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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
19/* This is used purely for kernel/trace/trace_syscalls.c */
20typedef long (*sys_call_ptr_t)(const struct pt_regs *);
21extern const sys_call_ptr_t sys_call_table[];
22
23/*
24 * Only the low 32 bits of orig_ax are meaningful, so we return int.
25 * This importantly ignores the high bits on 64-bit, so comparisons
26 * sign-extend the low 32 bits.
27 */
28static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
29{
30 return regs->orig_ax;
31}
32
33static inline void syscall_set_nr(struct task_struct *task,
34 struct pt_regs *regs,
35 int nr)
36{
37 regs->orig_ax = nr;
38}
39
40static inline void syscall_rollback(struct task_struct *task,
41 struct pt_regs *regs)
42{
43 regs->ax = regs->orig_ax;
44}
45
46static inline long syscall_get_error(struct task_struct *task,
47 struct pt_regs *regs)
48{
49 unsigned long error = regs->ax;
50#ifdef CONFIG_IA32_EMULATION
51 /*
52 * TS_COMPAT is set for 32-bit syscall entries and then
53 * remains set until we return to user mode.
54 */
55 if (task->thread_info.status & (TS_COMPAT|TS_I386_REGS_POKED))
56 /*
57 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
58 * and will match correctly in comparisons.
59 */
60 error = (long) (int) error;
61#endif
62 return IS_ERR_VALUE(error) ? error : 0;
63}
64
65static inline long syscall_get_return_value(struct task_struct *task,
66 struct pt_regs *regs)
67{
68 return regs->ax;
69}
70
71static inline void syscall_set_return_value(struct task_struct *task,
72 struct pt_regs *regs,
73 int error, long val)
74{
75 regs->ax = (long) error ?: val;
76}
77
78#ifdef CONFIG_X86_32
79
80static inline void syscall_get_arguments(struct task_struct *task,
81 struct pt_regs *regs,
82 unsigned long *args)
83{
84 args[0] = regs->bx;
85 args[1] = regs->cx;
86 args[2] = regs->dx;
87 args[3] = regs->si;
88 args[4] = regs->di;
89 args[5] = regs->bp;
90}
91
92static inline void syscall_set_arguments(struct task_struct *task,
93 struct pt_regs *regs,
94 const unsigned long *args)
95{
96 regs->bx = args[0];
97 regs->cx = args[1];
98 regs->dx = args[2];
99 regs->si = args[3];
100 regs->di = args[4];
101 regs->bp = args[5];
102}
103
104static inline int syscall_get_arch(struct task_struct *task)
105{
106 return AUDIT_ARCH_I386;
107}
108
109#else /* CONFIG_X86_64 */
110
111static inline void syscall_get_arguments(struct task_struct *task,
112 struct pt_regs *regs,
113 unsigned long *args)
114{
115# ifdef CONFIG_IA32_EMULATION
116 if (task->thread_info.status & TS_COMPAT) {
117 *args++ = regs->bx;
118 *args++ = regs->cx;
119 *args++ = regs->dx;
120 *args++ = regs->si;
121 *args++ = regs->di;
122 *args = regs->bp;
123 } else
124# endif
125 {
126 *args++ = regs->di;
127 *args++ = regs->si;
128 *args++ = regs->dx;
129 *args++ = regs->r10;
130 *args++ = regs->r8;
131 *args = regs->r9;
132 }
133}
134
135static inline void syscall_set_arguments(struct task_struct *task,
136 struct pt_regs *regs,
137 const unsigned long *args)
138{
139# ifdef CONFIG_IA32_EMULATION
140 if (task->thread_info.status & TS_COMPAT) {
141 regs->bx = *args++;
142 regs->cx = *args++;
143 regs->dx = *args++;
144 regs->si = *args++;
145 regs->di = *args++;
146 regs->bp = *args;
147 } else
148# endif
149 {
150 regs->di = *args++;
151 regs->si = *args++;
152 regs->dx = *args++;
153 regs->r10 = *args++;
154 regs->r8 = *args++;
155 regs->r9 = *args;
156 }
157}
158
159static inline int syscall_get_arch(struct task_struct *task)
160{
161 /* x32 tasks should be considered AUDIT_ARCH_X86_64. */
162 return (IS_ENABLED(CONFIG_IA32_EMULATION) &&
163 task->thread_info.status & TS_COMPAT)
164 ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
165}
166
167bool do_syscall_64(struct pt_regs *regs, long nr);
168void do_int80_emulation(struct pt_regs *regs);
169
170#endif /* CONFIG_X86_32 */
171
172void do_int80_syscall_32(struct pt_regs *regs);
173bool do_fast_syscall_32(struct pt_regs *regs);
174bool do_SYSENTER_32(struct pt_regs *regs);
175
176#endif /* _ASM_X86_SYSCALL_H */