1 /*
2  * Access to user system call parameters and results
3  *
4  * See asm-generic/syscall.h for function descriptions.
5  *
6  * Copyright (C) 2015 Mickaël Salaün <mic@digikod.net>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #ifndef __UM_SYSCALL_GENERIC_H
14 #define __UM_SYSCALL_GENERIC_H
15 
16 #include <asm/ptrace.h>
17 #include <linux/err.h>
18 #include <linux/sched.h>
19 #include <sysdep/ptrace.h>
20 
21 static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
22 {
23 
24 	return PT_REGS_SYSCALL_NR(regs);
25 }
26 
27 static inline void syscall_rollback(struct task_struct *task,
28 				    struct pt_regs *regs)
29 {
30 	/* do nothing */
31 }
32 
33 static inline long syscall_get_error(struct task_struct *task,
34 				     struct pt_regs *regs)
35 {
36 	const long error = regs_return_value(regs);
37 
38 	return IS_ERR_VALUE(error) ? error : 0;
39 }
40 
41 static inline long syscall_get_return_value(struct task_struct *task,
42 					    struct pt_regs *regs)
43 {
44 	return regs_return_value(regs);
45 }
46 
47 static inline void syscall_set_return_value(struct task_struct *task,
48 					    struct pt_regs *regs,
49 					    int error, long val)
50 {
51 	PT_REGS_SET_SYSCALL_RETURN(regs, (long) error ?: val);
52 }
53 
54 static inline void syscall_get_arguments(struct task_struct *task,
55 					 struct pt_regs *regs,
56 					 unsigned long *args)
57 {
58 	const struct uml_pt_regs *r = &regs->regs;
59 
60 	*args++ = UPT_SYSCALL_ARG1(r);
61 	*args++ = UPT_SYSCALL_ARG2(r);
62 	*args++ = UPT_SYSCALL_ARG3(r);
63 	*args++ = UPT_SYSCALL_ARG4(r);
64 	*args++ = UPT_SYSCALL_ARG5(r);
65 	*args   = UPT_SYSCALL_ARG6(r);
66 }
67 
68 static inline void syscall_set_arguments(struct task_struct *task,
69 					 struct pt_regs *regs,
70 					 const unsigned long *args)
71 {
72 	struct uml_pt_regs *r = &regs->regs;
73 
74 	UPT_SYSCALL_ARG1(r) = *args++;
75 	UPT_SYSCALL_ARG2(r) = *args++;
76 	UPT_SYSCALL_ARG3(r) = *args++;
77 	UPT_SYSCALL_ARG4(r) = *args++;
78 	UPT_SYSCALL_ARG5(r) = *args++;
79 	UPT_SYSCALL_ARG6(r) = *args;
80 }
81 
82 /* See arch/x86/um/asm/syscall.h for syscall_get_arch() definition. */
83 
84 #endif	/* __UM_SYSCALL_GENERIC_H */
85