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
syscall_get_nr(struct task_struct * task,struct pt_regs * regs)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
syscall_rollback(struct task_struct * task,struct pt_regs * regs)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
syscall_get_error(struct task_struct * task,struct pt_regs * regs)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
syscall_get_return_value(struct task_struct * task,struct pt_regs * regs)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
syscall_set_return_value(struct task_struct * task,struct pt_regs * regs,int error,long val)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
syscall_get_arguments(struct task_struct * task,struct pt_regs * regs,unsigned long * args)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
syscall_set_arguments(struct task_struct * task,struct pt_regs * regs,const unsigned long * args)81 static inline void syscall_set_arguments(struct task_struct *task,
82 struct pt_regs *regs,
83 const unsigned long *args)
84 {
85 unsigned int n = 6;
86
87 while (n-- > 0)
88 if (n > 0)
89 regs->gprs[2 + n] = args[n];
90 regs->orig_gpr2 = args[0];
91 }
92
syscall_get_arch(struct task_struct * task)93 static inline int syscall_get_arch(struct task_struct *task)
94 {
95 #ifdef CONFIG_COMPAT
96 if (test_tsk_thread_flag(task, TIF_31BIT))
97 return AUDIT_ARCH_S390;
98 #endif
99 return AUDIT_ARCH_S390X;
100 }
101
arch_syscall_is_vdso_sigreturn(struct pt_regs * regs)102 static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
103 {
104 return false;
105 }
106
107 #define SYSCALL_FMT_0
108 #define SYSCALL_FMT_1 , "0" (r2)
109 #define SYSCALL_FMT_2 , "d" (r3) SYSCALL_FMT_1
110 #define SYSCALL_FMT_3 , "d" (r4) SYSCALL_FMT_2
111 #define SYSCALL_FMT_4 , "d" (r5) SYSCALL_FMT_3
112 #define SYSCALL_FMT_5 , "d" (r6) SYSCALL_FMT_4
113 #define SYSCALL_FMT_6 , "d" (r7) SYSCALL_FMT_5
114
115 #define SYSCALL_PARM_0
116 #define SYSCALL_PARM_1 , long arg1
117 #define SYSCALL_PARM_2 SYSCALL_PARM_1, long arg2
118 #define SYSCALL_PARM_3 SYSCALL_PARM_2, long arg3
119 #define SYSCALL_PARM_4 SYSCALL_PARM_3, long arg4
120 #define SYSCALL_PARM_5 SYSCALL_PARM_4, long arg5
121 #define SYSCALL_PARM_6 SYSCALL_PARM_5, long arg6
122
123 #define SYSCALL_REGS_0
124 #define SYSCALL_REGS_1 \
125 register long r2 asm("2") = arg1
126 #define SYSCALL_REGS_2 \
127 SYSCALL_REGS_1; \
128 register long r3 asm("3") = arg2
129 #define SYSCALL_REGS_3 \
130 SYSCALL_REGS_2; \
131 register long r4 asm("4") = arg3
132 #define SYSCALL_REGS_4 \
133 SYSCALL_REGS_3; \
134 register long r5 asm("5") = arg4
135 #define SYSCALL_REGS_5 \
136 SYSCALL_REGS_4; \
137 register long r6 asm("6") = arg5
138 #define SYSCALL_REGS_6 \
139 SYSCALL_REGS_5; \
140 register long r7 asm("7") = arg6
141
142 #define GENERATE_SYSCALL_FUNC(nr) \
143 static __always_inline \
144 long syscall##nr(unsigned long syscall SYSCALL_PARM_##nr) \
145 { \
146 register unsigned long r1 asm ("1") = syscall; \
147 register long rc asm ("2"); \
148 SYSCALL_REGS_##nr; \
149 \
150 asm volatile ( \
151 " svc 0\n" \
152 : "=d" (rc) \
153 : "d" (r1) SYSCALL_FMT_##nr \
154 : "memory"); \
155 return rc; \
156 }
157
158 GENERATE_SYSCALL_FUNC(0)
159 GENERATE_SYSCALL_FUNC(1)
160 GENERATE_SYSCALL_FUNC(2)
161 GENERATE_SYSCALL_FUNC(3)
162 GENERATE_SYSCALL_FUNC(4)
163 GENERATE_SYSCALL_FUNC(5)
164 GENERATE_SYSCALL_FUNC(6)
165
166 #endif /* _ASM_SYSCALL_H */
167