From: Andy Lutomirski <luto@amacapital.net>
To: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
X86 ML <x86@kernel.org>, Borislav Petkov <bp@alien8.de>,
Nadav Amit <nadav.amit@gmail.com>,
Kees Cook <keescook@chromium.org>,
Brian Gerst <brgerst@gmail.com>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86, core)
Date: Thu, 16 Jun 2016 10:50:09 -0700 [thread overview]
Message-ID: <CALCETrUTwG+fNgJQP8wYsAbxzjzARUwJ05jaRs0XfFPDHTB+ZQ@mail.gmail.com> (raw)
In-Reply-To: <20160616060538.GA3923@osiris>
On Wed, Jun 15, 2016 at 11:05 PM, Heiko Carstens
<heiko.carstens@de.ibm.com> wrote:
> 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?
>
Hmm. My attempt to benchmark it caused some of the vmalloc core code
to hang. I'll dig around.
FWIW, I expect some overhead on clone/fork (if it's high, then that
would be a good reason to improve vmalloc) and a small
workload-dependent overhead due to increased TLB pressure.
--Andy
next prev parent reply other threads:[~2016-06-16 17:50 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-16 0:28 [PATCH 00/13] Virtually mapped stacks with guard pages (x86, core) Andy Lutomirski
2016-06-16 0:28 ` [PATCH 01/13] x86/mm/hotplug: Don't remove PGD entries in remove_pagetable() Andy Lutomirski
2016-06-16 0:28 ` [PATCH 02/13] x86/cpa: In populate_pgd, don't set the pgd entry until it's populated Andy Lutomirski
2016-06-16 0:28 ` [PATCH 03/13] x86/cpa: Warn if kernel_unmap_pages_in_pgd is used inappropriately Andy Lutomirski
2016-06-16 0:28 ` [PATCH 04/13] mm: Track NR_KERNEL_STACK in pages instead of number of stacks Andy Lutomirski
2016-06-16 11:10 ` Vladimir Davydov
2016-06-16 17:21 ` Andy Lutomirski
2016-06-16 19:20 ` Andy Lutomirski
2016-06-16 15:33 ` Josh Poimboeuf
2016-06-16 17:39 ` Andy Lutomirski
2016-06-16 19:39 ` Josh Poimboeuf
2016-06-16 0:28 ` [PATCH 05/13] mm: Move memcg stack accounting to account_kernel_stack Andy Lutomirski
2016-06-16 0:28 ` [PATCH 06/13] fork: Add generic vmalloced stack support Andy Lutomirski
2016-06-16 17:25 ` Kees Cook
2016-06-16 17:37 ` Andy Lutomirski
2016-06-16 0:28 ` [PATCH 07/13] x86/die: Don't try to recover from an OOPS on a non-default stack Andy Lutomirski
2016-06-16 0:28 ` [PATCH 08/13] x86/dumpstack: When OOPSing, rewind the stack before do_exit Andy Lutomirski
2016-06-16 17:50 ` Josh Poimboeuf
2016-06-16 17:57 ` Andy Lutomirski
2016-06-16 0:28 ` [PATCH 09/13] x86/dumpstack: When dumping stack bytes due to OOPS, start with regs->sp Andy Lutomirski
2016-06-16 11:56 ` Borislav Petkov
2016-07-08 12:07 ` [tip:x86/debug] x86/dumpstack: Honor supplied @regs arg tip-bot for Andy Lutomirski
2016-06-16 0:28 ` [PATCH 10/13] x86/dumpstack: Try harder to get a call trace on stack overflow Andy Lutomirski
2016-06-16 18:16 ` Josh Poimboeuf
2016-06-16 18:22 ` Andy Lutomirski
2016-06-16 18:33 ` Josh Poimboeuf
2016-06-16 18:37 ` Andy Lutomirski
2016-06-16 18:54 ` Josh Poimboeuf
2016-06-16 0:28 ` [PATCH 11/13] x86/dumpstack/64: Handle faults when printing the "Stack:" part of an OOPS Andy Lutomirski
2016-06-16 0:28 ` [PATCH 12/13] x86/mm/64: Enable vmapped stacks Andy Lutomirski
2016-06-16 4:17 ` Mika Penttilä
2016-06-16 5:33 ` Andy Lutomirski
2016-06-16 13:11 ` [kernel-hardening] " Rik van Riel
2016-06-16 0:28 ` [PATCH 13/13] x86/mm: Improve stack-overflow #PF handling Andy Lutomirski
2016-06-16 6:05 ` [PATCH 00/13] Virtually mapped stacks with guard pages (x86, core) Heiko Carstens
2016-06-16 17:50 ` Andy Lutomirski [this message]
2016-06-16 18:14 ` Andy Lutomirski
2016-06-16 21:27 ` Andy Lutomirski
2016-06-17 3:58 ` Andy Lutomirski
2016-06-17 7:27 ` Heiko Carstens
2016-06-17 17:38 ` Andy Lutomirski
2016-06-20 5:58 ` Heiko Carstens
2016-06-20 6:01 ` Andy Lutomirski
2016-06-20 7:07 ` Heiko Carstens
2016-06-16 17:24 ` Kees Cook
2016-07-04 22:31 [PATCH -v2 0/3] x86/MSR: Improve unhandled MSR access error message Borislav Petkov
2016-07-04 22:31 ` [PATCH -v2 1/3] x86/dumpstack: Honor supplied @regs arg Borislav Petkov
2016-07-04 22:31 ` [PATCH -v2 2/3] printk: Make the printk*once() variants return a value Borislav Petkov
2016-07-08 12:08 ` [tip:x86/debug] " tip-bot for Borislav Petkov
2016-07-09 2:40 ` Joe Perches
2016-07-09 7:50 ` Borislav Petkov
2016-07-09 17:56 ` Joe Perches
2016-07-10 6:49 ` Borislav Petkov
2016-07-10 8:23 ` Joe Perches
2016-07-10 12:06 ` Borislav Petkov
2016-07-10 12:33 ` Joe Perches
2016-07-04 22:31 ` [PATCH -v2 3/3] x86/dumpstack: Add show_stack_regs() and use it Borislav Petkov
2016-07-08 12:08 ` [tip:x86/debug] " tip-bot for Borislav Petkov
2016-07-06 12:58 ` [PATCH -v2 0/3] x86/MSR: Improve unhandled MSR access error message Andy Lutomirski
2016-07-06 13:11 ` Borislav Petkov
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=CALCETrUTwG+fNgJQP8wYsAbxzjzARUwJ05jaRs0XfFPDHTB+ZQ@mail.gmail.com \
--to=luto@amacapital.net \
--cc=bp@alien8.de \
--cc=brgerst@gmail.com \
--cc=heiko.carstens@de.ibm.com \
--cc=jpoimboe@redhat.com \
--cc=keescook@chromium.org \
--cc=kernel-hardening@lists.openwall.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=nadav.amit@gmail.com \
--cc=torvalds@linux-foundation.org \
--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;
as well as URLs for NNTP newsgroup(s).