panic: add TAINT_SOFTLOCKUP

This taint flag will be set if the system has ever entered a softlockup
state.  Similar to TAINT_WARN it is useful to know whether or not the
system has been in a softlockup state when debugging.

[akpm@linux-foundation.org: apply the taint before calling panic()]
Signed-off-by: Josh Hunt <johunt@akamai.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 51b29e9d2ba6..a8d6914030fe 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -368,6 +368,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
                         smp_mb__after_atomic();
                 }
 
+                add_taint(TAINT_SOFTLOCKUP, LOCKDEP_STILL_OK);
                 if (softlockup_panic)
                         panic("softlockup: hung tasks");
                 __this_cpu_write(soft_watchdog_warn, true);