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 19 enum 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 29 int 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 */ 37 struct aa_buffers { 38 char *buf[MAX_PATH_BUFFERS]; 39 }; 40 41 #include <linux/percpu.h> 42 #include <linux/preempt.h> 43 44 DECLARE_PER_CPU(struct aa_buffers, aa_buffers); 45 46 #define COUNT_ARGS(X...) COUNT_ARGS_HELPER(, ##X, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0) 47 #define COUNT_ARGS_HELPER(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, n, X...) n 48 #define CONCAT(X, Y) X ## Y 49 #define CONCAT_AFTER(X, Y) CONCAT(X, Y) 50 51 #define ASSIGN(FN, X, N) ((X) = FN(N)) 52 #define EVAL1(FN, X) ASSIGN(FN, X, 0) /*X = FN(0)*/ 53 #define EVAL2(FN, X, Y...) do { ASSIGN(FN, X, 1); EVAL1(FN, Y); } while (0) 54 #define EVAL(FN, X...) CONCAT_AFTER(EVAL, COUNT_ARGS(X))(FN, X) 55 56 #define for_each_cpu_buffer(I) for ((I) = 0; (I) < MAX_PATH_BUFFERS; (I)++) 57 58 #ifdef CONFIG_DEBUG_PREEMPT 59 #define AA_BUG_PREEMPT_ENABLED(X) AA_BUG(preempt_count() <= 0, X) 60 #else 61 #define AA_BUG_PREEMPT_ENABLED(X) /* nop */ 62 #endif 63 64 #define __get_buffer(N) ({ \ 65 struct aa_buffers *__cpu_var; \ 66 AA_BUG_PREEMPT_ENABLED("__get_buffer without preempt disabled"); \ 67 __cpu_var = this_cpu_ptr(&aa_buffers); \ 68 __cpu_var->buf[(N)]; }) 69 70 #define __get_buffers(X...) EVAL(__get_buffer, X) 71 72 #define __put_buffers(X, Y...) ((void)&(X)) 73 74 #define get_buffers(X...) \ 75 do { \ 76 preempt_disable(); \ 77 __get_buffers(X); \ 78 } while (0) 79 80 #define put_buffers(X, Y...) \ 81 do { \ 82 __put_buffers(X, Y); \ 83 preempt_enable(); \ 84 } while (0) 85 86 #endif /* __AA_PATH_H */ 87