Date: Fri, 20 Jan 2023 13:24:41 +0100
To: cygwin@cygwin.com
Subject: Re: Error: child_copy: cygheap read copy failed.
Message-ID: <Y8qICZ6RSub4TJNG@calimero.vinschen.de>
Mail-Followup-To: cygwin@cygwin.com
References: <20230120125633.05136d9ae091b097fc9f9cf5@nifty.ne.jp>
 <Y8p7VR4dXAZZDWmd@calimero.vinschen.de>
 <20230120211820.7e80fa2bf7332b351f3ba2a2@nifty.ne.jp>
MIME-Version: 1.0
Content-Disposition: inline
In-Reply-To: <20230120211820.7e80fa2bf7332b351f3ba2a2@nifty.ne.jp>
UI-OutboundReport: notjunk:1;M01:P0:3NSbmUtgbAE=;WtGcpBFVcr64VGUQEyGCjE7cfCZ
 mryVc9zy0pmh5PKtDzfdQZWiuwr1ggxh3qBy+dvIMyySSMprqGGm82iqzaV/2l33HHsMSP8Ix
 g7jNSZAlWWdLjV/7dWHFlx2pr82HU3jwWLaaQdYRRhdmEi1FsXnMPwZ4oHuBByJ03CGz3EJBG
 2ptQUi69DKdKdiUH1w4V9DEMMpQEi9SJgm4bU47+aRhk7HxwcehkifdXh/Z5qciAkLbs3xXQ9
 n8I3GnLmscwiCMsv/bwqMo51X1UG1ubjUC/G+42B1WKIb03jSqoFe0BuYpO1J2Tjj60F0nbYW
 xpdOgG1CvBR1uMawC/KUer1iPl+u6gQXlv+gofB5672P8l4qlUjwP4HNSnxBB7Z6L63NZr3Ko
 P/09bZ2iEfDv+IaqMEVeEk9KMs7r702IJvqgmccShqPB4BiXrFSWLKEQMAYVCuXjGB+W8pZar
 L6FVUTyaoxc/vSgau38fOXQ6Hgh7TEh67JKts9NzeCy0SErbwFeuN74Rt8G3H4UWcejysx2wD
 ClIpDPcR2p4bhD8cf5jyTP2MTzD6VrUGxr8/0To87DTUbF9qVvXN1A/w+LUBDrB7XJZLRt+pB
 6vmFxpfutSsJWkaEpio3SVvle52EVYWwrBEqrRrTSSMNOIjnnk3rMbbYCCZh2zOR1k47grwTi
 biivIWOBrp/L3ANIBz8y5nxpWFFFCWk4ownBxEBBrQ==
Precedence: list
From: Corinna Vinschen via Cygwin <cygwin@cygwin.com>
Reply-To: cygwin@cygwin.com
Cc: Corinna Vinschen <corinna-cygwin@cygwin.com>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Errors-To: cygwin-bounces+archive-cygwin=delorie.com@cygwin.com
Sender: "Cygwin" <cygwin-bounces+archive-cygwin=delorie.com@cygwin.com>

On Jan 20 21:18, Takashi Yano via Cygwin wrote:
> On Fri, 20 Jan 2023 12:30:29 +0100
> Corinna Vinschen wrote:
> > Also, your ffplay executable isn't high-entropy-VA enabled, by any
> > chance?
> 
> I'm sorry, but the high-entropy-va is ebabled.
> 
> $ peflags -v /usr/bin/ff{mpeg,probe,play}
> /usr/bin/ffmpeg: coff(0x022e[+executable_image,+line_nums_stripped,+local_syms_stripped,+bigaddr,+sepdbg]) pe(0x8160[+high-entropy-va,+dynamicbase,+nxcompat,+tsaware])
> /usr/bin/ffprobe: coff(0x022e[+executable_image,+line_nums_stripped,+local_syms_stripped,+bigaddr,+sepdbg]) pe(0x8160[+high-entropy-va,+dynamicbase,+nxcompat,+tsaware])
> /usr/bin/ffplay: coff(0x022e[+executable_image,+line_nums_stripped,+local_syms_stripped,+bigaddr,+sepdbg]) pe(0x8160[+high-entropy-va,+dynamicbase,+nxcompat,+tsaware])
> 
> peflags -e0 /usr/bin/ff{mpeg,probe,play} solves the issue.
> Thansk!

I'm glad to read that, actually!

> Shoud I remove dynamicbase flag as well?

I did a lot of local testing with ASLR locally, and it's fine for DLLs,
but not so much for the application executable itself.

You can keep dynamicbase for testing, but currently it's not advised
to do so, and you should definitely remove it for distro executables.


Thanks,
Corinna

-- 
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