[ros-diffs] [reactos] 04/11: [NTOS:CM] Add KCB array lock function prototypes & Other Stuff

[George Bișoc]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=c6230ba2553fad585a096…

commit c6230ba2553fad585a096dc8c24ca8c7c1573163
Author:     George Bișoc <george.bisoc(a)reactos.org>
AuthorDate: Thu Feb 16 20:25:10 2023 +0100
Commit:     George Bișoc <george.bisoc(a)reactos.org>
CommitDate: Sun Oct 1 20:06:01 2023 +0200

    [NTOS:CM] Add KCB array lock function prototypes & Other Stuff
    
    Implement CmpBuildAndLockKcbArray and CmpUnLockKcbArray prototypes, we'll gonna
need these
    to do the locking/unlocking of KCBs stacked up in an array. In addition implement some
CM
    constructs specifically for cache lookup implementation (more at documentation
remarks).
    
    === DOCUMENTATION REMARKS ===
    
    CMP_SUBKEY_LEVELS_DEPTH_LIMIT -- This is the limit of up to 32 subkey levels
    that the registry can permit. This is used in CmpComputeHashValue to ensure
    that we don't compute more than the limit of subkeys we're allowed to.
    
    CMP_KCBS_IN_ARRAY_LIMIT -- This is equal to CMP_SUBKEY_LEVELS_DEPTH_LIMIT
    plus the addition by 2. This construct is used as a limit of KCB elements
    the array can hold. 2 serves as an additional space for the array (one for
    the root object and another one as extra space so we don't blow up the stack
    array).
    
    CMP_LOCK_KCB_ARRAY_EXCLUSIVE & CMP_LOCK_KCB_ARRAY_SHARED -- These flags are used
exclusively
    for CmpBuildAndLockKcbArray and CmpLockKcbArray. Their meaning are obvious.
    
    CM_HASH_CACHE_STACK -- A structure used to store the hashes of KCBs for locking. It is
named
    "stack" because the way we store the hashes of KCBs is within an auxilliary
"outer stack array".
---
 ntoskrnl/include/internal/cm.h | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/ntoskrnl/include/internal/cm.h b/ntoskrnl/include/internal/cm.h
index 423c65b9a8d..da8bad2dbd0 100644
--- a/ntoskrnl/include/internal/cm.h
+++ b/ntoskrnl/include/internal/cm.h
@@ -95,6 +95,12 @@
 #define CMP_ENLIST_KCB_LOCKED_SHARED                    0x1
 #define CMP_ENLIST_KCB_LOCKED_EXCLUSIVE                 0x2
 
+//
+// CmpBuildAndLockKcbArray & CmpLockKcbArray Flags
+//
+#define CMP_LOCK_KCB_ARRAY_EXCLUSIVE                    0x1
+#define CMP_LOCK_KCB_ARRAY_SHARED                       0x2
+
 //
 // Unload Flags
 //
@@ -119,6 +125,12 @@
 #define CM_DELAYS_PER_PAGE                              \
     ((PAGE_SIZE - FIELD_OFFSET(CM_ALLOC_PAGE, AllocPage)) / sizeof(CM_DELAY_ALLOC))
 
+//
+// Cache Lookup & KCB Array constructs
+//
+#define CMP_SUBKEY_LEVELS_DEPTH_LIMIT   32
+#define CMP_KCBS_IN_ARRAY_LIMIT         (CMP_SUBKEY_LEVELS_DEPTH_LIMIT + 2)
+
 //
 // Value Search Results
 //
@@ -402,6 +414,15 @@ typedef struct _HIVE_LIST_ENTRY
     BOOLEAN Allocate;
 } HIVE_LIST_ENTRY, *PHIVE_LIST_ENTRY;
 
+//
+// Hash Cache Stack
+//
+typedef struct _CM_HASH_CACHE_STACK
+{
+    UNICODE_STRING NameOfKey;
+    ULONG ConvKey;
+} CM_HASH_CACHE_STACK, *PCM_HASH_CACHE_STACK;
+
 //
 // Parse context for Key Object
 //
@@ -993,6 +1014,23 @@ DelistKeyBodyFromKCB(
     IN BOOLEAN LockHeld
 );
 
+VOID
+NTAPI
+CmpUnLockKcbArray(
+    _In_ PULONG LockedKcbs
+);
+
+PULONG
+NTAPI
+CmpBuildAndLockKcbArray(
+    _In_ PCM_HASH_CACHE_STACK HashCacheStack,
+    _In_ ULONG KcbLockFlags,
+    _In_ PCM_KEY_CONTROL_BLOCK Kcb,
+    _Inout_ PULONG OuterStackArray,
+    _In_ ULONG TotalRemainingSubkeys,
+    _In_ ULONG MatchRemainSubkeyLevel
+);
+
 VOID
 NTAPI
 CmpAcquireTwoKcbLocksExclusiveByKey(
@@ -1084,6 +1122,7 @@ CmpCreateLinkNode(
     IN PHHIVE Hive,
     IN HCELL_INDEX Cell,
     IN PACCESS_STATE AccessState,
+    IN PULONG KcbsLocked,
     IN UNICODE_STRING Name,
     IN KPROCESSOR_MODE AccessMode,
     IN ULONG CreateOptions,