Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Access to user system call parameters and results
4 *
5 * Copyright IBM Corp. 2008
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
7 */
8
9#ifndef _ASM_SYSCALL_H
10#define _ASM_SYSCALL_H 1
11
12#include <uapi/linux/audit.h>
13#include <linux/sched.h>
14#include <linux/err.h>
15#include <asm/ptrace.h>
16
17extern const sys_call_ptr_t sys_call_table[];
18
19static inline long syscall_get_nr(struct task_struct *task,
20 struct pt_regs *regs)
21{
22 return test_pt_regs_flag(regs, PIF_SYSCALL) ?
23 (regs->int_code & 0xffff) : -1;
24}
25
26static inline void syscall_set_nr(struct task_struct *task,
27 struct pt_regs *regs,
28 int nr)
29{
30 /*
31 * Unlike syscall_get_nr(), syscall_set_nr() can be called only when
32 * the target task is stopped for tracing on entering syscall, so
33 * there is no need to have the same check syscall_get_nr() has.
34 */
35 regs->int_code = (regs->int_code & ~0xffff) | (nr & 0xffff);
36}
37
38static inline void syscall_rollback(struct task_struct *task,
39 struct pt_regs *regs)
40{
41 regs->gprs[2] = regs->orig_gpr2;
42}
43
44static inline long syscall_get_error(struct task_struct *task,
45 struct pt_regs *regs)
46{
47 unsigned long error = regs->gprs[2];
48
49 return IS_ERR_VALUE(error) ? error : 0;
50}
51
52static inline long syscall_get_return_value(struct task_struct *task,
53 struct pt_regs *regs)
54{
55 return regs->gprs[2];
56}
57
58static inline void syscall_set_return_value(struct task_struct *task,
59 struct pt_regs *regs,
60 int error, long val)
61{
62 set_pt_regs_flag(regs, PIF_SYSCALL_RET_SET);
63 regs->gprs[2] = error ? error : val;
64}
65
66static inline void syscall_get_arguments(struct task_struct *task,
67 struct pt_regs *regs,
68 unsigned long *args)
69{
70 unsigned long mask = -1UL;
71
72 for (int i = 1; i < 6; i++)
73 args[i] = regs->gprs[2 + i] & mask;
74
75 args[0] = regs->orig_gpr2 & mask;
76}
77
78static inline void syscall_set_arguments(struct task_struct *task,
79 struct pt_regs *regs,
80 const unsigned long *args)
81{
82 regs->orig_gpr2 = args[0];
83 for (int n = 1; n < 6; n++)
84 regs->gprs[2 + n] = args[n];
85}
86
87static inline int syscall_get_arch(struct task_struct *task)
88{
89 return AUDIT_ARCH_S390X;
90}
91
92static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
93{
94 return false;
95}
96
97#define SYSCALL_FMT_0
98#define SYSCALL_FMT_1 , "0" (r2)
99#define SYSCALL_FMT_2 , "d" (r3) SYSCALL_FMT_1
100#define SYSCALL_FMT_3 , "d" (r4) SYSCALL_FMT_2
101#define SYSCALL_FMT_4 , "d" (r5) SYSCALL_FMT_3
102#define SYSCALL_FMT_5 , "d" (r6) SYSCALL_FMT_4
103#define SYSCALL_FMT_6 , "d" (r7) SYSCALL_FMT_5
104
105#define SYSCALL_PARM_0
106#define SYSCALL_PARM_1 , long arg1
107#define SYSCALL_PARM_2 SYSCALL_PARM_1, long arg2
108#define SYSCALL_PARM_3 SYSCALL_PARM_2, long arg3
109#define SYSCALL_PARM_4 SYSCALL_PARM_3, long arg4
110#define SYSCALL_PARM_5 SYSCALL_PARM_4, long arg5
111#define SYSCALL_PARM_6 SYSCALL_PARM_5, long arg6
112
113#define SYSCALL_REGS_0
114#define SYSCALL_REGS_1 \
115 register long r2 asm("2") = arg1
116#define SYSCALL_REGS_2 \
117 SYSCALL_REGS_1; \
118 register long r3 asm("3") = arg2
119#define SYSCALL_REGS_3 \
120 SYSCALL_REGS_2; \
121 register long r4 asm("4") = arg3
122#define SYSCALL_REGS_4 \
123 SYSCALL_REGS_3; \
124 register long r5 asm("5") = arg4
125#define SYSCALL_REGS_5 \
126 SYSCALL_REGS_4; \
127 register long r6 asm("6") = arg5
128#define SYSCALL_REGS_6 \
129 SYSCALL_REGS_5; \
130 register long r7 asm("7") = arg6
131
132#define GENERATE_SYSCALL_FUNC(nr) \
133static __always_inline \
134long syscall##nr(unsigned long syscall SYSCALL_PARM_##nr) \
135{ \
136 register unsigned long r1 asm ("1") = syscall; \
137 register long rc asm ("2"); \
138 SYSCALL_REGS_##nr; \
139 \
140 asm volatile ( \
141 " svc 0" \
142 : "=d" (rc) \
143 : "d" (r1) SYSCALL_FMT_##nr \
144 : "memory"); \
145 return rc; \
146}
147
148GENERATE_SYSCALL_FUNC(0)
149GENERATE_SYSCALL_FUNC(1)
150GENERATE_SYSCALL_FUNC(2)
151GENERATE_SYSCALL_FUNC(3)
152GENERATE_SYSCALL_FUNC(4)
153GENERATE_SYSCALL_FUNC(5)
154GENERATE_SYSCALL_FUNC(6)
155
156#endif /* _ASM_SYSCALL_H */