cxgb3: Fix panic in free_tx_desc()

[karo-tx-linux.git] / kernel / jump_label.c

diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 460fd40112b362467efb731b59a2a37d68c0ea94..7be868bf25c69268e78c7eb7b50a7fb0d83dd1b4 100644 (file)
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -177,6 +177,89 @@ void jump_label_update(unsigned long key, enum jump_label_type type)
        mutex_unlock(&jump_label_mutex);
 }
 
+static int addr_conflict(struct jump_entry *entry, void *start, void *end)
+{
+       if (entry->code <= (unsigned long)end &&
+               entry->code + JUMP_LABEL_NOP_SIZE > (unsigned long)start)
+               return 1;
+
+       return 0;
+}
+
+#ifdef CONFIG_MODULES
+
+static int module_conflict(void *start, void *end)
+{
+       struct hlist_head *head;
+       struct hlist_node *node, *node_next, *module_node, *module_node_next;
+       struct jump_label_entry *e;
+       struct jump_label_module_entry *e_module;
+       struct jump_entry *iter;
+       int i, count;
+       int conflict = 0;
+
+       for (i = 0; i < JUMP_LABEL_TABLE_SIZE; i++) {
+               head = &jump_label_table[i];
+               hlist_for_each_entry_safe(e, node, node_next, head, hlist) {
+                       hlist_for_each_entry_safe(e_module, module_node,
+                                                       module_node_next,
+                                                       &(e->modules), hlist) {
+                               count = e_module->nr_entries;
+                               iter = e_module->table;
+                               while (count--) {
+                                       if (addr_conflict(iter, start, end)) {
+                                               conflict = 1;
+                                               goto out;
+                                       }
+                                       iter++;
+                               }
+                       }
+               }
+       }
+out:
+       return conflict;
+}
+
+#endif
+
+/***
+ * jump_label_text_reserved - check if addr range is reserved
+ * @start: start text addr
+ * @end: end text addr
+ *
+ * checks if the text addr located between @start and @end
+ * overlaps with any of the jump label patch addresses. Code
+ * that wants to modify kernel text should first verify that
+ * it does not overlap with any of the jump label addresses.
+ *
+ * returns 1 if there is an overlap, 0 otherwise
+ */
+int jump_label_text_reserved(void *start, void *end)
+{
+       struct jump_entry *iter;
+       struct jump_entry *iter_start = __start___jump_table;
+       struct jump_entry *iter_stop = __start___jump_table;
+       int conflict = 0;
+
+       mutex_lock(&jump_label_mutex);
+       iter = iter_start;
+       while (iter < iter_stop) {
+               if (addr_conflict(iter, start, end)) {
+                       conflict = 1;
+                       goto out;
+               }
+               iter++;
+       }
+
+       /* now check modules */
+#ifdef CONFIG_MODULES
+       conflict = module_conflict(start, end);
+#endif
+out:
+       mutex_unlock(&jump_label_mutex);
+       return conflict;
+}
+
 static __init int init_jump_label(void)
 {
        int ret;