Sometimes repairing a broken hive with a hive log does not always guarantee the hive
in question has fully recovered. In worst cases it could happen the LOG itself is even
corrupt too and that would certainly lead to a total unbootable system. This is most likely
if the victim hive is the SYSTEM hive.
This can be anyhow solved by the help of a mirror hive, or also called an "alternate hive".
Alternate hives serve the purpose as backup hives for primary hives of which there is still
a risk that is not worth taking. For now only the SYSTEM hive is granted the right to have
a backup alternate hive.
=== NOTE ===
Currently the SYSTEM hive can only base upon the alternate SYSTEM.ALT hive, which means the
corresponding LOG file never gets updated. When time comes the existing code must be adapted
to allow the possibility to use .ALT and .LOG hives simultaneously.
As we iterate over the chunk hive data pointer for hive bins that we are going
to enlist, we might encounter one or several bins that would get corrupted
during a premature abortion of a registry writing operation such as due to
a power outage of the system, hardware malfunction, etc.
Corruption at the level of hive bins is nasty because they contain actual cell
data of registry information such as keys, values etc. Assuming a bin is corrupt
in part we can fix it by recovering some of the bin properties that, theoretically,
could be fixed -- namely the signature, size and offset.
For size and offset we are more or less safe because a bin typically has a size
of a block, and the offset is the coordinate index of where a hive bin should lay at.
The newly implemented code for registry recovery makes the FreeLdr binary to grow
in size, to the point that it would BSOD because the PE image is too big.
For now we have to temporarily disable any of the newly added code, until
either FreeLdr is split into a basic PE bootloader image itself and a
"FreeLdrlib" that is used by the PE image to access various bootloader APIs
or another proper solution is found.
Thanks to CmCheckRegistry, the function can perform volatile data purging upon boot which this removes old hacky CmPrepareHive code. This also slightly refactors HvInitialize making it more proper.
=== DOCUMENTATION REMARKS ===
This implements (also enables some parts of code been decayed for years) the transacted writing of the registry. Transacted writing (or writing into registry in a transactional way) is an operation that ensures the successfulness can be achieved by monitoring two main points.
In CMLIB, such points are what we internally call them the primary and secondary sequences. A sequence is a numeric field that is incremented each time a writing operation (namely done with the FileWrite function and such) has successfully completed.
The primary sequence is incremented to suggest that the initial work of syncing the registry is in progress. During this phase, the base block header is written into the primary hive file and registry data is being written to said file in form of blocks. Afterwards the seconady sequence
is increment to report completion of the transactional writing of the registry. This operation occurs in HvpWriteHive function (invoked by HvSyncHive for syncing). If the transactional writing fails or if the lazy flushing of the registry fails, LOG files come into play.
Like HvpWriteHive, LOGs are updated by the HvpWriteLog which writes dirty data (base block header included) to the LOG themselves. These files serve for recovery and emergency purposes in case the primary machine hive has been damaged due to previous forced interruption of writing stuff into
the registry hive. With specific recovery algorithms, the data that's been gathered from a LOG will be applied to the primary hive, salvaging it. But if a LOG file is corrupt as well, then the system will perform resuscitation techniques by reconstructing the base block header to reasonable values,
reset the registry signature and whatnot.
This work is an inspiration from PR #3932 by mrmks04 (aka Max Korostil). I have continued his work by doing some more tweaks and whatnot. In addition to that, the whole transaction writing code is documented.
=== IMPORTANT NOTES ===
HvpWriteLog -- Currently this function lacks the ability to grow the log file size since we pretty much lack the necessary code that deals with hive shrinking and log shrinking/growing as well. This part is not super critical for us so this shall be left as a TODO for future.
HvLoadHive -- Currently there's a hack that prevents us from refactoring this function in a proper way. That is, we should not be reading the whole and prepare the hive storage using HvpInitializeMemoryHive which is strictly used for HINIT_MEMORY but rather we must read the hive file block by block
and deconstruct the read buffer from the file so that we can get the bins that we read from the file. With the hive bins we got the hive storage will be prepared based on such bins. If one of the bins is corrupt, self healing is applied in such scenario.
For this matter, if in any case the hive we'll be reading is corrupt we could potentially read corrupt data and lead the system into failure. So we have to perform header and data recovery as well before reading the whole hive.
CmCheckRegistry is a function that provides the necessary validation checks for a registry hive. This function usually comes into action when logs have been replayed for example, or when a registry hive internals have changed such as when saving a key, loading a key, etc.
This commit implements the whole Check Registry infrastructure (cmcheck.c) in CMLIB library for ease of usage and wide accessibility across parts of the OS. In addition, two more functions for registry checks are also implemented -- HvValidateHive and HvValidateBin.
Instead of having the CmCheckRegistry implementation in the kernel, it's better to have it in the Configuration Manager library instead (aka CMLIB). The benefits of having it in the library are the following:
- CmCheckRegistry can be used in FreeLdr to fix the SYSTEM hive
- It can be used on-demand in the kernel
- It can be used for offline registry repair tools
- It makes the underlying CmCheckRegistry implementation code debug-able in user mode
CORE-9195
CORE-6762
This implements cmheal.c file which provides the basic registry self-heal infrastructure needed by the public CmCheckRegistry function. The infrastructure provides a range of various self-heal helpers for the hive, such as subkey, class, values and node healing functions.
Add these NTSTATUS codes in the CMLIB library. STATUS_INVALID_PARAMETER will be used mostly for HvInitialize function, STATUS_REGISTRY_IO_FAILED for whatever routines that deal with reading or writing into a hive file.
=== DOCUMENTATION REMARKS ===
HBOOT_TYPE_REGULAR and HBOOT_TYPE_SELF_HEAL are boot type values set up by the CMLIB library (for the BootType field respectively). HBOOT_TYPE_REGULAR indicates a normal system boot whereas HBOOT_TYPE_SELF_HEAL indicates the system boot is assisted within self healing mode.
Whether the former or the latter value is set it's governed by both the kernel and the bootloader. The bootloader and the kernel negotiate together to determine if any of the registry properties (the hive, the base block, the registry base, etc) are so severed from corruption or not. In extreme cases where
registry healing is possible, the specific base block of the damaged hive will have its flags marked with HBOOT_TYPE_SELF_HEAL. At this point the boot phase procedure is orchestrated since the boot phase no longer goes on the default path but it's assisted, as I have already said above.
HBOOT_NO_BOOT_RECOVER, HBOOT_BOOT_RECOVERED_BY_HIVE_LOG and HBOOT_BOOT_RECOVERED_BY_ALTERNATE_HIVE on the other hand are identifiers for the BootRecover field of the BASE_BLOCK header structure. These are used exclusively by FreeLdr to tell the kernel if the bootloader recovered the SYSTEM hive or not. In case where the bootloader did recover the SYSTEM hive,
the kernel will perform a flush request on the dirty data down to disk. The (almost) worse case FreeLdr could not repair the main hive by applying log data, it will load the alternate mirror version of the hive.
In addition to that, declare other miscellaneous CMLIB identifiers for log transaction writes purposes.
- Uniform function declarations in .c and .h with fixes and SAL2 improvements.
- Use LDR_[UN]LOCK_LOADER_LOCK_FLAG_XXX correctly.
- Fix incorrect UsedSize calculation in LdrQueryProcessModuleInformationEx (caught by ThFabba).
- Whatever the callback request stop the enumeration or not in LdrEnumerateLoadedModules, the following operations should be the same.
- Fix 2 incorrect DPRINT1 that printed incorrect parameter.
- Return error if RtlAllocateHeap failed in LdrpGetProcedureAddress, and add comments about NT6.2 new changes.
This prevents the code from linking to __imp_*, which would pull in the symbol from the import library (e.g. kernel32), which creates problems with the GNU linker, which doesn't like to have the import and a static definition at the same time.
because George is having an open Draft PR since July 2022,
which might also touch this file on master in some years.
And it ofc is easier for me to revert my work now, then for him to
go through the great lengths of merging his work then.
bdasup: Addendum to 40c15ec (r46632).
kmixer: Addendum to 3e489bf (r42143).
mmixer: Addendum to c42d9f2 (r44872).
stream: Addendum to 4a0debf (r41662).
Serge plans a follow up that will remove all other remaining YDEBUG in the source tree.
The ones covered here he considered to be the most trivial ones.
- RtlpQuerySecurityDescriptor: Change argument type of first parameter from PISECURITY_DESCRIPTOR to PSECURITY_DESCRIPTOR, since it handles both absolute and self-relative SDs.
- RtlMakeSelfRelativeSD: rename first parameter from AbsoluteSD to SecurityDescriptor, since it handles both absolute and self-relative SDs.
- SepGetGroupFromDescriptor/SepGetOwnerFromDescriptor/SepGetDaclFromDescriptor/SepGetSaclFromDescriptor: Change parameter type from PVOID to PSECURITY_DESCRIPTOR for clarity.
SpareData and SpareLength need to be calculated correctly, as they are used
later in that function as well.
This allows to not overwrite Source UString when writing to Destination UString.
Fixes the problem described in the following JIRA issue, where services could
not start when installing ReactOS in a very-long-named directory.
CORE-18988
Previously it was in cpprt, which is a support library for C++, containing functions that are not exported by msvcrt. But since Vista __CxxFrameHandler3 is exported by msvcrt. Therefore move it to crt, and to satisfy pre-Vista configurations, also add it to msvcrtex.
Object ACEs are supported starting from Revision 4, the current code checks
if the revision is above Revision 4. An Object ACE has to be strictly set on that revision,
whereas Object ACLs can be of any revision starting from ACL_REVISION4.
Write the necessary ACL validation code for ACEs whose types are ACCESS_ALLOWED_OBJECT_ACE_TYPE
or ACCESS_DENIED_OBJECT_ACE_TYPE. This ensures each created object type ACL has valid ACE
contents.
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=48335
Signed-off-by: Piotr Caban <piotr@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>
wine commit id 6babdb5508bd2f1b659218483f5df76859898712 by Piotr Caban <piotr@codeweavers.com>
Signed-off-by: Piotr Caban <piotr@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>
wine commit id 48a447c5eb238d673ce5db4eeacf3ba4c1a9da90 by Piotr Caban <piotr@codeweavers.com>
