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
17 extern const sys_call_ptr_t sys_call_table[];
18 extern const sys_call_ptr_t sys_call_table_emu[];
19
20 static 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
27 static inline void syscall_rollback(struct task_struct *task,
28 struct pt_regs *regs)
29 {
30 regs->gprs[2] = regs->orig_gpr2;
31 }
32
33 static 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
49 static inline long syscall_get_return_value(struct task_struct *task,
50 struct pt_regs *regs)
51 {
52 return regs->gprs[2];
53 }
54
55 static 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
63 static 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 unsigned int n = 6;
69
70 #ifdef CONFIG_COMPAT
71 if (test_tsk_thread_flag(task, TIF_31BIT))
72 mask = 0xffffffff;
73 #endif
74 while (n-- > 0)
75 if (n > 0)
76 args[n] = regs->gprs[2 + n] & mask;
77
78 args[0] = regs->orig_gpr2 & mask;
79 }
80
81 static inline int syscall_get_arch(struct task_struct *task)
82 {
83 #ifdef CONFIG_COMPAT
84 if (test_tsk_thread_flag(task, TIF_31BIT))
85 return AUDIT_ARCH_S390;
86 #endif
87 return AUDIT_ARCH_S390X;
88 }
89
90 static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
91 {
92 return false;
93 }
94
95 #define SYSCALL_FMT_0
96 #define SYSCALL_FMT_1 , "" (r2)
97 #define SYSCALL_FMT_2 , "d" (r3) SYSCALL_FMT_1
98 #define SYSCALL_FMT_3 , "d" (r4) SYSCALL_FMT_2
99 #define SYSCALL_FMT_4 , "d" (r5) SYSCALL_FMT_3
100 #define SYSCALL_FMT_5 , "d" (r6) SYSCALL_FMT_4
101 #define SYSCALL_FMT_6 , "d" (r7) SYSCALL_FMT_5
102
103 #define SYSCALL_PARM_0
104 #define SYSCALL_PARM_1 , long arg1
105 #define SYSCALL_PARM_2 SYSCALL_PARM_1, long arg2
106 #define SYSCALL_PARM_3 SYSCALL_PARM_2, long arg3
107 #define SYSCALL_PARM_4 SYSCALL_PARM_3, long arg4
108 #define SYSCALL_PARM_5 SYSCALL_PARM_4, long arg5
109 #define SYSCALL_PARM_6 SYSCALL_PARM_5, long arg6
110
111 #define SYSCALL_REGS_0
112 #define SYSCALL_REGS_1 \
113 register long r2 asm("2") = arg1
114 #define SYSCALL_REGS_2 \
115 SYSCALL_REGS_1; \
116 register long r3 asm("3") = arg2
117 #define SYSCALL_REGS_3 \
118 SYSCALL_REGS_2; \
119 register long r4 asm("4") = arg3
120 #define SYSCALL_REGS_4 \
121 SYSCALL_REGS_3; \
122 register long r5 asm("5") = arg4
123 #define SYSCALL_REGS_5 \
124 SYSCALL_REGS_4; \
125 register long r6 asm("6") = arg5
126 #define SYSCALL_REGS_6 \
127 SYSCALL_REGS_5; \
128 register long r7 asm("7") = arg6
129
130 #define GENERATE_SYSCALL_FUNC(nr) \
131 static __always_inline \
132 long syscall##nr(unsigned long syscall SYSCALL_PARM_##nr) \
133 { \
134 register unsigned long r1 asm ("1") = syscall; \
135 register long rc asm ("2"); \
136 SYSCALL_REGS_##nr; \
137 \
138 asm volatile ( \
139 " svc 0\n" \
140 : "=d" (rc) \
141 : "d" (r1) SYSCALL_FMT_##nr \
142 : "memory"); \
143 return rc; \
144 }
145
146 GENERATE_SYSCALL_FUNC(0)
147 GENERATE_SYSCALL_FUNC(1)
148 GENERATE_SYSCALL_FUNC(2)
149 GENERATE_SYSCALL_FUNC(3)
150 GENERATE_SYSCALL_FUNC(4)
151 GENERATE_SYSCALL_FUNC(5)
152 GENERATE_SYSCALL_FUNC(6)
153
154 #endif /* _ASM_SYSCALL_H */
155
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.