1/*
 2 * AppArmor security module
 3 *
 4 * This file contains AppArmor basic path manipulation function definitions.
 5 *
 6 * Copyright (C) 1998-2008 Novell/SUSE
 7 * Copyright 2009-2010 Canonical Ltd.
 8 *
 9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation, version 2 of the
12 * License.
13 */
14
15#ifndef __AA_PATH_H
16#define __AA_PATH_H
17
18
19enum path_flags {
20	PATH_IS_DIR = 0x1,		/* path is a directory */
21	PATH_CONNECT_PATH = 0x4,	/* connect disconnected paths to / */
22	PATH_CHROOT_REL = 0x8,		/* do path lookup relative to chroot */
23	PATH_CHROOT_NSCONNECT = 0x10,	/* connect paths that are at ns root */
24
25	PATH_DELEGATE_DELETED = 0x08000, /* delegate deleted files */
26	PATH_MEDIATE_DELETED = 0x10000,	 /* mediate deleted paths */
27};
28
29int aa_path_name(const struct path *path, int flags, char *buffer,
30		 const char **name, const char **info,
31		 const char *disconnected);
32
33#define MAX_PATH_BUFFERS 2
34
35/* Per cpu buffers used during mediation */
36/* preallocated buffers to use during path lookups */
37struct aa_buffers {
38	char *buf[MAX_PATH_BUFFERS];
39};
40
41#include <linux/percpu.h>
42#include <linux/preempt.h>
43
44DECLARE_PER_CPU(struct aa_buffers, aa_buffers);
45
46#define ASSIGN(FN, X, N) ((X) = FN(N))
47#define EVAL1(FN, X) ASSIGN(FN, X, 0) /*X = FN(0)*/
48#define EVAL2(FN, X, Y...) do { ASSIGN(FN, X, 1);  EVAL1(FN, Y); } while (0)
49#define EVAL(FN, X...) CONCATENATE(EVAL, COUNT_ARGS(X))(FN, X)
 
50
51#define for_each_cpu_buffer(I) for ((I) = 0; (I) < MAX_PATH_BUFFERS; (I)++)
52
53#ifdef CONFIG_DEBUG_PREEMPT
54#define AA_BUG_PREEMPT_ENABLED(X) AA_BUG(preempt_count() <= 0, X)
55#else
56#define AA_BUG_PREEMPT_ENABLED(X) /* nop */
57#endif
58
59#define __get_buffer(N) ({					\
60	struct aa_buffers *__cpu_var; \
61	AA_BUG_PREEMPT_ENABLED("__get_buffer without preempt disabled");  \
62	__cpu_var = this_cpu_ptr(&aa_buffers);			\
63	__cpu_var->buf[(N)]; })
64
65#define __get_buffers(X...)    EVAL(__get_buffer, X)
66
67#define __put_buffers(X, Y...) ((void)&(X))
68
69#define get_buffers(X...)	\
70do {				\
71	preempt_disable();	\
72	__get_buffers(X);	\
73} while (0)
74
75#define put_buffers(X, Y...)	\
76do {				\
77	__put_buffers(X, Y);	\
78	preempt_enable();	\
79} while (0)
80
81#endif /* __AA_PATH_H */

 1/* SPDX-License-Identifier: GPL-2.0-only */
 2/*
 3 * AppArmor security module
 4 *
 5 * This file contains AppArmor basic path manipulation function definitions.
 6 *
 7 * Copyright (C) 1998-2008 Novell/SUSE
 8 * Copyright 2009-2010 Canonical Ltd.
 
 
 
 
 
 9 */
10
11#ifndef __AA_PATH_H
12#define __AA_PATH_H
13
14
15enum path_flags {
16	PATH_IS_DIR = 0x1,		/* path is a directory */
17	PATH_CONNECT_PATH = 0x4,	/* connect disconnected paths to / */
18	PATH_CHROOT_REL = 0x8,		/* do path lookup relative to chroot */
19	PATH_CHROOT_NSCONNECT = 0x10,	/* connect paths that are at ns root */
20
21	PATH_DELEGATE_DELETED = 0x08000, /* delegate deleted files */
22	PATH_MEDIATE_DELETED = 0x10000,	 /* mediate deleted paths */
23};
24
25int aa_path_name(const struct path *path, int flags, char *buffer,
26		 const char **name, const char **info,
27		 const char *disconnected);
28
29#define MAX_PATH_BUFFERS 2
30
31/* Per cpu buffers used during mediation */
32/* preallocated buffers to use during path lookups */
33struct aa_buffers {
34	char *buf[MAX_PATH_BUFFERS];
35};
36
37#include <linux/percpu.h>
38#include <linux/preempt.h>
39
40DECLARE_PER_CPU(struct aa_buffers, aa_buffers);
41
42#define ASSIGN(FN, A, X, N) ((X) = FN(A, N))
43#define EVAL1(FN, A, X) ASSIGN(FN, A, X, 0) /*X = FN(0)*/
44#define EVAL2(FN, A, X, Y...)	\
45	do { ASSIGN(FN, A, X, 1);  EVAL1(FN, A, Y); } while (0)
46#define EVAL(FN, A, X...) CONCATENATE(EVAL, COUNT_ARGS(X))(FN, A, X)
47
48#define for_each_cpu_buffer(I) for ((I) = 0; (I) < MAX_PATH_BUFFERS; (I)++)
49
50#ifdef CONFIG_DEBUG_PREEMPT
51#define AA_BUG_PREEMPT_ENABLED(X) AA_BUG(preempt_count() <= 0, X)
52#else
53#define AA_BUG_PREEMPT_ENABLED(X) /* nop */
54#endif
55
56#define __get_buffer(C, N) ({						\
 
57	AA_BUG_PREEMPT_ENABLED("__get_buffer without preempt disabled");  \
58	(C)->buf[(N)]; })
 
59
60#define __get_buffers(C, X...)    EVAL(__get_buffer, C, X)
61
62#define __put_buffers(X, Y...) ((void)&(X))
63
64#define get_buffers(X...)						\
65do {									\
66	struct aa_buffers *__cpu_var = get_cpu_ptr(&aa_buffers);	\
67	__get_buffers(__cpu_var, X);					\
68} while (0)
69
70#define put_buffers(X, Y...)		\
71do {					\
72	__put_buffers(X, Y);		\
73	put_cpu_ptr(&aa_buffers);	\
74} while (0)
75
76#endif /* __AA_PATH_H */