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From: Brian Inglis <Brian.Inglis@Shaw.ca>
To: cygwin-apps@cygwin.com
Subject: Re: [PATCH v2] peflags: add support for IMAGE_DLLCHARACTERISTICS_GUARD_CF
Date: Wed, 19 Apr 2023 09:06:59 -0600	[thread overview]
Message-ID: <a3a37ac6-e258-6cd2-c1b7-f1981fd8e9f3@Shaw.ca> (raw)
In-Reply-To: <CAE6_+Ufxw1J47U+tnhqEN_-xFPGXwwXBjGO4UdEzHvKQ9JXiSA@mail.gmail.com>

On 2023-04-18 10:47, Christoph Reiter wrote:
> On Tue, Apr 18, 2023 at 9:44 AM Corinna Vinschen wrote:
>> Pash pushed.  I new rebase 4.6.3 release with your patch is just
>> building.

Extended DLL Characteristics was added for IBT/CET/CFI and AMD/Intel Shadow 
Stack support has been available since W10 [20]20H1/[20]2004 in a PE Debug 
Directory entry with Debug Type IMAGE_DEBUG_TYPE_EX_DLLCHARACTERISTICS (20.) 
with value IMAGE_DLLCHARACTERISTICS_EX_CET_COMPAT (1)

https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#extended-dll-characteristics

Are there any plans to support those debug directory entries and flags in 
genpeimg and/or peflags, and Windows shadow stack support in mingw64 and/or Cygwin?

The Linux implementation is discussed in https://lwn.net/Articles/883340/ as 
Intel architected the (soon former) Linux CoW PTE bit combo Write 0 Dirty 1 as 
Shadow Stack page flag, possibly anticipating that they could contribute kernel 
patches to work around this more quickly than has transpired.

I got interested in this as I plan to add Linux cpuinfo flag user_shstk, on 
recent CPUs and Windows releases with that support, to next Cygwin cpuinfo patch.

-- 
Take care. Thanks, Brian Inglis              Calgary, Alberta, Canada

La perfection est atteinte                   Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter  not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer     but when there is no more to cut
                                 -- Antoine de Saint-Exupéry

      reply	other threads:[~2023-04-19 15:07 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-17 18:40 Christoph Reiter
2023-04-18  7:44 ` Corinna Vinschen
2023-04-18 16:47   ` Christoph Reiter
2023-04-19 15:06     ` Brian Inglis [this message]

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