1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2012 ARM Ltd. 4 */ 5 #ifndef __ASM_SYSCALL_H 6 #define __ASM_SYSCALL_H 7 8 #include <uapi/linux/audit.h> 9 #include <linux/compat.h> 10 #include <linux/err.h> 11 12 typedef long (*syscall_fn_t)(const struct pt_regs *regs); 13 14 extern const syscall_fn_t sys_call_table[]; 15 16 #ifdef CONFIG_COMPAT 17 extern const syscall_fn_t compat_sys_call_table[]; 18 #endif 19 20 static inline int syscall_get_nr(struct task_struct *task, 21 struct pt_regs *regs) 22 { 23 return regs->syscallno; 24 } 25 26 static inline void syscall_rollback(struct task_struct *task, 27 struct pt_regs *regs) 28 { 29 regs->regs[0] = regs->orig_x0; 30 } 31 32 33 static inline long syscall_get_error(struct task_struct *task, 34 struct pt_regs *regs) 35 { 36 unsigned long error = regs->regs[0]; 37 return IS_ERR_VALUE(error) ? error : 0; 38 } 39 40 static inline long syscall_get_return_value(struct task_struct *task, 41 struct pt_regs *regs) 42 { 43 return regs->regs[0]; 44 } 45 46 static inline void syscall_set_return_value(struct task_struct *task, 47 struct pt_regs *regs, 48 int error, long val) 49 { 50 regs->regs[0] = (long) error ? error : val; 51 } 52 53 #define SYSCALL_MAX_ARGS 6 54 55 static inline void syscall_get_arguments(struct task_struct *task, 56 struct pt_regs *regs, 57 unsigned long *args) 58 { 59 args[0] = regs->orig_x0; 60 args++; 61 62 memcpy(args, ®s->regs[1], 5 * sizeof(args[0])); 63 } 64 65 static inline void syscall_set_arguments(struct task_struct *task, 66 struct pt_regs *regs, 67 const unsigned long *args) 68 { 69 regs->orig_x0 = args[0]; 70 args++; 71 72 memcpy(®s->regs[1], args, 5 * sizeof(args[0])); 73 } 74 75 /* 76 * We don't care about endianness (__AUDIT_ARCH_LE bit) here because 77 * AArch64 has the same system calls both on little- and big- endian. 78 */ 79 static inline int syscall_get_arch(struct task_struct *task) 80 { 81 if (is_compat_thread(task_thread_info(task))) 82 return AUDIT_ARCH_ARM; 83 84 return AUDIT_ARCH_AARCH64; 85 } 86 87 #endif /* __ASM_SYSCALL_H */ 88