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 ((IS_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