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Release 4.15 security/tomoyo/gc.c

Directory: security/tomoyo
// SPDX-License-Identifier: GPL-2.0
/*
 * security/tomoyo/gc.c
 *
 * Copyright (C) 2005-2011  NTT DATA CORPORATION
 */

#include "common.h"
#include <linux/kthread.h>
#include <linux/slab.h>

/**
 * tomoyo_memory_free - Free memory for elements.
 *
 * @ptr:  Pointer to allocated memory.
 *
 * Returns nothing.
 *
 * Caller holds tomoyo_policy_lock mutex.
 */

static inline void tomoyo_memory_free(void *ptr) { tomoyo_memory_used[TOMOYO_MEMORY_POLICY] -= ksize(ptr); kfree(ptr); }

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Tetsuo Handa26100.00%1100.00%
Total26100.00%1100.00%

/* The list for "struct tomoyo_io_buffer". */ static LIST_HEAD(tomoyo_io_buffer_list); /* Lock for protecting tomoyo_io_buffer_list. */ static DEFINE_SPINLOCK(tomoyo_io_buffer_list_lock); /** * tomoyo_struct_used_by_io_buffer - Check whether the list element is used by /sys/kernel/security/tomoyo/ users or not. * * @element: Pointer to "struct list_head". * * Returns true if @element is used by /sys/kernel/security/tomoyo/ users, * false otherwise. */
static bool tomoyo_struct_used_by_io_buffer(const struct list_head *element) { struct tomoyo_io_buffer *head; bool in_use = false; spin_lock(&tomoyo_io_buffer_list_lock); list_for_each_entry(head, &tomoyo_io_buffer_list, list) { head->users++; spin_unlock(&tomoyo_io_buffer_list_lock); mutex_lock(&head->io_sem); if (head->r.domain == element || head->r.group == element || head->r.acl == element || &head->w.domain->list == element) in_use = true; mutex_unlock(&head->io_sem); spin_lock(&tomoyo_io_buffer_list_lock); head->users--; if (in_use) break; } spin_unlock(&tomoyo_io_buffer_list_lock); return in_use; }

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Tetsuo Handa131100.00%2100.00%
Total131100.00%2100.00%

/** * tomoyo_name_used_by_io_buffer - Check whether the string is used by /sys/kernel/security/tomoyo/ users or not. * * @string: String to check. * * Returns true if @string is used by /sys/kernel/security/tomoyo/ users, * false otherwise. */
static bool tomoyo_name_used_by_io_buffer(const char *string) { struct tomoyo_io_buffer *head; const size_t size = strlen(string) + 1; bool in_use = false; spin_lock(&tomoyo_io_buffer_list_lock); list_for_each_entry(head, &tomoyo_io_buffer_list, list) { int i; head->users++; spin_unlock(&tomoyo_io_buffer_list_lock); mutex_lock(&head->io_sem); for (i = 0; i < TOMOYO_MAX_IO_READ_QUEUE; i++) { const char *w = head->r.w[i]; if (w < string || w > string + size) continue; in_use = true; break; } mutex_unlock(&head->io_sem); spin_lock(&tomoyo_io_buffer_list_lock); head->users--; if (in_use) break; } spin_unlock(&tomoyo_io_buffer_list_lock); return in_use; }

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Tetsuo Handa150100.00%2100.00%
Total150100.00%2100.00%

/** * tomoyo_del_transition_control - Delete members in "struct tomoyo_transition_control". * * @element: Pointer to "struct list_head". * * Returns nothing. */
static inline void tomoyo_del_transition_control(struct list_head *element) { struct tomoyo_transition_control *ptr = container_of(element, typeof(*ptr), head.list); tomoyo_put_name(ptr->domainname); tomoyo_put_name(ptr->program); }

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Tetsuo Handa46100.00%3100.00%
Total46100.00%3100.00%

/** * tomoyo_del_aggregator - Delete members in "struct tomoyo_aggregator". * * @element: Pointer to "struct list_head". * * Returns nothing. */
static inline void tomoyo_del_aggregator(struct list_head *element) { struct tomoyo_aggregator *ptr = container_of(element, typeof(*ptr), head.list); tomoyo_put_name(ptr->original_name); tomoyo_put_name(ptr->aggregated_name); }

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Tetsuo Handa46100.00%4100.00%
Total46100.00%4100.00%

/** * tomoyo_del_manager - Delete members in "struct tomoyo_manager". * * @element: Pointer to "struct list_head". * * Returns nothing. */
static inline void tomoyo_del_manager(struct list_head *element) { struct tomoyo_manager *ptr = container_of(element, typeof(*ptr), head.list); tomoyo_put_name(ptr->manager); }

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Tetsuo Handa39100.00%4100.00%
Total39100.00%4100.00%

/** * tomoyo_del_acl - Delete members in "struct tomoyo_acl_info". * * @element: Pointer to "struct list_head". * * Returns nothing. */
static void tomoyo_del_acl(struct list_head *element) { struct tomoyo_acl_info *acl = container_of(element, typeof(*acl), list); tomoyo_put_condition(acl->cond); switch (acl->type) { case TOMOYO_TYPE_PATH_ACL: { struct tomoyo_path_acl *entry = container_of(acl, typeof(*entry), head); tomoyo_put_name_union(&entry->name); } break; case TOMOYO_TYPE_PATH2_ACL: { struct tomoyo_path2_acl *entry = container_of(acl, typeof(*entry), head); tomoyo_put_name_union(&entry->name1); tomoyo_put_name_union(&entry->name2); } break; case TOMOYO_TYPE_PATH_NUMBER_ACL: { struct tomoyo_path_number_acl *entry = container_of(acl, typeof(*entry), head); tomoyo_put_name_union(&entry->name); tomoyo_put_number_union(&entry->number); } break; case TOMOYO_TYPE_MKDEV_ACL: { struct tomoyo_mkdev_acl *entry = container_of(acl, typeof(*entry), head); tomoyo_put_name_union(&entry->name); tomoyo_put_number_union(&entry->mode); tomoyo_put_number_union(&entry->major); tomoyo_put_number_union(&entry->minor); } break; case TOMOYO_TYPE_MOUNT_ACL: { struct tomoyo_mount_acl *entry = container_of(acl, typeof(*entry), head); tomoyo_put_name_union(&entry->dev_name); tomoyo_put_name_union(&entry->dir_name); tomoyo_put_name_union(&entry->fs_type); tomoyo_put_number_union(&entry->flags); } break; case TOMOYO_TYPE_ENV_ACL: { struct tomoyo_env_acl *entry = container_of(acl, typeof(*entry), head); tomoyo_put_name(entry->env); } break; case TOMOYO_TYPE_INET_ACL: { struct tomoyo_inet_acl *entry = container_of(acl, typeof(*entry), head); tomoyo_put_group(entry->address.group); tomoyo_put_number_union(&entry->port); } break; case TOMOYO_TYPE_UNIX_ACL: { struct tomoyo_unix_acl *entry = container_of(acl, typeof(*entry), head); tomoyo_put_name_union(&entry->name); } break; case TOMOYO_TYPE_MANUAL_TASK_ACL: { struct tomoyo_task_acl *entry = container_of(acl, typeof(*entry), head); tomoyo_put_name(entry->domainname); } break; } }

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Tetsuo Handa403100.00%11100.00%
Total403100.00%11100.00%

/** * tomoyo_del_domain - Delete members in "struct tomoyo_domain_info". * * @element: Pointer to "struct list_head". * * Returns nothing. * * Caller holds tomoyo_policy_lock mutex. */
static inline void tomoyo_del_domain(struct list_head *element) { struct tomoyo_domain_info *domain = container_of(element, typeof(*domain), list); struct tomoyo_acl_info *acl; struct tomoyo_acl_info *tmp; /* * Since this domain is referenced from neither * "struct tomoyo_io_buffer" nor "struct cred"->security, we can delete * elements without checking for is_deleted flag. */ list_for_each_entry_safe(acl, tmp, &domain->acl_info_list, list) { tomoyo_del_acl(&acl->list); tomoyo_memory_free(acl); } tomoyo_put_name(domain->domainname); }

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Tetsuo Handa73100.00%3100.00%
Total73100.00%3100.00%

/** * tomoyo_del_condition - Delete members in "struct tomoyo_condition". * * @element: Pointer to "struct list_head". * * Returns nothing. */
void tomoyo_del_condition(struct list_head *element) { struct tomoyo_condition *cond = container_of(element, typeof(*cond), head.list); const u16 condc = cond->condc; const u16 numbers_count = cond->numbers_count; const u16 names_count = cond->names_count; const u16 argc = cond->argc; const u16 envc = cond->envc; unsigned int i; const struct tomoyo_condition_element *condp = (const struct tomoyo_condition_element *) (cond + 1); struct tomoyo_number_union *numbers_p = (struct tomoyo_number_union *) (condp + condc); struct tomoyo_name_union *names_p = (struct tomoyo_name_union *) (numbers_p + numbers_count); const struct tomoyo_argv *argv = (const struct tomoyo_argv *) (names_p + names_count); const struct tomoyo_envp *envp = (const struct tomoyo_envp *) (argv + argc); for (i = 0; i < numbers_count; i++) tomoyo_put_number_union(numbers_p++); for (i = 0; i < names_count; i++) tomoyo_put_name_union(names_p++); for (i = 0; i < argc; argv++, i++) tomoyo_put_name(argv->value); for (i = 0; i < envc; envp++, i++) { tomoyo_put_name(envp->name); tomoyo_put_name(envp->value); } }

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Tetsuo Handa253100.00%3100.00%
Total253100.00%3100.00%

/** * tomoyo_del_name - Delete members in "struct tomoyo_name". * * @element: Pointer to "struct list_head". * * Returns nothing. */
static inline void tomoyo_del_name(struct list_head *element) { /* Nothing to do. */ }

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Tetsuo Handa13100.00%3100.00%
Total13100.00%3100.00%

/** * tomoyo_del_path_group - Delete members in "struct tomoyo_path_group". * * @element: Pointer to "struct list_head". * * Returns nothing. */
static inline void tomoyo_del_path_group(struct list_head *element) { struct tomoyo_path_group *member = container_of(element, typeof(*member), head.list); tomoyo_put_name(member->member_name); }

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Tetsuo Handa39100.00%4100.00%
Total39100.00%4100.00%

/** * tomoyo_del_group - Delete "struct tomoyo_group". * * @element: Pointer to "struct list_head". * * Returns nothing. */
static inline void tomoyo_del_group(struct list_head *element) { struct tomoyo_group *group = container_of(element, typeof(*group), head.list); tomoyo_put_name(group->group_name); }

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Tetsuo Handa39100.00%5100.00%
Total39100.00%5100.00%

/** * tomoyo_del_address_group - Delete members in "struct tomoyo_address_group". * * @element: Pointer to "struct list_head". * * Returns nothing. */
static inline void tomoyo_del_address_group(struct list_head *element) { /* Nothing to do. */ }

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Tetsuo Handa13100.00%1100.00%
Total13100.00%1100.00%

/** * tomoyo_del_number_group - Delete members in "struct tomoyo_number_group". * * @element: Pointer to "struct list_head". * * Returns nothing. */
static inline void tomoyo_del_number_group(struct list_head *element) { /* Nothing to do. */ }

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Tetsuo Handa13100.00%4100.00%
Total13100.00%4100.00%

/** * tomoyo_try_to_gc - Try to kfree() an entry. * * @type: One of values in "enum tomoyo_policy_id". * @element: Pointer to "struct list_head". * * Returns nothing. * * Caller holds tomoyo_policy_lock mutex. */
static void tomoyo_try_to_gc(const enum tomoyo_policy_id type, struct list_head *element) { /* * __list_del_entry() guarantees that the list element became no longer * reachable from the list which the element was originally on (e.g. * tomoyo_domain_list). Also, synchronize_srcu() guarantees that the * list element became no longer referenced by syscall users. */ __list_del_entry(element); mutex_unlock(&tomoyo_policy_lock); synchronize_srcu(&tomoyo_ss); /* * However, there are two users which may still be using the list * element. We need to defer until both users forget this element. * * Don't kfree() until "struct tomoyo_io_buffer"->r.{domain,group,acl} * and "struct tomoyo_io_buffer"->w.domain forget this element. */ if (tomoyo_struct_used_by_io_buffer(element)) goto reinject; switch (type) { case TOMOYO_ID_TRANSITION_CONTROL: tomoyo_del_transition_control(element); break; case TOMOYO_ID_MANAGER: tomoyo_del_manager(element); break; case TOMOYO_ID_AGGREGATOR: tomoyo_del_aggregator(element); break; case TOMOYO_ID_GROUP: tomoyo_del_group(element); break; case TOMOYO_ID_PATH_GROUP: tomoyo_del_path_group(element); break; case TOMOYO_ID_ADDRESS_GROUP: tomoyo_del_address_group(element); break; case TOMOYO_ID_NUMBER_GROUP: tomoyo_del_number_group(element); break; case TOMOYO_ID_CONDITION: tomoyo_del_condition(element); break; case TOMOYO_ID_NAME: /* * Don't kfree() until all "struct tomoyo_io_buffer"->r.w[] * forget this element. */ if (tomoyo_name_used_by_io_buffer (container_of(element, typeof(struct tomoyo_name), head.list)->entry.name)) goto reinject; tomoyo_del_name(element); break; case TOMOYO_ID_ACL: tomoyo_del_acl(element); break; case TOMOYO_ID_DOMAIN: /* * Don't kfree() until all "struct cred"->security forget this * element. */ if (atomic_read(&container_of (element, typeof(struct tomoyo_domain_info), list)->users)) goto reinject; break; case TOMOYO_MAX_POLICY: break; } mutex_lock(&tomoyo_policy_lock); if (type == TOMOYO_ID_DOMAIN) tomoyo_del_domain(element); tomoyo_memory_free(element); return; reinject: /* * We can safely reinject this element here bacause * (1) Appending list elements and removing list elements are protected * by tomoyo_policy_lock mutex. * (2) Only this function removes list elements and this function is * exclusively executed by tomoyo_gc_mutex mutex. * are true. */ mutex_lock(&tomoyo_policy_lock); list_add_rcu(element, element->prev); }

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Tetsuo Handa243100.00%4100.00%
Total243100.00%4100.00%

/** * tomoyo_collect_member - Delete elements with "struct tomoyo_acl_head". * * @id: One of values in "enum tomoyo_policy_id". * @member_list: Pointer to "struct list_head". * * Returns nothing. */
static void tomoyo_collect_member(const enum tomoyo_policy_id id, struct list_head *member_list) { struct tomoyo_acl_head *member; struct tomoyo_acl_head *tmp; list_for_each_entry_safe(member, tmp, member_list, list) { if (!member->is_deleted) continue; member->is_deleted = TOMOYO_GC_IN_PROGRESS; tomoyo_try_to_gc(id, &member->list); } }

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Tetsuo Handa62100.00%4100.00%
Total62100.00%4100.00%

/** * tomoyo_collect_acl - Delete elements in "struct tomoyo_domain_info". * * @list: Pointer to "struct list_head". * * Returns nothing. */
static void tomoyo_collect_acl(struct list_head *list) { struct tomoyo_acl_info *acl; struct tomoyo_acl_info *tmp; list_for_each_entry_safe(acl, tmp, list, list) { if (!acl->is_deleted) continue; acl->is_deleted = TOMOYO_GC_IN_PROGRESS; tomoyo_try_to_gc(TOMOYO_ID_ACL, &acl->list); } }

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Tetsuo Handa57100.00%4100.00%
Total57100.00%4100.00%

/** * tomoyo_collect_entry - Try to kfree() deleted elements. * * Returns nothing. */
static void tomoyo_collect_entry(void) { int i; enum tomoyo_policy_id id; struct tomoyo_policy_namespace *ns; mutex_lock(&tomoyo_policy_lock); { struct tomoyo_domain_info *domain; struct tomoyo_domain_info *tmp; list_for_each_entry_safe(domain, tmp, &tomoyo_domain_list, list) { tomoyo_collect_acl(&domain->acl_info_list); if (!domain->is_deleted || atomic_read(&domain->users)) continue; tomoyo_try_to_gc(TOMOYO_ID_DOMAIN, &domain->list); } } list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) { for (id = 0; id < TOMOYO_MAX_POLICY; id++) tomoyo_collect_member(id, &ns->policy_list[id]); for (i = 0; i < TOMOYO_MAX_ACL_GROUPS; i++) tomoyo_collect_acl(&ns->acl_group[i]); } { struct tomoyo_shared_acl_head *ptr; struct tomoyo_shared_acl_head *tmp; list_for_each_entry_safe(ptr, tmp, &tomoyo_condition_list, list) { if (atomic_read(&ptr->users) > 0) continue; atomic_set(&ptr->users, TOMOYO_GC_IN_PROGRESS); tomoyo_try_to_gc(TOMOYO_ID_CONDITION, &ptr->list); } } list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) { for (i = 0; i < TOMOYO_MAX_GROUP; i++) { struct list_head *list = &ns->group_list[i]; struct tomoyo_group *group; struct tomoyo_group *tmp; switch (i) { case 0: id = TOMOYO_ID_PATH_GROUP; break; case 1: id = TOMOYO_ID_NUMBER_GROUP; break; default: id = TOMOYO_ID_ADDRESS_GROUP; break; } list_for_each_entry_safe(group, tmp, list, head.list) { tomoyo_collect_member(id, &group->member_list); if (!list_empty(&group->member_list) || atomic_read(&group->head.users) > 0) continue; atomic_set(&group->head.users, TOMOYO_GC_IN_PROGRESS); tomoyo_try_to_gc(TOMOYO_ID_GROUP, &group->head.list); } } } for (i = 0; i < TOMOYO_MAX_HASH; i++) { struct list_head *list = &tomoyo_name_list[i]; struct tomoyo_shared_acl_head *ptr; struct tomoyo_shared_acl_head *tmp; list_for_each_entry_safe(ptr, tmp, list, list) { if (atomic_read(&ptr->users) > 0) continue; atomic_set(&ptr->users, TOMOYO_GC_IN_PROGRESS); tomoyo_try_to_gc(TOMOYO_ID_NAME, &ptr->list); } } mutex_unlock(&tomoyo_policy_lock); }

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Tetsuo Handa434100.00%14100.00%
Total434100.00%14100.00%

/** * tomoyo_gc_thread - Garbage collector thread function. * * @unused: Unused. * * Returns 0. */
static int tomoyo_gc_thread(void *unused) { /* Garbage collector thread is exclusive. */ static DEFINE_MUTEX(tomoyo_gc_mutex); if (!mutex_trylock(&tomoyo_gc_mutex)) goto out; tomoyo_collect_entry(); { struct tomoyo_io_buffer *head; struct tomoyo_io_buffer *tmp; spin_lock(&tomoyo_io_buffer_list_lock); list_for_each_entry_safe(head, tmp, &tomoyo_io_buffer_list, list) { if (head->users) continue; list_del(&head->list); kfree(head->read_buf); kfree(head->write_buf); kfree(head); } spin_unlock(&tomoyo_io_buffer_list_lock); } mutex_unlock(&tomoyo_gc_mutex); out: /* This acts as do_exit(0). */ return 0; }

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Tetsuo Handa114100.00%2100.00%
Total114100.00%2100.00%

/** * tomoyo_notify_gc - Register/unregister /sys/kernel/security/tomoyo/ users. * * @head: Pointer to "struct tomoyo_io_buffer". * @is_register: True if register, false if unregister. * * Returns nothing. */
void tomoyo_notify_gc(struct tomoyo_io_buffer *head, const bool is_register) { bool is_write = false; spin_lock(&tomoyo_io_buffer_list_lock); if (is_register) { head->users = 1; list_add(&head->list, &tomoyo_io_buffer_list); } else { is_write = head->write_buf != NULL; if (!--head->users) { list_del(&head->list); kfree(head->read_buf); kfree(head->write_buf); kfree(head); } } spin_unlock(&tomoyo_io_buffer_list_lock); if (is_write) kthread_run(tomoyo_gc_thread, NULL, "GC for TOMOYO"); }

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PersonTokensPropCommitsCommitProp
Tetsuo Handa11499.13%266.67%
Mike Danese10.87%133.33%
Total115100.00%3100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Tetsuo Handa234999.79%2689.66%
Tejun Heo30.13%13.45%
Greg Kroah-Hartman10.04%13.45%
Mike Danese10.04%13.45%
Total2354100.00%29100.00%
Directory: security/tomoyo
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