- Stay attached while deleting the VAD node
- Acquire the appropriate working set lock when deleting a VAD node
- Both are needed for locking correctness
- Acquire the appropriate working set lock when calling MmLocateMemoryAreaByAddress
- Do not access MemoryArea without holding the lock (otherwise it can be pulled away under our feet)
- Fix range check for paged pool
These faults are handled by ARM³ and we don't need to check for a memory area. They can be recursive faults (e.g. from MiDeleteSystemPageableVm), so we might be holding the WS lock already. Passing it straight to ARM³ allows to acquire the WS lock below to look up the memory area.
This is a hack, because the kernel mode path can incur a recursive page fault with the AddressCreationLock acquired, which would lead to a recursive acquisition, once we do proper locking in MmAccessFault.
To properly fix this the PDE must be made valid, similar to the user mode path, but that is not that simple...
The code was passing 0 instead of SECTION_INHERIT::ViewUnmap (2). 0 isn't even a proper constant to be used here. It worked, because MmMapViewOfSection only compares against ViewShare (1) and treats everything else as ViewUnmap.
Now that the Memory Management is a bit more under control again,
and branching releases/0.4.15 is near,
do mute some frequent log-spam that got introduced during 0.4.15-dev'ing
regarding lazy-flushes and MM balancing.
It frequently logged even while being idle.
Slightly improve the headers of the two touched files.
No rocket-science.
As it turns out, those three functions were duplicating the same code
between each other. Reimplement these in terms of a common helper,
RtlFindExportedRoutineByName().
Indeed: MiFindExportedRoutineByName() was just MiLocateExportName()
but taking a PANSI_STRING instead of a NULL-terminated string.
A similar state of affairs also existed in Windows <= 2003, and the
MS guys also noticed it. Both routines have been then merged and renamed
to MiFindExportedRoutineByName() on Windows 8 (taking a PCSTR instead),
and finally renamed and exported as RtlFindExportedRoutineByName()
on Windows 10.
It was implemented in psmgr.c but in a recursive way. That implementation
is replaced, in the NameToOrdinal() helper, by the better non-recursive one
found in the MiLocateExportName() and MiFindExportedRoutineByName() functions.
This NameToOrdinal() helper is then called in lieu of the duplicated code
in MiLocateExportName() and MiFindExportedRoutineByName(). In addition,
one block of code in MiSnapThunk() is simplified in a similar manner.
MmGetSectionAssociation races with _MmSetPageEntrySectionSegment without sharing a lock. So we need to hold the PFN lock, until we have referenced the section segment found in the RMAP. This prevents that a section segment, which still has associated RMAPs from being deleted behind our back.
These are used in the paging path, when the page is currently in the process of being read from or written to the disk. While YieldProcessor() provides the chance to switch context to the other paging thread, it only does so, once the current thread's quantum has expired. On a single CPU system this effectively leads to busy waiting for the rest of the quantum. On SMP systems this could succeed earlier, thus reducing latency, but it would still contribute to high CPU usage, while waiting for the IO operation to complete, which is not what we want.
Using KeDelayExecutionThread() will instantly allow another thread to run, providing enough time to complete the IO operation.
Second parameter is optional, so mark it as such and check whether it was passed. Fixes a sporadic 0x24 bugcheck caused by access violation when running ReactOS on NTFS volume with WinXP ntfs.sys.
CORE-17627
When closing a file, fastfat zeroes it out from ValidDataLength up to the end of the file.
The ValidDataLength field is updated when the file content is actually written to disk.
There is currently a race between the file-close path and the page out path, leading to potential file corruptions when the zeroing happens after the memory has been flushed to disk.
Fix this by actually flushing the file to disk when unmapping files, with file lock acquired. This way, the FS driver cannot zero out the tail of the file while we're actually flushing it to disk.
MmLoadSystemImage has a PUNICODE_STRING NamePrefix parameter which is
currently unused in ReactOS. When the kernel loads the crash dump
storage stack drivers, the drivers will be loaded with MmLoadSystemImage
with a "dump_" or "hiber_" (for hibernation, which uses crash dump
stack too) prefix. This change adds in the prefix support, and is
supposed to push crash dump support forward.
CORE-376
What we have:
- Maximum number of pagefiles: 16
- Minimum pagefile size: 256 pages (1 MB when page size = 4096 bytes)
- Maximum pagefile size:
* 32-bit platforms: (1024 * 1024 - 1) pages (~ 4095 MB)
* x86 with PAE support: same size as for AMD x64
* x64 platform: (4 * 1024 * 1024 * 1024 - 1) pages (~ 16 TB)
* IA64 platform: (8 * 1024 * 1024 * 1024 - 1) pages (~ 32 TB)
Those are the values as supported and verified by the NT kernel.
Now, user-mode programs (including SMSS.EXE) have different opinions
on these, namely, they consider estimates directly in MB, respectively:
4095 MB, (16 * 1024 * 1024) MB, and (32 * 1024 * 1024) MB
(verified on Win2k3 and Win7 32 and 64 bits).
Also here, the minimum pagefile size is set to 2 MB.
Starting Windows 8+ (and 10), those values change slightly, and are
still not fully synchronized between NTOS:MM and SMSS. Finally, while
(x86 PAE and) AMD64 and ARM64 seem to share the maximum pagefile
size limit, 32-bit ARMv7 appears to use different limits than regular
x86 (2 GB instead of 4).
Please keep those values as they are for NT compatibility!
See the following references:
https://www.geoffchappell.com/studies/windows/km/ntoskrnl/api/mm/modwrite/create.htmhttps://techcommunity.microsoft.com/t5/ask-the-performance-team/what-is-the-page-file-for-anyway/ba-p/372608
+ Manual extraction of the values from different NT 6.2,6.3,10 builds.
[SMSS] Fill out in particular the x86-specific case for PAE.
[NTOS:MM] Some cleanup in the NtCreatePagingFile() code, namely:
- Clarify some comments;
- Validate the lower and upper bounds of the Minimum and Maximum sizes
(based on Windows behaviour as explained by Geoff + manual tests).
- Open the pagefile in case-insensitive;
- Simplify the loop that finds an existing matching pagefile;
- Simplify some failure exit paths;
- Add a "Missing validation steps TODO" comment block explaining the
existing code-hole.
