linux/arch/x86/include/asm/syscall.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Access to user system call parameters and results
 *
 * Copyright (C) 2008-2009 Red Hat, Inc.  All rights reserved.
 *
 * See asm-generic/syscall.h for descriptions of what we must do here.
 */

#ifndef _ASM_X86_SYSCALL_H
#define _ASM_X86_SYSCALL_H

#include <uapi/linux/audit.h>
#include <linux/sched.h>
#include <linux/err.h>
#include <asm/thread_info.h>	/* for TS_COMPAT */
#include <asm/unistd.h>

/* This is used purely for kernel/trace/trace_syscalls.c */
sys_call_ptr_t;
extern const sys_call_ptr_t sys_call_table[];

/*
 * These may not exist, but still put the prototypes in so we
 * can use IS_ENABLED().
 */
extern long ia32_sys_call(const struct pt_regs *, unsigned int nr);
extern long x32_sys_call(const struct pt_regs *, unsigned int nr);
extern long x64_sys_call(const struct pt_regs *, unsigned int nr);

/*
 * Only the low 32 bits of orig_ax are meaningful, so we return int.
 * This importantly ignores the high bits on 64-bit, so comparisons
 * sign-extend the low 32 bits.
 */
static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
{ … }

static inline void syscall_rollback(struct task_struct *task,
				    struct pt_regs *regs)
{ … }

static inline long syscall_get_error(struct task_struct *task,
				     struct pt_regs *regs)
{ … }

static inline long syscall_get_return_value(struct task_struct *task,
					    struct pt_regs *regs)
{ … }

static inline void syscall_set_return_value(struct task_struct *task,
					    struct pt_regs *regs,
					    int error, long val)
{ … }

#ifdef CONFIG_X86_32

static inline void syscall_get_arguments(struct task_struct *task,
					 struct pt_regs *regs,
					 unsigned long *args)
{
	memcpy(args, &regs->bx, 6 * sizeof(args[0]));
}

static inline int syscall_get_arch(struct task_struct *task)
{
	return AUDIT_ARCH_I386;
}

#else	 /* CONFIG_X86_64 */

static inline void syscall_get_arguments(struct task_struct *task,
					 struct pt_regs *regs,
					 unsigned long *args)
{ … }

static inline int syscall_get_arch(struct task_struct *task)
{ … }

bool do_syscall_64(struct pt_regs *regs, int nr);
void do_int80_emulation(struct pt_regs *regs);

#endif	/* CONFIG_X86_32 */

void do_int80_syscall_32(struct pt_regs *regs);
bool do_fast_syscall_32(struct pt_regs *regs);
bool do_SYSENTER_32(struct pt_regs *regs);

#endif	/* _ASM_X86_SYSCALL_H */