1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Access to user system call parameters and results
4 *
5 * Copyright (C) 2008-2009 Red Hat, Inc.  All rights reserved.
6 *
7 * See asm-generic/syscall.h for descriptions of what we must do here.
8 */
9
10#ifndef _ASM_X86_SYSCALL_H
11#define _ASM_X86_SYSCALL_H
12
13#include <uapi/linux/audit.h>
14#include <linux/sched.h>
15#include <linux/err.h>
16#include <asm/thread_info.h>	/* for TS_COMPAT */
17#include <asm/unistd.h>
18
19typedef long (*sys_call_ptr_t)(const struct pt_regs *);
20extern const sys_call_ptr_t sys_call_table[];
21
22#if defined(CONFIG_X86_32)
23#define ia32_sys_call_table sys_call_table
24#else
25/*
26 * These may not exist, but still put the prototypes in so we
27 * can use IS_ENABLED().
28 */
29extern const sys_call_ptr_t ia32_sys_call_table[];
30extern const sys_call_ptr_t x32_sys_call_table[];
31#endif
32
33/*
34 * Only the low 32 bits of orig_ax are meaningful, so we return int.
35 * This importantly ignores the high bits on 64-bit, so comparisons
36 * sign-extend the low 32 bits.
37 */
38static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
39{
40	return regs->orig_ax;
41}
42
43static inline void syscall_rollback(struct task_struct *task,
44				    struct pt_regs *regs)
45{
46	regs->ax = regs->orig_ax;
47}
48
49static inline long syscall_get_error(struct task_struct *task,
50				     struct pt_regs *regs)
51{
52	unsigned long error = regs->ax;
53#ifdef CONFIG_IA32_EMULATION
54	/*
55	 * TS_COMPAT is set for 32-bit syscall entries and then
56	 * remains set until we return to user mode.
57	 */
58	if (task->thread_info.status & (TS_COMPAT|TS_I386_REGS_POKED))
59		/*
60		 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
61		 * and will match correctly in comparisons.
62		 */
63		error = (long) (int) error;
64#endif
65	return IS_ERR_VALUE(error) ? error : 0;
66}
67
68static inline long syscall_get_return_value(struct task_struct *task,
69					    struct pt_regs *regs)
70{
71	return regs->ax;
72}
73
74static inline void syscall_set_return_value(struct task_struct *task,
75					    struct pt_regs *regs,
76					    int error, long val)
77{
78	regs->ax = (long) error ?: val;
79}
80
81#ifdef CONFIG_X86_32
82
83static inline void syscall_get_arguments(struct task_struct *task,
84					 struct pt_regs *regs,
85					 unsigned long *args)
86{
87	memcpy(args, &regs->bx, 6 * sizeof(args[0]));
88}
89
90static inline int syscall_get_arch(struct task_struct *task)
91{
92	return AUDIT_ARCH_I386;
93}
94
95#else	 /* CONFIG_X86_64 */
96
97static inline void syscall_get_arguments(struct task_struct *task,
98					 struct pt_regs *regs,
99					 unsigned long *args)
100{
101# ifdef CONFIG_IA32_EMULATION
102	if (task->thread_info.status & TS_COMPAT) {
103		*args++ = regs->bx;
104		*args++ = regs->cx;
105		*args++ = regs->dx;
106		*args++ = regs->si;
107		*args++ = regs->di;
108		*args   = regs->bp;
109	} else
110# endif
111	{
112		*args++ = regs->di;
113		*args++ = regs->si;
114		*args++ = regs->dx;
115		*args++ = regs->r10;
116		*args++ = regs->r8;
117		*args   = regs->r9;
118	}
119}
120
121static inline int syscall_get_arch(struct task_struct *task)
122{
123	/* x32 tasks should be considered AUDIT_ARCH_X86_64. */
124	return (IS_ENABLED(CONFIG_IA32_EMULATION) &&
125		task->thread_info.status & TS_COMPAT)
126		? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
127}
128
129void do_syscall_64(struct pt_regs *regs, int nr);
130
131#endif	/* CONFIG_X86_32 */
132
133void do_int80_syscall_32(struct pt_regs *regs);
134long do_fast_syscall_32(struct pt_regs *regs);
135long do_SYSENTER_32(struct pt_regs *regs);
136
137#endif	/* _ASM_X86_SYSCALL_H */
138