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