[reactos] 07/09: [NTOS:CM] Simplify CmpGetRegistryPath to avoid unnecessary stack buffers. CORE-15882

[Thomas Faber]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=047a3bf79ab21d84fb480d...

commit 047a3bf79ab21d84fb480d8df99dd087aca97976
Author:     Thomas Faber [e-mail]
AuthorDate: Wed Apr 17 10:25:52 2019 +0200
Commit:     Thomas Faber [e-mail]
CommitDate: Sun May 5 10:39:22 2019 +0200

[NTOS:CM] Simplify CmpGetRegistryPath to avoid unnecessary stack buffers. CORE-15882
---
 ntoskrnl/config/cmsysini.c | 30 ++++++++++++------------------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/ntoskrnl/config/cmsysini.c b/ntoskrnl/config/cmsysini.c
index d672ead8c2..c773f1f569 100644
--- a/ntoskrnl/config/cmsysini.c
+++ b/ntoskrnl/config/cmsysini.c
@@ -1166,32 +1166,24 @@ CmpCreateRegistryRoot(VOID)
     return TRUE;
 }

-static NTSTATUS
-CmpGetRegistryPath(OUT PWCHAR ConfigPath)
+static PCWSTR
+CmpGetRegistryPath(VOID)
 {
-    /* Just use default path */
-    wcscpy(ConfigPath, L"\SystemRoot");
+    PCWSTR ConfigPath;

/* Check if we are booted in setup */
     if (!ExpInTextModeSetup)
     {
-        /* Add registry path */
-#if 0
-        ResultSize = wcslen(ConfigPath);
-        if (ResultSize && ConfigPath[ResultSize - 1] == L'\')
-            ConfigPath[ResultSize - 1] = UNICODE_NULL;
-#endif
-        wcscat(ConfigPath, L"\System32\Config\");
+        ConfigPath = L"\SystemRoot\System32\Config\";
     }
     else
     {
-        wcscat(ConfigPath, L"\");
+        ConfigPath = L"\SystemRoot\";
     }

DPRINT1("CmpGetRegistryPath: ConfigPath = '%S'\n", ConfigPath);

-    /* Done */
-    return STATUS_SUCCESS;
+    return ConfigPath;
 }

_Function_class_(KSTART_ROUTINE)
@@ -1199,7 +1191,8 @@ VOID
 NTAPI
 CmpLoadHiveThread(IN PVOID StartContext)
 {
-    WCHAR FileBuffer[MAX_PATH], RegBuffer[MAX_PATH], ConfigPath[MAX_PATH];
+    WCHAR FileBuffer[MAX_PATH], RegBuffer[MAX_PATH];
+    PCWSTR ConfigPath;
     UNICODE_STRING TempName, FileName, RegName;
     ULONG i, ErrorResponse, WorkerCount, Length;
     USHORT FileStart;
@@ -1222,7 +1215,7 @@ CmpLoadHiveThread(IN PVOID StartContext)
     RtlInitEmptyUnicodeString(&RegName, RegBuffer, sizeof(RegBuffer));

/* Now build the system root path */
-    CmpGetRegistryPath(ConfigPath);
+    ConfigPath = CmpGetRegistryPath();
     RtlInitUnicodeString(&TempName, ConfigPath);
     RtlAppendUnicodeStringToString(&FileName, &TempName);
     FileStart = FileName.Length;
@@ -1364,7 +1357,8 @@ VOID
 NTAPI
 CmpInitializeHiveList(VOID)
 {
-    WCHAR FileBuffer[MAX_PATH], RegBuffer[MAX_PATH], ConfigPath[MAX_PATH];
+    WCHAR FileBuffer[MAX_PATH], RegBuffer[MAX_PATH];
+    PCWSTR ConfigPath;
     UNICODE_STRING TempName, FileName, RegName;
     HANDLE Thread;
     NTSTATUS Status;
@@ -1381,7 +1375,7 @@ CmpInitializeHiveList(VOID)
     RtlInitEmptyUnicodeString(&RegName, RegBuffer, sizeof(RegBuffer));

/* Now build the system root path */
-    CmpGetRegistryPath(ConfigPath);
+    ConfigPath = CmpGetRegistryPath();
     RtlInitUnicodeString(&TempName, ConfigPath);
     RtlAppendUnicodeStringToString(&FileName, &TempName);