From: Borislav Petkov <bp@alien8.de>
To: Andy Lutomirski <luto@amacapital.net>
Cc: "Kees Cook" <keescook@chromium.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Oleg Nesterov" <oleg@redhat.com>,
"Denys Vlasenko" <vda.linux@googlemail.com>,
"Brian Gerst" <brgerst@gmail.com>,
"Frédéric Weisbecker" <fweisbec@gmail.com>,
"X86 ML" <x86@kernel.org>, "Rik van Riel" <riel@redhat.com>
Subject: Re: [PATCH v2 03/14] notifiers: Assert that RCU is watching in notify_die
Date: Mon, 22 Jun 2015 20:15:28 +0200 [thread overview]
Message-ID: <20150622181528.GE20244@pd.tnic> (raw)
In-Reply-To: <CALCETrW9owchn_kf9aC5HQ76a61H4S=jdY60Hpg3D43Nn+m7LQ@mail.gmail.com>
On Mon, Jun 22, 2015 at 10:37:39AM -0700, Andy Lutomirski wrote:
> But if we OOPS, we'll OOPS after the lockdep splat and the lockdep
> splat will scroll off the screen, right? Am I missing something here?
No, you're not.
> notify_die is called before the actual OOPS code is invoked in traps.c.
Yes, and with this assertion, you get to potentially print two
dump_stack()'s back-to-back instead of the one from traps.c.
And if the machine is about to be wedged solid soon anyway, we want to
dump as less (not-so-important) blurb to serial/console as possible. And
in this case, my suspicion is not that the lockdep splat will scroll
off the screen but that we might freeze before we even issue the whole
thing.
That's why I think we should be conservative and make the lockdep splat
come out second, if possible.
Am I making more sense now?
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
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next prev parent reply other threads:[~2015-06-22 18:15 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-18 19:08 [PATCH v2 00/14] x86: Rewrite exit-to-userspace code Andy Lutomirski
2015-06-18 19:08 ` [PATCH v2 01/14] uml: Fix do_signal() prototype Andy Lutomirski
2015-06-18 19:08 ` [PATCH v2 02/14] context_tracking: Add ct_state and CT_WARN_ON Andy Lutomirski
2015-06-18 19:08 ` [PATCH v2 03/14] notifiers: Assert that RCU is watching in notify_die Andy Lutomirski
2015-06-22 11:36 ` Borislav Petkov
2015-06-22 16:26 ` Andy Lutomirski
2015-06-22 16:33 ` Borislav Petkov
2015-06-22 17:03 ` Andy Lutomirski
2015-06-22 17:24 ` Borislav Petkov
2015-06-22 17:37 ` Andy Lutomirski
2015-06-22 18:15 ` Borislav Petkov [this message]
2015-06-22 19:48 ` Andy Lutomirski
2015-06-23 8:56 ` Ingo Molnar
2015-06-23 11:08 ` Borislav Petkov
2015-06-18 19:08 ` [PATCH v2 04/14] x86: Move C entry and exit code to arch/x86/entry/common.c Andy Lutomirski
2015-06-18 19:08 ` [PATCH v2 05/14] x86/traps: Assert that we're in CONTEXT_KERNEL in exception entries Andy Lutomirski
2015-06-18 19:08 ` [PATCH v2 06/14] x86/entry: Add enter_from_user_mode and use it in syscalls Andy Lutomirski
2015-06-18 19:08 ` [PATCH v2 07/14] x86/entry: Add new, comprehensible entry and exit hooks Andy Lutomirski
2015-06-18 19:08 ` [PATCH v2 08/14] x86/entry/64: Really create an error-entry-from-usermode code path Andy Lutomirski
2015-06-18 19:08 ` [PATCH v2 09/14] x86/entry/64: Migrate 64-bit and compat syscalls to new exit hooks Andy Lutomirski
2015-06-18 19:08 ` [PATCH v2 10/14] x86/asm/entry/64: Save all regs on interrupt entry Andy Lutomirski
2015-06-18 19:08 ` [PATCH v2 11/14] x86/asm/entry/64: Simplify irq stack pt_regs handling Andy Lutomirski
2015-06-18 19:08 ` [PATCH v2 12/14] x86/asm/entry/64: Migrate error and interrupt exit work to C Andy Lutomirski
2015-06-18 19:08 ` [PATCH v2 13/14] x86/entry: Remove exception_enter from trap handlers Andy Lutomirski
2015-06-18 19:08 ` [PATCH v2 14/14] x86/entry: Remove SCHEDULE_USER and asm/context-tracking.h Andy Lutomirski
2015-06-22 19:50 ` [PATCH v2 00/14] x86: Rewrite exit-to-userspace code Andy Lutomirski
2015-06-23 5:32 ` Andy Lutomirski
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