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 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 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 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 76 static inline void syscall_rollback(struct task_struct *task, 77 struct pt_regs *regs) 78 { 79 /* Do nothing */ 80 } 81 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 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 n++; 107 } 108 109 while (n--) 110 ret |= mips_get_syscall_arg(args++, task, regs, i++); 111 112 /* 113 * No way to communicate an error because this is a void function. 114 */ 115 #if 0 116 return ret; 117 #endif 118 } 119 120 extern const unsigned long sys_call_table[]; 121 extern const unsigned long sys32_call_table[]; 122 extern const unsigned long sysn32_call_table[]; 123 124 static inline int syscall_get_arch(void) 125 { 126 int arch = AUDIT_ARCH_MIPS; 127 #ifdef CONFIG_64BIT 128 if (!test_thread_flag(TIF_32BIT_REGS)) { 129 arch |= __AUDIT_ARCH_64BIT; 130 /* N32 sets only TIF_32BIT_ADDR */ 131 if (test_thread_flag(TIF_32BIT_ADDR)) 132 arch |= __AUDIT_ARCH_CONVENTION_MIPS64_N32; 133 } 134 #endif 135 #if defined(__LITTLE_ENDIAN) 136 arch |= __AUDIT_ARCH_LE; 137 #endif 138 return arch; 139 } 140 141 #endif /* __ASM_MIPS_SYSCALL_H */ 142