From: Dave Hansen <dave@sr71.net>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Kees Cook <keescook@google.com>,
LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>, "x86@kernel.org" <x86@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Dave Hansen <dave.hansen@linux.intel.com>
Subject: Re: [PATCH 31/32] x86, pkeys: execute-only support
Date: Mon, 14 Dec 2015 16:26:42 -0800 [thread overview]
Message-ID: <566F5E42.9000009@sr71.net> (raw)
In-Reply-To: <CALCETrXhNXx_csPnXcSaPvgY52NN8kadvd8XG8FQ3dcMfvftOg@mail.gmail.com>
On 12/14/2015 03:47 PM, Andy Lutomirski wrote:
> On Mon, Dec 14, 2015 at 3:44 PM, Dave Hansen <dave@sr71.net> wrote:
>> On 12/14/2015 03:39 PM, Andy Lutomirski wrote:
>>>>> Nope. My linker-fu is weak.
>>>>>
>>>>> Can we even depend on the linker by itself? Even if the sections were
>>>>> marked --x, we can't actually use them with those permissions unless we
>>>>> have protection keys.
>>>>>
>>>>> Do we need some special tag on the section to tell the linker to map it
>>>>> as --x under some conditions and r-x for others?
>>>>>
>>> Why? Wouldn't --x just end up acting like r-x if PKRU is absent?
>>
>> An app doing --x would expect it to be unreadable. I don't think we can
>> just silently turn it in to r-x.
>
> I don't see why. After all, an app doing --x right now gets rx. An
> app doing r-- still gets r-x on some systems.
... and you're right. I'd managed to convince myself otherwise, somehow.
Let me go see if I can get the execve() code to make one of these
mappings if I hand it properly-aligned sections.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
WARNING: multiple messages have this Message-ID (diff)
From: Dave Hansen <dave@sr71.net>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Kees Cook <keescook@google.com>,
LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>, "x86@kernel.org" <x86@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Dave Hansen <dave.hansen@linux.intel.com>
Subject: Re: [PATCH 31/32] x86, pkeys: execute-only support
Date: Mon, 14 Dec 2015 16:26:42 -0800 [thread overview]
Message-ID: <566F5E42.9000009@sr71.net> (raw)
In-Reply-To: <CALCETrXhNXx_csPnXcSaPvgY52NN8kadvd8XG8FQ3dcMfvftOg@mail.gmail.com>
On 12/14/2015 03:47 PM, Andy Lutomirski wrote:
> On Mon, Dec 14, 2015 at 3:44 PM, Dave Hansen <dave@sr71.net> wrote:
>> On 12/14/2015 03:39 PM, Andy Lutomirski wrote:
>>>>> Nope. My linker-fu is weak.
>>>>>
>>>>> Can we even depend on the linker by itself? Even if the sections were
>>>>> marked --x, we can't actually use them with those permissions unless we
>>>>> have protection keys.
>>>>>
>>>>> Do we need some special tag on the section to tell the linker to map it
>>>>> as --x under some conditions and r-x for others?
>>>>>
>>> Why? Wouldn't --x just end up acting like r-x if PKRU is absent?
>>
>> An app doing --x would expect it to be unreadable. I don't think we can
>> just silently turn it in to r-x.
>
> I don't see why. After all, an app doing --x right now gets rx. An
> app doing r-- still gets r-x on some systems.
... and you're right. I'd managed to convince myself otherwise, somehow.
Let me go see if I can get the execve() code to make one of these
mappings if I hand it properly-aligned sections.
next prev parent reply other threads:[~2015-12-15 0:26 UTC|newest]
Thread overview: 96+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-14 19:05 [PATCH 00/32] x86: Memory Protection Keys (v7) Dave Hansen
2015-12-14 19:05 ` Dave Hansen
2015-12-14 19:05 ` [PATCH 01/32] mm, gup: introduce concept of "foreign" get_user_pages() Dave Hansen
2015-12-14 19:05 ` Dave Hansen
2016-01-05 10:51 ` Vlastimil Babka
2016-01-05 10:51 ` Vlastimil Babka
2016-01-06 17:43 ` Dave Hansen
2016-01-06 17:43 ` Dave Hansen
2015-12-14 19:05 ` [PATCH 02/32] x86, fpu: add placeholder for Processor Trace XSAVE state Dave Hansen
2015-12-14 19:05 ` Dave Hansen
2015-12-14 19:05 ` [PATCH 03/32] x86, pkeys: Add Kconfig option Dave Hansen
2015-12-14 19:05 ` Dave Hansen
2015-12-14 19:05 ` [PATCH 04/32] x86, pkeys: cpuid bit definition Dave Hansen
2015-12-14 19:05 ` Dave Hansen
2015-12-14 19:05 ` [PATCH 05/32] x86, pkeys: define new CR4 bit Dave Hansen
2015-12-14 19:05 ` Dave Hansen
2015-12-14 19:05 ` [PATCH 06/32] x86, pkeys: add PKRU xsave fields and data structure(s) Dave Hansen
2015-12-14 19:05 ` Dave Hansen
2015-12-14 19:05 ` [PATCH 07/32] x86, pkeys: PTE bits for storing protection key Dave Hansen
2015-12-14 19:05 ` Dave Hansen
2015-12-14 19:05 ` [PATCH 08/32] x86, pkeys: new page fault error code bit: PF_PK Dave Hansen
2015-12-14 19:05 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 09/32] x86, pkeys: store protection in high VMA flags Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 10/32] x86, pkeys: arch-specific protection bits Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 11/32] x86, pkeys: pass VMA down in to fault signal generation code Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 12/32] signals, pkeys: notify userspace about protection key faults Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 13/32] x86, pkeys: fill in pkey field in siginfo Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 14/32] x86, pkeys: add functions to fetch PKRU Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:56 ` Thomas Gleixner
2015-12-14 19:06 ` [PATCH 15/32] mm: factor out VMA fault permission checking Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 16/32] x86, mm: simplify get_user_pages() PTE bit handling Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:56 ` Thomas Gleixner
2015-12-14 19:06 ` [PATCH 17/32] x86, pkeys: check VMAs and PTEs for protection keys Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 18/32] mm: add gup flag to indicate "foreign" mm access Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 19/32] x86, pkeys: optimize fault handling in access_error() Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 20/32] x86, pkeys: differentiate instruction fetches Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 21/32] x86, pkeys: dump PKRU with other kernel registers Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 22/32] x86, pkeys: dump PTE pkey in /proc/pid/smaps Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2016-01-05 13:32 ` Vlastimil Babka
2016-01-05 13:32 ` Vlastimil Babka
2016-01-06 17:46 ` Dave Hansen
2016-01-06 17:46 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 23/32] x86, pkeys: add Kconfig prompt to existing config option Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 24/32] x86, pkeys: actually enable Memory Protection Keys in CPU Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 20:00 ` Thomas Gleixner
2015-12-14 19:06 ` [PATCH 25/32] mm, multi-arch: pass a protection key in to calc_vm_flag_bits() Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 26/32] x86, pkeys: add arch_validate_pkey() Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 27/32] x86: separate out LDT init from context init Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 28/32] x86, fpu: allow setting of XSAVE state Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 29/32] x86, pkeys: allow kernel to modify user pkey rights register Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 30/32] x86, pkeys: create an x86 arch_calc_vm_prot_bits() for VMA flags Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 19:06 ` [PATCH 31/32] x86, pkeys: execute-only support Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2015-12-14 20:05 ` Kees Cook
2015-12-14 20:05 ` Kees Cook
2015-12-14 23:37 ` Dave Hansen
2015-12-14 23:37 ` Dave Hansen
2015-12-14 23:39 ` Andy Lutomirski
2015-12-14 23:39 ` Andy Lutomirski
2015-12-14 23:41 ` Kees Cook
2015-12-14 23:41 ` Kees Cook
2015-12-14 23:44 ` Dave Hansen
2015-12-14 23:44 ` Dave Hansen
2015-12-14 23:47 ` Andy Lutomirski
2015-12-14 23:47 ` Andy Lutomirski
2015-12-15 0:26 ` Dave Hansen [this message]
2015-12-15 0:26 ` Dave Hansen
2015-12-14 23:39 ` Kees Cook
2015-12-14 23:39 ` Kees Cook
2015-12-14 19:06 ` [PATCH 32/32] x86, pkeys: Documentation Dave Hansen
2015-12-14 19:06 ` Dave Hansen
2016-03-29 9:24 ` [tip:x86/urgent] x86/mm/pkeys: Add missing Documentation tip-bot for Dave Hansen
2015-12-24 11:37 ` [PATCH 00/32] x86: Memory Protection Keys (v7) Michael Kerrisk (man-pages)
2015-12-24 11:37 ` Michael Kerrisk (man-pages)
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=566F5E42.9000009@sr71.net \
--to=dave@sr71.net \
--cc=akpm@linux-foundation.org \
--cc=dave.hansen@linux.intel.com \
--cc=keescook@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@amacapital.net \
--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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.