Alexandre Julliard : ntdll: Fixup CPU information for old Wow64 mode.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: da7411fdb3b87dc4549470c70f6fe73562c78b9e
URL:    https://gitlab.winehq.org/wine/wine/-/commit/da7411fdb3b87dc4549470c70f6fe73...

Author: Alexandre Julliard 
Date:   Thu Mar 23 13:17:52 2023 +0100

ntdll: Fixup CPU information for old Wow64 mode.

---

dlls/ntdll/tests/wow64.c | 15 +++++++++++----
 dlls/ntdll/unix/system.c |  9 +++++++--
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/dlls/ntdll/tests/wow64.c b/dlls/ntdll/tests/wow64.c
index eff3ff59dc2..8ecbbe68c12 100644
--- a/dlls/ntdll/tests/wow64.c
+++ b/dlls/ntdll/tests/wow64.c
@@ -68,6 +68,17 @@ static void init(void)

if (!IsWow64Process( GetCurrentProcess(), &is_wow64 )) is_wow64 = FALSE;

+    if (is_wow64)
+    {
+        TEB64 *teb64 = ULongToPtr( NtCurrentTeb()->GdiBatchCount );
+
+        if (teb64)
+        {
+            PEB64 *peb64 = ULongToPtr(teb64->Peb);
+            old_wow64 = !peb64->LdrData;
+        }
+    }
+
 #define GET_PROC(func) p##func = (void *)GetProcAddress( ntdll, #func )
     GET_PROC( NtQuerySystemInformation );
     GET_PROC( NtQuerySystemInformationEx );
@@ -102,10 +113,6 @@ static void init(void)
         case PROCESSOR_ARCHITECTURE_AMD64:
             native_machine = IMAGE_FILE_MACHINE_AMD64;
             break;
-        case PROCESSOR_ARCHITECTURE_INTEL:
-            old_wow64 = TRUE;
-            native_machine = IMAGE_FILE_MACHINE_AMD64;
-            break;
         }
     }

diff --git a/dlls/ntdll/unix/system.c b/dlls/ntdll/unix/system.c
index 54fd72e56ba..0ba38f88038 100644
--- a/dlls/ntdll/unix/system.c
+++ b/dlls/ntdll/unix/system.c
@@ -2570,8 +2570,13 @@ NTSTATUS WINAPI NtQuerySystemInformation( SYSTEM_INFORMATION_CLASS class,
     case SystemCpuInformation:  /* 1 */
         if (size >= (len = sizeof(cpu_info)))
         {
-            if (!info) ret = STATUS_ACCESS_VIOLATION;
-            else memcpy(info, &cpu_info, len);
+            SYSTEM_CPU_INFORMATION cpu = cpu_info;
+
+#ifndef _WIN64
+            if (is_wow64 && cpu.ProcessorArchitecture == PROCESSOR_ARCHITECTURE_INTEL)
+                cpu.ProcessorArchitecture = PROCESSOR_ARCHITECTURE_AMD64;
+#endif
+            memcpy(info, &cpu, len);
         }
         else ret = STATUS_INFO_LENGTH_MISMATCH;
         break;