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/audit.h> 17 #include <linux/elf-em.h> 18 #include <linux/kernel.h> 19 #include <linux/sched.h> 20 #include <linux/uaccess.h> 21 #include <asm/ptrace.h> 22 23 static inline long syscall_get_nr(struct task_struct *task, 24 struct pt_regs *regs) 25 { 26 return regs->regs[2]; 27 } 28 29 static inline unsigned long mips_get_syscall_arg(unsigned long *arg, 30 struct task_struct *task, struct pt_regs *regs, unsigned int n) 31 { 32 unsigned long usp = regs->regs[29]; 33 34 switch (n) { 35 case 0: case 1: case 2: case 3: 36 *arg = regs->regs[4 + n]; 37 38 return 0; 39 40 #ifdef CONFIG_32BIT 41 case 4: case 5: case 6: case 7: 42 return get_user(*arg, (int *)usp + 4 * n); 43 #endif 44 45 #ifdef CONFIG_64BIT 46 case 4: case 5: case 6: case 7: 47 #ifdef CONFIG_MIPS32_O32 48 if (test_thread_flag(TIF_32BIT_REGS)) 49 return get_user(*arg, (int *)usp + 4 * n); 50 else 51 #endif 52 *arg = regs->regs[4 + n]; 53 54 return 0; 55 #endif 56 57 default: 58 BUG(); 59 } 60 } 61 62 static inline long syscall_get_return_value(struct task_struct *task, 63 struct pt_regs *regs) 64 { 65 return regs->regs[2]; 66 } 67 68 static inline void syscall_set_return_value(struct task_struct *task, 69 struct pt_regs *regs, 70 int error, long val) 71 { 72 if (error) { 73 regs->regs[2] = -error; 74 regs->regs[7] = -1; 75 } else { 76 regs->regs[2] = val; 77 regs->regs[7] = 0; 78 } 79 } 80 81 static inline void syscall_get_arguments(struct task_struct *task, 82 struct pt_regs *regs, 83 unsigned int i, unsigned int n, 84 unsigned long *args) 85 { 86 unsigned long arg; 87 int ret; 88 89 while (n--) 90 ret |= mips_get_syscall_arg(&arg, task, regs, i++); 91 92 /* 93 * No way to communicate an error because this is a void function. 94 */ 95 #if 0 96 return ret; 97 #endif 98 } 99 100 extern const unsigned long sys_call_table[]; 101 extern const unsigned long sys32_call_table[]; 102 extern const unsigned long sysn32_call_table[]; 103 104 static inline int __syscall_get_arch(void) 105 { 106 int arch = EM_MIPS; 107 #ifdef CONFIG_64BIT 108 arch |= __AUDIT_ARCH_64BIT; 109 #endif 110 #if defined(__LITTLE_ENDIAN) 111 arch |= __AUDIT_ARCH_LE; 112 #endif 113 return arch; 114 } 115 116 #endif /* __ASM_MIPS_SYSCALL_H */ 117