+/* Return 1 if all garbages are collected, otherwise 0. */
+static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx)
+{
+ kip->slot_used[idx] = SLOT_CLEAN;
+ kip->nused--;
+ if (kip->nused == 0) {
+ /*
+ * Page is no longer in use. Free it unless
+ * it's the last one. We keep the last one
+ * so as not to have to set it up again the
+ * next time somebody inserts a probe.
+ */
+ hlist_del(&kip->hlist);
+ if (hlist_empty(&kprobe_insn_pages)) {
+ INIT_HLIST_NODE(&kip->hlist);
+ hlist_add_head(&kip->hlist,
+ &kprobe_insn_pages);
+ } else {
+ module_free(NULL, kip->insns);
+ kfree(kip);
+ }
+ return 1;
+ }
+ return 0;
+}
+
+static int __kprobes collect_garbage_slots(void)
+{
+ struct kprobe_insn_page *kip;
+ struct hlist_node *pos, *next;
+
+ /* Ensure no-one is preepmted on the garbages */
+ if (check_safety() != 0)
+ return -EAGAIN;
+
+ hlist_for_each_safe(pos, next, &kprobe_insn_pages) {
+ int i;
+ kip = hlist_entry(pos, struct kprobe_insn_page, hlist);
+ if (kip->ngarbage == 0)
+ continue;
+ kip->ngarbage = 0; /* we will collect all garbages */
+ for (i = 0; i < INSNS_PER_PAGE; i++) {
+ if (kip->slot_used[i] == SLOT_DIRTY &&
+ collect_one_slot(kip, i))
+ break;
+ }
+ }
+ kprobe_garbage_slots = 0;
+ return 0;
+}
+
+void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty)