[PATCH V2] print kdump kernel loaded status in stack dump

[Dave Young <dyoung@redhat.com>]

It is useful to print kdump kernel loaded status in dump_stack() 
especially when panic happens so that we can differenciate 
kdump kernel early hang and a normal panic in a bug report.

Signed-off-by: Dave Young <dyoung@redhat.com>
---
[v1 -> v2] merge the status in other line as Andi Kleen suggested
 kernel/printk/printk.c |    3 +++
---
 kernel/printk/printk.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- linux-x86.orig/kernel/printk/printk.c
+++ linux-x86/kernel/printk/printk.c
@@ -48,6 +48,7 @@
 #include <linux/sched/clock.h>
 #include <linux/sched/debug.h>
 #include <linux/sched/task_stack.h>
+#include <linux/kexec.h>
 
 #include <linux/uaccess.h>
 #include <asm/sections.h>
@@ -3118,9 +3119,11 @@ void __init dump_stack_set_arch_desc(con
  */
 void dump_stack_print_info(const char *log_lvl)
 {
-	printk("%sCPU: %d PID: %d Comm: %.20s %s %s %.*s\n",
+	printk("%sCPU: %d PID: %d Comm: %.20s %s%s %s %.*s\n",
 	       log_lvl, raw_smp_processor_id(), current->pid, current->comm,
-	       print_tainted(), init_utsname()->release,
+	       kexec_crash_loaded() ? "Kdump: loaded " : "",
+	       print_tainted(),
+	       init_utsname()->release,
 	       (int)strcspn(init_utsname()->version, " "),
 	       init_utsname()->version);