/* Copyright (C) 1992, 93, 1995-2000, 2002, 2003, 2005, 2006
Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper, <drepper@gnu.ai.mit.edu>, August 1995.
ARM changes by Philip Blundell, <pjb27@cam.ac.uk>, May 1997.
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. */
#ifndef _LINUX_ARM_SYSDEP_H
#define _LINUX_ARM_SYSDEP_H 1
#include <sys/syscall.h>
/* There is some commonality. */
#include <sysdeps/arm/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
#define SWI_BASE (0x900000)
#define SYS_ify(syscall_name) (__NR_##syscall_name)
#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 R0
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 safely
test with -4095. */
#undef PSEUDO
#define PSEUDO(name, syscall_name, args) \
.text; \
ENTRY (name); \
DO_CALL (syscall_name, args); \
cmn r0, $4096;
#define PSEUDO_RET \
RETINSTR(cc, lr); \
b PLTJMP(SYSCALL_ERROR)
#undef ret
#define ret PSEUDO_RET
#undef PSEUDO_END
#define PSEUDO_END(name) \
SYSCALL_ERROR_HANDLER \
END (name)
#undef PSEUDO_NOERRNO
#define PSEUDO_NOERRNO(name, syscall_name, args) \
.text; \
ENTRY (name); \
DO_CALL (syscall_name, args);
#define PSEUDO_RET_NOERRNO \
DO_RET (lr);
#undef ret_NOERRNO
#define ret_NOERRNO PSEUDO_RET_NOERRNO
#undef PSEUDO_END_NOERRNO
#define PSEUDO_END_NOERRNO(name) \
END (name)
/* The function has to return the error code. */
#undef PSEUDO_ERRVAL
#define PSEUDO_ERRVAL(name, syscall_name, args) \
.text; \
ENTRY (name) \
DO_CALL (syscall_name, args); \
rsb r0, r0, #0
#undef PSEUDO_END_ERRVAL
#define PSEUDO_END_ERRVAL(name) \
END (name)
#define ret_ERRVAL PSEUDO_RET_NOERRNO
#if NOT_IN_libc
# define SYSCALL_ERROR __local_syscall_error
# ifdef RTLD_PRIVATE_ERRNO
# define SYSCALL_ERROR_HANDLER \
__local_syscall_error: \
ldr r1, 1f; \
rsb r0, r0, #0; \
0: str r0, [pc, r1]; \
mvn r0, #0; \
DO_RET(lr); \
1: .word C_SYMBOL_NAME(rtld_errno) - 0b - 8;
# else
# define SYSCALL_ERROR_HANDLER \
__local_syscall_error: \
str lr, [sp, #-4]!; \
str r0, [sp, #-4]!; \
bl PLTJMP(C_SYMBOL_NAME(__errno_location)); \
ldr r1, [sp], #4; \
rsb r1, r1, #0; \
str r1, [r0]; \
mvn r0, #0; \
ldr pc, [sp], #4;
# endif
#else
# define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */
# define SYSCALL_ERROR __syscall_error
#endif
/* Linux takes system call args in registers:
syscall number in the SWI instruction
arg 1 r0
arg 2 r1
arg 3 r2
arg 4 r3
arg 5 r4 (this is different from the APCS convention)
arg 6 r5
arg 7 r6
The compiler is going to form a call by coming here, through PSEUDO, with
arguments
syscall number in the DO_CALL macro
arg 1 r0
arg 2 r1
arg 3 r2
arg 4 r3
arg 5 [sp]
arg 6 [sp+4]
arg 7 [sp+8]
We need to shuffle values between R4..R6 and the stack so that the
caller's v1..v3 and stack frame are not corrupted, and the kernel
sees the right arguments.
*/
#undef DO_CALL
#if defined(__ARM_EABI__)
#define DO_CALL(syscall_name, args) \
DOARGS_##args \
mov ip, r7; \
ldr r7, =SYS_ify (syscall_name); \
swi 0x0; \
mov r7, ip; \
UNDOARGS_##args
#else
#define DO_CALL(syscall_name, args) \
DOARGS_##args \
swi SYS_ify (syscall_name); \
UNDOARGS_##args
#endif
#define DOARGS_0 /* nothing */
#define DOARGS_1 /* nothing */
#define DOARGS_2 /* nothing */
#define DOARGS_3 /* nothing */
#define DOARGS_4 /* nothing */
#define DOARGS_5 str r4, [sp, $-4]!; ldr r4, [sp, $4];
#define DOARGS_6 mov ip, sp; stmfd sp!, {r4, r5}; ldmia ip, {r4, r5};
#define DOARGS_7 mov ip, sp; stmfd sp!, {r4, r5, r6}; ldmia ip, {r4, r5, r6};
#define UNDOARGS_0 /* nothing */
#define UNDOARGS_1 /* nothing */
#define UNDOARGS_2 /* nothing */
#define UNDOARGS_3 /* nothing */
#define UNDOARGS_4 /* nothing */
#define UNDOARGS_5 ldr r4, [sp], $4;
#define UNDOARGS_6 ldmfd sp!, {r4, r5};
#define UNDOARGS_7 ldmfd sp!, {r4, r5, r6};
#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 = INTERNAL_SYSCALL (name, , nr, args); \
if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (_sys_result, ), 0)) \
{ \
__set_errno (INTERNAL_SYSCALL_ERRNO (_sys_result, )); \
_sys_result = (unsigned int) -1; \
} \
(int) _sys_result; })
#undef INTERNAL_SYSCALL_DECL
#define INTERNAL_SYSCALL_DECL(err) do { } while (0)
#undef INTERNAL_SYSCALL_RAW
#if defined(__thumb__)
/* Hide the use of r7 from the compiler, this would be a lot
* easier but for the fact that the syscalls can exceed 255.
* For the moment the LOAD_ARG_7 is sacrificed.
* We can't use push/pop inside the asm because that breaks
* unwinding (ie. thread cancellation).
*/
#define INTERNAL_SYSCALL_RAW(name, err, nr, args...) \
({ unsigned int _sys_result; \
{ \
int _sys_buf[2]; \
register int _a1 __asm__ ("a1"); \
register int *_v3 __asm__ ("v3") = _sys_buf; \
LOAD_ARGS_##nr (args) \
*_v3 = (int) (name); \
__asm__ __volatile__ ("str r7, [v3, #4]\n" \
"\tldr r7, [v3]\n" \
"\tswi 0 @ syscall " #name "\n" \
"\tldr r7, [v3, #4]" \
: "=r" (_a1) \
: "r" (_v3) ASM_ARGS_##nr \
: "memory"); \
_sys_result = _a1; \
} \
(int) _sys_result; })
#elif defined(__ARM_EABI__)
#define INTERNAL_SYSCALL_RAW(name, err, nr, args...) \
({unsigned int _sys_result; \
{ \
register int _a1 __asm__ ("r0"), _nr __asm__ ("r7"); \
LOAD_ARGS_##nr (args) \
_nr = name; \
__asm__ __volatile__ ("swi 0x0 @ syscall " #name \
: "=r" (_a1) \
: "r" (_nr) ASM_ARGS_##nr \
: "memory"); \
_sys_result = _a1; \
} \
(int) _sys_result; })
#else /* !defined(__ARM_EABI__) */
#define INTERNAL_SYSCALL_RAW(name, err, nr, args...) \
({ unsigned int _sys_result; \
{ \
register int _a1 __asm__ ("a1"); \
LOAD_ARGS_##nr (args) \
__asm__ __volatile__ ("swi %1 @ syscall " #name \
: "=r" (_a1) \
: "i" (name) ASM_ARGS_##nr \
: "memory"); \
_sys_result = _a1; \
} \
(int) _sys_result; })
#endif
#undef INTERNAL_SYSCALL
#define INTERNAL_SYSCALL(name, err, nr, args...) \
INTERNAL_SYSCALL_RAW(SYS_ify(name), err, nr, args)
#undef INTERNAL_SYSCALL_ARM
#define INTERNAL_SYSCALL_ARM(name, err, nr, args...) \
INTERNAL_SYSCALL_RAW(__ARM_NR_##name, err, nr, args)
#undef INTERNAL_SYSCALL_ERROR_P
#define INTERNAL_SYSCALL_ERROR_P(val, err) \
((unsigned int) (val) >= 0xfffff001u)
#undef INTERNAL_SYSCALL_ERRNO
#define INTERNAL_SYSCALL_ERRNO(val, err) (-(val))
#define LOAD_ARGS_0()
#define ASM_ARGS_0
#define LOAD_ARGS_1(a1) \
_a1 = (int) (a1); \
LOAD_ARGS_0 ()
#define ASM_ARGS_1 ASM_ARGS_0, "r" (_a1)
#define LOAD_ARGS_2(a1, a2) \
register int _a2 __asm__ ("a2") = (int) (a2); \
LOAD_ARGS_1 (a1)
#define ASM_ARGS_2 ASM_ARGS_1, "r" (_a2)
#define LOAD_ARGS_3(a1, a2, a3) \
register int _a3 __asm__ ("a3") = (int) (a3); \
LOAD_ARGS_2 (a1, a2)
#define ASM_ARGS_3 ASM_ARGS_2, "r" (_a3)
#define LOAD_ARGS_4(a1, a2, a3, a4) \
register int _a4 __asm__ ("a4") = (int) (a4); \
LOAD_ARGS_3 (a1, a2, a3)
#define ASM_ARGS_4 ASM_ARGS_3, "r" (_a4)
#define LOAD_ARGS_5(a1, a2, a3, a4, a5) \
register int _v1 __asm__ ("v1") = (int) (a5); \
LOAD_ARGS_4 (a1, a2, a3, a4)
#define ASM_ARGS_5 ASM_ARGS_4, "r" (_v1)
#define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6) \
register int _v2 __asm__ ("v2") = (int) (a6); \
LOAD_ARGS_5 (a1, a2, a3, a4, a5)
#define ASM_ARGS_6 ASM_ARGS_5, "r" (_v2)
#define LOAD_ARGS_7(a1, a2, a3, a4, a5, a6, a7) \
register int _v3 __asm__ ("v3") = (int) (a7); \
LOAD_ARGS_6 (a1, a2, a3, a4, a5, a6)
#define ASM_ARGS_7 ASM_ARGS_6, "r" (_v3)
#if defined(__ARM_EABI__)
#undef INTERNAL_SYSCALL_NCS
#define INTERNAL_SYSCALL_NCS(number, err, nr, args...) \
INTERNAL_SYSCALL_RAW(number, err, nr, args)
#else
/* We can't implement non-constant syscalls directly since the syscall
number is normally encoded in the instruction. So use SYS_syscall. */
#undef INTERNAL_SYSCALL_NCS
#define INTERNAL_SYSCALL_NCS(number, err, nr, args...) \
INTERNAL_SYSCALL_NCS_##nr (number, err, args)
#define INTERNAL_SYSCALL_NCS_0(number, err, args...) \
INTERNAL_SYSCALL (syscall, err, 1, number, args)
#define INTERNAL_SYSCALL_NCS_1(number, err, args...) \
INTERNAL_SYSCALL (syscall, err, 2, number, args)
#define INTERNAL_SYSCALL_NCS_2(number, err, args...) \
INTERNAL_SYSCALL (syscall, err, 3, number, args)
#define INTERNAL_SYSCALL_NCS_3(number, err, args...) \
INTERNAL_SYSCALL (syscall, err, 4, number, args)
#define INTERNAL_SYSCALL_NCS_4(number, err, args...) \
INTERNAL_SYSCALL (syscall, err, 5, number, args)
#define INTERNAL_SYSCALL_NCS_5(number, err, args...) \
INTERNAL_SYSCALL (syscall, err, 6, number, args)
#endif
#endif /* __ASSEMBLER__ */
#endif /* linux/arm/sysdep.h */