TOMOYO: Add garbage collector.
This patch adds garbage collector support to TOMOYO.
Elements are protected by "struct srcu_struct tomoyo_ss".
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c
index 9557168..c00df45 100644
--- a/security/tomoyo/realpath.c
+++ b/security/tomoyo/realpath.c
@@ -205,9 +205,9 @@
}
/* 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_memory_ok - Check memory quota.
@@ -222,26 +222,30 @@
bool tomoyo_memory_ok(void *ptr)
{
int allocated_len = ptr ? ksize(ptr) : 0;
- bool result = false;
- if (!ptr || (tomoyo_quota_for_elements &&
- tomoyo_allocated_memory_for_elements
- + allocated_len > tomoyo_quota_for_elements)) {
- printk(KERN_WARNING "ERROR: Out of memory "
- "for tomoyo_alloc_element().\n");
- if (!tomoyo_policy_loaded)
- panic("MAC Initialization failed.\n");
- } else {
- result = true;
- tomoyo_allocated_memory_for_elements += allocated_len;
+ 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;
}
- return result;
+ 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_memory_free - Free memory for elements.
+ *
+ * @ptr: Pointer to allocated memory.
+ */
+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.
@@ -249,7 +253,9 @@
* "/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_get_name - Allocate permanent memory for string data.
@@ -260,7 +266,6 @@
*/
const struct tomoyo_path_info *tomoyo_get_name(const char *name)
{
- static DEFINE_MUTEX(lock);
struct tomoyo_name_entry *ptr;
unsigned int hash;
int len;
@@ -272,7 +277,7 @@
len = strlen(name) + 1;
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))
continue;
@@ -281,9 +286,9 @@
}
ptr = kzalloc(sizeof(*ptr) + len, GFP_KERNEL);
allocated_len = ptr ? ksize(ptr) : 0;
- if (!ptr || (tomoyo_quota_for_savename &&
- tomoyo_allocated_memory_for_savename + allocated_len
- > tomoyo_quota_for_savename)) {
+ 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_get_name().\n");
@@ -292,14 +297,14 @@
ptr = NULL;
goto out;
}
- tomoyo_allocated_memory_for_savename += allocated_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);
list_add_tail(&ptr->list, head);
out:
- mutex_unlock(&lock);
+ mutex_unlock(&tomoyo_name_list_lock);
return ptr ? &ptr->entry : NULL;
}
@@ -334,28 +339,19 @@
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 policy
+ = atomic_read(&tomoyo_policy_memory_size);
char buffer[64];
memset(buffer, 0, sizeof(buffer));
- if (tomoyo_quota_for_savename)
+ if (tomoyo_quota_for_policy)
snprintf(buffer, sizeof(buffer) - 1,
" (Quota: %10u)",
- tomoyo_quota_for_savename);
+ tomoyo_quota_for_policy);
else
buffer[0] = '\0';
- tomoyo_io_printf(head, "Shared: %10u%s\n", shared, buffer);
- if (tomoyo_quota_for_elements)
- snprintf(buffer, sizeof(buffer) - 1,
- " (Quota: %10u)",
- tomoyo_quota_for_elements);
- else
- buffer[0] = '\0';
- tomoyo_io_printf(head, "Private: %10u%s\n", private, buffer);
- tomoyo_io_printf(head, "Total: %10u\n", shared + private);
+ tomoyo_io_printf(head, "Policy: %10u%s\n", policy, buffer);
+ tomoyo_io_printf(head, "Total: %10u\n", policy);
head->read_eof = true;
}
return 0;
@@ -373,9 +369,7 @@
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;
}