#define DECLARE_LIFUNC(ret_type, name, args) \
ret_type name args
#define DEFINE_LIFUNC(scope, selector_qual, ret_type, name, args) \
__asm__ (scope "\t" #name "\n" \
"\t.type\t" #name ",@function\n" \
#name ":\n" \
"\tjmp *" #name "_selector\n" \
"\t.size\t" #name ",\t. - "#name); \
selector_qual ret_type (*name##_selector)args __used; \
DECLARE_LIFUNC(ret_type, name, args)
#define DEFINE_STATIC_LIFUNC(ret_type, name, args) \
DEFINE_LIFUNC(".local", static, ret_type, name, args)
#define DEFINE_GLOBAL_LIFUNC(ret_type, name, args) \
DEFINE_LIFUNC(".globl", , ret_type, name, args)
#define DEFINE_IFUNC(qual, ret_type, name, args, resolver_qual) \
resolver_qual ret_type (*name##_resolver(void))args __used; \
qual ret_type name args __attribute__((ifunc(#name "_resolver"))); \
resolver_qual ret_type (*name##_resolver(void))args
#endif