linux-kernel - Re: [PATCH] x86, vdso32: fix out of memory handling setup vDSO

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 20 Mar 2014 08:18:39 -0700
From:	Andy Lutomirski <luto@...capital.net>
To:	Thomas Gleixner <tglx@...utronix.de>
Cc:	Stefani Seibold <stefani@...bold.net>,
	Greg KH <gregkh@...uxfoundation.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	X86 ML <x86@...nel.org>, Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, Andi Kleen <ak@...ux.intel.com>,
	Andrea Arcangeli <aarcange@...hat.com>,
	John Stultz <john.stultz@...aro.org>,
	Pavel Emelyanov <xemul@...allels.com>,
	Cyrill Gorcunov <gorcunov@...nvz.org>,
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	Martin Runge <Martin.Runge@...de-schwarz.com>,
	Andreas Brief <Andreas.Brief@...de-schwarz.com>
Subject: Re: [PATCH] x86, vdso32: fix out of memory handling setup vDSO

On Thu, Mar 20, 2014 at 8:15 AM, Thomas Gleixner <tglx@...utronix.de> wrote:
> On Thu, 20 Mar 2014, Andy Lutomirski wrote:
>> On Thu, Mar 20, 2014 at 5:30 AM, Thomas Gleixner <tglx@...utronix.de> wrote:
>> > On Thu, 20 Mar 2014, Stefani Seibold wrote:
>> >> All complains are design decisions not made by me. I will send a patch
>> >> for the GFP_ATOMIC thing. For the other one it would be the best to ask
>> >> Andy for the reason.
>> >
>> > I'm not saying it's your fault, but if we rework code, then we really
>> > should question such things. What happens if you remove the x32 call
>> > and make the x64 subsys thing valid for both cases?
>> >
>>
>> It's not just that.  The x86_64 and x32 vdso page arrays are *far*
>> cleaner than the 32-bit variant.  They manage to do the entire vdso
>> setup dance without any allocation at all.  This avoids silly
>> questions about error handling and GFP_KERNEL :)
>>
>> See vdso/vdso.S for the rather small amount of magic needed.
>
> Is there any reason why we can't use that for x86_32 ?
>

Not really.  I'll play with it a bit.

> Thanks,
>
>         tglx



-- 
Andy Lutomirski
AMA Capital Management, LLC
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/