1 /*
2 * Copyright (c) 2018 Linaro Limited.
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 /**
8 * @file
9 * @brief x86 (IA32) specific syscall header
10 *
11 * This header contains the x86 specific syscall interface. It is
12 * included by the syscall interface architecture-abstraction header
13 * (include/arch/syscall.h)
14 */
15
16 #ifndef ZEPHYR_INCLUDE_ARCH_X86_IA32_SYSCALL_H_
17 #define ZEPHYR_INCLUDE_ARCH_X86_IA32_SYSCALL_H_
18
19 #define USER_CODE_SEG 0x2b /* at dpl=3 */
20 #define USER_DATA_SEG 0x33 /* at dpl=3 */
21
22 #ifdef CONFIG_USERSPACE
23 #ifndef _ASMLANGUAGE
24
25 #include <zephyr/types.h>
26 #include <stdbool.h>
27 #include <zephyr/linker/sections.h>
28
29 #ifdef __cplusplus
30 extern "C" {
31 #endif
32
33 /* Syscall invocation macros. x86-specific machine constraints used to ensure
34 * args land in the proper registers, see implementation of
35 * z_x86_syscall_entry_stub in userspace.S
36 */
37
38 __pinned_func
arch_syscall_invoke6(uintptr_t arg1,uintptr_t arg2,uintptr_t arg3,uintptr_t arg4,uintptr_t arg5,uintptr_t arg6,uintptr_t call_id)39 static inline uintptr_t arch_syscall_invoke6(uintptr_t arg1, uintptr_t arg2,
40 uintptr_t arg3, uintptr_t arg4,
41 uintptr_t arg5, uintptr_t arg6,
42 uintptr_t call_id)
43 {
44 uint32_t ret;
45
46 __asm__ volatile("push %%ebp\n\t"
47 "mov %[arg6], %%ebp\n\t"
48 "int $0x80\n\t"
49 "pop %%ebp\n\t"
50 : "=a" (ret)
51 : "S" (call_id), "a" (arg1), "d" (arg2),
52 "c" (arg3), "b" (arg4), "D" (arg5),
53 [arg6] "m" (arg6)
54 : "memory");
55 return ret;
56 }
57
58 __pinned_func
arch_syscall_invoke5(uintptr_t arg1,uintptr_t arg2,uintptr_t arg3,uintptr_t arg4,uintptr_t arg5,uintptr_t call_id)59 static inline uintptr_t arch_syscall_invoke5(uintptr_t arg1, uintptr_t arg2,
60 uintptr_t arg3, uintptr_t arg4,
61 uintptr_t arg5,
62 uintptr_t call_id)
63 {
64 uint32_t ret;
65
66 __asm__ volatile("int $0x80"
67 : "=a" (ret)
68 : "S" (call_id), "a" (arg1), "d" (arg2),
69 "c" (arg3), "b" (arg4), "D" (arg5)
70 : "memory");
71 return ret;
72 }
73
74 __pinned_func
arch_syscall_invoke4(uintptr_t arg1,uintptr_t arg2,uintptr_t arg3,uintptr_t arg4,uintptr_t call_id)75 static inline uintptr_t arch_syscall_invoke4(uintptr_t arg1, uintptr_t arg2,
76 uintptr_t arg3, uintptr_t arg4,
77 uintptr_t call_id)
78 {
79 uint32_t ret;
80
81 __asm__ volatile("int $0x80"
82 : "=a" (ret)
83 : "S" (call_id), "a" (arg1), "d" (arg2), "c" (arg3),
84 "b" (arg4)
85 : "memory");
86 return ret;
87 }
88
89 __pinned_func
arch_syscall_invoke3(uintptr_t arg1,uintptr_t arg2,uintptr_t arg3,uintptr_t call_id)90 static inline uintptr_t arch_syscall_invoke3(uintptr_t arg1, uintptr_t arg2,
91 uintptr_t arg3,
92 uintptr_t call_id)
93 {
94 uint32_t ret;
95
96 __asm__ volatile("int $0x80"
97 : "=a" (ret)
98 : "S" (call_id), "a" (arg1), "d" (arg2), "c" (arg3)
99 : "memory");
100 return ret;
101 }
102
103 __pinned_func
arch_syscall_invoke2(uintptr_t arg1,uintptr_t arg2,uintptr_t call_id)104 static inline uintptr_t arch_syscall_invoke2(uintptr_t arg1, uintptr_t arg2,
105 uintptr_t call_id)
106 {
107 uint32_t ret;
108
109 __asm__ volatile("int $0x80"
110 : "=a" (ret)
111 : "S" (call_id), "a" (arg1), "d" (arg2)
112 : "memory"
113 );
114 return ret;
115 }
116
117 __pinned_func
arch_syscall_invoke1(uintptr_t arg1,uintptr_t call_id)118 static inline uintptr_t arch_syscall_invoke1(uintptr_t arg1,
119 uintptr_t call_id)
120 {
121 uint32_t ret;
122
123 __asm__ volatile("int $0x80"
124 : "=a" (ret)
125 : "S" (call_id), "a" (arg1)
126 : "memory"
127 );
128 return ret;
129 }
130
131 __pinned_func
arch_syscall_invoke0(uintptr_t call_id)132 static inline uintptr_t arch_syscall_invoke0(uintptr_t call_id)
133 {
134 uint32_t ret;
135
136 __asm__ volatile("int $0x80"
137 : "=a" (ret)
138 : "S" (call_id)
139 : "memory"
140 );
141 return ret;
142 }
143
144 __pinned_func
arch_is_user_context(void)145 static inline bool arch_is_user_context(void)
146 {
147 int cs;
148
149 /* On x86, read the CS register (which cannot be manually set) */
150 __asm__ volatile ("mov %%cs, %[cs_val]" : [cs_val] "=r" (cs));
151
152 return cs == USER_CODE_SEG;
153 }
154
155
156 #ifdef __cplusplus
157 }
158 #endif
159
160 #endif /* _ASMLANGUAGE */
161 #endif /* CONFIG_USERSPACE */
162 #endif /* ZEPHYR_INCLUDE_ARCH_X86_IA32_SYSCALL_H_ */
163
