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 <linux/err.h>
17 #include <asm/ptrace.h>
18
19 /*
20 * The syscall table always contains 32 bit pointers since we know that the
21 * address of the function to be called is (way) below 4GB. So the "int"
22 * type here is what we want [need] for both 32 bit and 64 bit systems.
23 */
24 extern const unsigned int sys_call_table[];
25
syscall_get_nr(struct task_struct * task,struct pt_regs * regs)26 static inline long syscall_get_nr(struct task_struct *task,
27 struct pt_regs *regs)
28 {
29 return test_tsk_thread_flag(task, TIF_SYSCALL) ?
30 (regs->int_code & 0xffff) : -1;
31 }
32
syscall_rollback(struct task_struct * task,struct pt_regs * regs)33 static inline void syscall_rollback(struct task_struct *task,
34 struct pt_regs *regs)
35 {
36 regs->gprs[2] = regs->orig_gpr2;
37 }
38
syscall_get_error(struct task_struct * task,struct pt_regs * regs)39 static inline long syscall_get_error(struct task_struct *task,
40 struct pt_regs *regs)
41 {
42 return IS_ERR_VALUE(regs->gprs[2]) ? regs->gprs[2] : 0;
43 }
44
syscall_get_return_value(struct task_struct * task,struct pt_regs * regs)45 static inline long syscall_get_return_value(struct task_struct *task,
46 struct pt_regs *regs)
47 {
48 return regs->gprs[2];
49 }
50
syscall_set_return_value(struct task_struct * task,struct pt_regs * regs,int error,long val)51 static inline void syscall_set_return_value(struct task_struct *task,
52 struct pt_regs *regs,
53 int error, long val)
54 {
55 regs->gprs[2] = error ? -error : val;
56 }
57
syscall_get_arguments(struct task_struct * task,struct pt_regs * regs,unsigned int i,unsigned int n,unsigned long * args)58 static inline void syscall_get_arguments(struct task_struct *task,
59 struct pt_regs *regs,
60 unsigned int i, unsigned int n,
61 unsigned long *args)
62 {
63 unsigned long mask = -1UL;
64
65 BUG_ON(i + n > 6);
66 #ifdef CONFIG_COMPAT
67 if (test_tsk_thread_flag(task, TIF_31BIT))
68 mask = 0xffffffff;
69 #endif
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
syscall_set_arguments(struct task_struct * task,struct pt_regs * regs,unsigned int i,unsigned int n,const unsigned long * args)77 static 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 while (n-- > 0)
84 if (i + n > 0)
85 regs->gprs[2 + i + n] = args[n];
86 if (i == 0)
87 regs->orig_gpr2 = args[0];
88 }
89
90 #endif /* _ASM_SYSCALL_H */
91