1 files changed, 75 insertions, 217 deletions

diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c
index 18369d497eb8..cf7d61f781b9 100644
--- a/security/tomoyo/realpath.c
+++ b/security/tomoyo/realpath.c
@@ -14,9 +14,8 @@
 #include <linux/mnt_namespace.h>
 #include <linux/fs_struct.h>
 #include <linux/hash.h>
-
+#include <linux/magic.h>
 #include "common.h"
-#include "realpath.h"
 
 /**
  * tomoyo_encode: Convert binary string to ascii string.
@@ -89,30 +88,15 @@ int tomoyo_realpath_from_path2(struct path *path, char *newname,
                 sp = dentry->d_op->d_dname(dentry, newname + offset,
                                            newname_len - offset);
         } else {
-                /* Taken from d_namespace_path(). */
-                struct path root;
-                struct path ns_root = { };
-                struct path tmp;
+                struct path ns_root = {.mnt = NULL, .dentry = NULL};
 
-                read_lock(&current->fs->lock);
-                root = current->fs->root;
-                path_get(&root);
-                read_unlock(&current->fs->lock);
-                spin_lock(&vfsmount_lock);
-                if (root.mnt && root.mnt->mnt_ns)
-                        ns_root.mnt = mntget(root.mnt->mnt_ns->root);
-                if (ns_root.mnt)
-                        ns_root.dentry = dget(ns_root.mnt->mnt_root);
-                spin_unlock(&vfsmount_lock);
                 spin_lock(&dcache_lock);
-                tmp = ns_root;
-                sp = __d_path(path, &tmp, newname, newname_len);
+                /* go to whatever namespace root we are under */
+                sp = __d_path(path, &ns_root, newname, newname_len);
                 spin_unlock(&dcache_lock);
-                path_put(&root);
-                path_put(&ns_root);
                 /* Prepend "/proc" prefix if using internal proc vfs mount. */
-                if (!IS_ERR(sp) && (path->mnt->mnt_parent == path->mnt) &&
-                    (strcmp(path->mnt->mnt_sb->s_type->name, "proc") == 0)) {
+                if (!IS_ERR(sp) && (path->mnt->mnt_flags & MNT_INTERNAL) &&
+                    (path->mnt->mnt_sb->s_magic == PROC_SUPER_MAGIC)) {
                         sp -= 5;
                         if (sp >= newname)
                                 memcpy(sp, "/proc", 5);
@@ -149,12 +133,12 @@ int tomoyo_realpath_from_path2(struct path *path, char *newname,
  *
  * Returns the realpath of the given @path on success, NULL otherwise.
  *
- * These functions use tomoyo_alloc(), so the caller must call tomoyo_free()
+ * These functions use kzalloc(), so the caller must call kfree()
  * if these functions didn't return NULL.
  */
 char *tomoyo_realpath_from_path(struct path *path)
 {
-        char *buf = tomoyo_alloc(sizeof(struct tomoyo_page_buffer));
+        char *buf = kzalloc(sizeof(struct tomoyo_page_buffer), GFP_KERNEL);
 
         BUILD_BUG_ON(sizeof(struct tomoyo_page_buffer)
                      <= TOMOYO_MAX_PATHNAME_LEN - 1);
@@ -163,7 +147,7 @@ char *tomoyo_realpath_from_path(struct path *path)
         if (tomoyo_realpath_from_path2(path, buf,
                                        TOMOYO_MAX_PATHNAME_LEN - 1) == 0)
                 return buf;
-        tomoyo_free(buf);
+        kfree(buf);
         return NULL;
 }
 
@@ -206,98 +190,47 @@ char *tomoyo_realpath_nofollow(const char *pathname)
 }
 
 /* Memory allocated for non-string data. */
-static unsigned int tomoyo_allocated_memory_for_elements;
-/* Quota for holding non-string data. */
-static unsigned int tomoyo_quota_for_elements;
+static atomic_t tomoyo_policy_memory_size;
+/* Quota for holding policy. */
+static unsigned int tomoyo_quota_for_policy;
 
 /**
- * tomoyo_alloc_element - Allocate permanent memory for structures.
+ * tomoyo_memory_ok - Check memory quota.
  *
- * @size: Size in bytes.
+ * @ptr: Pointer to allocated memory.
  *
- * Returns pointer to allocated memory on success, NULL otherwise.
+ * Returns true on success, false otherwise.
  *
- * Memory has to be zeroed.
- * The RAM is chunked, so NEVER try to kfree() the returned pointer.
+ * Caller holds tomoyo_policy_lock.
+ * Memory pointed by @ptr will be zeroed on success.
  */
-void *tomoyo_alloc_element(const unsigned int size)
+bool tomoyo_memory_ok(void *ptr)
 {
-        static char *buf;
-        static DEFINE_MUTEX(lock);
-        static unsigned int buf_used_len = PATH_MAX;
-        char *ptr = NULL;
-        /*Assumes sizeof(void *) >= sizeof(long) is true. */
-        const unsigned int word_aligned_size
-                = roundup(size, max(sizeof(void *), sizeof(long)));
-        if (word_aligned_size > PATH_MAX)
-                return NULL;
-        mutex_lock(&lock);
-        if (buf_used_len + word_aligned_size > PATH_MAX) {
-                if (!tomoyo_quota_for_elements ||
-                    tomoyo_allocated_memory_for_elements
-                    + PATH_MAX <= tomoyo_quota_for_elements)
-                        ptr = kzalloc(PATH_MAX, GFP_KERNEL);
-                if (!ptr) {
-                        printk(KERN_WARNING "ERROR: Out of memory "
-                               "for tomoyo_alloc_element().\n");
-                        if (!tomoyo_policy_loaded)
-                                panic("MAC Initialization failed.\n");
-                } else {
-                        buf = ptr;
-                        tomoyo_allocated_memory_for_elements += PATH_MAX;
-                        buf_used_len = word_aligned_size;
-                        ptr = buf;
-                }
-        } else if (word_aligned_size) {
-                int i;
-                ptr = buf + buf_used_len;
-                buf_used_len += word_aligned_size;
-                for (i = 0; i < word_aligned_size; i++) {
-                        if (!ptr[i])
-                                continue;
-                        printk(KERN_ERR "WARNING: Reserved memory was tainted! "
-                               "The system might go wrong.\n");
-                        ptr[i] = '\0';
-                }
+        int allocated_len = ptr ? ksize(ptr) : 0;
+        atomic_add(allocated_len, &tomoyo_policy_memory_size);
+        if (ptr && (!tomoyo_quota_for_policy ||
+                    atomic_read(&tomoyo_policy_memory_size)
+                    <= tomoyo_quota_for_policy)) {
+                memset(ptr, 0, allocated_len);
+                return true;
         }
-        mutex_unlock(&lock);
-        return ptr;
+        printk(KERN_WARNING "ERROR: Out of memory "
+               "for tomoyo_alloc_element().\n");
+        if (!tomoyo_policy_loaded)
+                panic("MAC Initialization failed.\n");
+        return false;
 }
 
-/* Memory allocated for string data in bytes. */
-static unsigned int tomoyo_allocated_memory_for_savename;
-/* Quota for holding string data in bytes. */
-static unsigned int tomoyo_quota_for_savename;
-
-/*
- * TOMOYO uses this hash only when appending a string into the string
- * table. Frequency of appending strings is very low. So we don't need
- * large (e.g. 64k) hash size. 256 will be sufficient.
- */
-#define TOMOYO_HASH_BITS  8
-#define TOMOYO_MAX_HASH (1u<<TOMOYO_HASH_BITS)
-
-/*
- * tomoyo_name_entry is a structure which is used for linking
- * "struct tomoyo_path_info" into tomoyo_name_list .
+/**
+ * tomoyo_memory_free - Free memory for elements.
  *
- * Since tomoyo_name_list manages a list of strings which are shared by
- * multiple processes (whereas "struct tomoyo_path_info" inside
- * "struct tomoyo_path_info_with_data" is not shared), a reference counter will
- * be added to "struct tomoyo_name_entry" rather than "struct tomoyo_path_info"
- * when TOMOYO starts supporting garbage collector.
+ * @ptr:  Pointer to allocated memory.
  */
-struct tomoyo_name_entry {
-        struct list_head list;
-        struct tomoyo_path_info entry;
-};
-
-/* Structure for available memory region. */
-struct tomoyo_free_memory_block_list {
-        struct list_head list;
-        char *ptr;             /* Pointer to a free area. */
-        int len;               /* Length of the area.     */
-};
+void tomoyo_memory_free(void *ptr)
+{
+        atomic_sub(ksize(ptr), &tomoyo_policy_memory_size);
+        kfree(ptr);
+}
 
 /*
  * tomoyo_name_list is used for holding string data used by TOMOYO.
@@ -305,87 +238,58 @@ struct tomoyo_free_memory_block_list {
  * "/lib/libc-2.5.so"), TOMOYO shares string data in the form of
  * "const struct tomoyo_path_info *".
  */
-static struct list_head tomoyo_name_list[TOMOYO_MAX_HASH];
+struct list_head tomoyo_name_list[TOMOYO_MAX_HASH];
+/* Lock for protecting tomoyo_name_list . */
+DEFINE_MUTEX(tomoyo_name_list_lock);
 
 /**
- * tomoyo_save_name - Allocate permanent memory for string data.
+ * tomoyo_get_name - Allocate permanent memory for string data.
  *
  * @name: The string to store into the permernent memory.
  *
  * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
- *
- * The RAM is shared, so NEVER try to modify or kfree() the returned name.
  */
-const struct tomoyo_path_info *tomoyo_save_name(const char *name)
+const struct tomoyo_path_info *tomoyo_get_name(const char *name)
 {
-        static LIST_HEAD(fmb_list);
-        static DEFINE_MUTEX(lock);
         struct tomoyo_name_entry *ptr;
         unsigned int hash;
-        /* fmb contains available size in bytes.
-           fmb is removed from the fmb_list when fmb->len becomes 0. */
-        struct tomoyo_free_memory_block_list *fmb;
         int len;
-        char *cp;
+        int allocated_len;
         struct list_head *head;
 
         if (!name)
                 return NULL;
         len = strlen(name) + 1;
-        if (len > TOMOYO_MAX_PATHNAME_LEN) {
-                printk(KERN_WARNING "ERROR: Name too long "
-                       "for tomoyo_save_name().\n");
-                return NULL;
-        }
         hash = full_name_hash((const unsigned char *) name, len - 1);
         head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)];
-
-        mutex_lock(&lock);
+        mutex_lock(&tomoyo_name_list_lock);
         list_for_each_entry(ptr, head, list) {
-                if (hash == ptr->entry.hash && !strcmp(name, ptr->entry.name))
-                        goto out;
-        }
-        list_for_each_entry(fmb, &fmb_list, list) {
-                if (len <= fmb->len)
-                        goto ready;
+                if (hash != ptr->entry.hash || strcmp(name, ptr->entry.name))
+                        continue;
+                atomic_inc(&ptr->users);
+                goto out;
         }
-        if (!tomoyo_quota_for_savename ||
-            tomoyo_allocated_memory_for_savename + PATH_MAX
-            <= tomoyo_quota_for_savename)
-                cp = kzalloc(PATH_MAX, GFP_KERNEL);
-        else
-                cp = NULL;
-        fmb = kzalloc(sizeof(*fmb), GFP_KERNEL);
-        if (!cp || !fmb) {
-                kfree(cp);
-                kfree(fmb);
+        ptr = kzalloc(sizeof(*ptr) + len, GFP_KERNEL);
+        allocated_len = ptr ? ksize(ptr) : 0;
+        if (!ptr || (tomoyo_quota_for_policy &&
+                     atomic_read(&tomoyo_policy_memory_size) + allocated_len
+                     > tomoyo_quota_for_policy)) {
+                kfree(ptr);
                 printk(KERN_WARNING "ERROR: Out of memory "
-                       "for tomoyo_save_name().\n");
+                       "for tomoyo_get_name().\n");
                 if (!tomoyo_policy_loaded)
                         panic("MAC Initialization failed.\n");
                 ptr = NULL;
                 goto out;
         }
-        tomoyo_allocated_memory_for_savename += PATH_MAX;
-        list_add(&fmb->list, &fmb_list);
-        fmb->ptr = cp;
-        fmb->len = PATH_MAX;
- ready:
-        ptr = tomoyo_alloc_element(sizeof(*ptr));
-        if (!ptr)
-                goto out;
-        ptr->entry.name = fmb->ptr;
-        memmove(fmb->ptr, name, len);
+        atomic_add(allocated_len, &tomoyo_policy_memory_size);
+        ptr->entry.name = ((char *) ptr) + sizeof(*ptr);
+        memmove((char *) ptr->entry.name, name, len);
+        atomic_set(&ptr->users, 1);
         tomoyo_fill_path_info(&ptr->entry);
-        fmb->ptr += len;
-        fmb->len -= len;
         list_add_tail(&ptr->list, head);
-        if (fmb->len == 0) {
-                list_del(&fmb->list);
-                kfree(fmb);
-        }
  out:
-        mutex_unlock(&lock);
+        mutex_unlock(&tomoyo_name_list_lock);
         return ptr ? &ptr->entry : NULL;
 }
 
@@ -400,45 +304,14 @@ void __init tomoyo_realpath_init(void)
         for (i = 0; i < TOMOYO_MAX_HASH; i++)
                 INIT_LIST_HEAD(&tomoyo_name_list[i]);
         INIT_LIST_HEAD(&tomoyo_kernel_domain.acl_info_list);
-        tomoyo_kernel_domain.domainname = tomoyo_save_name(TOMOYO_ROOT_NAME);
-        list_add_tail(&tomoyo_kernel_domain.list, &tomoyo_domain_list);
-        down_read(&tomoyo_domain_list_lock);
+        tomoyo_kernel_domain.domainname = tomoyo_get_name(TOMOYO_ROOT_NAME);
+        /*
+         * tomoyo_read_lock() is not needed because this function is
+         * called before the first "delete" request.
+         */
+        list_add_tail_rcu(&tomoyo_kernel_domain.list, &tomoyo_domain_list);
         if (tomoyo_find_domain(TOMOYO_ROOT_NAME) != &tomoyo_kernel_domain)
                 panic("Can't register tomoyo_kernel_domain");
-        up_read(&tomoyo_domain_list_lock);
-}
-
-/* Memory allocated for temporary purpose. */
-static atomic_t tomoyo_dynamic_memory_size;
-
-/**
- * tomoyo_alloc - Allocate memory for temporary purpose.
- *
- * @size: Size in bytes.
- *
- * Returns pointer to allocated memory on success, NULL otherwise.
- */
-void *tomoyo_alloc(const size_t size)
-{
-        void *p = kzalloc(size, GFP_KERNEL);
-        if (p)
-                atomic_add(ksize(p), &tomoyo_dynamic_memory_size);
-        return p;
-}
-
-/**
- * tomoyo_free - Release memory allocated by tomoyo_alloc().
- *
- * @p: Pointer returned by tomoyo_alloc(). May be NULL.
- *
- * Returns nothing.
- */
-void tomoyo_free(const void *p)
-{
-        if (p) {
-                atomic_sub(ksize(p), &tomoyo_dynamic_memory_size);
-                kfree(p);
-        }
 }
 
 /**
@@ -451,32 +324,19 @@ void tomoyo_free(const void *p)
 int tomoyo_read_memory_counter(struct tomoyo_io_buffer *head)
 {
         if (!head->read_eof) {
-                const unsigned int shared
-                        = tomoyo_allocated_memory_for_savename;
-                const unsigned int private
-                        = tomoyo_allocated_memory_for_elements;
-                const unsigned int dynamic
-                        = atomic_read(&tomoyo_dynamic_memory_size);
+                const unsigned int policy
+                        = atomic_read(&tomoyo_policy_memory_size);
                 char buffer[64];
 
                 memset(buffer, 0, sizeof(buffer));
-                if (tomoyo_quota_for_savename)
-                        snprintf(buffer, sizeof(buffer) - 1,
-                                 "   (Quota: %10u)",
-                                 tomoyo_quota_for_savename);
-                else
-                        buffer[0] = '\0';
-                tomoyo_io_printf(head, "Shared:  %10u%s\n", shared, buffer);
-                if (tomoyo_quota_for_elements)
+                if (tomoyo_quota_for_policy)
                         snprintf(buffer, sizeof(buffer) - 1,
                                  "   (Quota: %10u)",
-                                 tomoyo_quota_for_elements);
+                                 tomoyo_quota_for_policy);
                 else
                         buffer[0] = '\0';
-                tomoyo_io_printf(head, "Private: %10u%s\n", private, buffer);
-                tomoyo_io_printf(head, "Dynamic: %10u\n", dynamic);
-                tomoyo_io_printf(head, "Total:   %10u\n",
-                                 shared + private + dynamic);
+                tomoyo_io_printf(head, "Policy:  %10u%s\n", policy, buffer);
+                tomoyo_io_printf(head, "Total:   %10u\n", policy);
                 head->read_eof = true;
         }
         return 0;
@@ -494,9 +354,7 @@ int tomoyo_write_memory_quota(struct tomoyo_io_buffer *head)
         char *data = head->write_buf;
         unsigned int size;
 
-        if (sscanf(data, "Shared: %u", &size) == 1)
-                tomoyo_quota_for_savename = size;
-        else if (sscanf(data, "Private: %u", &size) == 1)
-                tomoyo_quota_for_elements = size;
+        if (sscanf(data, "Policy: %u", &size) == 1)
+                tomoyo_quota_for_policy = size;
         return 0;
 }