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 static inline long syscall_get_nr(struct task_struct *task, 19 struct pt_regs *regs) 20 { 21 return regs->svcnr ? regs->svcnr : -1; 22 } 23 24 static inline void syscall_rollback(struct task_struct *task, 25 struct pt_regs *regs) 26 { 27 regs->gprs[2] = regs->orig_gpr2; 28 } 29 30 static inline long syscall_get_error(struct task_struct *task, 31 struct pt_regs *regs) 32 { 33 return (regs->gprs[2] >= -4096UL) ? -regs->gprs[2] : 0; 34 } 35 36 static inline long syscall_get_return_value(struct task_struct *task, 37 struct pt_regs *regs) 38 { 39 return regs->gprs[2]; 40 } 41 42 static inline void syscall_set_return_value(struct task_struct *task, 43 struct pt_regs *regs, 44 int error, long val) 45 { 46 regs->gprs[2] = error ? -error : val; 47 } 48 49 static inline void syscall_get_arguments(struct task_struct *task, 50 struct pt_regs *regs, 51 unsigned int i, unsigned int n, 52 unsigned long *args) 53 { 54 unsigned long mask = -1UL; 55 56 BUG_ON(i + n > 6); 57 #ifdef CONFIG_COMPAT 58 if (test_tsk_thread_flag(task, TIF_31BIT)) 59 mask = 0xffffffff; 60 #endif 61 if (i + n == 6) 62 args[--n] = regs->args[0] & mask; 63 while (n-- > 0) 64 if (i + n > 0) 65 args[n] = regs->gprs[2 + i + n] & mask; 66 if (i == 0) 67 args[0] = regs->orig_gpr2 & mask; 68 } 69 70 static inline void syscall_set_arguments(struct task_struct *task, 71 struct pt_regs *regs, 72 unsigned int i, unsigned int n, 73 const unsigned long *args) 74 { 75 BUG_ON(i + n > 6); 76 if (i + n == 6) 77 regs->args[0] = args[--n]; 78 while (n-- > 0) 79 if (i + n > 0) 80 regs->gprs[2 + i + n] = args[n]; 81 if (i == 0) 82 regs->orig_gpr2 = args[0]; 83 } 84 85 #endif /* _ASM_SYSCALL_H */ 86