mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-02 09:40:13 +00:00
212 lines
7.0 KiB
C
212 lines
7.0 KiB
C
/* Copyright (C) 1996, 1997, 1998, 2000 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Written by Andreas Schwab, <schwab@issan.informatik.uni-dortmund.de>,
|
|
December 1995.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#include <sysdeps/unix/sysdep.h>
|
|
#include <sysdeps/m68k/sysdep.h>
|
|
|
|
/* For Linux we can use the system call table in the header file
|
|
/usr/include/asm/unistd.h
|
|
of the kernel. But these symbols do not follow the SYS_* syntax
|
|
so we have to redefine the `SYS_ify' macro here. */
|
|
#undef SYS_ify
|
|
#ifdef __STDC__
|
|
# define SYS_ify(syscall_name) __NR_##syscall_name
|
|
#else
|
|
# define SYS_ify(syscall_name) __NR_/**/syscall_name
|
|
#endif
|
|
|
|
#ifdef __ASSEMBLER__
|
|
|
|
/* Linux uses a negative return value to indicate syscall errors, unlike
|
|
most Unices, which use the condition codes' carry flag.
|
|
|
|
Since version 2.1 the return value of a system call might be negative
|
|
even if the call succeeded. E.g., the `lseek' system call might return
|
|
a large offset. Therefore we must not anymore test for < 0, but test
|
|
for a real error by making sure the value in %d0 is a real error
|
|
number. Linus said he will make sure the no syscall returns a value
|
|
in -1 .. -4095 as a valid result so we can savely test with -4095. */
|
|
|
|
/* We don't want the label for the error handler to be visible in the symbol
|
|
table when we define it here. */
|
|
#ifdef PIC
|
|
#define SYSCALL_ERROR_LABEL .Lsyscall_error
|
|
#else
|
|
#define SYSCALL_ERROR_LABEL __syscall_error
|
|
#endif
|
|
|
|
#undef PSEUDO
|
|
#define PSEUDO(name, syscall_name, args) \
|
|
.text; \
|
|
ENTRY (name) \
|
|
DO_CALL (syscall_name, args); \
|
|
cmp.l &-4095, %d0; \
|
|
jcc SYSCALL_ERROR_LABEL
|
|
|
|
#undef PSEUDO_END
|
|
#define PSEUDO_END(name) \
|
|
SYSCALL_ERROR_HANDLER; \
|
|
END (name)
|
|
|
|
#ifdef PIC
|
|
/* Store (- %d0) into errno through the GOT. */
|
|
#ifdef _LIBC_REENTRANT
|
|
#define SYSCALL_ERROR_HANDLER \
|
|
SYSCALL_ERROR_LABEL: \
|
|
neg.l %d0; \
|
|
move.l %d0, -(%sp); \
|
|
jbsr __errno_location@PLTPC; \
|
|
move.l (%sp)+, (%a0); \
|
|
move.l &-1, %d0; \
|
|
/* Copy return value to %a0 for syscalls that are declared to return \
|
|
a pointer (e.g., mmap). */ \
|
|
move.l %d0, %a0; \
|
|
rts;
|
|
#else /* !_LIBC_REENTRANT */
|
|
#define SYSCALL_ERROR_HANDLER \
|
|
SYSCALL_ERROR_LABEL: \
|
|
move.l (errno@GOTPC, %pc), %a0; \
|
|
neg.l %d0; \
|
|
move.l %d0, (%a0); \
|
|
move.l &-1, %d0; \
|
|
/* Copy return value to %a0 for syscalls that are declared to return \
|
|
a pointer (e.g., mmap). */ \
|
|
move.l %d0, %a0; \
|
|
rts;
|
|
#endif /* _LIBC_REENTRANT */
|
|
#else
|
|
#define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */
|
|
#endif /* PIC */
|
|
|
|
/* Linux takes system call arguments in registers:
|
|
|
|
syscall number %d0 call-clobbered
|
|
arg 1 %d1 call-clobbered
|
|
arg 2 %d2 call-saved
|
|
arg 3 %d3 call-saved
|
|
arg 4 %d4 call-saved
|
|
arg 5 %d5 call-saved
|
|
|
|
The stack layout upon entering the function is:
|
|
|
|
20(%sp) Arg# 5
|
|
16(%sp) Arg# 4
|
|
12(%sp) Arg# 3
|
|
8(%sp) Arg# 2
|
|
4(%sp) Arg# 1
|
|
(%sp) Return address
|
|
|
|
(Of course a function with say 3 arguments does not have entries for
|
|
arguments 4 and 5.)
|
|
|
|
Separate move's are faster than movem, but need more space. Since
|
|
speed is more important, we don't use movem. Since %a0 and %a1 are
|
|
scratch registers, we can use them for saving as well. */
|
|
|
|
#define DO_CALL(syscall_name, args) \
|
|
move.l &SYS_ify(syscall_name), %d0; \
|
|
DOARGS_##args \
|
|
trap &0; \
|
|
UNDOARGS_##args
|
|
|
|
#define DOARGS_0 /* No arguments to frob. */
|
|
#define UNDOARGS_0 /* No arguments to unfrob. */
|
|
#define _DOARGS_0(n) /* No arguments to frob. */
|
|
|
|
#define DOARGS_1 _DOARGS_1 (4)
|
|
#define _DOARGS_1(n) move.l n(%sp), %d1; _DOARGS_0 (n)
|
|
#define UNDOARGS_1 UNDOARGS_0
|
|
|
|
#define DOARGS_2 _DOARGS_2 (8)
|
|
#define _DOARGS_2(n) move.l %d2, %a0; move.l n(%sp), %d2; _DOARGS_1 (n-4)
|
|
#define UNDOARGS_2 UNDOARGS_1; move.l %a0, %d2
|
|
|
|
#define DOARGS_3 _DOARGS_3 (12)
|
|
#define _DOARGS_3(n) move.l %d3, %a1; move.l n(%sp), %d3; _DOARGS_2 (n-4)
|
|
#define UNDOARGS_3 UNDOARGS_2; move.l %a1, %d3
|
|
|
|
#define DOARGS_4 _DOARGS_4 (16)
|
|
#define _DOARGS_4(n) move.l %d4, -(%sp); move.l n+4(%sp), %d4; _DOARGS_3 (n)
|
|
#define UNDOARGS_4 UNDOARGS_3; move.l (%sp)+, %d4
|
|
|
|
#define DOARGS_5 _DOARGS_5 (20)
|
|
#define _DOARGS_5(n) move.l %d5, -(%sp); move.l n+4(%sp), %d5; _DOARGS_4 (n)
|
|
#define UNDOARGS_5 UNDOARGS_4; move.l (%sp)+, %d5
|
|
|
|
|
|
#define ret rts
|
|
#if 0 /* Not used by Linux */
|
|
#define r0 %d0
|
|
#define r1 %d1
|
|
#define MOVE(x,y) movel x , y
|
|
#endif
|
|
|
|
#else /* not __ASSEMBLER__ */
|
|
|
|
/* Define a macro which expands into the inline wrapper code for a system
|
|
call. */
|
|
#undef INLINE_SYSCALL
|
|
#define INLINE_SYSCALL(name, nr, args...) \
|
|
({ unsigned int _sys_result; \
|
|
{ \
|
|
LOAD_ARGS_##nr (args) \
|
|
register int _d0 asm ("%d0") = __NR_##name; \
|
|
asm volatile ("trap #0" \
|
|
: "=d" (_d0) \
|
|
: "0" (_d0) ASM_ARGS_##nr \
|
|
: "memory"); \
|
|
_sys_result = _d0; \
|
|
} \
|
|
if (_sys_result >= (unsigned int) -4095) \
|
|
{ \
|
|
__set_errno (-_sys_result); \
|
|
_sys_result = (unsigned int) -1; \
|
|
} \
|
|
(int) _sys_result; })
|
|
|
|
#define LOAD_ARGS_0()
|
|
#define ASM_ARGS_0
|
|
#define LOAD_ARGS_1(a1) \
|
|
register int _d1 asm ("d1") = (int) (a1); \
|
|
LOAD_ARGS_0 ()
|
|
#define ASM_ARGS_1 ASM_ARGS_0, "d" (_d1)
|
|
#define LOAD_ARGS_2(a1, a2) \
|
|
register int _d2 asm ("d2") = (int) (a2); \
|
|
LOAD_ARGS_1 (a1)
|
|
#define ASM_ARGS_2 ASM_ARGS_1, "d" (_d2)
|
|
#define LOAD_ARGS_3(a1, a2, a3) \
|
|
register int _d3 asm ("d3") = (int) (a3); \
|
|
LOAD_ARGS_2 (a1, a2)
|
|
#define ASM_ARGS_3 ASM_ARGS_2, "d" (_d3)
|
|
#define LOAD_ARGS_4(a1, a2, a3, a4) \
|
|
register int _d4 asm ("d4") = (int) (a4); \
|
|
LOAD_ARGS_3 (a1, a2, a3)
|
|
#define ASM_ARGS_4 ASM_ARGS_3, "d" (_d4)
|
|
#define LOAD_ARGS_5(a1, a2, a3, a4, a5) \
|
|
register int _d5 asm ("d5") = (int) (a5); \
|
|
LOAD_ARGS_4 (a1, a2, a3, a4)
|
|
#define ASM_ARGS_5 ASM_ARGS_4, "d" (_d5)
|
|
#define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6) \
|
|
register int _a0 asm ("a0") = (int) (a6); \
|
|
LOAD_ARGS_5 (a1, a2, a3, a4, a5)
|
|
#define ASM_ARGS_6 ASM_ARGS_5, "a" (_a0)
|
|
|
|
#endif /* not __ASSEMBLER__ */
|