From: Thomas Gleixner <tglx@linutronix.de>
To: Andy Lutomirski <luto@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>, X86 ML <x86@kernel.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Sean Christopherson <sean.j.christopherson@intel.com>
Subject: Re: [patch V2 28/29] x86/irq/64: Remap the IRQ stack with guard pages
Date: Mon, 8 Apr 2019 00:44:24 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.21.1904080043390.1840@nanos.tec.linutronix.de> (raw)
In-Reply-To: <CALCETrWF_YgQODJ=Rpm2MnhFxJXCfoo4H792hUQni0GS9on7og@mail.gmail.com>
On Sat, 6 Apr 2019, Andy Lutomirski wrote:
> On Fri, Apr 5, 2019 at 8:11 AM Thomas Gleixner <tglx@linutronix.de> wrote:
> >
> > From: Andy Lutomirski <luto@kernel.org>
> >
> > The IRQ stack lives in percpu space, so an IRQ handler that overflows it
> > will overwrite other data structures.
> >
> > Use vmap() to remap the IRQ stack so that it will have the usual guard
> > pages that vmap/vmalloc allocations have. With this the kernel will panic
> > immediately on an IRQ stack overflow.
>
> The 0day bot noticed that this dies with DEBUG_PAGEALLOC on. This is
> because the store_stackinfo() function is utter garbage and this patch
> correctly detects just how broken it is. The attached patch "fixes"
> it. (It also contains a reliability improvement that should probably
> get folded in, but is otherwise unrelated.)
>
> A real fix would remove the generic kstack_end() function entirely
> along with __HAVE_ARCH_KSTACK_END and would optionally replace
> store_stackinfo() with something useful. Josh, do we have a generic
> API to do a little stack walk like this? Otherwise, I don't think it
> would be the end of the world to just remove the offending code.
Actually we have: save_stack_trace()
next prev parent reply other threads:[~2019-04-07 22:44 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-05 15:06 [patch V2 00/29] x86: Add guard pages to exception and interrupt stacks Thomas Gleixner
2019-04-05 15:06 ` [patch V2 01/29] x86/irq/64: Limit IST stack overflow check to #DB stack Thomas Gleixner
2019-04-05 15:07 ` [patch V2 02/29] x86/dumpstack: Fix off-by-one errors in stack identification Thomas Gleixner
2019-04-05 15:44 ` Sean Christopherson
2019-04-05 15:07 ` [patch V2 03/29] x86/irq/64: Remove a hardcoded irq_stack_union access Thomas Gleixner
2019-04-05 16:37 ` Sean Christopherson
2019-04-05 16:38 ` Sean Christopherson
2019-04-05 17:18 ` Josh Poimboeuf
2019-04-05 17:47 ` Thomas Gleixner
2019-04-05 15:07 ` [patch V2 04/29] x86/irq/64: Sanitize the top/bottom confusion Thomas Gleixner
2019-04-05 16:54 ` Sean Christopherson
2019-04-05 15:07 ` [patch V2 05/29] x86/idt: Remove unused macro SISTG Thomas Gleixner
2019-04-05 15:07 ` [patch V2 06/29] x86/exceptions: Remove unused stack defines on 32bit Thomas Gleixner
2019-04-05 15:07 ` [patch V2 07/29] x86/exceptions: Make IST index zero based Thomas Gleixner
2019-04-05 18:59 ` Sean Christopherson
2019-04-05 15:07 ` [patch V2 08/29] x86/cpu_entry_area: Cleanup setup functions Thomas Gleixner
2019-04-05 19:25 ` Sean Christopherson
2019-04-05 15:07 ` [patch V2 09/29] x86/exceptions: Add structs for exception stacks Thomas Gleixner
2019-04-05 20:48 ` Sean Christopherson
2019-04-05 20:50 ` Sean Christopherson
2019-04-05 21:00 ` Thomas Gleixner
2019-04-05 15:07 ` [patch V2 10/29] x86/cpu_entry_area: Prepare for IST guard pages Thomas Gleixner
2019-04-05 15:07 ` [patch V2 11/29] x86/cpu_entry_area: Provide exception stack accessor Thomas Gleixner
2019-04-05 15:07 ` [patch V2 12/29] x86/traps: Use cpu_entry_area instead of orig_ist Thomas Gleixner
2019-04-05 15:07 ` [patch V2 13/29] x86/irq/64: Use cpu entry area " Thomas Gleixner
2019-04-05 15:07 ` [patch V2 14/29] x86/dumpstack/64: Use cpu_entry_area " Thomas Gleixner
2019-04-05 15:07 ` [patch V2 15/29] x86/cpu: Prepare TSS.IST setup for guard pages Thomas Gleixner
2019-04-05 15:07 ` [patch V2 16/29] x86/cpu: Remove orig_ist array Thomas Gleixner
2019-04-05 15:07 ` [patch V2 17/29] x86/exceptions: Disconnect IST index and stack order Thomas Gleixner
2019-04-05 21:57 ` Josh Poimboeuf
2019-04-05 22:00 ` Thomas Gleixner
2019-04-05 15:07 ` [patch V2 18/29] x86/exceptions: Enable IST guard pages Thomas Gleixner
2019-04-05 15:07 ` [patch V2 19/29] x86/exceptions: Split debug IST stack Thomas Gleixner
2019-04-05 20:55 ` Sean Christopherson
2019-04-05 21:01 ` Thomas Gleixner
2019-04-05 15:07 ` [patch V2 20/29] x86/dumpstack/64: Speedup in_exception_stack() Thomas Gleixner
2019-04-05 21:55 ` Josh Poimboeuf
2019-04-05 21:56 ` Thomas Gleixner
2019-04-05 15:07 ` [patch V2 21/29] x86/irq/32: Define IRQ_STACK_SIZE Thomas Gleixner
2019-04-05 15:07 ` [patch V2 22/29] x86/irq/32: Make irq stack a character array Thomas Gleixner
2019-04-05 15:07 ` [patch V2 23/29] x86/irq/32: Rename hard/softirq_stack to hard/softirq_stack_ptr Thomas Gleixner
2019-04-05 15:07 ` [patch V2 24/29] x86/irq/64: Rename irq_stack_ptr to hardirq_stack_ptr Thomas Gleixner
2019-04-05 15:07 ` [patch V2 25/29] x86/irq/32: Invoke irq_ctx_init() from init_IRQ() Thomas Gleixner
2019-04-05 15:27 ` Juergen Gross
2019-04-05 15:07 ` [patch V2 26/29] x86/irq/32: Handle irq stack allocation failure proper Thomas Gleixner
2019-04-05 15:07 ` [patch V2 27/29] x86/irq/64: Split the IRQ stack into its own pages Thomas Gleixner
2019-04-05 15:07 ` [patch V2 28/29] x86/irq/64: Remap the IRQ stack with guard pages Thomas Gleixner
2019-04-07 4:56 ` Andy Lutomirski
2019-04-07 6:08 ` Thomas Gleixner
2019-04-07 9:28 ` Andy Lutomirski
2019-04-07 9:34 ` Thomas Gleixner
2019-04-07 14:03 ` Andy Lutomirski
2019-04-07 22:44 ` Thomas Gleixner [this message]
2019-04-08 2:23 ` Andy Lutomirski
2019-04-08 6:46 ` Thomas Gleixner
2019-04-08 16:18 ` Andy Lutomirski
2019-04-08 16:36 ` Josh Poimboeuf
2019-04-08 16:44 ` Thomas Gleixner
2019-04-08 18:19 ` Thomas Gleixner
2019-04-05 15:07 ` [patch V2 29/29] x86/irq/64: Remove stack overflow debug code Thomas Gleixner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=alpine.DEB.2.21.1904080043390.1840@nanos.tec.linutronix.de \
--to=tglx@linutronix.de \
--cc=jpoimboe@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=sean.j.christopherson@intel.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®