summaryrefslogtreecommitdiffstats
path: root/include/linux/seccomp.h
blob: 84f6320da50f0a9fe03f30154b9137f9b42dfc74 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
#ifndef _LINUX_SECCOMP_H
#define _LINUX_SECCOMP_H

#include <linux/compiler.h>
#include <linux/types.h>


/* Valid values for seccomp.mode and prctl(PR_SET_SECCOMP, <mode>) */
#define SECCOMP_MODE_DISABLED	0 /* seccomp is not in use. */
#define SECCOMP_MODE_STRICT	1 /* uses hard-coded filter. */
#define SECCOMP_MODE_FILTER	2 /* uses user-supplied filter. */

/*
 * All BPF programs must return a 32-bit value.
 * The bottom 16-bits are for optional return data.
 * The upper 16-bits are ordered from least permissive values to most.
 *
 * The ordering ensures that a min_t() over composed return values always
 * selects the least permissive choice.
 */
#define SECCOMP_RET_KILL	0x00000000U /* kill the task immediately */
#define SECCOMP_RET_TRAP	0x00030000U /* disallow and force a SIGSYS */
#define SECCOMP_RET_ERRNO	0x00050000U /* returns an errno */
#define SECCOMP_RET_TRACE	0x7ff00000U /* pass to a tracer or disallow */
#define SECCOMP_RET_ALLOW	0x7fff0000U /* allow */

/* Masks for the return value sections. */
#define SECCOMP_RET_ACTION	0x7fff0000U
#define SECCOMP_RET_DATA	0x0000ffffU

/**
 * struct seccomp_data - the format the BPF program executes over.
 * @nr: the system call number
 * @arch: indicates system call convention as an AUDIT_ARCH_* value
 *        as defined in <linux/audit.h>.
 * @instruction_pointer: at the time of the system call.
 * @args: up to 6 system call arguments always stored as 64-bit values
 *        regardless of the architecture.
 */
struct seccomp_data {
	int nr;
	__u32 arch;
	__u64 instruction_pointer;
	__u64 args[6];
};

#ifdef __KERNEL__
#ifdef CONFIG_SECCOMP

#include <linux/thread_info.h>
#include <asm/seccomp.h>

struct seccomp_filter;
/**
 * struct seccomp - the state of a seccomp'ed process
 *
 * @mode:  indicates one of the valid values above for controlled
 *         system calls available to a process.
 * @filter: The metadata and ruleset for determining what system calls
 *          are allowed for a task.
 *
 *          @filter must only be accessed from the context of current as there
 *          is no locking.
 */
struct seccomp {
	int mode;
	struct seccomp_filter *filter;
};

extern int __secure_computing(int);
static inline int secure_computing(int this_syscall)
{
	if (unlikely(test_thread_flag(TIF_SECCOMP)))
		return  __secure_computing(this_syscall);
	return 0;
}

/* A wrapper for architectures supporting only SECCOMP_MODE_STRICT. */
static inline void secure_computing_strict(int this_syscall)
{
	BUG_ON(secure_computing(this_syscall) != 0);
}

extern long prctl_get_seccomp(void);
extern long prctl_set_seccomp(unsigned long, char __user *);

static inline int seccomp_mode(struct seccomp *s)
{
	return s->mode;
}

#else /* CONFIG_SECCOMP */

#include <linux/errno.h>

struct seccomp { };
struct seccomp_filter { };

static inline int secure_computing(int this_syscall) { return 0; }
static inline void secure_computing_strict(int this_syscall) { return; }

static inline long prctl_get_seccomp(void)
{
	return -EINVAL;
}

static inline long prctl_set_seccomp(unsigned long arg2, char __user *arg3)
{
	return -EINVAL;
}

static inline int seccomp_mode(struct seccomp *s)
{
	return 0;
}
#endif /* CONFIG_SECCOMP */

#ifdef CONFIG_SECCOMP_FILTER
extern void put_seccomp_filter(struct task_struct *tsk);
extern void get_seccomp_filter(struct task_struct *tsk);
extern u32 seccomp_bpf_load(int off);
#else  /* CONFIG_SECCOMP_FILTER */
static inline void put_seccomp_filter(struct task_struct *tsk)
{
	return;
}
static inline void get_seccomp_filter(struct task_struct *tsk)
{
	return;
}
#endif /* CONFIG_SECCOMP_FILTER */
#endif /* __KERNEL__ */
#endif /* _LINUX_SECCOMP_H */