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
This reverts commit e1a45a2720, reversing
changes made to bd7edd8651.
The change rendered pressure-vessel non-functional on muvm-based setups
like Fedora Asahi Remix.
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.
We don't need to be informed of our own mappings, avoids a deadlock that
occurs if the ThreadCreationMutex lifetime is extended when creating a
thread.
Consider a page with two blocks in it, A and B. Block A performs SMC on B then A.
With the previous logic, the SMC write of B would unprotect the page and then
the inline SMC touching A would not be detected and a single-step would not be forced.
Rather than relying on wine-specific alphabetical behaviour, that
has since been changed. Rely on their addresses being sorted which
is more stable behaviour also present in Windows.
Billy Laws