TOMOYO: Remove usage counter for temporary memory.

TOMOYO was using own memory usage counter for detecting memory leak.
But as kernel 2.6.31 introduced memory leak detection mechanism
( CONFIG_DEBUG_KMEMLEAK ), we no longer need to have own counter.

We remove usage counter for memory used for permission checks, but we keep
usage counter for memory used for policy so that we can apply quota.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

security/tomoyo/common.c

@@ -750,7 +750,7 @@ bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
  *
  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
  *
- * This function uses tomoyo_alloc(), so the caller must call tomoyo_free()
+ * This function uses kzalloc(), so the caller must call kfree()
  * if this function didn't return NULL.
  */
 static const char *tomoyo_get_exe(void)
@@ -1248,7 +1248,7 @@ static bool tomoyo_is_policy_manager(void)
 			last_pid = pid;
 		}
 	}
-	tomoyo_free(exe);
+	kfree(exe);
 	return found;
 }
 
@@ -1931,7 +1931,7 @@ static int tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
  */
 static int tomoyo_open_control(const u8 type, struct file *file)
 {
-	struct tomoyo_io_buffer *head = tomoyo_alloc(sizeof(*head));
+	struct tomoyo_io_buffer *head = kzalloc(sizeof(*head), GFP_KERNEL);
 
 	if (!head)
 		return -ENOMEM;
@@ -1992,9 +1992,9 @@ static int tomoyo_open_control(const u8 type, struct file *file)
 	} else {
 		if (!head->readbuf_size)
 			head->readbuf_size = 4096 * 2;
-		head->read_buf = tomoyo_alloc(head->readbuf_size);
+		head->read_buf = kzalloc(head->readbuf_size, GFP_KERNEL);
 		if (!head->read_buf) {
-			tomoyo_free(head);
+			kfree(head);
 			return -ENOMEM;
 		}
 	}
@@ -2006,10 +2006,10 @@ static int tomoyo_open_control(const u8 type, struct file *file)
 		head->write = NULL;
 	} else if (head->write) {
 		head->writebuf_size = 4096 * 2;
-		head->write_buf = tomoyo_alloc(head->writebuf_size);
+		head->write_buf = kzalloc(head->writebuf_size, GFP_KERNEL);
 		if (!head->write_buf) {
-			tomoyo_free(head->read_buf);
-			tomoyo_free(head);
+			kfree(head->read_buf);
+			kfree(head);
 			return -ENOMEM;
 		}
 	}
@@ -2141,11 +2141,11 @@ static int tomoyo_close_control(struct file *file)
 
 	tomoyo_read_unlock(head->reader_idx);
 	/* Release memory used for policy I/O. */
-	tomoyo_free(head->read_buf);
+	kfree(head->read_buf);
 	head->read_buf = NULL;
-	tomoyo_free(head->write_buf);
+	kfree(head->write_buf);
 	head->write_buf = NULL;
-	tomoyo_free(head);
+	kfree(head);
 	head = NULL;
 	file->private_data = NULL;
 	return 0;

security/tomoyo/common.h

@@ -89,7 +89,7 @@ struct tomoyo_path_info {
  * "struct tomoyo_path_info_with_data".
  */
 struct tomoyo_path_info_with_data {
-	/* Keep "head" first, for this pointer is passed to tomoyo_free(). */
+	/* Keep "head" first, for this pointer is passed to kfree(). */
 	struct tomoyo_path_info head;
 	char barrier1[16]; /* Safeguard for overrun. */
 	char body[TOMOYO_MAX_PATHNAME_LEN];

security/tomoyo/domain.c

@@ -787,7 +787,7 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
 	 * This function assumes that the size of buffer returned by
 	 * tomoyo_realpath() = TOMOYO_MAX_PATHNAME_LEN.
 	 */
-	struct tomoyo_page_buffer *tmp = tomoyo_alloc(sizeof(*tmp));
+	struct tomoyo_page_buffer *tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
 	struct tomoyo_domain_info *old_domain = tomoyo_domain();
 	struct tomoyo_domain_info *domain = NULL;
 	const char *old_domain_name = old_domain->domainname->name;
@@ -902,8 +902,8 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
 	if (!domain)
 		domain = old_domain;
 	bprm->cred->security = domain;
-	tomoyo_free(real_program_name);
-	tomoyo_free(symlink_program_name);
-	tomoyo_free(tmp);
+	kfree(real_program_name);
+	kfree(symlink_program_name);
+	kfree(tmp);
 	return retval;
 }

security/tomoyo/file.c

@@ -150,7 +150,8 @@ static bool tomoyo_strendswith(const char *name, const char *tail)
 static struct tomoyo_path_info *tomoyo_get_path(struct path *path)
 {
 	int error;
-	struct tomoyo_path_info_with_data *buf = tomoyo_alloc(sizeof(*buf));
+	struct tomoyo_path_info_with_data *buf = kzalloc(sizeof(*buf),
+							 GFP_KERNEL);
 
 	if (!buf)
 		return NULL;
@@ -162,7 +163,7 @@ static struct tomoyo_path_info *tomoyo_get_path(struct path *path)
 		tomoyo_fill_path_info(&buf->head);
 		return &buf->head;
 	}
-	tomoyo_free(buf);
+	kfree(buf);
 	return NULL;
 }
 
@@ -1227,7 +1228,7 @@ int tomoyo_check_open_permission(struct tomoyo_domain_info *domain,
 						     TOMOYO_TYPE_TRUNCATE_ACL,
 							     buf, mode);
  out:
-	tomoyo_free(buf);
+	kfree(buf);
 	tomoyo_read_unlock(idx);
 	if (!is_enforce)
 		error = 0;
@@ -1273,7 +1274,7 @@ int tomoyo_check_1path_perm(struct tomoyo_domain_info *domain,
 	error = tomoyo_check_single_path_permission2(domain, operation, buf,
 						     mode);
  out:
-	tomoyo_free(buf);
+	kfree(buf);
 	tomoyo_read_unlock(idx);
 	if (!is_enforce)
 		error = 0;
@@ -1312,7 +1313,7 @@ int tomoyo_check_rewrite_permission(struct tomoyo_domain_info *domain,
 						     TOMOYO_TYPE_REWRITE_ACL,
 						     buf, mode);
  out:
-	tomoyo_free(buf);
+	kfree(buf);
 	tomoyo_read_unlock(idx);
 	if (!is_enforce)
 		error = 0;
@@ -1379,8 +1380,8 @@ int tomoyo_check_2path_perm(struct tomoyo_domain_info * const domain,
 					      false);
 	}
  out:
-	tomoyo_free(buf1);
-	tomoyo_free(buf2);
+	kfree(buf1);
+	kfree(buf2);
 	tomoyo_read_unlock(idx);
 	if (!is_enforce)
 		error = 0;

security/tomoyo/realpath.c

@@ -150,12 +150,12 @@ 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);
@@ -164,7 +164,7 @@ 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;
 }
 
@@ -346,39 +346,6 @@ void __init tomoyo_realpath_init(void)
 		panic("Can't register tomoyo_kernel_domain");
 }
 
-/* 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);
-	}
-}
-
 /**
  * tomoyo_read_memory_counter - Check for memory usage in bytes.
  *
@@ -393,8 +360,6 @@ int tomoyo_read_memory_counter(struct tomoyo_io_buffer *head)
 			= tomoyo_allocated_memory_for_savename;
 		const unsigned int private
 			= tomoyo_allocated_memory_for_elements;
-		const unsigned int dynamic
-			= atomic_read(&tomoyo_dynamic_memory_size);
 		char buffer[64];
 
 		memset(buffer, 0, sizeof(buffer));
@@ -412,9 +377,7 @@ int tomoyo_read_memory_counter(struct tomoyo_io_buffer *head)
 		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, "Total:   %10u\n", shared + private);
 		head->read_eof = true;
 	}
 	return 0;

security/tomoyo/realpath.h

@@ -25,7 +25,7 @@ int tomoyo_realpath_from_path2(struct path *path, char *newname,
 
 /*
  * Returns realpath(3) of the given pathname but ignores chroot'ed root.
- * 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(const char *pathname);
@@ -45,12 +45,6 @@ bool tomoyo_memory_ok(void *ptr);
  */
 const struct tomoyo_path_info *tomoyo_save_name(const char *name);
 
-/* Allocate memory for temporary use (e.g. permission checks). */
-void *tomoyo_alloc(const size_t size);
-
-/* Free memory allocated by tomoyo_alloc(). */
-void tomoyo_free(const void *p);
-
 /* Check for memory usage. */
 int tomoyo_read_memory_counter(struct tomoyo_io_buffer *head);