From: Andy Lutomirski <luto@kernel.org>
To: Ingo Molnar <mingo@kernel.org>, Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>, X86 ML <x86@kernel.org>,
Borislav Petkov <bpetkov@suse.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Brian Gerst <brgerst@gmail.com>,
Dave Hansen <dave.hansen@intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [PATCH v2 00/18] Entry stack switching
Date: Wed, 22 Nov 2017 08:23:20 -0800 [thread overview]
Message-ID: <CALCETrVvpNVzixzAubip8-=8v=gE+Z_0CyXX117dmdbeXozEVQ@mail.gmail.com> (raw)
In-Reply-To: <20171122062257.ivp5fbcy2k4mlfdm@gmail.com>
On Tue, Nov 21, 2017 at 10:22 PM, Ingo Molnar <mingo@kernel.org> wrote:
>
> * Andy Lutomirski <luto@kernel.org> wrote:
>
>> This sets up stack switching, including for SYSCALL. I think it's
>> in decent shape.
>>
>> Known issues:
>> - I think we're going to want a way to turn the stack switching on and
>> off either at boot time or at runtime. It should be fairly straightforward
>> to make it work.
>>
>> - I think the ORC unwinder isn't so good at dealing with stack overflows.
>> It bails too early (I think), resulting in lots of ? entries. This
>> isn't a regression with this series -- it's just something that could
>> be improved.
>>
>> Ingo, patch 1 may be tip/urgent material. It fixes what I think is
>> a bug in Xen. I'm having a hard time testing because it's being
>> masked by a bigger unrelated bug that's keeping Xen from booting
>> when configured to hit the bug I'm fixing. (The latter bug goes at
>> least back to v4.13, I think I know roughtly what's wrong, and I've
>> reported it to the maintainers.)
>
> Hm, with this series the previous IRQ vector bug appears again:
>
> [ 51.156370] do_IRQ: 16.34 No irq handler for vector
> [ 57.511030] do_IRQ: 16.34 No irq handler for vector
> [ 57.528335] do_IRQ: 16.34 No irq handler for vector
> [ 57.533256] do_IRQ: 16.34 No irq handler for vector
> [ 63.991913] do_IRQ: 16.34 No irq handler for vector
> [ 63.996810] do_IRQ: 16.34 No irq handler for vector
>
> I've attached the reproducer config. Note that the system appears to be working to
> a certain extent (I could ssh to it and extract its config), but produces these
> warnings sporadically.
I'll try to reproduce this, but this is weird. This is vector 34,
which is, or could be, a genuine IRQ vector. The only way I can think
of that my series would have caused this is if I very severely broke
common_interrupt, but I don't see how that could have happened without
breaking everything. It's also weird that you're seeing this only on
CPU 16. Maybe it's worth adding a WARN_ON to that warning to get a
stack trace just in case.
Thomas, any insight here?
> but don't get the IRQ vector warnings.
Ingo, are you saying that you only get the IRQ vector warnings with
the SYSCALL hwframe fix applied? That's bizarre.
Anyway, I booted your config (more or less -- I munged it through
virtme-configkernel --update first) with 17 vCPUs and it seems fine.
Is the issue reliable enough to bisect?
next prev parent reply other threads:[~2017-11-22 16:23 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-22 4:43 [PATCH v2 00/18] Entry stack switching Andy Lutomirski
2017-11-22 4:43 ` [PATCH v2 01/18] x86/entry/64: Fix entry_SYSCALL_64_after_hwframe IRQ tracing Andy Lutomirski
2017-11-22 5:35 ` Ingo Molnar
2017-11-22 7:45 ` [tip:x86/urgent] x86/entry/64: Fix entry_SYSCALL_64_after_hwframe() " tip-bot for Andy Lutomirski
2017-11-22 4:43 ` [PATCH v2 02/18] x86/asm/64: Allocate and enable the SYSENTER stack Andy Lutomirski
2017-11-22 4:43 ` [PATCH v2 03/18] x86/dumpstack: Add get_stack_info() support for " Andy Lutomirski
2017-11-22 12:10 ` Borislav Petkov
2017-11-22 4:43 ` [PATCH v2 04/18] x86/gdt: Put per-cpu GDT remaps in ascending order Andy Lutomirski
2017-11-22 11:05 ` Borislav Petkov
2017-11-22 15:26 ` Andy Lutomirski
2017-11-22 4:44 ` [PATCH v2 05/18] x86/fixmap: Generalize the GDT fixmap mechanism Andy Lutomirski
2017-11-22 15:33 ` Borislav Petkov
2017-11-22 17:16 ` Andy Lutomirski
2017-11-22 17:32 ` Borislav Petkov
2017-11-23 15:24 ` Andy Lutomirski
2017-11-23 19:24 ` Thomas Gleixner
2017-11-22 4:44 ` [PATCH v2 06/18] x86/kasan/64: Teach KASAN about the cpu_entry_area Andy Lutomirski
2017-11-22 6:19 ` Ingo Molnar
2017-11-22 9:05 ` Andrey Ryabinin
2017-11-22 15:22 ` Andy Lutomirski
2017-11-23 10:08 ` Andrey Ryabinin
2017-11-23 15:22 ` Andy Lutomirski
2017-11-22 4:44 ` [PATCH v2 07/18] x86/asm: Fix assumptions that the HW TSS is at the beginning of cpu_tss Andy Lutomirski
2017-11-22 19:06 ` Borislav Petkov
2017-11-22 4:44 ` [PATCH v2 08/18] x86/dumpstack: Handle stack overflow on all stacks Andy Lutomirski
2017-11-23 11:19 ` Borislav Petkov
2017-11-22 4:44 ` [PATCH v2 09/18] x86/asm: Move SYSENTER_stack to the beginning of struct tss_struct Andy Lutomirski
2017-11-23 12:00 ` Borislav Petkov
2017-11-23 13:16 ` Denys Vlasenko
2017-11-23 15:02 ` Andy Lutomirski
2017-11-23 19:30 ` Thomas Gleixner
2017-11-22 4:44 ` [PATCH v2 10/18] x86/asm: Remap the TSS into the cpu entry area Andy Lutomirski
2017-11-23 19:32 ` Thomas Gleixner
2017-11-23 19:55 ` Borislav Petkov
2017-11-23 20:15 ` Andy Lutomirski
2017-11-23 20:37 ` Borislav Petkov
2017-11-24 2:40 ` Andy Lutomirski
2017-11-24 4:17 ` Andy Lutomirski
2017-11-22 4:44 ` [PATCH v2 11/18] x86/asm/64: Separate cpu_current_top_of_stack from TSS.sp0 Andy Lutomirski
2017-11-23 19:34 ` Thomas Gleixner
2017-11-22 4:44 ` [PATCH v2 12/18] x86/espfix/64: Stop assuming that pt_regs is on the entry stack Andy Lutomirski
2017-11-23 19:36 ` Thomas Gleixner
2017-11-22 4:44 ` [PATCH v2 13/18] x86/asm/64: Use a percpu trampoline stack for IDT entries Andy Lutomirski
2017-11-23 23:44 ` Thomas Gleixner
2017-11-24 4:14 ` Andy Lutomirski
2017-11-22 4:44 ` [PATCH v2 14/18] x86/asm/64: Return to userspace from the trampoline stack Andy Lutomirski
2017-11-22 4:44 ` [PATCH v2 15/18] x86/entry/64: Create a percpu SYSCALL entry trampoline Andy Lutomirski
2017-11-22 4:44 ` [PATCH v2 16/18] x86/irq: Remove an old outdated comment about context tracking races Andy Lutomirski
2017-11-22 4:44 ` [PATCH v2 17/18] x86/irq/64: In the stack overflow warning, print the offending IP Andy Lutomirski
2017-11-22 4:44 ` [PATCH v2 18/18] x86/entry/64: Move the IST stacks into cpu_entry_area Andy Lutomirski
2017-11-22 6:22 ` [PATCH v2 00/18] Entry stack switching Ingo Molnar
2017-11-22 6:36 ` Ingo Molnar
2017-11-22 16:23 ` Andy Lutomirski [this message]
2017-11-23 6:21 ` Ingo Molnar
2017-11-23 6:44 ` Ingo Molnar
2017-11-23 6:58 ` Ingo Molnar
2017-11-23 15:29 ` Andy Lutomirski
2017-11-23 16:41 ` Thomas Gleixner
2017-11-22 7:39 ` WARNING: can't dereference registers at ffffc90004dfff60 for ip error_entry+0x7d/0xd0 (Re: [PATCH v2 00/18] Entry stack switching) Ingo Molnar
2017-11-22 7:43 ` Ingo Molnar
2017-11-22 13:55 ` Josh Poimboeuf
2017-11-22 15:19 ` Andy Lutomirski
2017-11-22 15:56 ` Ingo Molnar
2017-11-22 16:35 ` Andy Lutomirski
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