#define MAX_STACK_ENTRIES 100
#define STACK_ERR_BUF_SIZE 128
+#define SIGNALS_TIMEOUT 15
+
struct klp_patch *klp_transition_patch;
static int klp_target_state = KLP_UNDEFINED;
-static bool klp_forced = false;
+static unsigned int klp_signals_cnt;
/*
* This work can be performed periodically to finish patching or unpatching any
klp_transition_patch->mod->name,
klp_target_state == KLP_PATCHED ? "patching" : "unpatching");
+ if (klp_transition_patch->replace && klp_target_state == KLP_PATCHED) {
+ klp_discard_replaced_patches(klp_transition_patch);
+ klp_discard_nops(klp_transition_patch);
+ }
+
if (klp_target_state == KLP_UNPATCHED) {
/*
* All tasks have transitioned to KLP_UNPATCHED so we can now
pr_notice("'%s': %s complete\n", klp_transition_patch->mod->name,
klp_target_state == KLP_PATCHED ? "patching" : "unpatching");
- /*
- * klp_forced set implies unbounded increase of module's ref count if
- * the module is disabled/enabled in a loop.
- */
- if (!klp_forced && klp_target_state == KLP_UNPATCHED)
- module_put(klp_transition_patch->mod);
-
klp_target_state = KLP_UNDEFINED;
klp_transition_patch = NULL;
}
* Check for the to-be-patched function
* (the previous func).
*/
- ops = klp_find_ops(func->old_addr);
+ ops = klp_find_ops(func->old_func);
if (list_is_singular(&ops->func_stack)) {
/* original function */
- func_addr = func->old_addr;
+ func_addr = (unsigned long)func->old_func;
func_size = func->old_size;
} else {
/* previously patched function */
}
+/*
+ * Sends a fake signal to all non-kthread tasks with TIF_PATCH_PENDING set.
+ * Kthreads with TIF_PATCH_PENDING set are woken up.
+ */
+static void klp_send_signals(void)
+{
+ struct task_struct *g, *task;
+
+ if (klp_signals_cnt == SIGNALS_TIMEOUT)
+ pr_notice("signaling remaining tasks\n");
+
+ read_lock(&tasklist_lock);
+ for_each_process_thread(g, task) {
+ if (!klp_patch_pending(task))
+ continue;
+
+ /*
+ * There is a small race here. We could see TIF_PATCH_PENDING
+ * set and decide to wake up a kthread or send a fake signal.
+ * Meanwhile the task could migrate itself and the action
+ * would be meaningless. It is not serious though.
+ */
+ if (task->flags & PF_KTHREAD) {
+ /*
+ * Wake up a kthread which sleeps interruptedly and
+ * still has not been migrated.
+ */
+ wake_up_state(task, TASK_INTERRUPTIBLE);
+ } else {
+ /*
+ * Send fake signal to all non-kthread tasks which are
+ * still not migrated.
+ */
+ spin_lock_irq(&task->sighand->siglock);
+ signal_wake_up(task, 0);
+ spin_unlock_irq(&task->sighand->siglock);
+ }
+ }
+ read_unlock(&tasklist_lock);
+}
+
/*
* Try to switch all remaining tasks to the target patch state by walking the
* stacks of sleeping tasks and looking for any to-be-patched or
{
unsigned int cpu;
struct task_struct *g, *task;
+ struct klp_patch *patch;
bool complete = true;
WARN_ON_ONCE(klp_target_state == KLP_UNDEFINED);
put_online_cpus();
if (!complete) {
+ if (klp_signals_cnt && !(klp_signals_cnt % SIGNALS_TIMEOUT))
+ klp_send_signals();
+ klp_signals_cnt++;
+
/*
* Some tasks weren't able to be switched over. Try again
* later and/or wait for other methods like kernel exit
}
/* we're done, now cleanup the data structures */
+ patch = klp_transition_patch;
klp_complete_transition();
+
+ /*
+ * It would make more sense to free the patch in
+ * klp_complete_transition() but it is called also
+ * from klp_cancel_transition().
+ */
+ if (!patch->enabled) {
+ klp_free_patch_start(patch);
+ schedule_work(&patch->free_work);
+ }
}
/*
if (task->patch_state != klp_target_state)
set_tsk_thread_flag(task, TIF_PATCH_PENDING);
}
+
+ klp_signals_cnt = 0;
}
/*
/* TIF_PATCH_PENDING gets copied in setup_thread_stack() */
}
-/*
- * Sends a fake signal to all non-kthread tasks with TIF_PATCH_PENDING set.
- * Kthreads with TIF_PATCH_PENDING set are woken up. Only admin can request this
- * action currently.
- */
-void klp_send_signals(void)
-{
- struct task_struct *g, *task;
-
- pr_notice("signaling remaining tasks\n");
-
- read_lock(&tasklist_lock);
- for_each_process_thread(g, task) {
- if (!klp_patch_pending(task))
- continue;
-
- /*
- * There is a small race here. We could see TIF_PATCH_PENDING
- * set and decide to wake up a kthread or send a fake signal.
- * Meanwhile the task could migrate itself and the action
- * would be meaningless. It is not serious though.
- */
- if (task->flags & PF_KTHREAD) {
- /*
- * Wake up a kthread which sleeps interruptedly and
- * still has not been migrated.
- */
- wake_up_state(task, TASK_INTERRUPTIBLE);
- } else {
- /*
- * Send fake signal to all non-kthread tasks which are
- * still not migrated.
- */
- spin_lock_irq(&task->sighand->siglock);
- signal_wake_up(task, 0);
- spin_unlock_irq(&task->sighand->siglock);
- }
- }
- read_unlock(&tasklist_lock);
-}
-
/*
* Drop TIF_PATCH_PENDING of all tasks on admin's request. This forces an
* existing transition to finish.
*/
void klp_force_transition(void)
{
+ struct klp_patch *patch;
struct task_struct *g, *task;
unsigned int cpu;
for_each_possible_cpu(cpu)
klp_update_patch_state(idle_task(cpu));
- klp_forced = true;
+ klp_for_each_patch(patch)
+ patch->forced = true;
}
projects / linux-2.6-microblaze.git / blobdiff