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 | typedef long (*sys_call_ptr_t)(const struct pt_regs *); |
20 | extern 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 | */ |
29 | extern const sys_call_ptr_t ia32_sys_call_table[]; |
30 | extern 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 | */ |
38 | static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) |
39 | { |
40 | return regs->orig_ax; |
41 | } |
42 | |
43 | static inline void syscall_rollback(struct task_struct *task, |
44 | struct pt_regs *regs) |
45 | { |
46 | regs->ax = regs->orig_ax; |
47 | } |
48 | |
49 | static 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 | |
68 | static inline long syscall_get_return_value(struct task_struct *task, |
69 | struct pt_regs *regs) |
70 | { |
71 | return regs->ax; |
72 | } |
73 | |
74 | static 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 | |
83 | static inline void syscall_get_arguments(struct task_struct *task, |
84 | struct pt_regs *regs, |
85 | unsigned long *args) |
86 | { |
87 | memcpy(args, ®s->bx, 6 * sizeof(args[0])); |
88 | } |
89 | |
90 | static inline int syscall_get_arch(struct task_struct *task) |
91 | { |
92 | return AUDIT_ARCH_I386; |
93 | } |
94 | |
95 | #else /* CONFIG_X86_64 */ |
96 | |
97 | static 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 | |
121 | static 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 | |
129 | bool do_syscall_64(struct pt_regs *regs, int nr); |
130 | |
131 | #endif /* CONFIG_X86_32 */ |
132 | |
133 | void do_int80_syscall_32(struct pt_regs *regs); |
134 | bool do_fast_syscall_32(struct pt_regs *regs); |
135 | bool do_SYSENTER_32(struct pt_regs *regs); |
136 | |
137 | #endif /* _ASM_X86_SYSCALL_H */ |
138 | |