1/* 2 * AppArmor security module 3 * 4 * This file contains basic common functions used in AppArmor 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#include <linux/slab.h> 16#include <linux/string.h> 17#include <linux/vmalloc.h> 18 19#include "include/audit.h" 20 21 22/** 23 * aa_split_fqname - split a fqname into a profile and namespace name 24 * @fqname: a full qualified name in namespace profile format (NOT NULL) 25 * @ns_name: pointer to portion of the string containing the ns name (NOT NULL) 26 * 27 * Returns: profile name or NULL if one is not specified 28 * 29 * Split a namespace name from a profile name (see policy.c for naming 30 * description). If a portion of the name is missing it returns NULL for 31 * that portion. 32 * 33 * NOTE: may modify the @fqname string. The pointers returned point 34 * into the @fqname string. 35 */ 36char *aa_split_fqname(char *fqname, char **ns_name) 37{ 38 char *name = strim(fqname); 39 40 *ns_name = NULL; 41 if (name[0] == ':') { 42 char *split = strchr(&name[1], ':'); 43 *ns_name = skip_spaces(&name[1]); 44 if (split) { 45 /* overwrite ':' with \0 */ 46 *split = 0; 47 name = skip_spaces(split + 1); 48 } else 49 /* a ns name without a following profile is allowed */ 50 name = NULL; 51 } 52 if (name && *name == 0) 53 name = NULL; 54 55 return name; 56} 57 58/** 59 * aa_info_message - log a none profile related status message 60 * @str: message to log 61 */ 62void aa_info_message(const char *str) 63{ 64 if (audit_enabled) { 65 struct common_audit_data sa; 66 COMMON_AUDIT_DATA_INIT(&sa, NONE); 67 sa.aad.info = str; 68 aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, NULL); 69 } 70 printk(KERN_INFO "AppArmor: %s\n", str); 71} 72 73/** 74 * kvmalloc - do allocation preferring kmalloc but falling back to vmalloc 75 * @size: size of allocation 76 * 77 * Return: allocated buffer or NULL if failed 78 * 79 * It is possible that policy being loaded from the user is larger than 80 * what can be allocated by kmalloc, in those cases fall back to vmalloc. 81 */ 82void *kvmalloc(size_t size) 83{ 84 void *buffer = NULL; 85 86 if (size == 0) 87 return NULL; 88 89 /* do not attempt kmalloc if we need more than 16 pages at once */ 90 if (size <= (16*PAGE_SIZE)) 91 buffer = kmalloc(size, GFP_NOIO | __GFP_NOWARN); 92 if (!buffer) { 93 /* see kvfree for why size must be at least work_struct size 94 * when allocated via vmalloc 95 */ 96 if (size < sizeof(struct work_struct)) 97 size = sizeof(struct work_struct); 98 buffer = vmalloc(size); 99 } 100 return buffer; 101} 102 103/** 104 * do_vfree - workqueue routine for freeing vmalloced memory 105 * @work: data to be freed 106 * 107 * The work_struct is overlaid to the data being freed, as at the point 108 * the work is scheduled the data is no longer valid, be its freeing 109 * needs to be delayed until safe. 110 */ 111static void do_vfree(struct work_struct *work) 112{ 113 vfree(work); 114} 115 116/** 117 * kvfree - free an allocation do by kvmalloc 118 * @buffer: buffer to free (MAYBE_NULL) 119 * 120 * Free a buffer allocated by kvmalloc 121 */ 122void kvfree(void *buffer) 123{ 124 if (is_vmalloc_addr(buffer)) { 125 /* Data is no longer valid so just use the allocated space 126 * as the work_struct 127 */ 128 struct work_struct *work = (struct work_struct *) buffer; 129 INIT_WORK(work, do_vfree); 130 schedule_work(work); 131 } else 132 kfree(buffer); 133} 134