xref: /openbmc/linux/arch/s390/include/asm/syscall.h (revision 7962c2ed)
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_get_arch(struct task_struct * task)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 
arch_syscall_is_vdso_sigreturn(struct pt_regs * regs)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 , "0" (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