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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[];
18extern const sys_call_ptr_t sys_call_table_emu[];
19
20static inline long syscall_get_nr(struct task_struct *task,
21 struct pt_regs *regs)
22{
23 return test_pt_regs_flag(regs, PIF_SYSCALL) ?
24 (regs->int_code & 0xffff) : -1;
25}
26
27static inline void syscall_rollback(struct task_struct *task,
28 struct pt_regs *regs)
29{
30 regs->gprs[2] = regs->orig_gpr2;
31}
32
33static inline long syscall_get_error(struct task_struct *task,
34 struct pt_regs *regs)
35{
36 unsigned long error = regs->gprs[2];
37#ifdef CONFIG_COMPAT
38 if (test_tsk_thread_flag(task, TIF_31BIT)) {
39 /*
40 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
41 * and will match correctly in comparisons.
42 */
43 error = (long)(int)error;
44 }
45#endif
46 return IS_ERR_VALUE(error) ? error : 0;
47}
48
49static inline long syscall_get_return_value(struct task_struct *task,
50 struct pt_regs *regs)
51{
52 return regs->gprs[2];
53}
54
55static inline void syscall_set_return_value(struct task_struct *task,
56 struct pt_regs *regs,
57 int error, long val)
58{
59 set_pt_regs_flag(regs, PIF_SYSCALL_RET_SET);
60 regs->gprs[2] = error ? error : val;
61}
62
63static inline void syscall_get_arguments(struct task_struct *task,
64 struct pt_regs *regs,
65 unsigned long *args)
66{
67 unsigned long mask = -1UL;
68
69#ifdef CONFIG_COMPAT
70 if (test_tsk_thread_flag(task, TIF_31BIT))
71 mask = 0xffffffff;
72#endif
73 for (int i = 1; i < 6; i++)
74 args[i] = regs->gprs[2 + i] & mask;
75
76 args[0] = regs->orig_gpr2 & mask;
77}
78
79static inline int syscall_get_arch(struct task_struct *task)
80{
81#ifdef CONFIG_COMPAT
82 if (test_tsk_thread_flag(task, TIF_31BIT))
83 return AUDIT_ARCH_S390;
84#endif
85 return AUDIT_ARCH_S390X;
86}
87
88static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
89{
90 return false;
91}
92
93#define SYSCALL_FMT_0
94#define SYSCALL_FMT_1 , "0" (r2)
95#define SYSCALL_FMT_2 , "d" (r3) SYSCALL_FMT_1
96#define SYSCALL_FMT_3 , "d" (r4) SYSCALL_FMT_2
97#define SYSCALL_FMT_4 , "d" (r5) SYSCALL_FMT_3
98#define SYSCALL_FMT_5 , "d" (r6) SYSCALL_FMT_4
99#define SYSCALL_FMT_6 , "d" (r7) SYSCALL_FMT_5
100
101#define SYSCALL_PARM_0
102#define SYSCALL_PARM_1 , long arg1
103#define SYSCALL_PARM_2 SYSCALL_PARM_1, long arg2
104#define SYSCALL_PARM_3 SYSCALL_PARM_2, long arg3
105#define SYSCALL_PARM_4 SYSCALL_PARM_3, long arg4
106#define SYSCALL_PARM_5 SYSCALL_PARM_4, long arg5
107#define SYSCALL_PARM_6 SYSCALL_PARM_5, long arg6
108
109#define SYSCALL_REGS_0
110#define SYSCALL_REGS_1 \
111 register long r2 asm("2") = arg1
112#define SYSCALL_REGS_2 \
113 SYSCALL_REGS_1; \
114 register long r3 asm("3") = arg2
115#define SYSCALL_REGS_3 \
116 SYSCALL_REGS_2; \
117 register long r4 asm("4") = arg3
118#define SYSCALL_REGS_4 \
119 SYSCALL_REGS_3; \
120 register long r5 asm("5") = arg4
121#define SYSCALL_REGS_5 \
122 SYSCALL_REGS_4; \
123 register long r6 asm("6") = arg5
124#define SYSCALL_REGS_6 \
125 SYSCALL_REGS_5; \
126 register long r7 asm("7") = arg6
127
128#define GENERATE_SYSCALL_FUNC(nr) \
129static __always_inline \
130long syscall##nr(unsigned long syscall SYSCALL_PARM_##nr) \
131{ \
132 register unsigned long r1 asm ("1") = syscall; \
133 register long rc asm ("2"); \
134 SYSCALL_REGS_##nr; \
135 \
136 asm volatile ( \
137 " svc 0\n" \
138 : "=d" (rc) \
139 : "d" (r1) SYSCALL_FMT_##nr \
140 : "memory"); \
141 return rc; \
142}
143
144GENERATE_SYSCALL_FUNC(0)
145GENERATE_SYSCALL_FUNC(1)
146GENERATE_SYSCALL_FUNC(2)
147GENERATE_SYSCALL_FUNC(3)
148GENERATE_SYSCALL_FUNC(4)
149GENERATE_SYSCALL_FUNC(5)
150GENERATE_SYSCALL_FUNC(6)
151
152#endif /* _ASM_SYSCALL_H */