Workaround bug in EvtFormatMessage (#105636)

* Workaround bug in EvtFormatMessage * Add issue comment for 100198 * Use stackalloc buffer
dotnet · Jul 30, 2024 · ee3b1f0 · ee3b1f0
1 parent 852420c
commit ee3b1f0
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Showing 2 changed files with 9 additions and 5 deletions.
diff --git a/src/libraries/System.Diagnostics.EventLog/src/System/Diagnostics/Reader/NativeWrapper.cs b/src/libraries/System.Diagnostics.EventLog/src/System/Diagnostics/Reader/NativeWrapper.cs
@@ -482,7 +482,8 @@ internal static EventLogHandle EvtGetPublisherMetadataPropertyHandle(EventLogHan
         public static string EvtFormatMessage(EventLogHandle handle, uint msgId)
         {
             int bufferNeeded;
-            bool status = UnsafeNativeMethods.EvtFormatMessage(handle, EventLogHandle.Zero, msgId, 0, null, UnsafeNativeMethods.EvtFormatMessageFlags.EvtFormatMessageId, 0, null, out bufferNeeded);
+            Span<char> emptyBuffer = [ '\0' ]; // issue: https://github.com/dotnet/runtime/issues/100198
+            bool status = UnsafeNativeMethods.EvtFormatMessage(handle, EventLogHandle.Zero, msgId, 0, null, UnsafeNativeMethods.EvtFormatMessageFlags.EvtFormatMessageId, 0, emptyBuffer, out bufferNeeded);
             int error = Marshal.GetLastWin32Error();
 
             // ERROR_EVT_UNRESOLVED_VALUE_INSERT and its cousins are commonly returned for raw message text.
@@ -933,7 +934,8 @@ public static IList<object> EvtRenderBufferWithContextUserOrValues(EventLogHandl
         public static string EvtFormatMessageRenderName(EventLogHandle pmHandle, EventLogHandle eventHandle, UnsafeNativeMethods.EvtFormatMessageFlags flag)
         {
             int bufferNeeded;
-            bool status = UnsafeNativeMethods.EvtFormatMessage(pmHandle, eventHandle, 0, 0, null, flag, 0, null, out bufferNeeded);
+            Span<char> emptyBuffer = [ '\0' ]; // issue: https://github.com/dotnet/runtime/issues/100198
+            bool status = UnsafeNativeMethods.EvtFormatMessage(pmHandle, eventHandle, 0, 0, null, flag, 0, emptyBuffer, out bufferNeeded);
             int error = Marshal.GetLastWin32Error();
 
             if (!status && error != UnsafeNativeMethods.ERROR_EVT_UNRESOLVED_VALUE_INSERT
@@ -985,11 +987,12 @@ public static IEnumerable<string> EvtFormatMessageRenderKeywords(EventLogHandle
         {
             IntPtr buffer = IntPtr.Zero;
             int bufferNeeded;
+            Span<char> emptyBuffer = [ '\0' ]; // issue: https://github.com/dotnet/runtime/issues/100198
 
             try
             {
                 List<string> keywordsList = new List<string>();
-                bool status = UnsafeNativeMethods.EvtFormatMessageBuffer(pmHandle, eventHandle, 0, 0, IntPtr.Zero, flag, 0, IntPtr.Zero, out bufferNeeded);
+                bool status = UnsafeNativeMethods.EvtFormatMessage(pmHandle, eventHandle, 0, 0, null, flag, 0, emptyBuffer, out bufferNeeded);
                 int error = Marshal.GetLastWin32Error();
 
                 if (!status)
@@ -1071,6 +1074,7 @@ public static string EvtRenderBookmark(EventLogHandle eventHandle)
         public static string EvtFormatMessageFormatDescription(EventLogHandle handle, EventLogHandle eventHandle, string[] values)
         {
             int bufferNeeded;
+            Span<char> emptyBuffer = [ '\0' ]; // issue: https://github.com/dotnet/runtime/issues/100198
 
             UnsafeNativeMethods.EvtStringVariant[] stringVariants = new UnsafeNativeMethods.EvtStringVariant[values.Length];
             for (int i = 0; i < values.Length; i++)
@@ -1079,7 +1083,7 @@ public static string EvtFormatMessageFormatDescription(EventLogHandle handle, Ev
                 stringVariants[i].StringVal = values[i];
             }
 
-            bool status = UnsafeNativeMethods.EvtFormatMessage(handle, eventHandle, 0xffffffff, values.Length, stringVariants, UnsafeNativeMethods.EvtFormatMessageFlags.EvtFormatMessageEvent, 0, null, out bufferNeeded);
+            bool status = UnsafeNativeMethods.EvtFormatMessage(handle, eventHandle, 0xffffffff, values.Length, stringVariants, UnsafeNativeMethods.EvtFormatMessageFlags.EvtFormatMessageEvent, 0, emptyBuffer, out bufferNeeded);
             int error = Marshal.GetLastWin32Error();
 
             if (!status && error != UnsafeNativeMethods.ERROR_EVT_UNRESOLVED_VALUE_INSERT

diff --git a/...ibraries/System.Diagnostics.EventLog/src/System/Diagnostics/Reader/UnsafeNativeMethods.cs b/...ibraries/System.Diagnostics.EventLog/src/System/Diagnostics/Reader/UnsafeNativeMethods.cs
@@ -762,7 +762,7 @@ internal static partial bool EvtFormatMessage(
                              EvtStringVariant[] values,
                              EvtFormatMessageFlags flags,
                              int bufferSize,
-                             [Out] char[]? buffer,
+                             Span<char> buffer,
                              out int bufferUsed);
 
         [LibraryImport(Interop.Libraries.Wevtapi, EntryPoint = "EvtFormatMessage", SetLastError = true)]