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 <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 24 static inline long syscall_get_nr(struct task_struct *task, 25 struct pt_regs *regs) 26 { 27 return regs->regs[2]; 28 } 29 30 static inline unsigned long mips_get_syscall_arg(unsigned long *arg, 31 struct task_struct *task, struct pt_regs *regs, unsigned int n) 32 { 33 unsigned long usp __maybe_unused = regs->regs[29]; 34 35 switch (n) { 36 case 0: case 1: case 2: case 3: 37 *arg = regs->regs[4 + n]; 38 39 return 0; 40 41 #ifdef CONFIG_32BIT 42 case 4: case 5: case 6: case 7: 43 return get_user(*arg, (int *)usp + n); 44 #endif 45 46 #ifdef CONFIG_64BIT 47 case 4: case 5: case 6: case 7: 48 #ifdef CONFIG_MIPS32_O32 49 if (test_thread_flag(TIF_32BIT_REGS)) 50 return get_user(*arg, (int *)usp + n); 51 else 52 #endif 53 *arg = regs->regs[4 + n]; 54 55 return 0; 56 #endif 57 58 default: 59 BUG(); 60 } 61 62 unreachable(); 63 } 64 65 static inline long syscall_get_return_value(struct task_struct *task, 66 struct pt_regs *regs) 67 { 68 return regs->regs[2]; 69 } 70 71 static inline void syscall_set_return_value(struct task_struct *task, 72 struct pt_regs *regs, 73 int error, long val) 74 { 75 if (error) { 76 regs->regs[2] = -error; 77 regs->regs[7] = -1; 78 } else { 79 regs->regs[2] = val; 80 regs->regs[7] = 0; 81 } 82 } 83 84 static inline void syscall_get_arguments(struct task_struct *task, 85 struct pt_regs *regs, 86 unsigned int i, unsigned int n, 87 unsigned long *args) 88 { 89 int ret; 90 91 while (n--) 92 ret |= mips_get_syscall_arg(args++, task, regs, i++); 93 94 /* 95 * No way to communicate an error because this is a void function. 96 */ 97 #if 0 98 return ret; 99 #endif 100 } 101 102 extern const unsigned long sys_call_table[]; 103 extern const unsigned long sys32_call_table[]; 104 extern const unsigned long sysn32_call_table[]; 105 106 static inline int __syscall_get_arch(void) 107 { 108 int arch = EM_MIPS; 109 #ifdef CONFIG_64BIT 110 arch |= __AUDIT_ARCH_64BIT; 111 #endif 112 #if defined(__LITTLE_ENDIAN) 113 arch |= __AUDIT_ARCH_LE; 114 #endif 115 return arch; 116 } 117 118 #endif /* __ASM_MIPS_SYSCALL_H */ 119