1 /* 2 * Access to user system call parameters and results 3 * 4 * See asm-generic/syscall.h for function descriptions. 5 * 6 * Copyright (C) 2015 Mickaël Salaün <mic@digikod.net> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 #ifndef __UM_SYSCALL_GENERIC_H 14 #define __UM_SYSCALL_GENERIC_H 15 16 #include <asm/ptrace.h> 17 #include <linux/err.h> 18 #include <linux/sched.h> 19 #include <sysdep/ptrace.h> 20 21 static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) 22 { 23 24 return PT_REGS_SYSCALL_NR(regs); 25 } 26 27 static inline void syscall_rollback(struct task_struct *task, 28 struct pt_regs *regs) 29 { 30 /* do nothing */ 31 } 32 33 static inline long syscall_get_error(struct task_struct *task, 34 struct pt_regs *regs) 35 { 36 const long error = regs_return_value(regs); 37 38 return IS_ERR_VALUE(error) ? error : 0; 39 } 40 41 static inline long syscall_get_return_value(struct task_struct *task, 42 struct pt_regs *regs) 43 { 44 return regs_return_value(regs); 45 } 46 47 static inline void syscall_set_return_value(struct task_struct *task, 48 struct pt_regs *regs, 49 int error, long val) 50 { 51 PT_REGS_SET_SYSCALL_RETURN(regs, (long) error ?: val); 52 } 53 54 static inline void syscall_get_arguments(struct task_struct *task, 55 struct pt_regs *regs, 56 unsigned int i, unsigned int n, 57 unsigned long *args) 58 { 59 const struct uml_pt_regs *r = ®s->regs; 60 61 switch (i) { 62 case 0: 63 if (!n--) 64 break; 65 *args++ = UPT_SYSCALL_ARG1(r); 66 case 1: 67 if (!n--) 68 break; 69 *args++ = UPT_SYSCALL_ARG2(r); 70 case 2: 71 if (!n--) 72 break; 73 *args++ = UPT_SYSCALL_ARG3(r); 74 case 3: 75 if (!n--) 76 break; 77 *args++ = UPT_SYSCALL_ARG4(r); 78 case 4: 79 if (!n--) 80 break; 81 *args++ = UPT_SYSCALL_ARG5(r); 82 case 5: 83 if (!n--) 84 break; 85 *args++ = UPT_SYSCALL_ARG6(r); 86 case 6: 87 if (!n--) 88 break; 89 default: 90 BUG(); 91 break; 92 } 93 } 94 95 static inline void syscall_set_arguments(struct task_struct *task, 96 struct pt_regs *regs, 97 unsigned int i, unsigned int n, 98 const unsigned long *args) 99 { 100 struct uml_pt_regs *r = ®s->regs; 101 102 switch (i) { 103 case 0: 104 if (!n--) 105 break; 106 UPT_SYSCALL_ARG1(r) = *args++; 107 case 1: 108 if (!n--) 109 break; 110 UPT_SYSCALL_ARG2(r) = *args++; 111 case 2: 112 if (!n--) 113 break; 114 UPT_SYSCALL_ARG3(r) = *args++; 115 case 3: 116 if (!n--) 117 break; 118 UPT_SYSCALL_ARG4(r) = *args++; 119 case 4: 120 if (!n--) 121 break; 122 UPT_SYSCALL_ARG5(r) = *args++; 123 case 5: 124 if (!n--) 125 break; 126 UPT_SYSCALL_ARG6(r) = *args++; 127 case 6: 128 if (!n--) 129 break; 130 default: 131 BUG(); 132 break; 133 } 134 } 135 136 /* See arch/x86/um/asm/syscall.h for syscall_get_arch() definition. */ 137 138 #endif /* __UM_SYSCALL_GENERIC_H */ 139