[PATCH 05/22] ntdll: Only lock loader_section when calling application callbacks().

Paul Gofman pgofman at codeweavers.com
Fri Oct 1 13:20:50 CDT 2021


Signed-off-by: Paul Gofman <pgofman at codeweavers.com>
---
 dlls/ntdll/loader.c | 59 ++++++++++++++++++++++++++++++++++++++++-----
 include/winternl.h  |  2 +-
 2 files changed, 54 insertions(+), 7 deletions(-)

diff --git a/dlls/ntdll/loader.c b/dlls/ntdll/loader.c
index 3081bb31434..4eb1eac09ed 100644
--- a/dlls/ntdll/loader.c
+++ b/dlls/ntdll/loader.c
@@ -160,6 +160,8 @@ static RTL_CRITICAL_SECTION_DEBUG critsect_debug =
 };
 static RTL_CRITICAL_SECTION loader_section = { &critsect_debug, -1, 0, 0, 0, 0 };
 
+static RTL_SRWLOCK loader_srw_lock;
+
 static CRITICAL_SECTION dlldir_section;
 static CRITICAL_SECTION_DEBUG dlldir_critsect_debug =
 {
@@ -217,24 +219,58 @@ static inline BOOL contains_path( LPCWSTR name )
     return ((*name && (name[1] == ':')) || wcschr(name, '/') || wcschr(name, '\\'));
 }
 
+/*************************************************************************
+ *		inc_recursion_count
+ *
+ * Increment thread local internal loader lock recursion count and return the old value.
+ */
+static ULONG inc_recursion_count(void)
+{
+    return NtCurrentTeb()->Spare2++;
+}
+
+/*************************************************************************
+ *		dec_recursion_count
+ *
+ * Decrement thread local internal loader lock recursion count and return the new value.
+ */
+static ULONG dec_recursion_count(void)
+{
+    return --NtCurrentTeb()->Spare2;
+}
+
 /*************************************************************************
  *		lock_loader_exclusive
  *
- * Take exclusive loader lock.
+ * Take exclusive ownership of internal loader lock.
+ * Recursive locking is allowed.
  */
 static void lock_loader_exclusive(void)
 {
-    RtlEnterCriticalSection( &loader_section );
+    ULONG recursion_count = inc_recursion_count();
+
+    TRACE( "recursion_count %u.\n", recursion_count );
+    if (!recursion_count && !RtlDllShutdownInProgress())
+        RtlAcquireSRWLockExclusive( &loader_srw_lock );
 }
 
 /*************************************************************************
  *		unlock_loader
  *
- * Release loader lock.
+ * Release internal loader lock.
  */
 static void unlock_loader(void)
 {
-    RtlLeaveCriticalSection( &loader_section );
+    ULONG recursion_count = dec_recursion_count();
+
+    TRACE( "recursion_count %u.\n", recursion_count );
+
+    if (RtlDllShutdownInProgress()) return;
+
+    assert( recursion_count != ~0u );
+
+    if (!recursion_count)
+        RtlReleaseSRWLockExclusive( &loader_srw_lock );
 }
 
 #define RTL_UNLOAD_EVENT_TRACE_NUMBER 64
@@ -494,6 +530,7 @@ static void call_ldr_notifications( ULONG reason, LDR_DATA_TABLE_ENTRY *module )
     data.Loaded.DllBase     = module->DllBase;
     data.Loaded.SizeOfImage = module->SizeOfImage;
 
+    RtlEnterCriticalSection( &loader_section );
     RtlEnterCriticalSection( &ldr_notifications_section );
     LIST_FOR_EACH_ENTRY_SAFE( notify, notify_next, &ldr_notifications, struct ldr_notification, entry )
     {
@@ -506,6 +543,7 @@ static void call_ldr_notifications( ULONG reason, LDR_DATA_TABLE_ENTRY *module )
                 notify->callback, reason, &data, notify->context );
     }
     RtlLeaveCriticalSection( &ldr_notifications_section );
+    RtlLeaveCriticalSection( &loader_section );
 }
 
 /*************************************************************************
@@ -1355,6 +1393,8 @@ static void call_tls_callbacks( HMODULE module, UINT reason )
     dir = RtlImageDirectoryEntryToData( module, TRUE, IMAGE_DIRECTORY_ENTRY_TLS, &dirsize );
     if (!dir || !dir->AddressOfCallBacks) return;
 
+    RtlEnterCriticalSection( &loader_section );
+
     for (callback = (const PIMAGE_TLS_CALLBACK *)dir->AddressOfCallBacks; *callback; callback++)
     {
         TRACE_(relay)("\1Call TLS callback (proc=%p,module=%p,reason=%s,reserved=0)\n",
@@ -1373,6 +1413,8 @@ static void call_tls_callbacks( HMODULE module, UINT reason )
         TRACE_(relay)("\1Ret  TLS callback (proc=%p,module=%p,reason=%s,reserved=0)\n",
                       *callback, module, reason_names[reason] );
     }
+
+    RtlLeaveCriticalSection( &loader_section );
 }
 
 /*************************************************************************
@@ -1405,6 +1447,8 @@ static NTSTATUS MODULE_InitDLL( WINE_MODREF *wm, UINT reason, LPVOID lpReserved
     else TRACE("(%p %s,%s,%p) - CALL\n", module, debugstr_w(wm->ldr.BaseDllName.Buffer),
                reason_names[reason], lpReserved );
 
+    RtlEnterCriticalSection( &loader_section );
+
     __TRY
     {
         retv = call_dll_entry_point( entry, module, reason, lpReserved );
@@ -1419,6 +1463,8 @@ static NTSTATUS MODULE_InitDLL( WINE_MODREF *wm, UINT reason, LPVOID lpReserved
     }
     __ENDTRY
 
+    RtlLeaveCriticalSection( &loader_section );
+
     /* The state of the module list may have changed due to the call
        to the dll. We cannot assume that this module has not been
        deleted.  */
@@ -1658,7 +1704,7 @@ NTSTATUS WINAPI LdrEnumerateLoadedModules( void *unknown, LDRENUMPROC callback,
         return STATUS_INVALID_PARAMETER;
 
     lock_loader_exclusive();
-
+    RtlEnterCriticalSection( &loader_section );
     mark = &NtCurrentTeb()->Peb->LdrData->InMemoryOrderModuleList;
     for (entry = mark->Flink; entry != mark; entry = entry->Flink)
     {
@@ -1666,7 +1712,7 @@ NTSTATUS WINAPI LdrEnumerateLoadedModules( void *unknown, LDRENUMPROC callback,
         callback( mod, context, &stop );
         if (stop) break;
     }
-
+    RtlLeaveCriticalSection( &loader_section );
     unlock_loader();
     return STATUS_SUCCESS;
 }
@@ -3901,6 +3947,7 @@ void WINAPI LdrInitializeThunk( CONTEXT *context, ULONG_PTR unknown2, ULONG_PTR
     {
         TRACE( "Initializing loader locks.\n" );
         RtlInitializeSRWLock( &ldr_data_srw_lock );
+        RtlInitializeSRWLock( &loader_srw_lock );
     }
 
     lock_loader_exclusive();
diff --git a/include/winternl.h b/include/winternl.h
index b6f93c116d8..521454396b4 100644
--- a/include/winternl.h
+++ b/include/winternl.h
@@ -466,7 +466,7 @@ typedef struct _TEB
     PVOID                        Instrumentation[16];               /* f2c/16b8 */
     PVOID                        WinSockData;                       /* f6c/1738 */
     ULONG                        GdiBatchCount;                     /* f70/1740 */
-    ULONG                        Spare2;                            /* f74/1744 */
+    ULONG                        Spare2;                            /* f74/1744 used for ntdll loader data in Wine */
     ULONG                        GuaranteedStackBytes;              /* f78/1748 */
     PVOID                        ReservedForPerf;                   /* f7c/1750 */
     PVOID                        ReservedForOle;                    /* f80/1758 */
-- 
2.31.1




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