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/asm-offsets.h> /* For NR_syscalls */
17 #include <asm/thread_info.h> /* for TS_COMPAT */
18 #include <asm/unistd.h>
19
20 #ifdef CONFIG_X86_64
21 typedef asmlinkage long (*sys_call_ptr_t)(const struct pt_regs *);
22 #else
23 typedef asmlinkage long (*sys_call_ptr_t)(unsigned long, unsigned long,
24 unsigned long, unsigned long,
25 unsigned long, unsigned long);
26 #endif /* CONFIG_X86_64 */
27 extern const sys_call_ptr_t sys_call_table[];
28
29 #if defined(CONFIG_X86_32)
30 #define ia32_sys_call_table sys_call_table
31 #define __NR_syscall_compat_max __NR_syscall_max
32 #define IA32_NR_syscalls NR_syscalls
33 #endif
34
35 #if defined(CONFIG_IA32_EMULATION)
36 extern const sys_call_ptr_t ia32_sys_call_table[];
37 #endif
38
39 #ifdef CONFIG_X86_X32_ABI
40 extern const sys_call_ptr_t x32_sys_call_table[];
41 #endif
42
43 /*
44 * Only the low 32 bits of orig_ax are meaningful, so we return int.
45 * This importantly ignores the high bits on 64-bit, so comparisons
46 * sign-extend the low 32 bits.
47 */
syscall_get_nr(struct task_struct * task,struct pt_regs * regs)48 static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
49 {
50 return regs->orig_ax;
51 }
52
syscall_rollback(struct task_struct * task,struct pt_regs * regs)53 static inline void syscall_rollback(struct task_struct *task,
54 struct pt_regs *regs)
55 {
56 regs->ax = regs->orig_ax;
57 }
58
syscall_get_error(struct task_struct * task,struct pt_regs * regs)59 static inline long syscall_get_error(struct task_struct *task,
60 struct pt_regs *regs)
61 {
62 unsigned long error = regs->ax;
63 #ifdef CONFIG_IA32_EMULATION
64 /*
65 * TS_COMPAT is set for 32-bit syscall entries and then
66 * remains set until we return to user mode.
67 */
68 if (task->thread_info.status & (TS_COMPAT|TS_I386_REGS_POKED))
69 /*
70 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
71 * and will match correctly in comparisons.
72 */
73 error = (long) (int) error;
74 #endif
75 return IS_ERR_VALUE(error) ? error : 0;
76 }
77
syscall_get_return_value(struct task_struct * task,struct pt_regs * regs)78 static inline long syscall_get_return_value(struct task_struct *task,
79 struct pt_regs *regs)
80 {
81 return regs->ax;
82 }
83
syscall_set_return_value(struct task_struct * task,struct pt_regs * regs,int error,long val)84 static inline void syscall_set_return_value(struct task_struct *task,
85 struct pt_regs *regs,
86 int error, long val)
87 {
88 regs->ax = (long) error ?: val;
89 }
90
91 #ifdef CONFIG_X86_32
92
syscall_get_arguments(struct task_struct * task,struct pt_regs * regs,unsigned long * args)93 static inline void syscall_get_arguments(struct task_struct *task,
94 struct pt_regs *regs,
95 unsigned long *args)
96 {
97 memcpy(args, ®s->bx, 6 * sizeof(args[0]));
98 }
99
syscall_set_arguments(struct task_struct * task,struct pt_regs * regs,unsigned int i,unsigned int n,const unsigned long * args)100 static inline void syscall_set_arguments(struct task_struct *task,
101 struct pt_regs *regs,
102 unsigned int i, unsigned int n,
103 const unsigned long *args)
104 {
105 BUG_ON(i + n > 6);
106 memcpy(®s->bx + i, args, n * sizeof(args[0]));
107 }
108
syscall_get_arch(struct task_struct * task)109 static inline int syscall_get_arch(struct task_struct *task)
110 {
111 return AUDIT_ARCH_I386;
112 }
113
114 #else /* CONFIG_X86_64 */
115
syscall_get_arguments(struct task_struct * task,struct pt_regs * regs,unsigned long * args)116 static inline void syscall_get_arguments(struct task_struct *task,
117 struct pt_regs *regs,
118 unsigned long *args)
119 {
120 # ifdef CONFIG_IA32_EMULATION
121 if (task->thread_info.status & TS_COMPAT) {
122 *args++ = regs->bx;
123 *args++ = regs->cx;
124 *args++ = regs->dx;
125 *args++ = regs->si;
126 *args++ = regs->di;
127 *args = regs->bp;
128 } else
129 # endif
130 {
131 *args++ = regs->di;
132 *args++ = regs->si;
133 *args++ = regs->dx;
134 *args++ = regs->r10;
135 *args++ = regs->r8;
136 *args = regs->r9;
137 }
138 }
139
syscall_set_arguments(struct task_struct * task,struct pt_regs * regs,const unsigned long * args)140 static inline void syscall_set_arguments(struct task_struct *task,
141 struct pt_regs *regs,
142 const unsigned long *args)
143 {
144 # ifdef CONFIG_IA32_EMULATION
145 if (task->thread_info.status & TS_COMPAT) {
146 regs->bx = *args++;
147 regs->cx = *args++;
148 regs->dx = *args++;
149 regs->si = *args++;
150 regs->di = *args++;
151 regs->bp = *args;
152 } else
153 # endif
154 {
155 regs->di = *args++;
156 regs->si = *args++;
157 regs->dx = *args++;
158 regs->r10 = *args++;
159 regs->r8 = *args++;
160 regs->r9 = *args;
161 }
162 }
163
syscall_get_arch(struct task_struct * task)164 static inline int syscall_get_arch(struct task_struct *task)
165 {
166 /* x32 tasks should be considered AUDIT_ARCH_X86_64. */
167 return (IS_ENABLED(CONFIG_IA32_EMULATION) &&
168 task->thread_info.status & TS_COMPAT)
169 ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
170 }
171 #endif /* CONFIG_X86_32 */
172
173 #endif /* _ASM_X86_SYSCALL_H */
174
