The PR #6649 which fixed an issue with orphaned KCBs leaking in memory which also pointed to unloaded registry hives, it also brought a problem.
In CmpEnumerateOpenSubKeys there is a risk of getting hit by a deadlock as we enumerate the cache table to remove empty cache entries.
Fundamentally CmpEnumerateOpenSubKeys locks down a KCB from cache for exclusive use in order to tear down its contents from memory but it doesn't address the fact a KCB might have already been locked in the same calling thread, leading to a recursion.
This leads to random hangs when unloading a hive during system startup (tipically on a clean install).
The solution here is to simply lock the whole registry when we unload a hive so that we don't have to worry the KCBs are getting tampered by anybody else. This also simplifies the code.
Although locking the entire registry while other apps are doing registry related operations to other hives can cause overhead. If this turns out to be bad then we have to rethink the locking mechanism here.
CORE-19539
- Annotate the CmpEnumerateOpenSubKeys function with SAL2
- When removing an orphaned cached KCB, ensure that it is locked before clearing it from cache table entries
In particular remove some extra-parentheses around single code tokens,
and replace few "DPRINT1 + while (TRUE);" by UNIMPLEMENTED_DBGBREAK.
+ Improve some comments.
Probe the data before allocating a copy buffer. Otherwise NtSetValueKey returns an unexpected status code in case of too large data size.
This fixes the NtSetValueKey ntdll api tests.
- Rework CmpSetSystemValues() and remove its 1st-stage text-mode setup hack, since a real registry hive will be used for 1st-stage either.
- Lock, then unlock the registry in NtInitializeRegistry when initializing the hives & flusher.
- Call CmpInitializeHiveList() (i.e., initialize the other hives like \Software, \User, \.Default) only when we are not in setup-mode.
svn path=/branches/setup_improvements/; revision=74747
- Improve the capture of OBJECT_ATTRIBUTES parameters that are passed
(by pointer) to the Cm* helper functions, and the capture of
UNICODE_STRINGs.
- Correctly differentiate user-mode vs. kernel-mode root directory handles
(in OBJECT_ATTRIBUTES): note that most of the Cm* APIs expect their
parameters to be kernel-mode (pointers, handles...).
CORE-13448
- Validate the information class parameter in NtQueryValueKey().
- Call the post-callback in NtSetValueKey() only if the callback
has been registered and the CmSetValueKey() call is executed.
