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 */ 23 extern const unsigned int sys_call_table[]; 24 25 static inline long syscall_get_nr(struct task_struct *task, 26 struct pt_regs *regs) 27 { 28 return regs->svcnr ? regs->svcnr : -1; 29 } 30 31 static inline void syscall_rollback(struct task_struct *task, 32 struct pt_regs *regs) 33 { 34 regs->gprs[2] = regs->orig_gpr2; 35 } 36 37 static 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 43 static inline long syscall_get_return_value(struct task_struct *task, 44 struct pt_regs *regs) 45 { 46 return regs->gprs[2]; 47 } 48 49 static 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 56 static 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 while (n-- > 0) 69 if (i + n > 0) 70 args[n] = regs->gprs[2 + i + n] & mask; 71 if (i == 0) 72 args[0] = regs->orig_gpr2 & mask; 73 } 74 75 static inline void syscall_set_arguments(struct task_struct *task, 76 struct pt_regs *regs, 77 unsigned int i, unsigned int n, 78 const unsigned long *args) 79 { 80 BUG_ON(i + n > 6); 81 while (n-- > 0) 82 if (i + n > 0) 83 regs->gprs[2 + i + n] = args[n]; 84 if (i == 0) 85 regs->orig_gpr2 = args[0]; 86 } 87 88 #endif /* _ASM_SYSCALL_H */ 89