1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Access to user system call parameters and results
4  *
5  * See asm-generic/syscall.h for function descriptions.
6  *
7  * Copyright (C) 2015 Mickaël Salaün <mic@digikod.net>
8  */
9 
10 #ifndef __UM_SYSCALL_GENERIC_H
11 #define __UM_SYSCALL_GENERIC_H
12 
13 #include <asm/ptrace.h>
14 #include <linux/err.h>
15 #include <linux/sched.h>
16 #include <sysdep/ptrace.h>
17 
18 static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
19 {
20 
21 	return PT_REGS_SYSCALL_NR(regs);
22 }
23 
24 static inline void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr)
25 {
26 	PT_REGS_SYSCALL_NR(regs) = nr;
27 }
28 
29 static inline void syscall_rollback(struct task_struct *task,
30 				    struct pt_regs *regs)
31 {
32 	/* do nothing */
33 }
34 
35 static inline long syscall_get_error(struct task_struct *task,
36 				     struct pt_regs *regs)
37 {
38 	const long error = regs_return_value(regs);
39 
40 	return IS_ERR_VALUE(error) ? error : 0;
41 }
42 
43 static inline long syscall_get_return_value(struct task_struct *task,
44 					    struct pt_regs *regs)
45 {
46 	return regs_return_value(regs);
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 	PT_REGS_SET_SYSCALL_RETURN(regs, (long) error ?: val);
54 }
55 
56 static inline void syscall_get_arguments(struct task_struct *task,
57 					 struct pt_regs *regs,
58 					 unsigned long *args)
59 {
60 	const struct uml_pt_regs *r = &regs->regs;
61 
62 	*args++ = UPT_SYSCALL_ARG1(r);
63 	*args++ = UPT_SYSCALL_ARG2(r);
64 	*args++ = UPT_SYSCALL_ARG3(r);
65 	*args++ = UPT_SYSCALL_ARG4(r);
66 	*args++ = UPT_SYSCALL_ARG5(r);
67 	*args   = UPT_SYSCALL_ARG6(r);
68 }
69 
70 static inline void syscall_set_arguments(struct task_struct *task,
71 					 struct pt_regs *regs,
72 					 const unsigned long *args)
73 {
74 	struct uml_pt_regs *r = &regs->regs;
75 
76 	UPT_SYSCALL_ARG1(r) = *args++;
77 	UPT_SYSCALL_ARG2(r) = *args++;
78 	UPT_SYSCALL_ARG3(r) = *args++;
79 	UPT_SYSCALL_ARG4(r) = *args++;
80 	UPT_SYSCALL_ARG5(r) = *args++;
81 	UPT_SYSCALL_ARG6(r) = *args;
82 }
83 
84 /* See arch/x86/um/asm/syscall.h for syscall_get_arch() definition. */
85 
86 #endif	/* __UM_SYSCALL_GENERIC_H */
87