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From: Andrew Morton <akpm@linux-foundation.org>
To: Joerg Vehlow <lkml@jv-coder.de>
Cc: Steven Rostedt <rostedt@goodmis.org>,
	linux-kernel@vger.kernel.org,
	Joerg Vehlow <joerg.vehlow@aox-tech.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	Huang Ying <ying.huang@intel.com>
Subject: Re: [BUG RT] dump-capture kernel not executed for panic in interrupt context
Date: Mon, 27 Jul 2020 16:36:55 -0700	[thread overview]
Message-ID: <20200727163655.8c94c8e245637b62311f5053@linux-foundation.org> (raw)
In-Reply-To: <cbbf7926-148e-7acb-dc03-3f055d73364b@jv-coder.de>

On Wed, 22 Jul 2020 06:30:53 +0200 Joerg Vehlow <lkml@jv-coder.de> wrote:

> >> About 12 years ago this was not implemented using a mutex, but using xchg.
> >> See: 8c5a1cf0ad3ac5fcdf51314a63b16a440870f6a2
> > Yes, that commit is wrong, because mutex_trylock() is not to be taken in
> > interrupt context, where crash_kexec() looks like it can be called.

Yup, mutex_trylock() from interrupt is improper.  Well dang, that's a
bit silly.  Presumably the 2006 spin_lock_mutex() wasn't taken with
irqs-off.

Ho hum, did you look at switching the kexec code back to the xchg
approach?


  parent reply	other threads:[~2020-07-27 23:36 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-28 11:41 [BUG RT] dump-capture kernel not executed for panic in interrupt context Joerg Vehlow
2020-05-28 12:46 ` Steven Rostedt
2020-07-22  4:30   ` Joerg Vehlow
2020-07-22 20:51     ` Steven Rostedt
2020-07-27 23:36     ` Andrew Morton [this message]
2020-08-21 10:25       ` Joerg Vehlow
2020-08-21 15:08         ` Steven Rostedt
2020-08-21 20:47           ` Andrew Morton
2020-08-21 21:03             ` Steven Rostedt
2020-08-22 12:32               ` peterz
2020-08-22 23:49                 ` Steven Rostedt
2020-09-07 11:41                   ` peterz
2020-09-07 12:49                     ` Valentin Schneider
2020-09-14 19:00                     ` Steven Rostedt
2020-09-07 10:51               ` Joerg Vehlow
2020-09-07 11:46                 ` peterz
2020-09-07 12:03                   ` Joerg Vehlow
2020-09-07 16:23                     ` peterz
2020-09-08  5:48                       ` Joerg Vehlow
2020-09-09  5:46                         ` Joerg Vehlow
2020-09-11 22:48                           ` Eric W. Biederman
2020-09-14  6:03                             ` Joerg Vehlow
2020-09-14 16:46                               ` Eric W. Biederman

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