1 | /* |
2 | * Access to user system call parameters and results |
3 | * |
4 | * Copyright (C) 2008-2009 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 <uapi/linux/audit.h> |
17 | #include <linux/sched.h> |
18 | #include <linux/err.h> |
19 | #include <asm/asm-offsets.h> /* For NR_syscalls */ |
20 | #include <asm/thread_info.h> /* for TS_COMPAT */ |
21 | #include <asm/unistd.h> |
22 | |
23 | #ifdef CONFIG_X86_64 |
24 | typedef asmlinkage long (*sys_call_ptr_t)(const struct pt_regs *); |
25 | #else |
26 | typedef asmlinkage long (*sys_call_ptr_t)(unsigned long, unsigned long, |
27 | unsigned long, unsigned long, |
28 | unsigned long, unsigned long); |
29 | #endif /* CONFIG_X86_64 */ |
30 | extern const sys_call_ptr_t sys_call_table[]; |
31 | |
32 | #if defined(CONFIG_X86_32) |
33 | #define ia32_sys_call_table sys_call_table |
34 | #define __NR_syscall_compat_max __NR_syscall_max |
35 | #define IA32_NR_syscalls NR_syscalls |
36 | #endif |
37 | |
38 | #if defined(CONFIG_IA32_EMULATION) |
39 | extern const sys_call_ptr_t ia32_sys_call_table[]; |
40 | #endif |
41 | |
42 | /* |
43 | * Only the low 32 bits of orig_ax are meaningful, so we return int. |
44 | * This importantly ignores the high bits on 64-bit, so comparisons |
45 | * sign-extend the low 32 bits. |
46 | */ |
47 | static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) |
48 | { |
49 | return regs->orig_ax; |
50 | } |
51 | |
52 | static inline void syscall_rollback(struct task_struct *task, |
53 | struct pt_regs *regs) |
54 | { |
55 | regs->ax = regs->orig_ax; |
56 | } |
57 | |
58 | static inline long syscall_get_error(struct task_struct *task, |
59 | struct pt_regs *regs) |
60 | { |
61 | unsigned long error = regs->ax; |
62 | #ifdef CONFIG_IA32_EMULATION |
63 | /* |
64 | * TS_COMPAT is set for 32-bit syscall entries and then |
65 | * remains set until we return to user mode. |
66 | */ |
67 | if (task->thread_info.status & (TS_COMPAT|TS_I386_REGS_POKED)) |
68 | /* |
69 | * Sign-extend the value so (int)-EFOO becomes (long)-EFOO |
70 | * and will match correctly in comparisons. |
71 | */ |
72 | error = (long) (int) error; |
73 | #endif |
74 | return IS_ERR_VALUE(error) ? error : 0; |
75 | } |
76 | |
77 | static inline long syscall_get_return_value(struct task_struct *task, |
78 | struct pt_regs *regs) |
79 | { |
80 | return regs->ax; |
81 | } |
82 | |
83 | static inline void syscall_set_return_value(struct task_struct *task, |
84 | struct pt_regs *regs, |
85 | int error, long val) |
86 | { |
87 | regs->ax = (long) error ?: val; |
88 | } |
89 | |
90 | #ifdef CONFIG_X86_32 |
91 | |
92 | static inline void syscall_get_arguments(struct task_struct *task, |
93 | struct pt_regs *regs, |
94 | unsigned int i, unsigned int n, |
95 | unsigned long *args) |
96 | { |
97 | BUG_ON(i + n > 6); |
98 | memcpy(args, ®s->bx + i, n * sizeof(args[0])); |
99 | } |
100 | |
101 | static inline void syscall_set_arguments(struct task_struct *task, |
102 | struct pt_regs *regs, |
103 | unsigned int i, unsigned int n, |
104 | const unsigned long *args) |
105 | { |
106 | BUG_ON(i + n > 6); |
107 | memcpy(®s->bx + i, args, n * sizeof(args[0])); |
108 | } |
109 | |
110 | static inline int syscall_get_arch(void) |
111 | { |
112 | return AUDIT_ARCH_I386; |
113 | } |
114 | |
115 | #else /* CONFIG_X86_64 */ |
116 | |
117 | static inline void syscall_get_arguments(struct task_struct *task, |
118 | struct pt_regs *regs, |
119 | unsigned int i, unsigned int n, |
120 | unsigned long *args) |
121 | { |
122 | # ifdef CONFIG_IA32_EMULATION |
123 | if (task->thread_info.status & TS_COMPAT) |
124 | switch (i) { |
125 | case 0: |
126 | if (!n--) break; |
127 | *args++ = regs->bx; |
128 | case 1: |
129 | if (!n--) break; |
130 | *args++ = regs->cx; |
131 | case 2: |
132 | if (!n--) break; |
133 | *args++ = regs->dx; |
134 | case 3: |
135 | if (!n--) break; |
136 | *args++ = regs->si; |
137 | case 4: |
138 | if (!n--) break; |
139 | *args++ = regs->di; |
140 | case 5: |
141 | if (!n--) break; |
142 | *args++ = regs->bp; |
143 | case 6: |
144 | if (!n--) break; |
145 | default: |
146 | BUG(); |
147 | break; |
148 | } |
149 | else |
150 | # endif |
151 | switch (i) { |
152 | case 0: |
153 | if (!n--) break; |
154 | *args++ = regs->di; |
155 | case 1: |
156 | if (!n--) break; |
157 | *args++ = regs->si; |
158 | case 2: |
159 | if (!n--) break; |
160 | *args++ = regs->dx; |
161 | case 3: |
162 | if (!n--) break; |
163 | *args++ = regs->r10; |
164 | case 4: |
165 | if (!n--) break; |
166 | *args++ = regs->r8; |
167 | case 5: |
168 | if (!n--) break; |
169 | *args++ = regs->r9; |
170 | case 6: |
171 | if (!n--) break; |
172 | default: |
173 | BUG(); |
174 | break; |
175 | } |
176 | } |
177 | |
178 | static inline void syscall_set_arguments(struct task_struct *task, |
179 | struct pt_regs *regs, |
180 | unsigned int i, unsigned int n, |
181 | const unsigned long *args) |
182 | { |
183 | # ifdef CONFIG_IA32_EMULATION |
184 | if (task->thread_info.status & TS_COMPAT) |
185 | switch (i) { |
186 | case 0: |
187 | if (!n--) break; |
188 | regs->bx = *args++; |
189 | case 1: |
190 | if (!n--) break; |
191 | regs->cx = *args++; |
192 | case 2: |
193 | if (!n--) break; |
194 | regs->dx = *args++; |
195 | case 3: |
196 | if (!n--) break; |
197 | regs->si = *args++; |
198 | case 4: |
199 | if (!n--) break; |
200 | regs->di = *args++; |
201 | case 5: |
202 | if (!n--) break; |
203 | regs->bp = *args++; |
204 | case 6: |
205 | if (!n--) break; |
206 | default: |
207 | BUG(); |
208 | break; |
209 | } |
210 | else |
211 | # endif |
212 | switch (i) { |
213 | case 0: |
214 | if (!n--) break; |
215 | regs->di = *args++; |
216 | case 1: |
217 | if (!n--) break; |
218 | regs->si = *args++; |
219 | case 2: |
220 | if (!n--) break; |
221 | regs->dx = *args++; |
222 | case 3: |
223 | if (!n--) break; |
224 | regs->r10 = *args++; |
225 | case 4: |
226 | if (!n--) break; |
227 | regs->r8 = *args++; |
228 | case 5: |
229 | if (!n--) break; |
230 | regs->r9 = *args++; |
231 | case 6: |
232 | if (!n--) break; |
233 | default: |
234 | BUG(); |
235 | break; |
236 | } |
237 | } |
238 | |
239 | static inline int syscall_get_arch(void) |
240 | { |
241 | /* x32 tasks should be considered AUDIT_ARCH_X86_64. */ |
242 | return in_ia32_syscall() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64; |
243 | } |
244 | #endif /* CONFIG_X86_32 */ |
245 | |
246 | #endif /* _ASM_X86_SYSCALL_H */ |
247 | |