You mean it contains copies of existing Linux functions which the Grsecurity authors have edited? That makes sense. A lot of the comments here seem to be about how tightly it interfaces with Linux, which is surely a different thing.
static void account_kernel_stack(struct task_struct *tsk, int account)
{
- void *stack = task_stack_page(tsk);
struct vm_struct *vm = task_stack_vm_area(tsk);
BUILD_BUG_ON(IS_ENABLED(CONFIG_VMAP_STACK) && PAGE_SIZE % 1024 != 0);
@@ -303,8 +357,12 @@ static void account_kernel_stack(struct task_struct *tsk, int account)
* All stack pages are in the same zone and belong to the
* same memcg.
*/
+#ifdef CONFIG_GRKERNSEC_KSTACKOVERFLOW
+ struct page *first_page = virt_to_page(tsk->lowmem_stack);
+#else
+ void *stack = task_stack_page(tsk);
struct page *first_page = virt_to_page(stack);
-
+#endif
mod_zone_page_state(page_zone(first_page), NR_KERNEL_STACK_KB,
THREAD_SIZE / 1024 * account);
Grsecurity isn't Linux plus some additional code. It's a modified version of Linux. Saying that a Linux 4.11 kernel patched with grsecurity isn't a derived work of Linux 4.11 is like saying that a Linux 4.11 kernel patched with patch-4.12.patch [1], otherwise known as Linux 4.12, is not a derived work of 4.11
