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 /* O32 ABI syscall() - Either 64-bit with O32 or 32-bit */ 33 if ((config_enabled(CONFIG_32BIT) || 34 test_tsk_thread_flag(task, TIF_32BIT_REGS)) && 35 (regs->regs[2] == __NR_syscall)) 36 return regs->regs[4]; 37 else 38 return regs->regs[2]; 39 } 40 41 static inline unsigned long mips_get_syscall_arg(unsigned long *arg, 42 struct task_struct *task, struct pt_regs *regs, unsigned int n) 43 { 44 unsigned long usp __maybe_unused = regs->regs[29]; 45 46 switch (n) { 47 case 0: case 1: case 2: case 3: 48 *arg = regs->regs[4 + n]; 49 50 return 0; 51 52 #ifdef CONFIG_32BIT 53 case 4: case 5: case 6: case 7: 54 return get_user(*arg, (int *)usp + n); 55 #endif 56 57 #ifdef CONFIG_64BIT 58 case 4: case 5: case 6: case 7: 59 #ifdef CONFIG_MIPS32_O32 60 if (test_thread_flag(TIF_32BIT_REGS)) 61 return get_user(*arg, (int *)usp + n); 62 else 63 #endif 64 *arg = regs->regs[4 + n]; 65 66 return 0; 67 #endif 68 69 default: 70 BUG(); 71 } 72 73 unreachable(); 74 } 75 76 static inline long syscall_get_return_value(struct task_struct *task, 77 struct pt_regs *regs) 78 { 79 return regs->regs[2]; 80 } 81 82 static inline void syscall_rollback(struct task_struct *task, 83 struct pt_regs *regs) 84 { 85 /* Do nothing */ 86 } 87 88 static inline void syscall_set_return_value(struct task_struct *task, 89 struct pt_regs *regs, 90 int error, long val) 91 { 92 if (error) { 93 regs->regs[2] = -error; 94 regs->regs[7] = -1; 95 } else { 96 regs->regs[2] = val; 97 regs->regs[7] = 0; 98 } 99 } 100 101 static inline void syscall_get_arguments(struct task_struct *task, 102 struct pt_regs *regs, 103 unsigned int i, unsigned int n, 104 unsigned long *args) 105 { 106 int ret; 107 /* O32 ABI syscall() - Either 64-bit with O32 or 32-bit */ 108 if ((config_enabled(CONFIG_32BIT) || 109 test_tsk_thread_flag(task, TIF_32BIT_REGS)) && 110 (regs->regs[2] == __NR_syscall)) { 111 i++; 112 n++; 113 } 114 115 while (n--) 116 ret |= mips_get_syscall_arg(args++, task, regs, i++); 117 118 /* 119 * No way to communicate an error because this is a void function. 120 */ 121 #if 0 122 return ret; 123 #endif 124 } 125 126 extern const unsigned long sys_call_table[]; 127 extern const unsigned long sys32_call_table[]; 128 extern const unsigned long sysn32_call_table[]; 129 130 static inline int syscall_get_arch(void) 131 { 132 int arch = AUDIT_ARCH_MIPS; 133 #ifdef CONFIG_64BIT 134 if (!test_thread_flag(TIF_32BIT_REGS)) { 135 arch |= __AUDIT_ARCH_64BIT; 136 /* N32 sets only TIF_32BIT_ADDR */ 137 if (test_thread_flag(TIF_32BIT_ADDR)) 138 arch |= __AUDIT_ARCH_CONVENTION_MIPS64_N32; 139 } 140 #endif 141 #if defined(__LITTLE_ENDIAN) 142 arch |= __AUDIT_ARCH_LE; 143 #endif 144 return arch; 145 } 146 147 #endif /* __ASM_MIPS_SYSCALL_H */ 148