Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86, core)

From	Heiko Carstens <heiko.carstens@de.ibm.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86, core)
Date	2016-06-16 08:10 +0200
Message-ID	<rKyF3-4EY-9@gated-at.bofh.it> (permalink)
References	<rKtm1-1aF-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, Jun 15, 2016 at 05:28:22PM -0700, Andy Lutomirski wrote:
> Since the dawn of time, a kernel stack overflow has been a real PITA
> to debug, has caused nondeterministic crashes some time after the
> actual overflow, and has generally been easy to exploit for root.
> 
> With this series, arches can enable HAVE_ARCH_VMAP_STACK.  Arches
> that enable it (just x86 for now) get virtually mapped stacks with
> guard pages.  This causes reliable faults when the stack overflows.
> 
> If the arch implements it well, we get a nice OOPS on stack overflow
> (as opposed to panicing directly or otherwise exploding badly).  On
> x86, the OOPS is nice, has a usable call trace, and the overflowing
> task is killed cleanly.

Do you have numbers which reflect the performance impact of this change?

Thread

[PATCH 00/13] Virtually mapped stacks with guard pages (x86, core) Andy Lutomirski <luto@kernel.org> - 2016-06-16 02:30 +0200
  [PATCH 01/13] x86/mm/hotplug: Don't remove PGD entries in remove_pagetable() Andy Lutomirski <luto@kernel.org> - 2016-06-16 02:30 +0200
  [PATCH 12/13] x86/mm/64: Enable vmapped stacks Andy Lutomirski <luto@kernel.org> - 2016-06-16 02:30 +0200
    Re: [PATCH 12/13] x86/mm/64: Enable vmapped stacks Andy Lutomirski <luto@amacapital.net> - 2016-06-16 07:40 +0200
      Re: [kernel-hardening] Re: [PATCH 12/13] x86/mm/64: Enable vmapped  stacks Rik van Riel <riel@redhat.com> - 2016-06-16 15:20 +0200
  [PATCH 03/13] x86/cpa: Warn if kernel_unmap_pages_in_pgd is used inappropriately Andy Lutomirski <luto@kernel.org> - 2016-06-16 02:30 +0200
  [PATCH 08/13] x86/dumpstack: When OOPSing, rewind the stack before do_exit Andy Lutomirski <luto@kernel.org> - 2016-06-16 02:40 +0200
    Re: [PATCH 08/13] x86/dumpstack: When OOPSing, rewind the stack  before do_exit Josh Poimboeuf <jpoimboe@redhat.com> - 2016-06-16 20:00 +0200
      Re: [PATCH 08/13] x86/dumpstack: When OOPSing, rewind the stack  before do_exit Andy Lutomirski <luto@amacapital.net> - 2016-06-16 20:00 +0200
  [PATCH 02/13] x86/cpa: In populate_pgd, don't set the pgd entry until it's populated Andy Lutomirski <luto@kernel.org> - 2016-06-16 02:40 +0200
  [PATCH 06/13] fork: Add generic vmalloced stack support Andy Lutomirski <luto@kernel.org> - 2016-06-16 02:40 +0200
    Re: [PATCH 06/13] fork: Add generic vmalloced stack support Kees Cook <keescook@chromium.org> - 2016-06-16 19:30 +0200
      Re: [PATCH 06/13] fork: Add generic vmalloced stack support Andy Lutomirski <luto@amacapital.net> - 2016-06-16 19:40 +0200
  [PATCH 07/13] x86/die: Don't try to recover from an OOPS on a non-default stack Andy Lutomirski <luto@kernel.org> - 2016-06-16 02:40 +0200
  [PATCH 10/13] x86/dumpstack: Try harder to get a call trace on stack overflow Andy Lutomirski <luto@kernel.org> - 2016-06-16 02:40 +0200
    Re: [PATCH 10/13] x86/dumpstack: Try harder to get a call trace on  stack overflow Josh Poimboeuf <jpoimboe@redhat.com> - 2016-06-16 20:20 +0200
      Re: [PATCH 10/13] x86/dumpstack: Try harder to get a call trace on  stack overflow Andy Lutomirski <luto@amacapital.net> - 2016-06-16 20:30 +0200
        Re: [PATCH 10/13] x86/dumpstack: Try harder to get a call trace on  stack overflow Andy Lutomirski <luto@amacapital.net> - 2016-06-16 20:40 +0200
          Re: [PATCH 10/13] x86/dumpstack: Try harder to get a call trace on  stack overflow Josh Poimboeuf <jpoimboe@redhat.com> - 2016-06-16 21:00 +0200
        Re: [PATCH 10/13] x86/dumpstack: Try harder to get a call trace on  stack overflow Josh Poimboeuf <jpoimboe@redhat.com> - 2016-06-16 20:40 +0200
  Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86,  core) Heiko Carstens <heiko.carstens@de.ibm.com> - 2016-06-16 08:10 +0200
    Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86, core) Andy Lutomirski <luto@amacapital.net> - 2016-06-16 20:00 +0200
      Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86, core) Andy Lutomirski <luto@amacapital.net> - 2016-06-16 20:20 +0200
        Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86, core) Andy Lutomirski <luto@amacapital.net> - 2016-06-16 23:30 +0200
    Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86, core) Andy Lutomirski <luto@amacapital.net> - 2016-06-17 06:00 +0200
      Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86,  core) Heiko Carstens <heiko.carstens@de.ibm.com> - 2016-06-17 09:30 +0200
        Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86, core) Andy Lutomirski <luto@amacapital.net> - 2016-06-17 19:40 +0200
          Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86,  core) Heiko Carstens <heiko.carstens@de.ibm.com> - 2016-06-20 08:00 +0200
            Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86, core) Andy Lutomirski <luto@amacapital.net> - 2016-06-20 08:10 +0200
              Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86,  core) Heiko Carstens <heiko.carstens@de.ibm.com> - 2016-06-20 09:40 +0200
  Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86, core) Kees Cook <keescook@chromium.org> - 2016-06-16 19:30 +0200

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