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 19:24:00 +0200 [thread overview]
Message-ID: <20150622172400.GD20244@pd.tnic> (raw)
In-Reply-To: <CALCETrUDeKq1HKpDrbzDExb2sk7hXSe0E0yQ7eZdhfHH4e1baA@mail.gmail.com>
On Mon, Jun 22, 2015 at 10:03:30AM -0700, Andy Lutomirski wrote:
> The rcu_lockdep_assert should be merely a warning, not a full OOPS.
It is still pretty huge, see below.
> I think that, if rcu_lockdep_assert hangs, then we should fix that
> rather than avoiding debugging checks.
The RCU assertion firing might be unrelated to the oops happening and
could prevent us from seeing the real splat.
[ 0.048815]
[ 0.050493] ===============================
[ 0.052005] [ INFO: suspicious RCU usage. ]
[ 0.056007] 4.1.0-rc8+ #4 Not tainted
[ 0.060005] -------------------------------
[ 0.064005] arch/x86/kernel/cpu/amd.c:677 BOINK!
[ 0.066758]
[ 0.066758] other info that might help us debug this:
[ 0.066758]
[ 0.068006]
[ 0.068006] rcu_scheduler_active = 0, debug_locks = 0
[ 0.072005] no locks held by swapper/0/0.
[ 0.076005]
[ 0.076005] stack backtrace:
[ 0.080006] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.1.0-rc8+ #4
[ 0.083331] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[ 0.084021] 0000000000000000 ffffffff81967eb8 ffffffff816709c7 0000000000000000
[ 0.092005] ffffffff81975580 ffffffff81967ee8 ffffffff8109e8cd 0000000000000000
[ 0.097227] ffffffff81a3aec0 ffffffff81cad9c0 ffffffff81cb42c0 ffffffff81967f38
[ 0.104005] Call Trace:
[ 0.106021] [<ffffffff816709c7>] dump_stack+0x4f/0x7b
[ 0.108007] [<ffffffff8109e8cd>] lockdep_rcu_suspicious+0xfd/0x130
[ 0.112007] [<ffffffff81017f74>] init_amd+0x34/0x560
[ 0.116007] [<ffffffff810164e2>] identify_cpu+0x242/0x3b0
[ 0.119068] [<ffffffff81c27172>] identify_boot_cpu+0x10/0x7e
[ 0.120006] [<ffffffff81c27214>] check_bugs+0x9/0x2d
[ 0.124007] [<ffffffff81c1fe8e>] start_kernel+0x40e/0x425
[ 0.128007] [<ffffffff81c1f495>] x86_64_start_reservations+0x2a/0x2c
[ 0.132009] [<ffffffff81c1f582>] x86_64_start_kernel+0xeb/0xef
--
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 17:24 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 [this message]
2015-06-22 17:37 ` Andy Lutomirski
2015-06-22 18:15 ` Borislav Petkov
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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