This MR adds support for creating file mapping objects backed by large pages on Linux, by making the following changes:
## wineserver
* On Linux, `create_temp_file` will first attempt to use memfds as the backing fd. If it fails, it'll return to the current codepath, creating a temporary file in either the server or config directory.
* The created memfd will be sealed against writes, if the caller requesting the appropriate page protection flags.
* This removes the requirement that FDs be only created on filesystems/directories that aren't `noexec`.
* In the server method `create_mapping` , if large pages have been requested by the caller, hold that the calling thread's token holds `SeLockMemoryPrivilege` .
* Additionally, add `SeLockMemoryPrivilege` to the list of privileges enabled for the Administrator.
## `ntdll`
* Add `virtual_get_min_large_page_size` and its exported wrapper `wine_unix_get_min_large_page_size`.
* On Linux, the minimum page size is determined by going through `/sys/kernel/mm/hugepages`. If hugepage support was not detected, `STATUS_NOT_SUPPORTED` is returned instead. On other platforms, the older hard-coded value of 2\*1024\*1024 is returned instead.
* `NtCreateSection` will validate certain parameters if large pages are requested. Specifically, it will return STATUS_INVALID_PARAMETER if the requested mapping is not anonymous/unnamed, or the size is not a multiple of the minimum supported page size.
## `kernelbase`
* `GetLargePageMinimum` will use `wine_unix_get_min_large_page_size`.
## `kernel32/tests`
* Add new test test_large_page_file_mapping, which validates privilege enforcements and parameter validation while creating large pages backed file mapping obejcts. The tests are skipped if `GetLargePageMinimum` returns 0.
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v23: ntdll: Use PAGEMAP_SCAN to implement get_working_set_ex, if available.
kernel32: Add tests for large page mapping support.
https://gitlab.winehq.org/wine/wine/-/merge_requests/5769
On Fri Jun 7 14:39:29 2024 +0000, Gabriel Ivăncescu wrote:
> I see, if you look at it that way it makes sense to use IID, yeah (I was
> thinking of the functions as complete separate entities rather than
> interface implementations).
> I still think it's slightly better to just pass/store func_info_t as a
> container though—it's not just the args but everywhere else we need to
> store it (like in ProxyFunction as I mentioned), now it's one less field
> to worry about. And besides, if we ever do need to change it at some
> point later, it will be much easier without affecting call sites.
Current func info is more than (id,iid) carrier, it would only make things more confusing to reuse it as an opaque with constrains like that. We could introduce a new struct, if needed.
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https://gitlab.winehq.org/wine/wine/-/merge_requests/5444#note_73651