[PATCH 2/2] kernelbase: Use ProcessImageFileNameWin32 in GetModuleFileNameExW.

[Jacek Caban]

From: Jacek Caban

Allows retrieving the process image name even if the process has not yet completed loader initialization.

Fixes LLDB versions newer than 15.

LLVM-Issue: https://github.com/llvm/llvm-project/issues/131319
---
 dlls/kernelbase/debug.c       | 50 ++++++++++++++++++++++++-----------
 dlls/psapi/tests/psapi_main.c | 25 ++++++++++++++++--
 2 files changed, 57 insertions(+), 18 deletions(-)

diff --git a/dlls/kernelbase/debug.c b/dlls/kernelbase/debug.c
index 5e3b46f11e7..7143a69c367 100644
--- a/dlls/kernelbase/debug.c
+++ b/dlls/kernelbase/debug.c
@@ -1501,29 +1501,47 @@ DWORD WINAPI DECLSPEC_HOTPATCH GetModuleFileNameExW( HANDLE process, HMODULE mod

if (!size) return 0;

-    if (!IsWow64Process( process, &wow64 )) return 0;
-
-    if (is_win64 && wow64)
+    if (module)
     {
-        LDR_DATA_TABLE_ENTRY32 ldr_module32;
+        if (!IsWow64Process( process, &wow64 )) return 0;

-        if (get_ldr_module32( process, module, &ldr_module32 ))
+        if (is_win64 && wow64)
         {
-            len = ldr_module32.FullDllName.Length / sizeof(WCHAR);
-            if (ReadProcessMemory( process, (void *)(DWORD_PTR)ldr_module32.FullDllName.Buffer,
-                                   name, min( len, size ) * sizeof(WCHAR), NULL ))
-                found = TRUE;
+            LDR_DATA_TABLE_ENTRY32 ldr_module32;
+
+            if (get_ldr_module32( process, module, &ldr_module32 ))
+            {
+                len = ldr_module32.FullDllName.Length / sizeof(WCHAR);
+                if (ReadProcessMemory( process, (void *)(DWORD_PTR)ldr_module32.FullDllName.Buffer,
+                                       name, min( len, size ) * sizeof(WCHAR), NULL ))
+                    found = TRUE;
+            }
+        }
+        if (!found)
+        {
+            LDR_DATA_TABLE_ENTRY ldr_module;
+
+            if (!get_ldr_module(process, module, &ldr_module)) return 0;
+            len = ldr_module.FullDllName.Length / sizeof(WCHAR);
+            if (!ReadProcessMemory( process, ldr_module.FullDllName.Buffer,
+                                    name, min( len, size ) * sizeof(WCHAR), NULL ))
+                return 0;
         }
     }
-    if (!found)
+    else
     {
-        LDR_DATA_TABLE_ENTRY ldr_module;
+        BYTE buffer[sizeof(UNICODE_STRING) + MAX_PATH*sizeof(WCHAR)];  /* this buffer should be enough */
+        void *dynamic_buffer = NULL;
+        UNICODE_STRING *result;
+        NTSTATUS status;

-        if (!get_ldr_module(process, module, &ldr_module)) return 0;
-        len = ldr_module.FullDllName.Length / sizeof(WCHAR);
-        if (!ReadProcessMemory( process, ldr_module.FullDllName.Buffer,
-                                name, min( len, size ) * sizeof(WCHAR), NULL ))
-            return 0;
+        status = get_process_image_file_name( process, buffer, sizeof(buffer), &dynamic_buffer, &result );
+        if (!status)
+        {
+            len = result->Length / sizeof(WCHAR);
+            memcpy( name, result->Buffer, min( len, size - 1 ) * sizeof(WCHAR) );
+            HeapFree( GetProcessHeap(), 0, dynamic_buffer );
+        }
     }

if (len < size)
diff --git a/dlls/psapi/tests/psapi_main.c b/dlls/psapi/tests/psapi_main.c
index 92529447afa..797c41a0a6b 100644
--- a/dlls/psapi/tests/psapi_main.c
+++ b/dlls/psapi/tests/psapi_main.c
@@ -991,9 +991,11 @@ static void test_GetProcessImageFileName(void)
 static void test_GetModuleFileNameEx(void)
 {
     HMODULE hMod = GetModuleHandleA(NULL);
+    STARTUPINFOW si = { sizeof(si) };
+    PROCESS_INFORMATION pi;
     char szModExPath[MAX_PATH+1], szModPath[MAX_PATH+1];
-    WCHAR buffer[MAX_PATH];
-    DWORD ret;
+    WCHAR buffer[MAX_PATH], buffer2[MAX_PATH];
+    DWORD ret, size, size2;

SetLastError(0xdeadbeef);
     ret = GetModuleFileNameExA(NULL, hMod, szModExPath, sizeof(szModExPath));
@@ -1051,6 +1053,25 @@ static void test_GetModuleFileNameEx(void)
         ok(GetLastError() == 0xdeadbeef, "got error %ld\n", GetLastError());
         ok( buffer[0] == 0xcc, "buffer modified %s\n", wine_dbgstr_w(buffer) );
     }
+
+    /* Verify that retrieving the main process image file name works on a suspended process,
+     * where the loader has not yet had a chance to initialize the PEB. */
+    wcscpy(buffer, L"C:\windows\system32\msinfo32.exe");
+    ret = CreateProcessW(NULL, buffer, NULL, NULL, FALSE, CREATE_SUSPENDED, NULL, NULL, &si, &pi);
+    ok(ret, "CreateProcessW failed: %lu\n", GetLastError());
+
+    size = GetModuleFileNameExW(pi.hProcess, NULL, buffer, ARRAYSIZE(buffer));
+    ok(size, "GetModuleFileNameExW failed: %lu\n", GetLastError());
+    ok(size == wcslen(buffer), "unexpected size %lu\n", size);
+
+    size2 = ARRAYSIZE(buffer2);
+    ret = QueryFullProcessImageNameW(pi.hProcess, 0, buffer2, &size2);
+    ok(size == size2, "got size %lu, expected %lu\n", size, size2);
+    ok(!wcscmp(buffer, buffer2), "unexpected image name %s, expected %s\n", debugstr_w(buffer), debugstr_w(buffer2));
+
+    TerminateProcess(pi.hProcess, 0);
+    CloseHandle(pi.hThread);
+    CloseHandle(pi.hProcess);
 }

static void test_GetModuleBaseName(void)