freebsd-skq/libexec/rtld-elf/rtld_lock.h
Konstantin Belousov 9b33518ada rtld_lock.h: add some comments about versioning of struct RtldLockInfo
Sponsored by:	The FreeBSD Foundation
MFC after:	6 days
2021-04-11 11:16:13 +03:00

104 lines
3.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright 2003 Alexander Kabaev.
* All rights reserved.
*
* 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 ``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 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 _RTLD_LOCK_H_
#define _RTLD_LOCK_H_
#define RTLI_VERSION_ONE 0x01
#define RTLI_VERSION 0x02
#define MAX_RTLD_LOCKS 8
/*
* This structure is part of the ABI between rtld and threading
* libraries, like libthr and even libc_r. Its layout is fixed and
* can be changed only by appending new fields at the end, with the
* bump of RTLI_VERSION.
*/
struct RtldLockInfo
{
/*
* Valid if the object calling _rtld_thread_init() exported
* symbol _pli_rtli_version. Otherwise assume RTLI_VERSION_ONE.
*/
unsigned int rtli_version;
void *(*lock_create)(void);
void (*lock_destroy)(void *);
void (*rlock_acquire)(void *);
void (*wlock_acquire)(void *);
void (*lock_release)(void *);
int (*thread_set_flag)(int);
int (*thread_clr_flag)(int);
void (*at_fork)(void);
/* Version 2 fields */
char *(*dlerror_loc)(void);
int *(*dlerror_seen)(void);
int dlerror_loc_sz;
};
#if defined(IN_RTLD) || defined(PTHREAD_KERNEL)
void _rtld_thread_init(struct RtldLockInfo *) __exported;
void _rtld_atfork_pre(int *) __exported;
void _rtld_atfork_post(int *) __exported;
#endif /* IN_RTLD || PTHREAD_KERNEL */
#ifdef IN_RTLD
struct rtld_lock;
typedef struct rtld_lock *rtld_lock_t;
extern rtld_lock_t rtld_bind_lock;
extern rtld_lock_t rtld_libc_lock;
extern rtld_lock_t rtld_phdr_lock;
extern struct RtldLockInfo lockinfo;
#define RTLD_LOCK_UNLOCKED 0
#define RTLD_LOCK_RLOCKED 1
#define RTLD_LOCK_WLOCKED 2
struct Struct_RtldLockState;
typedef struct Struct_RtldLockState RtldLockState;
void rlock_acquire(rtld_lock_t, RtldLockState *);
void wlock_acquire(rtld_lock_t, RtldLockState *);
void lock_release(rtld_lock_t, RtldLockState *);
void lock_upgrade(rtld_lock_t, RtldLockState *);
void lock_restart_for_upgrade(RtldLockState *);
void dlerror_dflt_init(void);
#endif /* IN_RTLD */
#endif