Fix DAC stack overflow in GetUsefulGlobals API

[mikem8361]

A typo that caused stack recursion.

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[elinor-fung]

Ack, sorry. Thanks.

[lambdageek]

We may need to backport this to preview 7 @tommcdon @mikem8361 if it's not too late

[tommcdon]

@mikem8361 do our SOS tests hit this code path? Does this affect dump analysis, !analyze? What platforms/architectures are affected?

[mikem8361]

The first thing SOS does for any command is to call this API. Yes, the SOS failed and !analyze will fail even with the new CLRMA code because it calls this API also. All platforms are affected.

[mikem8361]

@leculver, this issue breaks SOS in .NET 9 preview 7. Do you think this is a blocking bug?

[tommcdon]

/backport to release/9.0-preview7

[github-actions]

Started backporting to release/9.0-preview7: https://github.com/dotnet/runtime/actions/runs/10253145361

[leculver]

I don't think this will break standard VS/WinDbg debugging. It will make all Watson/!analyze crashes useless, and it means we won't be able to solve any "real" bugs in Preview 7 if they come up. It's rare that we use Watson for a preview build, and it's rare to get a serious bug in preview that we need to debug via SOS.

So, @tommcdon and folks, it's up to you to do that calculus... Either take this fix for P7, or not be able to debug any potential serious issue that requires SOS without a lot of work. (We can work around this if needed for a single crash dump, but it's time consuming and super annoying. We can't work around this for Watson/!analyze, they will need a fix or be broken for this preview.)