1#ifndef _LINUX_SECCOMP_H
2#define _LINUX_SECCOMP_H
3
4#include <linux/compiler.h>
5#include <linux/types.h>
6
7
8/* Valid values for seccomp.mode and prctl(PR_SET_SECCOMP, <mode>) */
9#define SECCOMP_MODE_DISABLED	0 /* seccomp is not in use. */
10#define SECCOMP_MODE_STRICT	1 /* uses hard-coded filter. */
11#define SECCOMP_MODE_FILTER	2 /* uses user-supplied filter. */
12
13/*
14 * All BPF programs must return a 32-bit value.
15 * The bottom 16-bits are for optional return data.
16 * The upper 16-bits are ordered from least permissive values to most.
17 *
18 * The ordering ensures that a min_t() over composed return values always
19 * selects the least permissive choice.
20 */
21#define SECCOMP_RET_KILL	0x00000000U /* kill the task immediately */
22#define SECCOMP_RET_TRAP	0x00030000U /* disallow and force a SIGSYS */
23#define SECCOMP_RET_ERRNO	0x00050000U /* returns an errno */
24#define SECCOMP_RET_TRACE	0x7ff00000U /* pass to a tracer or disallow */
25#define SECCOMP_RET_ALLOW	0x7fff0000U /* allow */
26
27/* Masks for the return value sections. */
28#define SECCOMP_RET_ACTION	0x7fff0000U
29#define SECCOMP_RET_DATA	0x0000ffffU
30
31/**
32 * struct seccomp_data - the format the BPF program executes over.
33 * @nr: the system call number
34 * @arch: indicates system call convention as an AUDIT_ARCH_* value
35 *        as defined in <linux/audit.h>.
36 * @instruction_pointer: at the time of the system call.
37 * @args: up to 6 system call arguments always stored as 64-bit values
38 *        regardless of the architecture.
39 */
40struct seccomp_data {
41	int nr;
42	__u32 arch;
43	__u64 instruction_pointer;
44	__u64 args[6];
45};
46
47#ifdef __KERNEL__
48#ifdef CONFIG_SECCOMP
49
50#include <linux/thread_info.h>
51#include <asm/seccomp.h>
52
53struct seccomp_filter;
54/**
55 * struct seccomp - the state of a seccomp'ed process
56 *
57 * @mode:  indicates one of the valid values above for controlled
58 *         system calls available to a process.
59 * @filter: The metadata and ruleset for determining what system calls
60 *          are allowed for a task.
61 *
62 *          @filter must only be accessed from the context of current as there
63 *          is no locking.
64 */
65struct seccomp {
66	int mode;
67	struct seccomp_filter *filter;
68};
69
70extern int __secure_computing(int);
71static inline int secure_computing(int this_syscall)
72{
73	if (unlikely(test_thread_flag(TIF_SECCOMP)))
74		return  __secure_computing(this_syscall);
75	return 0;
76}
77
78/* A wrapper for architectures supporting only SECCOMP_MODE_STRICT. */
79static inline void secure_computing_strict(int this_syscall)
80{
81	BUG_ON(secure_computing(this_syscall) != 0);
82}
83
84extern long prctl_get_seccomp(void);
85extern long prctl_set_seccomp(unsigned long, char __user *);
86
87static inline int seccomp_mode(struct seccomp *s)
88{
89	return s->mode;
90}
91
92#else /* CONFIG_SECCOMP */
93
94#include <linux/errno.h>
95
96struct seccomp { };
97struct seccomp_filter { };
98
99static inline int secure_computing(int this_syscall) { return 0; }
100static inline void secure_computing_strict(int this_syscall) { return; }
101
102static inline long prctl_get_seccomp(void)
103{
104	return -EINVAL;
105}
106
107static inline long prctl_set_seccomp(unsigned long arg2, char __user *arg3)
108{
109	return -EINVAL;
110}
111
112static inline int seccomp_mode(struct seccomp *s)
113{
114	return 0;
115}
116#endif /* CONFIG_SECCOMP */
117
118#ifdef CONFIG_SECCOMP_FILTER
119extern void put_seccomp_filter(struct task_struct *tsk);
120extern void get_seccomp_filter(struct task_struct *tsk);
121extern u32 seccomp_bpf_load(int off);
122#else  /* CONFIG_SECCOMP_FILTER */
123static inline void put_seccomp_filter(struct task_struct *tsk)
124{
125	return;
126}
127static inline void get_seccomp_filter(struct task_struct *tsk)
128{
129	return;
130}
131#endif /* CONFIG_SECCOMP_FILTER */
132#endif /* __KERNEL__ */
133#endif /* _LINUX_SECCOMP_H */
134