---

yaml
---
r: 116629
b: refs/heads/master
c: 05736a4
h: refs/heads/master
i:
  116627: 5140c1e
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 43a15386c4faf913f7d70a47748c266d6210cd6e
+refs/heads/master: 05736a427f7e16be948ccbf39782bd3a6ae16b14

trunk/kernel/trace/ftrace.c

@@ -576,6 +576,16 @@ static void ftrace_shutdown_replenish(void)
 	ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL);
 }
 
+static void print_ip_ins(const char *fmt, unsigned char *p)
+{
+	int i;
+
+	printk(KERN_CONT "%s", fmt);
+
+	for (i = 0; i < MCOUNT_INSN_SIZE; i++)
+		printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
+}
+
 static int
 ftrace_code_disable(struct dyn_ftrace *rec)
 {
@@ -590,6 +600,23 @@ ftrace_code_disable(struct dyn_ftrace *rec)
 
 	failed = ftrace_modify_code(ip, call, nop);
 	if (failed) {
+		switch (failed) {
+		case 1:
+			WARN_ON_ONCE(1);
+			pr_info("ftrace faulted on modifying ");
+			print_ip_sym(ip);
+			break;
+		case 2:
+			WARN_ON_ONCE(1);
+			pr_info("ftrace failed to modify ");
+			print_ip_sym(ip);
+			print_ip_ins(" expected: ", call);
+			print_ip_ins(" actual: ", (unsigned char *)ip);
+			print_ip_ins(" replace: ", nop);
+			printk(KERN_CONT "\n");
+			break;
+		}
+
 		rec->flags |= FTRACE_FL_FAILED;
 		return 0;
 	}