There are still some other issues not addressed here, but it's a start.
Workarounds for false-positive reports:
- `RasterizerAccelerated`: Put a gigantic array behind a `unique_ptr`,
because UBSan has a [hardcoded limit](https://stackoverflow.com/questions/64531383/c-runtime-error-using-fsanitize-undefined-object-has-a-possibly-invalid-vp)
of how big it thinks objects can be, specifically when dealing with
offset-to-top values used with multiple inheritance. Hopefully this
doesn't have a performance impact.
- `QueryCacheBase::QueryCacheBase`: Avoid an operation that UBSan thinks
is UB even though it at least arguably isn't. See the link in the
comment for more information.
Fixes for correct reports:
- `PageTable`, `Memory`: Use `uintptr_t` values instead of pointers to
avoid UB from pointer overflow (when pointer arithmetic wraps around
the address space).
- `KScheduler::Reload`: `thread->GetOwnerProcess()` can be `nullptr`;
avoid calling methods on it in this case. (The existing code returns
a garbage reference to a field, which is then passed into
`LoadWatchpointArray`, and apparently it's never used, so it's
harmless in practice but still triggers UBSan.)
- `KAutoObject::Close`: This function calls `this->Destroy()`, which
overwrites the beginning of the object with junk (specifically a free
list pointer). Then it calls `this->UnregisterWithKernel()`. UBSan
complains about a type mismatch because the vtable has been
overwritten, and I believe this is indeed UB. `UnregisterWithKernel`
also loads `m_kernel` from the 'freed' object, which seems to be
technically safe (the overwriting doesn't extend as far as that
field), but seems dubious. Switch to a `static` method and load
`m_kernel` in advance.
This is a deviation from the reference time zone implementation. The
actual code will set a pointer to the time zone name here, but for us we
have a limited number of characters to work with, and the name of the
time zone here could be larger than 8 characters.
We can make the assumption that time zone names greater than five
characters in length include a comma that denotes more data. Nintendo
just truncates that data for the name, so we can do the same.
time_zone_manager: Check for length of array
Just to be double sure that we never break past the array length,
directly compare against it.
Reference implementation does not compare the booleans as we had them.
Use the correct ones as in the reference.
Also adds an assert. I have been made aware of a crash here and am
not able to reproduce currently.
Previously, we were mixing the raw CPU frequency and CNTFRQ.
The raw CPU frequency (1020 MHz) should've never been used as CNTPCT (whose frequency is CNTFRQ) is the only counter available.
This causes the emulated system's universal time to be on the user's clock, and the user time to
be off if they set a time zone.
time_manager: Remove GetExternalRtcTime
Uses C++20 tzdb to determine the system timezone. The switch uses the
597 posix time zones, so this needs tests if the system time zone isn't
posix-compliant.
