freebsd-skq/libexec/rtld-elf/rtld_lock.h
Konstantin Belousov 8569deaf1c Implement support for ELF filters in rtld. Both normal and auxillary
filters are implemented.

Filtees are loaded on demand, unless LD_LOADFLTR environment variable
is set or -z loadfltr was specified during the linking. This forces
rtld to upgrade read-locked rtld_bind_lock to write lock when it
encounters an object with filter during symbol lookup.

Consolidate common arguments of the symbol lookup functions in the
SymLook structure.  Track the state of the rtld locks in the
RtldLockState structure. Pass local RtldLockState through the rtld
symbol lookup calls to allow lock upgrades.

Reviewed by:	kan
Tested by:	Mykola Dzham <i levsha me>, nwhitehorn (powerpc)
2010-12-25 08:51:20 +00:00

76 lines
2.4 KiB
C

/*-
* 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 0x01
#define MAX_RTLD_LOCKS 8
struct RtldLockInfo
{
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);
};
extern void _rtld_thread_init(struct RtldLockInfo *);
extern void _rtld_atfork_pre(int *);
extern void _rtld_atfork_post(int *);
#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;
#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 *);
#endif /* IN_RTLD */
#endif