1 /*
2 * Access to user system call parameters and results
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * See asm-generic/syscall.h for descriptions of what we must do here.
9 *
10 * Copyright (C) 2012 Ralf Baechle <ralf@linux-mips.org>
11 */
12
13 #ifndef __ASM_MIPS_SYSCALL_H
14 #define __ASM_MIPS_SYSCALL_H
15
16 #include <linux/compiler.h>
17 #include <uapi/linux/audit.h>
18 #include <linux/elf-em.h>
19 #include <linux/kernel.h>
20 #include <linux/sched.h>
21 #include <linux/uaccess.h>
22 #include <asm/ptrace.h>
23 #include <asm/unistd.h>
24
25 #ifndef __NR_syscall /* Only defined if _MIPS_SIM == _MIPS_SIM_ABI32 */
26 #define __NR_syscall 4000
27 #endif
28
syscall_get_nr(struct task_struct * task,struct pt_regs * regs)29 static inline long syscall_get_nr(struct task_struct *task,
30 struct pt_regs *regs)
31 {
32 return current_thread_info()->syscall;
33 }
34
mips_get_syscall_arg(unsigned long * arg,struct task_struct * task,struct pt_regs * regs,unsigned int n)35 static inline unsigned long mips_get_syscall_arg(unsigned long *arg,
36 struct task_struct *task, struct pt_regs *regs, unsigned int n)
37 {
38 unsigned long usp __maybe_unused = regs->regs[29];
39
40 switch (n) {
41 case 0: case 1: case 2: case 3:
42 *arg = regs->regs[4 + n];
43
44 return 0;
45
46 #ifdef CONFIG_32BIT
47 case 4: case 5: case 6: case 7:
48 return get_user(*arg, (int *)usp + n);
49 #endif
50
51 #ifdef CONFIG_64BIT
52 case 4: case 5: case 6: case 7:
53 #ifdef CONFIG_MIPS32_O32
54 if (test_thread_flag(TIF_32BIT_REGS))
55 return get_user(*arg, (int *)usp + n);
56 else
57 #endif
58 *arg = regs->regs[4 + n];
59
60 return 0;
61 #endif
62
63 default:
64 BUG();
65 }
66
67 unreachable();
68 }
69
syscall_get_return_value(struct task_struct * task,struct pt_regs * regs)70 static inline long syscall_get_return_value(struct task_struct *task,
71 struct pt_regs *regs)
72 {
73 return regs->regs[2];
74 }
75
syscall_rollback(struct task_struct * task,struct pt_regs * regs)76 static inline void syscall_rollback(struct task_struct *task,
77 struct pt_regs *regs)
78 {
79 /* Do nothing */
80 }
81
syscall_set_return_value(struct task_struct * task,struct pt_regs * regs,int error,long val)82 static inline void syscall_set_return_value(struct task_struct *task,
83 struct pt_regs *regs,
84 int error, long val)
85 {
86 if (error) {
87 regs->regs[2] = -error;
88 regs->regs[7] = -1;
89 } else {
90 regs->regs[2] = val;
91 regs->regs[7] = 0;
92 }
93 }
94
syscall_get_arguments(struct task_struct * task,struct pt_regs * regs,unsigned int i,unsigned int n,unsigned long * args)95 static inline void syscall_get_arguments(struct task_struct *task,
96 struct pt_regs *regs,
97 unsigned int i, unsigned int n,
98 unsigned long *args)
99 {
100 int ret;
101 /* O32 ABI syscall() - Either 64-bit with O32 or 32-bit */
102 if ((config_enabled(CONFIG_32BIT) ||
103 test_tsk_thread_flag(task, TIF_32BIT_REGS)) &&
104 (regs->regs[2] == __NR_syscall))
105 i++;
106
107 while (n--)
108 ret |= mips_get_syscall_arg(args++, task, regs, i++);
109
110 /*
111 * No way to communicate an error because this is a void function.
112 */
113 #if 0
114 return ret;
115 #endif
116 }
117
118 extern const unsigned long sys_call_table[];
119 extern const unsigned long sys32_call_table[];
120 extern const unsigned long sysn32_call_table[];
121
syscall_get_arch(void)122 static inline int syscall_get_arch(void)
123 {
124 int arch = AUDIT_ARCH_MIPS;
125 #ifdef CONFIG_64BIT
126 if (!test_thread_flag(TIF_32BIT_REGS)) {
127 arch |= __AUDIT_ARCH_64BIT;
128 /* N32 sets only TIF_32BIT_ADDR */
129 if (test_thread_flag(TIF_32BIT_ADDR))
130 arch |= __AUDIT_ARCH_CONVENTION_MIPS64_N32;
131 }
132 #endif
133 #if defined(__LITTLE_ENDIAN)
134 arch |= __AUDIT_ARCH_LE;
135 #endif
136 return arch;
137 }
138
139 #endif /* __ASM_MIPS_SYSCALL_H */
140