Re: [PATCH v2 0/1] MR4834: ntdll: NtQuerySystemInformation(SystemProcessorPerformanceInformation) fix return value

[Dāvis Mosāns (davispuh) (＠davispuh)]

On Tue Jan 23 13:57:14 2024 +0000, Fabian Maurer wrote:
> It copies but then gives `STATUS_INFO_LENGTH_MISMATCH`? And returning
> `STATUS_ACCESS_VIOLATION` has priority over `STATUS_INFO_LENGTH_MISMATCH`?
> Not saying you're wrong, just wondering. Would you mind adding tests for that?

This is current behavior on Windows 10 22H2:
```
 NULL buffer and size = 0 -> STATUS_INFO_LENGTH_MISMATCH, ReturnLength=cpus*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION)
 NULL buffer and size > 0 -> STATUS_ACCESS_VIOLATION,     ReturnLength=0
valid buffer and size = 0 -> STATUS_INFO_LENGTH_MISMATCH, ReturnLength=cpus*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION)
valid buffer and size > 0 -> STATUS_INFO_LENGTH_MISMATCH, ReturnLength=cpus*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION)
valid buffer and size <    1*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION) -> STATUS_INFO_LENGTH_MISMATCH, ReturnLength=cpus*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION)
valid buffer and size =    1*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION) -> STATUS_SUCCESS,              ReturnLength=   1*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION)
valid buffer and size >    1*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION) -> STATUS_INFO_LENGTH_MISMATCH, ReturnLength=cpus*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION)
valid buffer and size =    2*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION) -> STATUS_SUCCESS,              ReturnLength=   2*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION)
valid buffer and size < cpus*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION) -> STATUS_INFO_LENGTH_MISMATCH, ReturnLength=cpus*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION)
valid buffer and size = cpus*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION) -> STATUS_SUCCESS,              ReturnLength=cpus*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION)
valid buffer and size > cpus*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION) -> STATUS_INFO_LENGTH_MISMATCH, ReturnLength=cpus*sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION)
```

Wine has few differences regarding this but here this MR fixes only single case
```
size % sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION) -> STATUS_SUCCESS
```

Handling of `STATUS_ACCESS_VIOLATION` and `ReturnLength` is not changed.

And regarding test, actually Wine already has such test, see [info.c#752](https://gitlab.winehq.org/wine/wine/-/blob/master/dlls/ntdll/tests/info.c?re...)
```c
ok( status == STATUS_SUCCESS || status == STATUS_INFO_LENGTH_MISMATCH /* vista */,
        "Expected STATUS_SUCCESS or STATUS_INFO_LENGTH_MISMATCH, got %08lx\n", status);

```
It looks like before Vista it returned `STATUS_SUCCESS` which is current Wine implementation, but since Vista it started to return `STATUS_INFO_LENGTH_MISMATCH` instead