freebsd-skq/lib/libc/amd64/SYS.h
John Birrell 75831c5b8f Build the syscalls (in libc, not libc_r) with weak symbols so that
libpthread can override them as required.
1998-05-05 22:06:16 +00:00

93 lines
3.6 KiB
C

/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* from: @(#)SYS.h 5.5 (Berkeley) 5/7/91
*
* $Id: SYS.h,v 1.11 1997/04/19 17:05:30 bde Exp $
*/
#include <sys/syscall.h>
#include "DEFS.h"
#define SYSCALL(x) 2: PIC_PROLOGUE; jmp PIC_PLT(HIDENAME(cerror)); \
ENTRY(__CONCAT(_,x)); \
.weak CNAME(x); \
.set CNAME(x),CNAME(__CONCAT(_,x)); \
lea __CONCAT(SYS_,x),%eax; KERNCALL; jb 2b
#define RSYSCALL(x) SYSCALL(x); ret
#define PSEUDO(x,y) ENTRY(__CONCAT(_,x)); \
.weak CNAME(x); \
.set CNAME(x),CNAME(__CONCAT(_,x)); \
lea __CONCAT(SYS_,y), %eax; KERNCALL; ret
/* gas messes up offset -- although we don't currently need it, do for BCS */
#define LCALL(x,y) .byte 0x9a ; .long y; .word x
/*
* Design note:
*
* The macros PSYSCALL() and PRSYSCALL() are intended for use where a
* syscall needs to be renamed in the threaded library. When building
* a normal library, they default to the traditional SYSCALL() and
* RSYSCALL(). This avoids the need to #ifdef _THREAD_SAFE everywhere
* that the renamed function needs to be called.
*/
#ifdef _THREAD_SAFE
/*
* For the thread_safe versions, we prepend _thread_sys_ to the function
* name so that the 'C' wrapper can go around the real name.
*/
#define PSYSCALL(x) 2: PIC_PROLOGUE; jmp PIC_PLT(HIDENAME(cerror)); \
ENTRY(__CONCAT(_thread_sys_,x)); \
lea __CONCAT(SYS_,x),%eax; KERNCALL; jb 2b
#define PRSYSCALL(x) PSYSCALL(x); ret
#define PPSEUDO(x,y) ENTRY(__CONCAT(_thread_sys_,x)); \
lea __CONCAT(SYS_,y), %eax; KERNCALL; ret
#else
/*
* The non-threaded library defaults to traditional syscalls where
* the function name matches the syscall name.
*/
#define PSYSCALL(x) SYSCALL(x)
#define PRSYSCALL(x) RSYSCALL(x)
#define PPSEUDO(x,y) PSEUDO(x,y)
#endif
#ifdef __ELF__
#define KERNCALL int $0x80 /* Faster */
#else
#define KERNCALL LCALL(7,0) /* The old way */
#endif