tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Access to user system call parameters and results
3 *
4 * Copyright (C) 2008 Red Hat, Inc. All rights reserved.
5 *
6 * This copyrighted material is made available to anyone wishing to use,
7 * modify, copy, or redistribute it subject to the terms and conditions
8 * of the GNU General Public License v.2.
9 *
10 * See asm-generic/syscall.h for descriptions of what we must do here.
11 */
12
13#ifndef _ASM_X86_SYSCALL_H
14#define _ASM_X86_SYSCALL_H
15
16#include <linux/sched.h>
17#include <linux/err.h>
18
19static inline long syscall_get_nr(struct task_struct *task,
20 struct pt_regs *regs)
21{
22 /*
23 * We always sign-extend a -1 value being set here,
24 * so this is always either -1L or a syscall number.
25 */
26 return regs->orig_ax;
27}
28
29static inline void syscall_rollback(struct task_struct *task,
30 struct pt_regs *regs)
31{
32 regs->ax = regs->orig_ax;
33}
34
35static inline long syscall_get_error(struct task_struct *task,
36 struct pt_regs *regs)
37{
38 unsigned long error = regs->ax;
39#ifdef CONFIG_IA32_EMULATION
40 /*
41 * TS_COMPAT is set for 32-bit syscall entries and then
42 * remains set until we return to user mode.
43 */
44 if (task_thread_info(task)->status & TS_COMPAT)
45 /*
46 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
47 * and will match correctly in comparisons.
48 */
49 error = (long) (int) error;
50#endif
51 return IS_ERR_VALUE(error) ? error : 0;
52}
53
54static inline long syscall_get_return_value(struct task_struct *task,
55 struct pt_regs *regs)
56{
57 return regs->ax;
58}
59
60static inline void syscall_set_return_value(struct task_struct *task,
61 struct pt_regs *regs,
62 int error, long val)
63{
64 regs->ax = (long) error ?: val;
65}
66
67#ifdef CONFIG_X86_32
68
69static inline void syscall_get_arguments(struct task_struct *task,
70 struct pt_regs *regs,
71 unsigned int i, unsigned int n,
72 unsigned long *args)
73{
74 BUG_ON(i + n > 6);
75 memcpy(args, ®s->bx + i, n * sizeof(args[0]));
76}
77
78static inline void syscall_set_arguments(struct task_struct *task,
79 struct pt_regs *regs,
80 unsigned int i, unsigned int n,
81 const unsigned long *args)
82{
83 BUG_ON(i + n > 6);
84 memcpy(®s->bx + i, args, n * sizeof(args[0]));
85}
86
87#else /* CONFIG_X86_64 */
88
89static inline void syscall_get_arguments(struct task_struct *task,
90 struct pt_regs *regs,
91 unsigned int i, unsigned int n,
92 unsigned long *args)
93{
94# ifdef CONFIG_IA32_EMULATION
95 if (task_thread_info(task)->status & TS_COMPAT)
96 switch (i) {
97 case 0:
98 if (!n--) break;
99 *args++ = regs->bx;
100 case 1:
101 if (!n--) break;
102 *args++ = regs->cx;
103 case 2:
104 if (!n--) break;
105 *args++ = regs->dx;
106 case 3:
107 if (!n--) break;
108 *args++ = regs->si;
109 case 4:
110 if (!n--) break;
111 *args++ = regs->di;
112 case 5:
113 if (!n--) break;
114 *args++ = regs->bp;
115 case 6:
116 if (!n--) break;
117 default:
118 BUG();
119 break;
120 }
121 else
122# endif
123 switch (i) {
124 case 0:
125 if (!n--) break;
126 *args++ = regs->di;
127 case 1:
128 if (!n--) break;
129 *args++ = regs->si;
130 case 2:
131 if (!n--) break;
132 *args++ = regs->dx;
133 case 3:
134 if (!n--) break;
135 *args++ = regs->r10;
136 case 4:
137 if (!n--) break;
138 *args++ = regs->r8;
139 case 5:
140 if (!n--) break;
141 *args++ = regs->r9;
142 case 6:
143 if (!n--) break;
144 default:
145 BUG();
146 break;
147 }
148}
149
150static inline void syscall_set_arguments(struct task_struct *task,
151 struct pt_regs *regs,
152 unsigned int i, unsigned int n,
153 const unsigned long *args)
154{
155# ifdef CONFIG_IA32_EMULATION
156 if (task_thread_info(task)->status & TS_COMPAT)
157 switch (i) {
158 case 0:
159 if (!n--) break;
160 regs->bx = *args++;
161 case 1:
162 if (!n--) break;
163 regs->cx = *args++;
164 case 2:
165 if (!n--) break;
166 regs->dx = *args++;
167 case 3:
168 if (!n--) break;
169 regs->si = *args++;
170 case 4:
171 if (!n--) break;
172 regs->di = *args++;
173 case 5:
174 if (!n--) break;
175 regs->bp = *args++;
176 case 6:
177 if (!n--) break;
178 default:
179 BUG();
180 break;
181 }
182 else
183# endif
184 switch (i) {
185 case 0:
186 if (!n--) break;
187 regs->di = *args++;
188 case 1:
189 if (!n--) break;
190 regs->si = *args++;
191 case 2:
192 if (!n--) break;
193 regs->dx = *args++;
194 case 3:
195 if (!n--) break;
196 regs->r10 = *args++;
197 case 4:
198 if (!n--) break;
199 regs->r8 = *args++;
200 case 5:
201 if (!n--) break;
202 regs->r9 = *args++;
203 case 6:
204 if (!n--) break;
205 default:
206 BUG();
207 break;
208 }
209}
210
211#endif /* CONFIG_X86_32 */
212
213#endif /* _ASM_X86_SYSCALL_H */