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 <asm/ptrace.h> 16 17 static inline long syscall_get_nr(struct task_struct *task, 18 struct pt_regs *regs) 19 { 20 if (regs->trap != __LC_SVC_OLD_PSW) 21 return -1; 22 return regs->gprs[2]; 23 } 24 25 static inline void syscall_rollback(struct task_struct *task, 26 struct pt_regs *regs) 27 { 28 regs->gprs[2] = regs->orig_gpr2; 29 } 30 31 static inline long syscall_get_error(struct task_struct *task, 32 struct pt_regs *regs) 33 { 34 return (regs->gprs[2] >= -4096UL) ? -regs->gprs[2] : 0; 35 } 36 37 static inline long syscall_get_return_value(struct task_struct *task, 38 struct pt_regs *regs) 39 { 40 return regs->gprs[2]; 41 } 42 43 static inline void syscall_set_return_value(struct task_struct *task, 44 struct pt_regs *regs, 45 int error, long val) 46 { 47 regs->gprs[2] = error ? -error : val; 48 } 49 50 static inline void syscall_get_arguments(struct task_struct *task, 51 struct pt_regs *regs, 52 unsigned int i, unsigned int n, 53 unsigned long *args) 54 { 55 BUG_ON(i + n > 6); 56 #ifdef CONFIG_COMPAT 57 if (test_tsk_thread_flag(task, TIF_31BIT)) { 58 if (i + n == 6) 59 args[--n] = (u32) regs->args[0]; 60 while (n-- > 0) 61 args[n] = (u32) regs->gprs[2 + i + n]; 62 } 63 #endif 64 if (i + n == 6) 65 args[--n] = regs->args[0]; 66 memcpy(args, ®s->gprs[2 + i], n * sizeof(args[0])); 67 } 68 69 static inline void syscall_set_arguments(struct task_struct *task, 70 struct pt_regs *regs, 71 unsigned int i, unsigned int n, 72 const unsigned long *args) 73 { 74 BUG_ON(i + n > 6); 75 if (i + n == 6) 76 regs->args[0] = args[--n]; 77 memcpy(®s->gprs[2 + i], args, n * sizeof(args[0])); 78 } 79 80 #endif /* _ASM_SYSCALL_H */ 81