| David Howells | a9df42e | 2010-12-03 15:59:50 +0000 | [diff] [blame] | 1 | /* Access to user system call parameters and results | 
 | 2 |  * | 
 | 3 |  * See asm-generic/syscall.h for function descriptions. | 
 | 4 |  * | 
 | 5 |  * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved. | 
 | 6 |  * Written by David Howells (dhowells@redhat.com) | 
 | 7 |  * | 
 | 8 |  * This program is free software; you can redistribute it and/or | 
 | 9 |  * modify it under the terms of the GNU General Public Licence | 
 | 10 |  * as published by the Free Software Foundation; either version | 
 | 11 |  * 2 of the Licence, or (at your option) any later version. | 
 | 12 |  */ | 
 | 13 |  | 
 | 14 | #ifndef _ASM_SYSCALL_H | 
 | 15 | #define _ASM_SYSCALL_H | 
 | 16 |  | 
 | 17 | #include <linux/sched.h> | 
 | 18 | #include <linux/err.h> | 
 | 19 |  | 
 | 20 | extern const unsigned long sys_call_table[]; | 
 | 21 |  | 
 | 22 | static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) | 
 | 23 | { | 
 | 24 | 	return regs->orig_d0; | 
 | 25 | } | 
 | 26 |  | 
 | 27 | static inline void syscall_rollback(struct task_struct *task, | 
 | 28 | 				    struct pt_regs *regs) | 
 | 29 | { | 
 | 30 | 	regs->d0 = regs->orig_d0; | 
 | 31 | } | 
 | 32 |  | 
 | 33 | static inline long syscall_get_error(struct task_struct *task, | 
 | 34 | 				     struct pt_regs *regs) | 
 | 35 | { | 
 | 36 | 	unsigned long error = regs->d0; | 
 | 37 | 	return IS_ERR_VALUE(error) ? error : 0; | 
 | 38 | } | 
 | 39 |  | 
 | 40 | static inline long syscall_get_return_value(struct task_struct *task, | 
 | 41 | 					    struct pt_regs *regs) | 
 | 42 | { | 
 | 43 | 	return regs->d0; | 
 | 44 | } | 
 | 45 |  | 
 | 46 | static inline void syscall_set_return_value(struct task_struct *task, | 
 | 47 | 					    struct pt_regs *regs, | 
 | 48 | 					    int error, long val) | 
 | 49 | { | 
 | 50 | 	regs->d0 = (long) error ?: val; | 
 | 51 | } | 
 | 52 |  | 
 | 53 | static inline void syscall_get_arguments(struct task_struct *task, | 
 | 54 | 					 struct pt_regs *regs, | 
 | 55 | 					 unsigned int i, unsigned int n, | 
 | 56 | 					 unsigned long *args) | 
 | 57 | { | 
 | 58 | 	switch (i) { | 
 | 59 | 	case 0: | 
 | 60 | 		if (!n--) break; | 
 | 61 | 		*args++ = regs->a0; | 
 | 62 | 	case 1: | 
 | 63 | 		if (!n--) break; | 
 | 64 | 		*args++ = regs->d1; | 
 | 65 | 	case 2: | 
 | 66 | 		if (!n--) break; | 
 | 67 | 		*args++ = regs->a3; | 
 | 68 | 	case 3: | 
 | 69 | 		if (!n--) break; | 
 | 70 | 		*args++ = regs->a2; | 
 | 71 | 	case 4: | 
 | 72 | 		if (!n--) break; | 
 | 73 | 		*args++ = regs->d3; | 
 | 74 | 	case 5: | 
 | 75 | 		if (!n--) break; | 
 | 76 | 		*args++ = regs->d2; | 
 | 77 | 	case 6: | 
 | 78 | 		if (!n--) break; | 
 | 79 | 	default: | 
 | 80 | 		BUG(); | 
 | 81 | 		break; | 
 | 82 | 	} | 
 | 83 | } | 
 | 84 |  | 
 | 85 | static inline void syscall_set_arguments(struct task_struct *task, | 
 | 86 | 					 struct pt_regs *regs, | 
 | 87 | 					 unsigned int i, unsigned int n, | 
 | 88 | 					 const unsigned long *args) | 
 | 89 | { | 
 | 90 | 	switch (i) { | 
 | 91 | 	case 0: | 
 | 92 | 		if (!n--) break; | 
 | 93 | 		regs->a0 = *args++; | 
 | 94 | 	case 1: | 
 | 95 | 		if (!n--) break; | 
 | 96 | 		regs->d1 = *args++; | 
 | 97 | 	case 2: | 
 | 98 | 		if (!n--) break; | 
 | 99 | 		regs->a3 = *args++; | 
 | 100 | 	case 3: | 
 | 101 | 		if (!n--) break; | 
 | 102 | 		regs->a2 = *args++; | 
 | 103 | 	case 4: | 
 | 104 | 		if (!n--) break; | 
 | 105 | 		regs->d3 = *args++; | 
 | 106 | 	case 5: | 
 | 107 | 		if (!n--) break; | 
 | 108 | 		regs->d2 = *args++; | 
 | 109 | 	case 6: | 
 | 110 | 		if (!n--) break; | 
 | 111 | 	default: | 
 | 112 | 		BUG(); | 
 | 113 | 		break; | 
 | 114 | 	} | 
 | 115 | } | 
 | 116 |  | 
 | 117 | #endif /* _ASM_SYSCALL_H */ |