Date: Wed, 2 Dec 2015 16:40:23 +0100
From: Borislav Petkov <bp@alien8.de>
To: =?utf-8?B?5rKz5ZCI6Iux5a6PIC8gS0FXQUnvvIxISURFSElSTw==?= 
	<hidehiro.kawai.ez@hitachi.com>
Cc: Jonathan Corbet <corbet@lwn.net>, Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>, Vivek Goyal <vgoyal@redhat.com>,
        Baoquan He <bhe@redhat.com>,
        "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
        "x86@kernel.org" <x86@kernel.org>,
        "kexec@lists.infradead.org" <kexec@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Michal Hocko <mhocko@kernel.org>,
        =?utf-8?B?5bmz5p2+6ZuF5bezIC8gSElSQU1BVFXvvIxNQVNBTUk=?= 
	<masami.hiramatsu.pt@hitachi.com>
Subject: Re: [V5 PATCH 3/4] kexec: Fix race between panic() and crash_kexec()
 called directly
Message-ID: <20151202154023.GH3783@pd.tnic>
References: <20151120093641.4285.97253.stgit@softrs>
 <20151120093648.4285.17715.stgit@softrs>
 <20151125095457.GB29499@pd.tnic>
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On Wed, Dec 02, 2015 at 11:57:38AM +0000, 河合英宏 / KAWAI，HIDEHIRO wrote:
> We can do so, but I think resetting panic_cpu always would be
> simpler and safer.

Well, I think executing code needlessly *especially* at panic time is
not all that rosy either.

Besides something like this:

	static bool kexec_failed;

	...

        if (crash_kexec_post_notifiers && !kexec_failed)
		kexec_failed = __crash_kexec(NULL);

is as simple as it gets.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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