---

yaml
---
r: 312213
b: refs/heads/master
c: 56bb4cf
h: refs/heads/master
i:
  312211: 70faade
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 77fc4af1b59d12ab3b1467adf0a5204806853123
+refs/heads/master: 56bb4cf6475d702d2fb00fc641aa6441097c0330

trunk/kernel/events/uprobes.c

@@ -1530,14 +1530,26 @@ static void handle_swbp(struct pt_regs *regs)
 	struct uprobe_task *utask;
 	struct uprobe *uprobe;
 	unsigned long bp_vaddr;
-	int is_swbp;
+	int uninitialized_var(is_swbp);
 
 	bp_vaddr = uprobe_get_swbp_addr(regs);
 	uprobe = find_active_uprobe(bp_vaddr, &is_swbp);
 
 	if (!uprobe) {
-		/* No matching uprobe; signal SIGTRAP. */
-		send_sig(SIGTRAP, current, 0);
+		if (is_swbp > 0) {
+			/* No matching uprobe; signal SIGTRAP. */
+			send_sig(SIGTRAP, current, 0);
+		} else {
+			/*
+			 * Either we raced with uprobe_unregister() or we can't
+			 * access this memory. The latter is only possible if
+			 * another thread plays with our ->mm. In both cases
+			 * we can simply restart. If this vma was unmapped we
+			 * can pretend this insn was not executed yet and get
+			 * the (correct) SIGSEGV after restart.
+			 */
+			instruction_pointer_set(regs, bp_vaddr);
+		}
 		return;
 	}