On 3/21/2024 11:15 AM, Corinna Vinschen via Cygwin wrote:
On Mar 21 09:58, Christian Franke via Cygwin wrote:
Corinna Vinschen via Cygwin wrote:
On Mar 20 12:39, Christian Franke via Cygwin wrote:
Corinna Vinschen via Cygwin wrote:
You have to create an application with an application manifest not
supporting your OS.
For Cygwin apps, this occured when you built, say, an executable under
Windows 8.1 before Windows 10 support was added to the Cygwin toolchain:
the manifest linked to the Cygwin executable didn't yet contain a GUID
entry for Windows 10 support.
In this case, RtlGetVersion returns an OS version 6.3 even when running
under the 10.0 kernel. This behaviour exists back 'til Windows Vista.
Could not reproduce the latter on Win10. I tested with recent Win10 and
Win11 and also found a Win10 1511 (and Slackware 1.1.2, Win3.1, OS/2, ...)
in my VM image museum.
Regardless of the exe manifest, RtlGetVersion and RtlGetNtVersionNumbers
return the correct versions:
10.0.22621 (Win11 22H2)
10.0.19045 (Win10 22H2)
10.0.10586 (Win10 1511)
Without a manifest, GetVersionEx returns:
6.2.9200 (Win8)
I just gave it a try on W11. The results are even more funny than I
anticipated:
I created a simple application just calling GetVersionEx, RtlGetVersion
and RtlGetNtVersionNumbers.
Linked with our Cygwin default manifest claiming W10 compatibility, the
result is the expected:
GetVersionEx : 10.0.22631
RtlGetVersion : 10.0.22631
RtlGetNtVersionNumbers: 10.0.22631
The "Operating system context" in Task Manager is empty.
Next I linked against a Windows 8.1 manifest:
GetVersionEx : 6.3.9600
RtlGetVersion : 10.0.22631
RtlGetNtVersionNumbers: 10.0.22631
So GetVersionEx reports Windows 8.1, RtlGetVersion/ RtlGetNtVersionNumbers
both report W10. The "Operating system context" in Task Manager reports
"Windows 8.1"
No surprise there.
Next I linked against a Windows 7 manifest:
GetVersionEx : 6.2.9200
RtlGetVersion : 10.0.22631
RtlGetNtVersionNumbers: 10.0.22631
So GetVersionEx reports Windows 8, not Windows 7.
However, the "Operating system context" in Task Manager reports
"Windows 7"
I also tried this with a Vista manifest:
GetVersionEx : 6.2.9200
RtlGetVersion : 10.0.22631
RtlGetNtVersionNumbers: 10.0.22631
"Windows Vista"
So Task Manager reports the right context per the manifest, but
GetVersionEx doesn't go below Windows 8.
Same goes for Windows 10...
GetVersionEx : 6.2.9200
RtlGetVersion : 10.0.19045
RtlGetNtVersionNumbers: 10.0.19045
"Windows Vista"
as well as for Windows 8.1:
GetVersionEx : 6.2.9200
RtlGetVersion : 6.3.9600
RtlGetNtVersionNumbers: 6.3.9600
"Windows Vista"
So, yeah, with your observations especially on older W10 versions and
with 8.1 doing the same thing, I guess we can safely drop the extra call
to RtlGetNtVersionNumbers now. After such a long time, I don't know
on which version of Windows we observed the problem.
For those interested in patch forensics, I searched the archives and
came up with two mail threads referring to GetVersionEx and RtlGetVersion:
https://cygwin.com/pipermail/cygwin/2013-November/211795.html
https://cygwin.com/pipermail/cygwin/2014-June/215836.html
Unfortunately I found*no* thread talking about RtlGetNtVersionNumbers,
so the only information we have now is the commit message of
https://cygwin.com/cgit/newlib-cygwin/commit/?id=48511f3d3847c
The code in that commit doesn't look right. RtlGetNtVersionNumbers is a
void function and the third parameter may not be just the build number.
The first two parameters are sort of known because the CRT used to use
it to get the major and minor version but passed NULL for the third
parameter.
typedef void (__stdcall *NTVERSION_INFO_FCN)(PDWORD, PDWORD, PDWORD);
I assume that it contains at least the build number and type (production
or checked), according to a blog post discussing it [1].
Here's results from a test program [2] with manifest on Windows 11:
>test-RtlGetNtVersionNumbers.exe
GetVersionExW: 10.0.22000
RtlGetVersion: 10.0.22000
RtlGetNtVersionNumbers: 10 major, 0 minor, 4026553840 unknown
LOWORD of unknown: 22000 (0x55f0)
HIWORD of unknown: 61440 (0xf000)
[1]:
https://dennisbabkin.com/blog/?t=how-to-tell-the-real-version-of-windows-your-app-is-running-on
[2]: https://gist.github.com/jay/ae07fba61fe6853f5620eb142c66807b
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