Allows WTF to work (mostly) with Wine by letting us VirtualName things,
and also allows madvise control of THP, which significantly cuts back
memory usage.
This works around the problem of Wine not giving us control of this by
using raw syscalls when wine is detected.
Based on top of #5362 so the THP disable controls are in.
Prevent suspension when flushing thread state to the WOW64 context
during BTCpuSetContext as suspension itself performs a flush. If
suspension were to occur halfway through FlushThreadStateContext then
the fact that the WOW64 context has been dirtied would be missed and the
new context would be partially overwritten with stale data from the FEX
thread state. Additionally if the context were to be dirtied by
suspension at any point during context merging in BTCpuSetContext the
input context could be lost.
Fixes occasional crashes when starting AC4.
Handling this safely requires blocking all compilation for the duration
of the read, as fault-based tracking doesn't work when wine's unix side
itself is the one performing the write into the RWX region (we cannot
catch unix faults).
Fixes a startup crash in Persona 5.
We have run out of EmulatorData slots on ARM64EC, so introduce this for
less-frequently accessed TLS data for which the additional cost doesn't
matter.
Windows will populate Size/Address with those of the underlying free
region. This is important for cross-process free operations, where the
the 'before' callback is still called after the memory is freed so
querying the size of the section (which is not freed) fails.
When the JIT CodeBuffer overflows, we will now catch accesses to the
guard page and longjump while restarting the JIT with a larger buffer
request.
Fixes#4877
If called back-to-back, the compiler can't optimize the object creation
resulting in multiple indirections. Save the creation and pass it
around, allowing the compiler to merge loadstores, and remove redundant
loads.
NFC
Only wired up for wow64 and arm64ec. Gives more granular control over
TSO enabling and disabling. Matches arm64ec volatile metadata except
with one more additional feature that whole modules can be disabled at a
time.
Once we know the mapped size of files in Linux then we'll be able to do
the same thing there, but there's not a full mechanism wired up for that
yet.
Taking this very slowly because this is very fickle code. The frontend
needs to manage GDT and LDT, but before we get there, we need to
actually add support for LDT in the backend. Split the segments to two
arrays so the JIT can actually update their cached values correctly.
Still treats GDT and LDT as mirrors like how the JIT previously did (By
it ignoring the selector's TI bit).
While most applications will just create ALL_ACCESS handles which
support the additional operations FEX needs over the regular windows syscall
(usually just QUERY_INFORMATION to lookup the thread object), it is
valid for them to pass in the minimal set required for each operation
and windows/wine will reject any other operations (e.g. querying the TEB
base on a handle with only the SUSPEND right). Windows permits
duplicating handles to extend their permissions given the process itself
has such permissions, so do that as necessary for the operations FEX
needs.
In the terminate case, if we don't return early then we will delete the
FEX thread object but the actual terminate call that follows will
fail, leaving the thread in a bad state.
Ryan Houdek