DMARC-Filter: OpenDMARC Filter v1.4.2 delorie.com 61R37AVg1427643
DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org C97E94BA2E10
Message-ID: <3e0de899-a7dd-8fea-7743-10e6b05cc6b6@cs.umass.edu>
Date: Thu, 26 Feb 2026 22:06:43 -0500
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.15.1
Subject: Re: Memmove causing program crashes, giving SIGTRAP in GDB(?)
Content-Language: en-US
To: KENNON J CONRAD <kennonconrad@comcast.net>,
        Dimitry Andric <dimitry@unified-streaming.com>
Cc: KENNON J CONRAD via Cygwin <cygwin@cygwin.com>
References: <547312365.1464244.1771958282029@connect.xfinity.com>
 <aZ7PrbisVR1R4A7v@dimstar.local.net>
 <1670201592.1489273.1772043520008@connect.xfinity.com>
 <e91d8b5b-2690-4271-aa74-e6226440e33d@SystematicSW.ab.ca>
 <1044918836.1507810.1772086967212@connect.xfinity.com>
 <1579472684.1508349.1772092747339@connect.xfinity.com>
 <aaABFf5iEowV1l7I@xps13> <1148572549.1808180.1772097444036@mail.yahoo.com>
 <1901597260.1508573.1772100378936@connect.xfinity.com>
 <0C965DD0-856E-41FF-B5A4-15E472292A32@unified-streaming.com>
 <483908609.1508714.1772103775739@connect.xfinity.com>
 <2346fd41-2500-0db6-5849-6788174b5a1d@cs.umass.edu>
 <1462848037.1521935.1772136952077@connect.xfinity.com>
 <399745a1-429a-ebb4-0f67-c32f6282caa6@cs.umass.edu>
 <1093316506.1533154.1772157883568@connect.xfinity.com>
In-Reply-To: <1093316506.1533154.1772157883568@connect.xfinity.com>
From: Eliot Moss via Cygwin <cygwin@cygwin.com>
Reply-To: Eliot Moss <moss@cs.umass.edu>
Content-Type: text/plain; charset="utf-8"; Format="flowed"
Sender: "Cygwin" <cygwin-bounces~archive-cygwin=delorie.com@cygwin.com>
Content-Transfer-Encoding: 8bit

On 2/26/2026 9:04 PM, KENNON J CONRAD wrote:
> Perhaps something like this?  Maybe I need to try a BIOS update?

Yes, something *like* these flaws.  The thing is to find out if your specific
processor has a flaw that needs an update, etc.

> Intel Haswell (and related architectures) processors may experience stability issues, including machine check errors (MCEs), due to a microcode bug related to REP MOVS (specifically REP MOVSB or REP MOVSQ) handling. These issues often cause system crashes or lockups, leading to microcode, BIOS/UEFI updates to resolve them.
> Debian Wiki
>   +4
> Issue: A high-rate of interrupts or specific memory operations can cause REP MOVS instructions to trigger Machine Check Errors (MCE) or internal errors (IERR) on older processors.
> Affected Processors: The bug primarily impacts older Intel processors, including Haswell and Broadwell architectures.
> Fix/Mitigation: The primary solution is to apply the latest motherboard BIOS/UEFI update, which contains the corrected microcode update (often labelled 20180108 or later).
> Background: This is linked to Intel’s efforts to fix security vulnerabilities (like Spectre), where early patches for Haswell/Broadwell caused unexpected instability, requiring further refinements.
> Debian Wiki
>   +4
> 
> -Kennon

EM


-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple