[Git][wine/wine][master] 2 commits: ntdll: Check for invalid gs_base in the 64-bit segv_handler.

[Alexandre Julliard (＠julliard)]

Alexandre Julliard pushed to branch master at wine / wine

Commits:
94447cee by William Horvath at 2025-08-18T13:10:21+02:00
ntdll: Check for invalid gs_base in the 64-bit segv_handler.

Adapted from check_invalid_gs in signal_i386.c. PE-side code can
manipulate %gs and cause the next call to NtCurrentTeb to segfault, as
the gs_base may be cleared with writes to %gs on x86_64 [1].

This would cause a recursive exception loop, as any PE-side code in the
exception handling chain after the segv_handler would run into the same
problem. So, catch this early, and manually repair the thread's gs_base
with the pthread TEB from the Unix side.

The 32-bit game "Alice: Madness Returns" is one example of this problem
occurring in the real world, when running under WoW64. However, this is
currently handled in Windows under both WoW64 and native 64-bit, so we should
handle both architectures as well.

[1]: https://bugs.winehq.org/show_bug.cgi?id=51152

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=57444

- - - - -
d628a532 by William Horvath at 2025-08-18T13:10:21+02:00
ntdll/tests: Re-enable a previously crashing test.

See https://bugs.winehq.org/show_bug.cgi?id=51152 for the bug
that led to commit 4e4847dd71a3c682356559a51705ccec93b2490e.
We can re-enable the %gs case now, as that no longer causes a crash.

- - - - -

2 changed files:

- dlls/ntdll/tests/exception.c
- dlls/ntdll/unix/signal_x86_64.c

View it on GitLab: https://gitlab.winehq.org/wine/wine/-/compare/e5f591f311812d821f7cf9a27fc4de...