LXR linux/arch/arm64/include/asm/syscall.h

   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
  12typedef long (*syscall_fn_t)(const struct pt_regs *regs);
  13
  14extern const syscall_fn_t sys_call_table[];
  15
  16#ifdef CONFIG_COMPAT
  17extern const syscall_fn_t compat_sys_call_table[];
  18#endif
  19
  20static inline int syscall_get_nr(struct task_struct *task,
  21                                 struct pt_regs *regs)
  22{
  23        return regs->syscallno;
  24}
  25
  26static inline void syscall_rollback(struct task_struct *task,
  27                                    struct pt_regs *regs)
  28{
  29        regs->regs[0] = regs->orig_x0;
  30}
  31
  32static inline long syscall_get_return_value(struct task_struct *task,
  33                                            struct pt_regs *regs)
  34{
  35        unsigned long val = regs->regs[0];
  36
  37        if (is_compat_thread(task_thread_info(task)))
  38                val = sign_extend64(val, 31);
  39
  40        return val;
  41}
  42
  43static inline long syscall_get_error(struct task_struct *task,
  44                                     struct pt_regs *regs)
  45{
  46        unsigned long error = syscall_get_return_value(task, regs);
  47
  48        return IS_ERR_VALUE(error) ? error : 0;
  49}
  50
  51static inline void syscall_set_return_value(struct task_struct *task,
  52                                            struct pt_regs *regs,
  53                                            int error, long val)
  54{
  55        if (error)
  56                val = error;
  57
  58        if (is_compat_thread(task_thread_info(task)))
  59                val = lower_32_bits(val);
  60
  61        regs->regs[0] = val;
  62}
  63
  64#define SYSCALL_MAX_ARGS 6
  65
  66static inline void syscall_get_arguments(struct task_struct *task,
  67                                         struct pt_regs *regs,
  68                                         unsigned long *args)
  69{
  70        args[0] = regs->orig_x0;
  71        args++;
  72
  73        memcpy(args, &regs->regs[1], 5 * sizeof(args[0]));
  74}
  75
  76static inline void syscall_set_arguments(struct task_struct *task,
  77                                         struct pt_regs *regs,
  78                                         const unsigned long *args)
  79{
  80        regs->orig_x0 = args[0];
  81        args++;
  82
  83        memcpy(&regs->regs[1], args, 5 * sizeof(args[0]));
  84}
  85
  86/*
  87 * We don't care about endianness (__AUDIT_ARCH_LE bit) here because
  88 * AArch64 has the same system calls both on little- and big- endian.
  89 */
  90static inline int syscall_get_arch(struct task_struct *task)
  91{
  92        if (is_compat_thread(task_thread_info(task)))
  93                return AUDIT_ARCH_ARM;
  94
  95        return AUDIT_ARCH_AARCH64;
  96}
  97
  98#endif  /* __ASM_SYSCALL_H */
  99