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 */ |
20 | typedef long (*sys_call_ptr_t)(const struct pt_regs *); |
21 | extern const sys_call_ptr_t sys_call_table[]; |
22 | |
23 | /* |
24 | * These may not exist, but still put the prototypes in so we |
25 | * can use IS_ENABLED(). |
26 | */ |
27 | extern long ia32_sys_call(const struct pt_regs *, unsigned int nr); |
28 | extern long x32_sys_call(const struct pt_regs *, unsigned int nr); |
29 | extern long x64_sys_call(const struct pt_regs *, unsigned int nr); |
30 | |
31 | /* |
32 | * Only the low 32 bits of orig_ax are meaningful, so we return int. |
33 | * This importantly ignores the high bits on 64-bit, so comparisons |
34 | * sign-extend the low 32 bits. |
35 | */ |
36 | static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) |
37 | { |
38 | return regs->orig_ax; |
39 | } |
40 | |
41 | static inline void syscall_rollback(struct task_struct *task, |
42 | struct pt_regs *regs) |
43 | { |
44 | regs->ax = regs->orig_ax; |
45 | } |
46 | |
47 | static inline long syscall_get_error(struct task_struct *task, |
48 | struct pt_regs *regs) |
49 | { |
50 | unsigned long error = regs->ax; |
51 | #ifdef CONFIG_IA32_EMULATION |
52 | /* |
53 | * TS_COMPAT is set for 32-bit syscall entries and then |
54 | * remains set until we return to user mode. |
55 | */ |
56 | if (task->thread_info.status & (TS_COMPAT|TS_I386_REGS_POKED)) |
57 | /* |
58 | * Sign-extend the value so (int)-EFOO becomes (long)-EFOO |
59 | * and will match correctly in comparisons. |
60 | */ |
61 | error = (long) (int) error; |
62 | #endif |
63 | return IS_ERR_VALUE(error) ? error : 0; |
64 | } |
65 | |
66 | static inline long syscall_get_return_value(struct task_struct *task, |
67 | struct pt_regs *regs) |
68 | { |
69 | return regs->ax; |
70 | } |
71 | |
72 | static inline void syscall_set_return_value(struct task_struct *task, |
73 | struct pt_regs *regs, |
74 | int error, long val) |
75 | { |
76 | regs->ax = (long) error ?: val; |
77 | } |
78 | |
79 | #ifdef CONFIG_X86_32 |
80 | |
81 | static inline void syscall_get_arguments(struct task_struct *task, |
82 | struct pt_regs *regs, |
83 | unsigned long *args) |
84 | { |
85 | memcpy(args, ®s->bx, 6 * sizeof(args[0])); |
86 | } |
87 | |
88 | static inline int syscall_get_arch(struct task_struct *task) |
89 | { |
90 | return AUDIT_ARCH_I386; |
91 | } |
92 | |
93 | #else /* CONFIG_X86_64 */ |
94 | |
95 | static inline void syscall_get_arguments(struct task_struct *task, |
96 | struct pt_regs *regs, |
97 | unsigned long *args) |
98 | { |
99 | # ifdef CONFIG_IA32_EMULATION |
100 | if (task->thread_info.status & TS_COMPAT) { |
101 | *args++ = regs->bx; |
102 | *args++ = regs->cx; |
103 | *args++ = regs->dx; |
104 | *args++ = regs->si; |
105 | *args++ = regs->di; |
106 | *args = regs->bp; |
107 | } else |
108 | # endif |
109 | { |
110 | *args++ = regs->di; |
111 | *args++ = regs->si; |
112 | *args++ = regs->dx; |
113 | *args++ = regs->r10; |
114 | *args++ = regs->r8; |
115 | *args = regs->r9; |
116 | } |
117 | } |
118 | |
119 | static inline int syscall_get_arch(struct task_struct *task) |
120 | { |
121 | /* x32 tasks should be considered AUDIT_ARCH_X86_64. */ |
122 | return (IS_ENABLED(CONFIG_IA32_EMULATION) && |
123 | task->thread_info.status & TS_COMPAT) |
124 | ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64; |
125 | } |
126 | |
127 | bool do_syscall_64(struct pt_regs *regs, int nr); |
128 | void do_int80_emulation(struct pt_regs *regs); |
129 | |
130 | #endif /* CONFIG_X86_32 */ |
131 | |
132 | void do_int80_syscall_32(struct pt_regs *regs); |
133 | bool do_fast_syscall_32(struct pt_regs *regs); |
134 | bool do_SYSENTER_32(struct pt_regs *regs); |
135 | |
136 | #endif /* _ASM_X86_SYSCALL_H */ |
137 | |