1 files changed, 27 insertions, 28 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 548890c7c0f5..6d7ef130f57e 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -19,7 +19,6 @@
 #include <linux/kallsyms.h>
 #include <linux/security.h>
 #include <linux/seq_file.h>
-#include <linux/notifier.h>
 #include <linux/irqflags.h>
 #include <linux/debugfs.h>
 #include <linux/tracefs.h>
@@ -9876,41 +9875,41 @@ static __init int tracer_init_tracefs(void)
 
 fs_initcall(tracer_init_tracefs);
 
-static int trace_panic_handler(struct notifier_block *this,
-			       unsigned long event, void *unused)
-{
-	if (ftrace_dump_on_oops)
-		ftrace_dump(ftrace_dump_on_oops);
-	return NOTIFY_OK;
-}
+static int trace_die_panic_handler(struct notifier_block *self,
+				unsigned long ev, void *unused);
 
 static struct notifier_block trace_panic_notifier = {
-	.notifier_call  = trace_panic_handler,
-	.next           = NULL,
-	.priority       = 150   /* priority: INT_MAX >= x >= 0 */
+	.notifier_call = trace_die_panic_handler,
+	.priority = INT_MAX - 1,
 };
 
-static int trace_die_handler(struct notifier_block *self,
-			     unsigned long val,
-			     void *data)
-{
-	switch (val) {
-	case DIE_OOPS:
-		if (ftrace_dump_on_oops)
-			ftrace_dump(ftrace_dump_on_oops);
-		break;
-	default:
-		break;
-	}
-	return NOTIFY_OK;
-}
-
 static struct notifier_block trace_die_notifier = {
-	.notifier_call = trace_die_handler,
-	.priority = 200
+	.notifier_call = trace_die_panic_handler,
+	.priority = INT_MAX - 1,
 };
 
 /*
+ * The idea is to execute the following die/panic callback early, in order
+ * to avoid showing irrelevant information in the trace (like other panic
+ * notifier functions); we are the 2nd to run, after hung_task/rcu_stall
+ * warnings get disabled (to prevent potential log flooding).
+ */
+static int trace_die_panic_handler(struct notifier_block *self,
+				unsigned long ev, void *unused)
+{
+	if (!ftrace_dump_on_oops)
+		return NOTIFY_DONE;
+
+	/* The die notifier requires DIE_OOPS to trigger */
+	if (self == &trace_die_notifier && ev != DIE_OOPS)
+		return NOTIFY_DONE;
+
+	ftrace_dump(ftrace_dump_on_oops);
+
+	return NOTIFY_DONE;
+}
+
+/*
  * printk is set to max of 1024, we really don't need it that big.
  * Nothing should be printing 1000 characters anyway.
  */