From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [PATCH 2/2] RFC: soft/hardlookup: taint kernel
Date: Thu, 9 May 2019 18:24:49 +0900
Message-ID: <20190509092449.GA10828@jagdpanzerIV>
References: <20190502194208.3535-1-daniel.vetter@ffwll.ch>
 <20190502194208.3535-2-daniel.vetter@ffwll.ch>
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To: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Intel Graphics Development <intel-gfx@lists.freedesktop.org>, LKML <linux-kernel@vger.kernel.org>, Daniel Vetter <daniel.vetter@intel.com>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@kernel.org>, Peter Zijlstra <peterz@infradead.org>, Valdis Kletnieks <valdis.kletnieks@vt.edu>, Laurence Oberman <loberman@redhat.com>, Vincent Whitchurch <vincent.whitchurch@axis.com>, Don Zickus <dzickus@redhat.com>, Andrew Morton <akpm@linux-foundation.org>, Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>, Sinan Kaya <okaya@kernel.org>
List-Id: intel-gfx@lists.freedesktop.org

On (05/02/19 21:42), Daniel Vetter wrote:
[..]
> @@ -469,6 +469,8 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
>  		add_taint(TAINT_SOFTLOCKUP, LOCKDEP_STILL_OK);
>  		if (softlockup_panic)
>  			panic("softlockup: hung tasks");
> +		else
> +			add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
>  		__this_cpu_write(soft_watchdog_warn, true);

Soft lockup sets TAINT_SOFTLOCKUP bit. Would it be enough for your CI?

[..]
> @@ -154,6 +154,8 @@ static void watchdog_overflow_callback(struct perf_event *event,
>
>  		if (hardlockup_panic)
>  			nmi_panic(regs, "Hard LOCKUP");
> +		else
> +			add_taint(TAINT_WARN, LOCKDEP_STILL_OK);

Maybe you can mirror what soft lockup does. Add a HARDLOCKUP taint bit

+++ b/include/linux/kernel.h
@@ -571,7 +571,8 @@ extern enum system_states {
 #define TAINT_LIVEPATCH                        15
 #define TAINT_AUX                      16
 #define TAINT_RANDSTRUCT               17
-#define TAINT_FLAGS_COUNT              18
+#define TAINT_HARDLOCKUP               18
+#define TAINT_FLAGS_COUNT              19

and then set TAINT_HARDLOCKUP in watchdog_overflow_callback().

Just a small idea, I'll leave this to more experienced people.

	-ss