Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / security / tomoyo / domain.c
diff --git a/kernel/security/tomoyo/domain.c b/kernel/security/tomoyo/domain.c
new file mode 100644 (file)
index 0000000..3865145
--- /dev/null
@@ -0,0 +1,901 @@
+/*
+ * security/tomoyo/domain.c
+ *
+ * Copyright (C) 2005-2011  NTT DATA CORPORATION
+ */
+
+#include "common.h"
+#include <linux/binfmts.h>
+#include <linux/slab.h>
+
+/* Variables definitions.*/
+
+/* The initial domain. */
+struct tomoyo_domain_info tomoyo_kernel_domain;
+
+/**
+ * tomoyo_update_policy - Update an entry for exception policy.
+ *
+ * @new_entry:       Pointer to "struct tomoyo_acl_info".
+ * @size:            Size of @new_entry in bytes.
+ * @param:           Pointer to "struct tomoyo_acl_param".
+ * @check_duplicate: Callback function to find duplicated entry.
+ *
+ * Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+int tomoyo_update_policy(struct tomoyo_acl_head *new_entry, const int size,
+                        struct tomoyo_acl_param *param,
+                        bool (*check_duplicate) (const struct tomoyo_acl_head
+                                                 *,
+                                                 const struct tomoyo_acl_head
+                                                 *))
+{
+       int error = param->is_delete ? -ENOENT : -ENOMEM;
+       struct tomoyo_acl_head *entry;
+       struct list_head *list = param->list;
+
+       if (mutex_lock_interruptible(&tomoyo_policy_lock))
+               return -ENOMEM;
+       list_for_each_entry_rcu(entry, list, list) {
+               if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS)
+                       continue;
+               if (!check_duplicate(entry, new_entry))
+                       continue;
+               entry->is_deleted = param->is_delete;
+               error = 0;
+               break;
+       }
+       if (error && !param->is_delete) {
+               entry = tomoyo_commit_ok(new_entry, size);
+               if (entry) {
+                       list_add_tail_rcu(&entry->list, list);
+                       error = 0;
+               }
+       }
+       mutex_unlock(&tomoyo_policy_lock);
+       return error;
+}
+
+/**
+ * tomoyo_same_acl_head - Check for duplicated "struct tomoyo_acl_info" entry.
+ *
+ * @a: Pointer to "struct tomoyo_acl_info".
+ * @b: Pointer to "struct tomoyo_acl_info".
+ *
+ * Returns true if @a == @b, false otherwise.
+ */
+static inline bool tomoyo_same_acl_head(const struct tomoyo_acl_info *a,
+                                       const struct tomoyo_acl_info *b)
+{
+       return a->type == b->type && a->cond == b->cond;
+}
+
+/**
+ * tomoyo_update_domain - Update an entry for domain policy.
+ *
+ * @new_entry:       Pointer to "struct tomoyo_acl_info".
+ * @size:            Size of @new_entry in bytes.
+ * @param:           Pointer to "struct tomoyo_acl_param".
+ * @check_duplicate: Callback function to find duplicated entry.
+ * @merge_duplicate: Callback function to merge duplicated entry.
+ *
+ * Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size,
+                        struct tomoyo_acl_param *param,
+                        bool (*check_duplicate) (const struct tomoyo_acl_info
+                                                 *,
+                                                 const struct tomoyo_acl_info
+                                                 *),
+                        bool (*merge_duplicate) (struct tomoyo_acl_info *,
+                                                 struct tomoyo_acl_info *,
+                                                 const bool))
+{
+       const bool is_delete = param->is_delete;
+       int error = is_delete ? -ENOENT : -ENOMEM;
+       struct tomoyo_acl_info *entry;
+       struct list_head * const list = param->list;
+
+       if (param->data[0]) {
+               new_entry->cond = tomoyo_get_condition(param);
+               if (!new_entry->cond)
+                       return -EINVAL;
+               /*
+                * Domain transition preference is allowed for only
+                * "file execute" entries.
+                */
+               if (new_entry->cond->transit &&
+                   !(new_entry->type == TOMOYO_TYPE_PATH_ACL &&
+                     container_of(new_entry, struct tomoyo_path_acl, head)
+                     ->perm == 1 << TOMOYO_TYPE_EXECUTE))
+                       goto out;
+       }
+       if (mutex_lock_interruptible(&tomoyo_policy_lock))
+               goto out;
+       list_for_each_entry_rcu(entry, list, list) {
+               if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS)
+                       continue;
+               if (!tomoyo_same_acl_head(entry, new_entry) ||
+                   !check_duplicate(entry, new_entry))
+                       continue;
+               if (merge_duplicate)
+                       entry->is_deleted = merge_duplicate(entry, new_entry,
+                                                           is_delete);
+               else
+                       entry->is_deleted = is_delete;
+               error = 0;
+               break;
+       }
+       if (error && !is_delete) {
+               entry = tomoyo_commit_ok(new_entry, size);
+               if (entry) {
+                       list_add_tail_rcu(&entry->list, list);
+                       error = 0;
+               }
+       }
+       mutex_unlock(&tomoyo_policy_lock);
+out:
+       tomoyo_put_condition(new_entry->cond);
+       return error;
+}
+
+/**
+ * tomoyo_check_acl - Do permission check.
+ *
+ * @r:           Pointer to "struct tomoyo_request_info".
+ * @check_entry: Callback function to check type specific parameters.
+ *
+ * Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+void tomoyo_check_acl(struct tomoyo_request_info *r,
+                     bool (*check_entry) (struct tomoyo_request_info *,
+                                          const struct tomoyo_acl_info *))
+{
+       const struct tomoyo_domain_info *domain = r->domain;
+       struct tomoyo_acl_info *ptr;
+       bool retried = false;
+       const struct list_head *list = &domain->acl_info_list;
+
+retry:
+       list_for_each_entry_rcu(ptr, list, list) {
+               if (ptr->is_deleted || ptr->type != r->param_type)
+                       continue;
+               if (!check_entry(r, ptr))
+                       continue;
+               if (!tomoyo_condition(r, ptr->cond))
+                       continue;
+               r->matched_acl = ptr;
+               r->granted = true;
+               return;
+       }
+       if (!retried) {
+               retried = true;
+               list = &domain->ns->acl_group[domain->group];
+               goto retry;
+       }
+       r->granted = false;
+}
+
+/* The list for "struct tomoyo_domain_info". */
+LIST_HEAD(tomoyo_domain_list);
+
+/**
+ * tomoyo_last_word - Get last component of a domainname.
+ *
+ * @name: Domainname to check.
+ *
+ * Returns the last word of @domainname.
+ */
+static const char *tomoyo_last_word(const char *name)
+{
+       const char *cp = strrchr(name, ' ');
+       if (cp)
+               return cp + 1;
+       return name;
+}
+
+/**
+ * tomoyo_same_transition_control - Check for duplicated "struct tomoyo_transition_control" entry.
+ *
+ * @a: Pointer to "struct tomoyo_acl_head".
+ * @b: Pointer to "struct tomoyo_acl_head".
+ *
+ * Returns true if @a == @b, false otherwise.
+ */
+static bool tomoyo_same_transition_control(const struct tomoyo_acl_head *a,
+                                          const struct tomoyo_acl_head *b)
+{
+       const struct tomoyo_transition_control *p1 = container_of(a,
+                                                                 typeof(*p1),
+                                                                 head);
+       const struct tomoyo_transition_control *p2 = container_of(b,
+                                                                 typeof(*p2),
+                                                                 head);
+       return p1->type == p2->type && p1->is_last_name == p2->is_last_name
+               && p1->domainname == p2->domainname
+               && p1->program == p2->program;
+}
+
+/**
+ * tomoyo_write_transition_control - Write "struct tomoyo_transition_control" list.
+ *
+ * @param: Pointer to "struct tomoyo_acl_param".
+ * @type:  Type of this entry.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tomoyo_write_transition_control(struct tomoyo_acl_param *param,
+                                   const u8 type)
+{
+       struct tomoyo_transition_control e = { .type = type };
+       int error = param->is_delete ? -ENOENT : -ENOMEM;
+       char *program = param->data;
+       char *domainname = strstr(program, " from ");
+       if (domainname) {
+               *domainname = '\0';
+               domainname += 6;
+       } else if (type == TOMOYO_TRANSITION_CONTROL_NO_KEEP ||
+                  type == TOMOYO_TRANSITION_CONTROL_KEEP) {
+               domainname = program;
+               program = NULL;
+       }
+       if (program && strcmp(program, "any")) {
+               if (!tomoyo_correct_path(program))
+                       return -EINVAL;
+               e.program = tomoyo_get_name(program);
+               if (!e.program)
+                       goto out;
+       }
+       if (domainname && strcmp(domainname, "any")) {
+               if (!tomoyo_correct_domain(domainname)) {
+                       if (!tomoyo_correct_path(domainname))
+                               goto out;
+                       e.is_last_name = true;
+               }
+               e.domainname = tomoyo_get_name(domainname);
+               if (!e.domainname)
+                       goto out;
+       }
+       param->list = &param->ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
+       error = tomoyo_update_policy(&e.head, sizeof(e), param,
+                                    tomoyo_same_transition_control);
+out:
+       tomoyo_put_name(e.domainname);
+       tomoyo_put_name(e.program);
+       return error;
+}
+
+/**
+ * tomoyo_scan_transition - Try to find specific domain transition type.
+ *
+ * @list:       Pointer to "struct list_head".
+ * @domainname: The name of current domain.
+ * @program:    The name of requested program.
+ * @last_name:  The last component of @domainname.
+ * @type:       One of values in "enum tomoyo_transition_type".
+ *
+ * Returns true if found one, false otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+static inline bool tomoyo_scan_transition
+(const struct list_head *list, const struct tomoyo_path_info *domainname,
+ const struct tomoyo_path_info *program, const char *last_name,
+ const enum tomoyo_transition_type type)
+{
+       const struct tomoyo_transition_control *ptr;
+       list_for_each_entry_rcu(ptr, list, head.list) {
+               if (ptr->head.is_deleted || ptr->type != type)
+                       continue;
+               if (ptr->domainname) {
+                       if (!ptr->is_last_name) {
+                               if (ptr->domainname != domainname)
+                                       continue;
+                       } else {
+                               /*
+                                * Use direct strcmp() since this is
+                                * unlikely used.
+                                */
+                               if (strcmp(ptr->domainname->name, last_name))
+                                       continue;
+                       }
+               }
+               if (ptr->program && tomoyo_pathcmp(ptr->program, program))
+                       continue;
+               return true;
+       }
+       return false;
+}
+
+/**
+ * tomoyo_transition_type - Get domain transition type.
+ *
+ * @ns:         Pointer to "struct tomoyo_policy_namespace".
+ * @domainname: The name of current domain.
+ * @program:    The name of requested program.
+ *
+ * Returns TOMOYO_TRANSITION_CONTROL_TRANSIT if executing @program causes
+ * domain transition across namespaces, TOMOYO_TRANSITION_CONTROL_INITIALIZE if
+ * executing @program reinitializes domain transition within that namespace,
+ * TOMOYO_TRANSITION_CONTROL_KEEP if executing @program stays at @domainname ,
+ * others otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+static enum tomoyo_transition_type tomoyo_transition_type
+(const struct tomoyo_policy_namespace *ns,
+ const struct tomoyo_path_info *domainname,
+ const struct tomoyo_path_info *program)
+{
+       const char *last_name = tomoyo_last_word(domainname->name);
+       enum tomoyo_transition_type type = TOMOYO_TRANSITION_CONTROL_NO_RESET;
+       while (type < TOMOYO_MAX_TRANSITION_TYPE) {
+               const struct list_head * const list =
+                       &ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
+               if (!tomoyo_scan_transition(list, domainname, program,
+                                           last_name, type)) {
+                       type++;
+                       continue;
+               }
+               if (type != TOMOYO_TRANSITION_CONTROL_NO_RESET &&
+                   type != TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE)
+                       break;
+               /*
+                * Do not check for reset_domain if no_reset_domain matched.
+                * Do not check for initialize_domain if no_initialize_domain
+                * matched.
+                */
+               type++;
+               type++;
+       }
+       return type;
+}
+
+/**
+ * tomoyo_same_aggregator - Check for duplicated "struct tomoyo_aggregator" entry.
+ *
+ * @a: Pointer to "struct tomoyo_acl_head".
+ * @b: Pointer to "struct tomoyo_acl_head".
+ *
+ * Returns true if @a == @b, false otherwise.
+ */
+static bool tomoyo_same_aggregator(const struct tomoyo_acl_head *a,
+                                  const struct tomoyo_acl_head *b)
+{
+       const struct tomoyo_aggregator *p1 = container_of(a, typeof(*p1),
+                                                         head);
+       const struct tomoyo_aggregator *p2 = container_of(b, typeof(*p2),
+                                                         head);
+       return p1->original_name == p2->original_name &&
+               p1->aggregated_name == p2->aggregated_name;
+}
+
+/**
+ * tomoyo_write_aggregator - Write "struct tomoyo_aggregator" list.
+ *
+ * @param: Pointer to "struct tomoyo_acl_param".
+ *
+ * Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+int tomoyo_write_aggregator(struct tomoyo_acl_param *param)
+{
+       struct tomoyo_aggregator e = { };
+       int error = param->is_delete ? -ENOENT : -ENOMEM;
+       const char *original_name = tomoyo_read_token(param);
+       const char *aggregated_name = tomoyo_read_token(param);
+       if (!tomoyo_correct_word(original_name) ||
+           !tomoyo_correct_path(aggregated_name))
+               return -EINVAL;
+       e.original_name = tomoyo_get_name(original_name);
+       e.aggregated_name = tomoyo_get_name(aggregated_name);
+       if (!e.original_name || !e.aggregated_name ||
+           e.aggregated_name->is_patterned) /* No patterns allowed. */
+               goto out;
+       param->list = &param->ns->policy_list[TOMOYO_ID_AGGREGATOR];
+       error = tomoyo_update_policy(&e.head, sizeof(e), param,
+                                    tomoyo_same_aggregator);
+out:
+       tomoyo_put_name(e.original_name);
+       tomoyo_put_name(e.aggregated_name);
+       return error;
+}
+
+/**
+ * tomoyo_find_namespace - Find specified namespace.
+ *
+ * @name: Name of namespace to find.
+ * @len:  Length of @name.
+ *
+ * Returns pointer to "struct tomoyo_policy_namespace" if found,
+ * NULL otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+static struct tomoyo_policy_namespace *tomoyo_find_namespace
+(const char *name, const unsigned int len)
+{
+       struct tomoyo_policy_namespace *ns;
+       list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
+               if (strncmp(name, ns->name, len) ||
+                   (name[len] && name[len] != ' '))
+                       continue;
+               return ns;
+       }
+       return NULL;
+}
+
+/**
+ * tomoyo_assign_namespace - Create a new namespace.
+ *
+ * @domainname: Name of namespace to create.
+ *
+ * Returns pointer to "struct tomoyo_policy_namespace" on success,
+ * NULL otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+struct tomoyo_policy_namespace *tomoyo_assign_namespace(const char *domainname)
+{
+       struct tomoyo_policy_namespace *ptr;
+       struct tomoyo_policy_namespace *entry;
+       const char *cp = domainname;
+       unsigned int len = 0;
+       while (*cp && *cp++ != ' ')
+               len++;
+       ptr = tomoyo_find_namespace(domainname, len);
+       if (ptr)
+               return ptr;
+       if (len >= TOMOYO_EXEC_TMPSIZE - 10 || !tomoyo_domain_def(domainname))
+               return NULL;
+       entry = kzalloc(sizeof(*entry) + len + 1, GFP_NOFS);
+       if (!entry)
+               return NULL;
+       if (mutex_lock_interruptible(&tomoyo_policy_lock))
+               goto out;
+       ptr = tomoyo_find_namespace(domainname, len);
+       if (!ptr && tomoyo_memory_ok(entry)) {
+               char *name = (char *) (entry + 1);
+               ptr = entry;
+               memmove(name, domainname, len);
+               name[len] = '\0';
+               entry->name = name;
+               tomoyo_init_policy_namespace(entry);
+               entry = NULL;
+       }
+       mutex_unlock(&tomoyo_policy_lock);
+out:
+       kfree(entry);
+       return ptr;
+}
+
+/**
+ * tomoyo_namespace_jump - Check for namespace jump.
+ *
+ * @domainname: Name of domain.
+ *
+ * Returns true if namespace differs, false otherwise.
+ */
+static bool tomoyo_namespace_jump(const char *domainname)
+{
+       const char *namespace = tomoyo_current_namespace()->name;
+       const int len = strlen(namespace);
+       return strncmp(domainname, namespace, len) ||
+               (domainname[len] && domainname[len] != ' ');
+}
+
+/**
+ * tomoyo_assign_domain - Create a domain or a namespace.
+ *
+ * @domainname: The name of domain.
+ * @transit:    True if transit to domain found or created.
+ *
+ * Returns pointer to "struct tomoyo_domain_info" on success, NULL otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+struct tomoyo_domain_info *tomoyo_assign_domain(const char *domainname,
+                                               const bool transit)
+{
+       struct tomoyo_domain_info e = { };
+       struct tomoyo_domain_info *entry = tomoyo_find_domain(domainname);
+       bool created = false;
+       if (entry) {
+               if (transit) {
+                       /*
+                        * Since namespace is created at runtime, profiles may
+                        * not be created by the moment the process transits to
+                        * that domain. Do not perform domain transition if
+                        * profile for that domain is not yet created.
+                        */
+                       if (tomoyo_policy_loaded &&
+                           !entry->ns->profile_ptr[entry->profile])
+                               return NULL;
+               }
+               return entry;
+       }
+       /* Requested domain does not exist. */
+       /* Don't create requested domain if domainname is invalid. */
+       if (strlen(domainname) >= TOMOYO_EXEC_TMPSIZE - 10 ||
+           !tomoyo_correct_domain(domainname))
+               return NULL;
+       /*
+        * Since definition of profiles and acl_groups may differ across
+        * namespaces, do not inherit "use_profile" and "use_group" settings
+        * by automatically creating requested domain upon domain transition.
+        */
+       if (transit && tomoyo_namespace_jump(domainname))
+               return NULL;
+       e.ns = tomoyo_assign_namespace(domainname);
+       if (!e.ns)
+               return NULL;
+       /*
+        * "use_profile" and "use_group" settings for automatically created
+        * domains are inherited from current domain. These are 0 for manually
+        * created domains.
+        */
+       if (transit) {
+               const struct tomoyo_domain_info *domain = tomoyo_domain();
+               e.profile = domain->profile;
+               e.group = domain->group;
+       }
+       e.domainname = tomoyo_get_name(domainname);
+       if (!e.domainname)
+               return NULL;
+       if (mutex_lock_interruptible(&tomoyo_policy_lock))
+               goto out;
+       entry = tomoyo_find_domain(domainname);
+       if (!entry) {
+               entry = tomoyo_commit_ok(&e, sizeof(e));
+               if (entry) {
+                       INIT_LIST_HEAD(&entry->acl_info_list);
+                       list_add_tail_rcu(&entry->list, &tomoyo_domain_list);
+                       created = true;
+               }
+       }
+       mutex_unlock(&tomoyo_policy_lock);
+out:
+       tomoyo_put_name(e.domainname);
+       if (entry && transit) {
+               if (created) {
+                       struct tomoyo_request_info r;
+                       tomoyo_init_request_info(&r, entry,
+                                                TOMOYO_MAC_FILE_EXECUTE);
+                       r.granted = false;
+                       tomoyo_write_log(&r, "use_profile %u\n",
+                                        entry->profile);
+                       tomoyo_write_log(&r, "use_group %u\n", entry->group);
+                       tomoyo_update_stat(TOMOYO_STAT_POLICY_UPDATES);
+               }
+       }
+       return entry;
+}
+
+/**
+ * tomoyo_environ - Check permission for environment variable names.
+ *
+ * @ee: Pointer to "struct tomoyo_execve".
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+static int tomoyo_environ(struct tomoyo_execve *ee)
+{
+       struct tomoyo_request_info *r = &ee->r;
+       struct linux_binprm *bprm = ee->bprm;
+       /* env_page.data is allocated by tomoyo_dump_page(). */
+       struct tomoyo_page_dump env_page = { };
+       char *arg_ptr; /* Size is TOMOYO_EXEC_TMPSIZE bytes */
+       int arg_len = 0;
+       unsigned long pos = bprm->p;
+       int offset = pos % PAGE_SIZE;
+       int argv_count = bprm->argc;
+       int envp_count = bprm->envc;
+       int error = -ENOMEM;
+
+       ee->r.type = TOMOYO_MAC_ENVIRON;
+       ee->r.profile = r->domain->profile;
+       ee->r.mode = tomoyo_get_mode(r->domain->ns, ee->r.profile,
+                                    TOMOYO_MAC_ENVIRON);
+       if (!r->mode || !envp_count)
+               return 0;
+       arg_ptr = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
+       if (!arg_ptr)
+               goto out;
+       while (error == -ENOMEM) {
+               if (!tomoyo_dump_page(bprm, pos, &env_page))
+                       goto out;
+               pos += PAGE_SIZE - offset;
+               /* Read. */
+               while (argv_count && offset < PAGE_SIZE) {
+                       if (!env_page.data[offset++])
+                               argv_count--;
+               }
+               if (argv_count) {
+                       offset = 0;
+                       continue;
+               }
+               while (offset < PAGE_SIZE) {
+                       const unsigned char c = env_page.data[offset++];
+
+                       if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
+                               if (c == '=') {
+                                       arg_ptr[arg_len++] = '\0';
+                               } else if (c == '\\') {
+                                       arg_ptr[arg_len++] = '\\';
+                                       arg_ptr[arg_len++] = '\\';
+                               } else if (c > ' ' && c < 127) {
+                                       arg_ptr[arg_len++] = c;
+                               } else {
+                                       arg_ptr[arg_len++] = '\\';
+                                       arg_ptr[arg_len++] = (c >> 6) + '0';
+                                       arg_ptr[arg_len++]
+                                               = ((c >> 3) & 7) + '0';
+                                       arg_ptr[arg_len++] = (c & 7) + '0';
+                               }
+                       } else {
+                               arg_ptr[arg_len] = '\0';
+                       }
+                       if (c)
+                               continue;
+                       if (tomoyo_env_perm(r, arg_ptr)) {
+                               error = -EPERM;
+                               break;
+                       }
+                       if (!--envp_count) {
+                               error = 0;
+                               break;
+                       }
+                       arg_len = 0;
+               }
+               offset = 0;
+       }
+out:
+       if (r->mode != TOMOYO_CONFIG_ENFORCING)
+               error = 0;
+       kfree(env_page.data);
+       kfree(arg_ptr);
+       return error;
+}
+
+/**
+ * tomoyo_find_next_domain - Find a domain.
+ *
+ * @bprm: Pointer to "struct linux_binprm".
+ *
+ * Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+int tomoyo_find_next_domain(struct linux_binprm *bprm)
+{
+       struct tomoyo_domain_info *old_domain = tomoyo_domain();
+       struct tomoyo_domain_info *domain = NULL;
+       const char *original_name = bprm->filename;
+       int retval = -ENOMEM;
+       bool reject_on_transition_failure = false;
+       const struct tomoyo_path_info *candidate;
+       struct tomoyo_path_info exename;
+       struct tomoyo_execve *ee = kzalloc(sizeof(*ee), GFP_NOFS);
+
+       if (!ee)
+               return -ENOMEM;
+       ee->tmp = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
+       if (!ee->tmp) {
+               kfree(ee);
+               return -ENOMEM;
+       }
+       /* ee->dump->data is allocated by tomoyo_dump_page(). */
+       tomoyo_init_request_info(&ee->r, NULL, TOMOYO_MAC_FILE_EXECUTE);
+       ee->r.ee = ee;
+       ee->bprm = bprm;
+       ee->r.obj = &ee->obj;
+       ee->obj.path1 = bprm->file->f_path;
+       /* Get symlink's pathname of program. */
+       retval = -ENOENT;
+       exename.name = tomoyo_realpath_nofollow(original_name);
+       if (!exename.name)
+               goto out;
+       tomoyo_fill_path_info(&exename);
+retry:
+       /* Check 'aggregator' directive. */
+       {
+               struct tomoyo_aggregator *ptr;
+               struct list_head *list =
+                       &old_domain->ns->policy_list[TOMOYO_ID_AGGREGATOR];
+               /* Check 'aggregator' directive. */
+               candidate = &exename;
+               list_for_each_entry_rcu(ptr, list, head.list) {
+                       if (ptr->head.is_deleted ||
+                           !tomoyo_path_matches_pattern(&exename,
+                                                        ptr->original_name))
+                               continue;
+                       candidate = ptr->aggregated_name;
+                       break;
+               }
+       }
+
+       /* Check execute permission. */
+       retval = tomoyo_execute_permission(&ee->r, candidate);
+       if (retval == TOMOYO_RETRY_REQUEST)
+               goto retry;
+       if (retval < 0)
+               goto out;
+       /*
+        * To be able to specify domainnames with wildcards, use the
+        * pathname specified in the policy (which may contain
+        * wildcard) rather than the pathname passed to execve()
+        * (which never contains wildcard).
+        */
+       if (ee->r.param.path.matched_path)
+               candidate = ee->r.param.path.matched_path;
+
+       /*
+        * Check for domain transition preference if "file execute" matched.
+        * If preference is given, make do_execve() fail if domain transition
+        * has failed, for domain transition preference should be used with
+        * destination domain defined.
+        */
+       if (ee->transition) {
+               const char *domainname = ee->transition->name;
+               reject_on_transition_failure = true;
+               if (!strcmp(domainname, "keep"))
+                       goto force_keep_domain;
+               if (!strcmp(domainname, "child"))
+                       goto force_child_domain;
+               if (!strcmp(domainname, "reset"))
+                       goto force_reset_domain;
+               if (!strcmp(domainname, "initialize"))
+                       goto force_initialize_domain;
+               if (!strcmp(domainname, "parent")) {
+                       char *cp;
+                       strncpy(ee->tmp, old_domain->domainname->name,
+                               TOMOYO_EXEC_TMPSIZE - 1);
+                       cp = strrchr(ee->tmp, ' ');
+                       if (cp)
+                               *cp = '\0';
+               } else if (*domainname == '<')
+                       strncpy(ee->tmp, domainname, TOMOYO_EXEC_TMPSIZE - 1);
+               else
+                       snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
+                                old_domain->domainname->name, domainname);
+               goto force_jump_domain;
+       }
+       /*
+        * No domain transition preference specified.
+        * Calculate domain to transit to.
+        */
+       switch (tomoyo_transition_type(old_domain->ns, old_domain->domainname,
+                                      candidate)) {
+       case TOMOYO_TRANSITION_CONTROL_RESET:
+force_reset_domain:
+               /* Transit to the root of specified namespace. */
+               snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "<%s>",
+                        candidate->name);
+               /*
+                * Make do_execve() fail if domain transition across namespaces
+                * has failed.
+                */
+               reject_on_transition_failure = true;
+               break;
+       case TOMOYO_TRANSITION_CONTROL_INITIALIZE:
+force_initialize_domain:
+               /* Transit to the child of current namespace's root. */
+               snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
+                        old_domain->ns->name, candidate->name);
+               break;
+       case TOMOYO_TRANSITION_CONTROL_KEEP:
+force_keep_domain:
+               /* Keep current domain. */
+               domain = old_domain;
+               break;
+       default:
+               if (old_domain == &tomoyo_kernel_domain &&
+                   !tomoyo_policy_loaded) {
+                       /*
+                        * Needn't to transit from kernel domain before
+                        * starting /sbin/init. But transit from kernel domain
+                        * if executing initializers because they might start
+                        * before /sbin/init.
+                        */
+                       domain = old_domain;
+                       break;
+               }
+force_child_domain:
+               /* Normal domain transition. */
+               snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
+                        old_domain->domainname->name, candidate->name);
+               break;
+       }
+force_jump_domain:
+       if (!domain)
+               domain = tomoyo_assign_domain(ee->tmp, true);
+       if (domain)
+               retval = 0;
+       else if (reject_on_transition_failure) {
+               printk(KERN_WARNING "ERROR: Domain '%s' not ready.\n",
+                      ee->tmp);
+               retval = -ENOMEM;
+       } else if (ee->r.mode == TOMOYO_CONFIG_ENFORCING)
+               retval = -ENOMEM;
+       else {
+               retval = 0;
+               if (!old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED]) {
+                       old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED] = true;
+                       ee->r.granted = false;
+                       tomoyo_write_log(&ee->r, "%s", tomoyo_dif
+                                        [TOMOYO_DIF_TRANSITION_FAILED]);
+                       printk(KERN_WARNING
+                              "ERROR: Domain '%s' not defined.\n", ee->tmp);
+               }
+       }
+ out:
+       if (!domain)
+               domain = old_domain;
+       /* Update reference count on "struct tomoyo_domain_info". */
+       atomic_inc(&domain->users);
+       bprm->cred->security = domain;
+       kfree(exename.name);
+       if (!retval) {
+               ee->r.domain = domain;
+               retval = tomoyo_environ(ee);
+       }
+       kfree(ee->tmp);
+       kfree(ee->dump.data);
+       kfree(ee);
+       return retval;
+}
+
+/**
+ * tomoyo_dump_page - Dump a page to buffer.
+ *
+ * @bprm: Pointer to "struct linux_binprm".
+ * @pos:  Location to dump.
+ * @dump: Poiner to "struct tomoyo_page_dump".
+ *
+ * Returns true on success, false otherwise.
+ */
+bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
+                     struct tomoyo_page_dump *dump)
+{
+       struct page *page;
+
+       /* dump->data is released by tomoyo_find_next_domain(). */
+       if (!dump->data) {
+               dump->data = kzalloc(PAGE_SIZE, GFP_NOFS);
+               if (!dump->data)
+                       return false;
+       }
+       /* Same with get_arg_page(bprm, pos, 0) in fs/exec.c */
+#ifdef CONFIG_MMU
+       if (get_user_pages(current, bprm->mm, pos, 1, 0, 1, &page, NULL) <= 0)
+               return false;
+#else
+       page = bprm->page[pos / PAGE_SIZE];
+#endif
+       if (page != dump->page) {
+               const unsigned int offset = pos % PAGE_SIZE;
+               /*
+                * Maybe kmap()/kunmap() should be used here.
+                * But remove_arg_zero() uses kmap_atomic()/kunmap_atomic().
+                * So do I.
+                */
+               char *kaddr = kmap_atomic(page);
+
+               dump->page = page;
+               memcpy(dump->data + offset, kaddr + offset,
+                      PAGE_SIZE - offset);
+               kunmap_atomic(kaddr);
+       }
+       /* Same with put_arg_page(page) in fs/exec.c */
+#ifdef CONFIG_MMU
+       put_page(page);
+#endif
+       return true;
+}