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 38 if (is_compat_thread(task_thread_info(task))) 39 error = sign_extend64(error, 31); 40 41 return IS_ERR_VALUE(error) ? error : 0; 42 } 43 44 static inline long syscall_get_return_value(struct task_struct *task, 45 struct pt_regs *regs) 46 { 47 return regs->regs[0]; 48 } 49 50 static inline void syscall_set_return_value(struct task_struct *task, 51 struct pt_regs *regs, 52 int error, long val) 53 { 54 if (error) 55 val = error; 56 57 if (is_compat_thread(task_thread_info(task))) 58 val = lower_32_bits(val); 59 60 regs->regs[0] = val; 61 } 62 63 #define SYSCALL_MAX_ARGS 6 64 65 static inline void syscall_get_arguments(struct task_struct *task, 66 struct pt_regs *regs, 67 unsigned long *args) 68 { 69 args[0] = regs->orig_x0; 70 args++; 71 72 memcpy(args, ®s->regs[1], 5 * sizeof(args[0])); 73 } 74 75 static inline void syscall_set_arguments(struct task_struct *task, 76 struct pt_regs *regs, 77 const unsigned long *args) 78 { 79 regs->orig_x0 = args[0]; 80 args++; 81 82 memcpy(®s->regs[1], args, 5 * sizeof(args[0])); 83 } 84 85 /* 86 * We don't care about endianness (__AUDIT_ARCH_LE bit) here because 87 * AArch64 has the same system calls both on little- and big- endian. 88 */ 89 static inline int syscall_get_arch(struct task_struct *task) 90 { 91 if (is_compat_thread(task_thread_info(task))) 92 return AUDIT_ARCH_ARM; 93 94 return AUDIT_ARCH_AARCH64; 95 } 96 97 #endif /* __ASM_SYSCALL_H */ 98