From: Andy Lutomirski <luto@amacapital.net>
To: Josh Poimboeuf <jpoimboe@redhat.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>,
Vladimir Davydov <vdavydov@virtuozzo.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: [kernel-hardening] Re: [PATCH 04/13] mm: Track NR_KERNEL_STACK in pages instead of number of stacks
Date: Thu, 16 Jun 2016 10:39:43 -0700 [thread overview]
Message-ID: <CALCETrXRONH1K1zAWAFN--Lsza+5bkgtmcMrgAY_nvT-e21C3w@mail.gmail.com> (raw)
In-Reply-To: <20160616153339.xvlsnhksqmkeusn4@treble>
On Thu, Jun 16, 2016 at 8:33 AM, Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> On Wed, Jun 15, 2016 at 05:28:26PM -0700, Andy Lutomirski wrote:
>> Currently, NR_KERNEL_STACK tracks the number of kernel stacks in a
>> zone. This only makes sense if each kernel stack exists entirely in
>> one zone, and allowing vmapped stacks could break this assumption.
>>
>> It turns out that the code for tracking kernel stack allocations in
>> units of pages is slightly simpler, so just switch to counting
>> pages.
>>
>> Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
>> Cc: Johannes Weiner <hannes@cmpxchg.org>
>> Cc: Michal Hocko <mhocko@kernel.org>
>> Cc: linux-mm@kvack.org
>> Signed-off-by: Andy Lutomirski <luto@kernel.org>
>> ---
>> fs/proc/meminfo.c | 2 +-
>> kernel/fork.c | 3 ++-
>> mm/page_alloc.c | 3 +--
>> 3 files changed, 4 insertions(+), 4 deletions(-)
>
> You missed another usage of NR_KERNEL_STACK in drivers/base/node.c.
Thanks.
The real reason I cc'd you was so you could look at
rewind_stack_do_exit and the sneaky trick I did in no_context in the
last patch, though. :) Both survive objtool, but I figured I'd check
with objtool's author as well. If there was a taint bit I could set
saying "kernel is hosed -- don't try to apply live patches any more",
I'd have extra confidence.
--Andy
next prev parent reply other threads:[~2016-06-16 17:39 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-16 0:28 [kernel-hardening] [PATCH 00/13] Virtually mapped stacks with guard pages (x86, core) Andy Lutomirski
2016-06-16 0:28 ` [kernel-hardening] [PATCH 01/13] x86/mm/hotplug: Don't remove PGD entries in remove_pagetable() Andy Lutomirski
2016-06-16 0:28 ` [kernel-hardening] [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 ` [kernel-hardening] [PATCH 03/13] x86/cpa: Warn if kernel_unmap_pages_in_pgd is used inappropriately Andy Lutomirski
2016-06-16 0:28 ` [kernel-hardening] [PATCH 04/13] mm: Track NR_KERNEL_STACK in pages instead of number of stacks Andy Lutomirski
2016-06-16 11:10 ` [kernel-hardening] " 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 [this message]
2016-06-16 19:39 ` Josh Poimboeuf
2016-06-16 0:28 ` [kernel-hardening] [PATCH 05/13] mm: Move memcg stack accounting to account_kernel_stack Andy Lutomirski
2016-06-16 0:28 ` [kernel-hardening] [PATCH 06/13] fork: Add generic vmalloced stack support Andy Lutomirski
2016-06-16 17:25 ` [kernel-hardening] " Kees Cook
2016-06-16 17:37 ` Andy Lutomirski
2016-06-16 0:28 ` [kernel-hardening] [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 ` [kernel-hardening] [PATCH 08/13] x86/dumpstack: When OOPSing, rewind the stack before do_exit Andy Lutomirski
2016-06-16 17:50 ` [kernel-hardening] " Josh Poimboeuf
2016-06-16 17:57 ` Andy Lutomirski
2016-06-16 0:28 ` [kernel-hardening] [PATCH 09/13] x86/dumpstack: When dumping stack bytes due to OOPS, start with regs->sp Andy Lutomirski
2016-06-16 11:56 ` [kernel-hardening] " Borislav Petkov
2016-06-16 0:28 ` [kernel-hardening] [PATCH 10/13] x86/dumpstack: Try harder to get a call trace on stack overflow Andy Lutomirski
2016-06-16 18:16 ` [kernel-hardening] " 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 ` [kernel-hardening] [PATCH 11/13] x86/dumpstack/64: Handle faults when printing the "Stack:" part of an OOPS Andy Lutomirski
2016-06-16 0:28 ` [kernel-hardening] [PATCH 12/13] x86/mm/64: Enable vmapped stacks Andy Lutomirski
2016-06-16 4:17 ` [kernel-hardening] " Mika Penttilä
2016-06-16 5:33 ` Andy Lutomirski
2016-06-16 13:11 ` Rik van Riel
2016-06-16 0:28 ` [kernel-hardening] [PATCH 13/13] x86/mm: Improve stack-overflow #PF handling Andy Lutomirski
2016-06-16 6:05 ` [kernel-hardening] Re: [PATCH 00/13] Virtually mapped stacks with guard pages (x86, core) Heiko Carstens
2016-06-16 17:50 ` Andy Lutomirski
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
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=CALCETrXRONH1K1zAWAFN--Lsza+5bkgtmcMrgAY_nvT-e21C3w@mail.gmail.com \
--to=luto@amacapital.net \
--cc=bp@alien8.de \
--cc=brgerst@gmail.com \
--cc=hannes@cmpxchg.org \
--cc=jpoimboe@redhat.com \
--cc=keescook@chromium.org \
--cc=kernel-hardening@lists.openwall.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=mhocko@kernel.org \
--cc=nadav.amit@gmail.com \
--cc=torvalds@linux-foundation.org \
--cc=vdavydov@virtuozzo.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;
as well as URLs for NNTP newsgroup(s).