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 */
syscall_get_nr(struct task_struct * task,struct pt_regs * regs)38 static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
39 {
40 return regs->orig_ax;
41 }
42
syscall_rollback(struct task_struct * task,struct pt_regs * regs)43 static inline void syscall_rollback(struct task_struct *task,
44 struct pt_regs *regs)
45 {
46 regs->ax = regs->orig_ax;
47 }
48
syscall_get_error(struct task_struct * task,struct pt_regs * regs)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
syscall_get_return_value(struct task_struct * task,struct pt_regs * regs)68 static inline long syscall_get_return_value(struct task_struct *task,
69 struct pt_regs *regs)
70 {
71 return regs->ax;
72 }
73
syscall_set_return_value(struct task_struct * task,struct pt_regs * regs,int error,long val)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
syscall_get_arguments(struct task_struct * task,struct pt_regs * regs,unsigned long * args)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
syscall_get_arch(struct task_struct * task)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
syscall_get_arguments(struct task_struct * task,struct pt_regs * regs,unsigned long * args)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
syscall_get_arch(struct task_struct * task)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 void 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 long do_fast_syscall_32(struct pt_regs *regs);
135 long do_SYSENTER_32(struct pt_regs *regs);
136
137 #endif /* _ASM_X86_SYSCALL_H */
138
