similar to: Status of Intel JCC Mitigations and Next Steps

FWIW I'm with Eli here if you need any more data points. -eric On Tue, Mar 24, 2020 at 8:21 PM Eli Friedman via llvm-dev < llvm-dev at lists.llvm.org> wrote: > Changing the length of a sequence of assembly instructions will break > someone’s code at some point. The length of a sequence of instructions is > known, in general, and people will write code to take advantage of

I agree we shouldn’t try to guess what the user is trying to do. There shouldn’t be an unbounded set of heuristic rules; “documented” implies some sort of promise of stability in addition to the actual text in the manual. And we shouldn’t try to guess whether the user’s code cares about the length of a specific instruction. I think you’re creating a false dichotomy here, though. There’s some

I met with the Propeller team today (we work for the same company but it was my first time meeting two members on the team:) ). One thing I have been reassured: * There is no general disassembly work. General disassembly work would assuredly frighten off developers. (Inherently unreliable, memory usage heavy and difficult to deal with CFI, debug information, etc) Minimal amount of plumbing work

I will reply those comments tomorrow. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20191204/f1111299/attachment.html>

On 6 February 2018 at 20:09, David Newall <openssh at davidnewall.com> wrote: > Do we need to do anything? It's not clear to me how SSH is vulnerable to > Spectre -- that is, how SSH can be used to execute a Spectre attack? I am more concerned with it being the target of a Spectre style attack. There's some long lived private data (host keys in the case of sshd, session keys

Hi folks, Firstly; apologies in advance for what is a head wrecker of keeping on top of the speculative mitigations and also if this is a duplicate email; my first copy didn't seem to make it into the archive. Also a disclaimer that I may have misunderstood elements of the below but please bear with me. I write this hoping to find out a bit more about the state of the relevant kernel

I'm also a bit unclear on that point. I think one input here has to be: what are some example, existing codebases we want to mitigate, and what should the user experience be to mitigate them? I don't think we can make good engineering tradeoffs without having concrete use cases to evaluate. Another point: it seems some mitigation options have already been added to the GNU toolchain

Hi everyone! I want to clarify the purpose and design of SESES. Thus far, I've characterized it as an LVI mitigation which is somewhat incorrect. SESES was built as a "big hammer." It is intended to protect against many side channel vulnerabilities (Spectre v1, Spectre v4, LVI, etc, etc) even though it was built in response to LVI. For folks protecting against LVI, this is an

On Fri, Aug 7, 2020 at 1:18 AM David Chisnall <David.Chisnall at cl.cam.ac.uk> wrote: > I think it would be useful for the discussion to have a clear threat model that this intends to defend against and a rough analysis of the security benefits that this is believed to bring. I view this as being even more about a ROP defense. Dealing with spill slots is, IMO, a separate issue, more

Hi, A new speculative cache side-channel vulnerability has been published at https://developer.arm.com/support/arm-security-updates/speculative-processor-vulnerability/downloads/straight-line-speculation, named "straight-line speculation”, CVE-2020-13844. In this email, I'd like to explain the toolchain mitigation we've prepared to mitigate against this vulnerability for AArch64.

Hi Xiang, On Wed, Nov 11, 2020 at 1:59 AM Zhang, Xiang1 <xiang1.zhang at intel.com> wrote: > Jeremy wrote: > > ... The value %0 is live up to and including the ADD64ri but not past it, meaning LLVM today will drop the DBG_VALUE ... > > Just a little puzzle about the " drop the DBG_VALUE ", maybe I didn't get your key point, >

Hi all! I'm running an up-to-date Centos-7 on an AMD Vishera 6300, 6 core CPU. I note that when I run the redhat script to test for spectre & meltdown I get this result for variant 2: Variant #2 (Spectre): Vulnerable CVE-2017-5715 - speculative execution branch target injection - Kernel with mitigation patches: OK - HW support / updated microcode: NO - IBRS: Not disabled on

Hi everyone, Some Intel processors have a newly disclosed vulnerability named Load Value Injection. One pager on Load Value Injection: https://software.intel.com/security-software-guidance/software-guidance/load-value-injection Deep dive on Load Value Injection: https://software.intel.com/security-software-guidance/insights/deep-dive-load-value-injection I wrote this compiler pass that can

Hi I think llvm-dev list (CC'ed) have more visibility in this. On Wed, 22 Apr 2020 at 22:18, milsegv via cfe-dev <cfe-dev at lists.llvm.org> wrote: > Hello everyone, > > It may not be the best place to ask this but I found nothing on the > internet about it. > I'm working on Spectre V1 detection and stumbled upon the mitigation > provided by clang, the

On 08/05/2018 05:54 AM, Michael S. Tsirkin wrote: > On Fri, Aug 03, 2018 at 08:21:26PM -0500, Benjamin Herrenschmidt wrote: >> On Fri, 2018-08-03 at 22:08 +0300, Michael S. Tsirkin wrote: >>>>>> Please go through these patches and review whether this approach broadly >>>>>> makes sense. I will appreciate suggestions, inputs, comments regarding

On 08/05/2018 05:54 AM, Michael S. Tsirkin wrote: > On Fri, Aug 03, 2018 at 08:21:26PM -0500, Benjamin Herrenschmidt wrote: >> On Fri, 2018-08-03 at 22:08 +0300, Michael S. Tsirkin wrote: >>>>>> Please go through these patches and review whether this approach broadly >>>>>> makes sense. I will appreciate suggestions, inputs, comments regarding

On Mon, Aug 06, 2018 at 04:36:43PM +0300, Michael S. Tsirkin wrote: > On Mon, Aug 06, 2018 at 02:32:28PM +0530, Anshuman Khandual wrote: > > On 08/05/2018 05:54 AM, Michael S. Tsirkin wrote: > > > On Fri, Aug 03, 2018 at 08:21:26PM -0500, Benjamin Herrenschmidt wrote: > > >> On Fri, 2018-08-03 at 22:08 +0300, Michael S. Tsirkin wrote: > >

On Mon, Aug 06, 2018 at 04:36:43PM +0300, Michael S. Tsirkin wrote: > On Mon, Aug 06, 2018 at 02:32:28PM +0530, Anshuman Khandual wrote: > > On 08/05/2018 05:54 AM, Michael S. Tsirkin wrote: > > > On Fri, Aug 03, 2018 at 08:21:26PM -0500, Benjamin Herrenschmidt wrote: > > >> On Fri, 2018-08-03 at 22:08 +0300, Michael S. Tsirkin wrote: > >

Hi. Both GCC and clang are adding mitigations for Spectre variant 2 although neither have yet made a release and neither are on by default. After trolling through and building release candidate branches for both I believe this is what is required for the ssh programs (although all the dependent libraries will also need to be built with mitigations, and I suspect libcrypto is a more likely

Hello all, I've been working for the last month or so on a comprehensive mitigation approach to variant #1 of Spectre. There are a bunch of reasons why this is desirable: - Critical software that is unlikely to be easily hand-mitigated (or where the performance tradeoff isn't worth it) will have a compelling option. - It gives us a baseline on performance for hand-mitigation. - Combined