1/* 2 * Access to user system call parameters and results 3 * 4 * Copyright IBM Corp. 2008 5 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License (version 2 only) 9 * as published by the Free Software Foundation. 10 */ 11 12#ifndef _ASM_SYSCALL_H 13#define _ASM_SYSCALL_H 1 14 15#include <linux/sched.h> 16#include <asm/ptrace.h> 17 18/* 19 * The syscall table always contains 32 bit pointers since we know that the 20 * address of the function to be called is (way) below 4GB. So the "int" 21 * type here is what we want [need] for both 32 bit and 64 bit systems. 22 */ 23extern const unsigned int sys_call_table[]; 24 25static inline long syscall_get_nr(struct task_struct *task, 26 struct pt_regs *regs) 27{ 28 return regs->svcnr ? regs->svcnr : -1; 29} 30 31static inline void syscall_rollback(struct task_struct *task, 32 struct pt_regs *regs) 33{ 34 regs->gprs[2] = regs->orig_gpr2; 35} 36 37static inline long syscall_get_error(struct task_struct *task, 38 struct pt_regs *regs) 39{ 40 return (regs->gprs[2] >= -4096UL) ? -regs->gprs[2] : 0; 41} 42 43static inline long syscall_get_return_value(struct task_struct *task, 44 struct pt_regs *regs) 45{ 46 return regs->gprs[2]; 47} 48 49static inline void syscall_set_return_value(struct task_struct *task, 50 struct pt_regs *regs, 51 int error, long val) 52{ 53 regs->gprs[2] = error ? -error : val; 54} 55 56static inline void syscall_get_arguments(struct task_struct *task, 57 struct pt_regs *regs, 58 unsigned int i, unsigned int n, 59 unsigned long *args) 60{ 61 unsigned long mask = -1UL; 62 63 BUG_ON(i + n > 6); 64#ifdef CONFIG_COMPAT 65 if (test_tsk_thread_flag(task, TIF_31BIT)) 66 mask = 0xffffffff; 67#endif 68 if (i + n == 6) 69 args[--n] = regs->args[0] & mask; 70 while (n-- > 0) 71 if (i + n > 0) 72 args[n] = regs->gprs[2 + i + n] & mask; 73 if (i == 0) 74 args[0] = regs->orig_gpr2 & mask; 75} 76 77static inline void syscall_set_arguments(struct task_struct *task, 78 struct pt_regs *regs, 79 unsigned int i, unsigned int n, 80 const unsigned long *args) 81{ 82 BUG_ON(i + n > 6); 83 if (i + n == 6) 84 regs->args[0] = args[--n]; 85 while (n-- > 0) 86 if (i + n > 0) 87 regs->gprs[2 + i + n] = args[n]; 88 if (i == 0) 89 regs->orig_gpr2 = args[0]; 90} 91 92#endif /* _ASM_SYSCALL_H */ 93