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-rw-r--r--kernel/trace/ftrace.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 7694f3e5979..4dda4f60a2a 100644
--- a/kernel/trace/ftrace.c
+++ b/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;
}