[Bug 53682] wineboot shows "user_check_not_lock BUG: holding USER lock" on aarch64 since wine-7.14

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=53682

Martin Storsjö  changed:

What    |Removed                     |Added
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--- Comment #7 from Martin Storsjö  ---
FYI I see others mentioning this issue, but I've successfully run most versions
of Wine after 7.14 on aarch64 without problems. I primarily run Wine headless
(with X disabled, built with "--without-freetype --without-x"), but I did a
recent build now with X enabled too, and I can open GUI apps (tested with
explorer.exe) just fine. The mentioned codepaths do get executed in my tests.

I don't quite follow exactly what the issue at hand is - the stack frame of
KeUserModeCallback gets clobbered/overlapped by another stack frame?

Can you provide a patch that adds verbose TRACE messages that show exactly
where this happens, so I can understand why this seems to work fine for me?
(I'm not saying the current code is correct, but I'm curious since I don't run
into the issue.) It's easy to grab the current SP register within functions
with inline assembly snippets like this:

DWORD64 sp;
    __asm__ __volatile__ ("mov %0, sp" : "=r"(sp)); 
    TRACE("sp %llx\n", sp);