From: "H. Peter Anvin" <hpa@linux.intel.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Kees Cook <keescook@chromium.org>, Linda Wang <lwang@redhat.com>,
Matt Fleming <matt.fleming@intel.com>
Subject: Re: [PATCH 00/11] x86: Supervisor Mode Access Prevention
Date: Fri, 21 Sep 2012 14:03:37 -0700 [thread overview]
Message-ID: <505CD629.1070402@linux.intel.com> (raw)
In-Reply-To: <20120921200846.GA25679@gmail.com>
On 09/21/2012 01:08 PM, Ingo Molnar wrote:
>
> * Linus Torvalds <torvalds@linux-foundation.org> wrote:
>
>> On Fri, Sep 21, 2012 at 12:43 PM, H. Peter Anvin <hpa@linux.intel.com> wrote:
>>
>>> Supervisor Mode Access Prevention (SMAP) is a new security
>>> feature disclosed by Intel in revision 014 of the Intel®
>>> Architecture Instruction Set Extensions Programming
>>> Reference:
>>
>> Looks good.
>>
>> Did this find any bugs, btw? We've had a few cases where we
>> forgot to use the proper user access function, and code just
>> happened to work because it all boils down to the same thing
>> and never got any page faults in practice anyway..
>
> The 4g:4g patch sweeped out most of the historic ones - so what
> we have are perhaps newer bugs (but those should be pretty rare,
> most new features are cross-arch).
>
A while ago I also did a mockup patch which switched %cr3 to
swapper_pg_dir while entering the kernel (basically where the CLAC
instructions go, plus the SYSCALL path; a restore was obviously needed,
too.) The performance was atrocious, but I didn't remember running into
any problems.
-hpa
next prev parent reply other threads:[~2012-09-21 21:03 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-21 19:43 [PATCH 00/11] x86: Supervisor Mode Access Prevention H. Peter Anvin
2012-09-21 19:43 ` [PATCH 01/11] x86, cpufeature: Add feature bit for SMAP H. Peter Anvin
2012-09-21 19:43 ` [PATCH 02/11] x86-32, mm: The WP test should be done on a kernel page H. Peter Anvin
2012-09-21 19:58 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 03/11] x86, smap: Add CR4 bit for SMAP H. Peter Anvin
2012-09-21 19:59 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 04/11] x86, alternative: Use .pushsection/.popsection H. Peter Anvin
2012-09-21 20:00 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 05/11] x86, alternative: Add header guards to <asm/alternative-asm.h> H. Peter Anvin
2012-09-21 20:01 ` [tip:x86/smap] x86, alternative: Add header guards to <asm/ alternative-asm.h> tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 06/11] x86, smap: Add a header file with macros for STAC/CLAC H. Peter Anvin
2012-09-21 20:02 ` [tip:x86/smap] x86, smap: Add a header file with macros for STAC/ CLAC tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 07/11] x86, uaccess: Merge prototypes for clear_user/__clear_user H. Peter Anvin
2012-09-21 20:03 ` [tip:x86/smap] x86, uaccess: Merge prototypes for clear_user/ __clear_user tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 08/11] x86, smap: Add STAC and CLAC instructions to control user space access H. Peter Anvin
2012-09-21 20:04 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-22 0:16 ` [tip:x86/smap] x86-32, smap: Add STAC/ CLAC instructions to 32-bit kernel entry tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 09/11] x86, smap: Turn on Supervisor Mode Access Prevention H. Peter Anvin
2012-09-21 20:05 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 10/11] x86, smap: A page fault due to SMAP is an oops H. Peter Anvin
2012-09-21 20:06 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 11/11] x86, smap: Reduce the SMAP overhead for signal handling H. Peter Anvin
2012-09-21 20:07 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:54 ` [PATCH 00/11] x86: Supervisor Mode Access Prevention Linus Torvalds
2012-09-21 19:57 ` H. Peter Anvin
2012-09-21 20:08 ` Ingo Molnar
2012-09-21 21:03 ` H. Peter Anvin [this message]
2012-09-21 21:09 ` Linus Torvalds
2012-09-21 21:12 ` H. Peter Anvin
2012-09-21 22:07 ` Eric W. Biederman
2012-09-21 22:12 ` H. Peter Anvin
2012-09-22 0:41 ` Eric W. Biederman
2012-09-24 23:27 ` [RFC PATCH] x86-32: Start out eflags and cr4 clean H. Peter Anvin
2012-09-25 13:27 ` Konrad Rzeszutek Wilk
2012-09-25 13:48 ` Ian Campbell
2012-09-26 11:29 ` Konrad Rzeszutek Wilk
2012-09-27 6:11 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-11-24 3:49 ` Yuhong Bao
2012-11-24 5:06 ` H. Peter Anvin
2012-09-27 6:11 ` [tip:x86/smap] x86, suspend: On wakeup always initialize cr4 and EFER tip-bot for H. Peter Anvin
2012-10-01 22:04 ` [tip:x86/urgent] x86, suspend: Correct the restore of CR4, EFER; skip computing EFLAGS.ID tip-bot for H. Peter Anvin
2012-10-02 6:52 ` tip-bot for H. Peter Anvin
2012-10-10 19:59 ` [RFC PATCH] x86-32: Start out eflags and cr4 clean Andres Salomon
2013-01-19 0:40 ` Andres Salomon
2013-01-19 0:42 ` H. Peter Anvin
2013-01-19 1:05 ` [Techteam] " Mitch Bradley
2013-01-19 2:35 ` H. Peter Anvin
2013-01-19 7:44 ` Mitch Bradley
2013-01-19 12:34 ` Daniel Drake
2013-01-19 19:15 ` [tip:x86/urgent] x86-32: Start out cr0 clean, disable paging before modifying cr3/4 tip-bot for H. Peter Anvin
2012-09-21 22:08 ` [PATCH 00/11] x86: Supervisor Mode Access Prevention Dave Jones
2012-09-21 22:10 ` H. Peter Anvin
2012-09-22 11:32 ` Ingo Molnar
2012-09-24 20:31 ` H. Peter Anvin
2012-09-24 20:43 ` Kees Cook
2012-09-24 20:51 ` H. Peter Anvin
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