Eric Pouech : ntdll: Fix export and calling convention of RtlUlonglongByteSwap().

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 495711c251bad8d39e13af7addfaccc938a2a670
URL:    https://gitlab.winehq.org/wine/wine/-/commit/495711c251bad8d39e13af7addfaccc...

Author: Eric Pouech <eric.pouech(a)gmail.com>
Date:   Mon Dec 12 16:58:12 2022 +0100

ntdll: Fix export and calling convention of RtlUlonglongByteSwap().

The RtlU*ByteSwap() family:
- has FASTCALL calling convention
- is only exported from ntdll and ntoskrnl.exe in 32bit mode
  (didn't check ARM though)

Wine's support for RtlUlonglongByteSwap() doesn't follow these constraints.
Note: in __fastcall, 64bit paramaters are passed on the stack, to
RtlUlonglongByteSwap() calling convention acts as __stdcall.

So:
- fix ntdll.spec (resp. ntoskrnl.exe.spec) to only export
  (resp. forward) RtlUlonglongByteSwap for i386
- always provide an inline implementation in winternl.h
- reimplement ntdll.RtlUlonglongByteSwap() for i386 with
  __fastcall calling convention.
- fix ntdll/tests/rtl.c to use correct calling convention.
- add test in ntdll/tests/rtl.c for inlined version.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=53536
Signed-off-by: Eric Pouech <eric.pouech(a)gmail.com>

---

 dlls/ntdll/ntdll.spec               |  2 +-
 dlls/ntdll/rtl.c                    | 12 ++++++++----
 dlls/ntdll/tests/rtl.c              | 24 ++++++++++++++----------
 dlls/ntoskrnl.exe/ntoskrnl.c        | 13 +++++++++++++
 dlls/ntoskrnl.exe/ntoskrnl.exe.spec |  2 +-
 include/winternl.h                  | 15 +++++++--------
 6 files changed, 44 insertions(+), 24 deletions(-)

diff --git a/dlls/ntdll/ntdll.spec b/dlls/ntdll/ntdll.spec
index 1e6576a5422..5b4cbbaa7fe 100644
--- a/dlls/ntdll/ntdll.spec
+++ b/dlls/ntdll/ntdll.spec
@@ -1039,7 +1039,7 @@
 @ stdcall RtlTryEnterCriticalSection(ptr)
 @ stdcall RtlUTF8ToUnicodeN(ptr long ptr ptr long)
 @ cdecl -i386 -norelay RtlUlongByteSwap() NTDLL_RtlUlongByteSwap
-@ cdecl -ret64 RtlUlonglongByteSwap(int64)
+@ stdcall -fastcall -arch=i386 -norelay RtlUlonglongByteSwap(int64)
 # @ stub RtlUnhandledExceptionFilter2
 # @ stub RtlUnhandledExceptionFilter
 @ stdcall RtlUnicodeStringToAnsiSize(ptr)
diff --git a/dlls/ntdll/rtl.c b/dlls/ntdll/rtl.c
index 5ff6205fe05..00bc16bbfa5 100644
--- a/dlls/ntdll/rtl.c
+++ b/dlls/ntdll/rtl.c
@@ -641,10 +641,14 @@ DWORD WINAPI RtlComputeCrc32(DWORD dwInitial, const BYTE *pData, INT iLen)
  * RETURNS
  *  The value with its bytes swapped.
  */
-ULONGLONG __cdecl RtlUlonglongByteSwap(ULONGLONG i)
-{
-  return ((ULONGLONG)RtlUlongByteSwap(i) << 32) | RtlUlongByteSwap(i>>32);
-}
+#ifdef __i386__
+__ASM_FASTCALL_FUNC(RtlUlonglongByteSwap, 8,
+                    "movl 4(%esp),%edx\n\t"
+                    "bswap %edx\n\t"
+                    "movl 8(%esp),%eax\n\t"
+                    "bswap %eax\n\t"
+                    "ret $8")
+#endif
 
 /*************************************************************************
  * RtlUlongByteSwap    [NTDLL.@]
diff --git a/dlls/ntdll/tests/rtl.c b/dlls/ntdll/tests/rtl.c
index 2e0bfb650e4..8f698454957 100644
--- a/dlls/ntdll/tests/rtl.c
+++ b/dlls/ntdll/tests/rtl.c
@@ -68,7 +68,7 @@ static VOID      (WINAPI  *pRtlMoveMemory)(LPVOID,LPCVOID,SIZE_T);
 static VOID      (WINAPI  *pRtlFillMemory)(LPVOID,SIZE_T,BYTE);
 static VOID      (WINAPI  *pRtlFillMemoryUlong)(LPVOID,SIZE_T,ULONG);
 static VOID      (WINAPI  *pRtlZeroMemory)(LPVOID,SIZE_T);
-static ULONGLONG (WINAPIV *pRtlUlonglongByteSwap)(ULONGLONG source);
+static ULONGLONG (FASTCALL *pRtlUlonglongByteSwap)(ULONGLONG source);
 static DWORD     (WINAPI *pRtlGetThreadErrorMode)(void);
 static NTSTATUS  (WINAPI *pRtlSetThreadErrorMode)(DWORD, LPDWORD);
 static NTSTATUS  (WINAPI *pRtlIpv4AddressToStringExA)(const IN_ADDR *, USHORT, LPSTR, PULONG);
@@ -319,18 +319,22 @@ static void test_RtlZeroMemory(void)
 
 static void test_RtlUlonglongByteSwap(void)
 {
-    ULONGLONG result;
+    ULONGLONG llresult;
 
-    if ( !pRtlUlonglongByteSwap )
+#ifdef _WIN64
+    /* the Rtl*ByteSwap() are always inlined and not exported from ntdll on 64bit */
+    llresult = RtlUlonglongByteSwap( 0x7654321087654321ull );
+    ok( 0x2143658710325476 == llresult,
+        "inlined RtlUlonglongByteSwap() returns %#I64x\n", llresult );
+#else
+    ok( pRtlUlonglongByteSwap != NULL, "RtlUlonglongByteSwap is not available\n");
+    if ( pRtlUlonglongByteSwap )
     {
-        win_skip("RtlUlonglongByteSwap is not available\n");
-        return;
+        llresult = pRtlUlonglongByteSwap( 0x7654321087654321ull );
+        ok( 0x2143658710325476ull == llresult,
+            "ntdll.RtlUlonglongByteSwap() returns %#I64x\n", llresult );
     }
-
-    result = pRtlUlonglongByteSwap( ((ULONGLONG)0x76543210 << 32) | 0x87654321 );
-    ok( (((ULONGLONG)0x21436587 << 32) | 0x10325476) == result,
-       "RtlUlonglongByteSwap(0x7654321087654321) returns 0x%s, expected 0x2143658710325476\n",
-       wine_dbgstr_longlong(result));
+#endif
 }
 
 
diff --git a/dlls/ntoskrnl.exe/ntoskrnl.c b/dlls/ntoskrnl.exe/ntoskrnl.c
index ce92f6805ab..9548eb98542 100644
--- a/dlls/ntoskrnl.exe/ntoskrnl.c
+++ b/dlls/ntoskrnl.exe/ntoskrnl.c
@@ -2185,6 +2185,19 @@ LONG FASTCALL NTOSKRNL_InterlockedIncrement( LONG volatile *dest )
     return InterlockedIncrement( dest );
 }
 
+#ifdef __i386__
+
+/*************************************************************************
+ *           RtlUlonglongByteSwap   (NTOSKRNL.EXE.@)
+ */
+__ASM_FASTCALL_FUNC(RtlUlonglongByteSwap, 8,
+                    "movl 4(%esp),%edx\n\t"
+                    "bswap %edx\n\t"
+                    "movl 8(%esp),%eax\n\t"
+                    "bswap %eax\n\t"
+                    "ret $8")
+
+#endif  /* __i386__ */
 
 /***********************************************************************
  *           ExAllocatePool   (NTOSKRNL.EXE.@)
diff --git a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
index 0a484829ca3..321083e5ac4 100644
--- a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
+++ b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
@@ -68,7 +68,7 @@
 @ stdcall -fastcall ObfReferenceObject(ptr)
 @ stub RtlPrefetchMemoryNonTemporal
 @ cdecl -i386 -norelay RtlUlongByteSwap()
-@ cdecl -ret64 RtlUlonglongByteSwap(int64)
+@ stdcall -fastcall -arch=i386 -norelay RtlUlonglongByteSwap(int64)
 @ cdecl -i386 -norelay RtlUshortByteSwap()
 @ stub WmiGetClock
 @ stub Kei386EoiHelper
diff --git a/include/winternl.h b/include/winternl.h
index 5a99827fe65..c720d962933 100644
--- a/include/winternl.h
+++ b/include/winternl.h
@@ -4567,7 +4567,6 @@ NTSYSAPI BOOLEAN   WINAPI RtlTryAcquireSRWLockExclusive(RTL_SRWLOCK *);
 NTSYSAPI BOOLEAN   WINAPI RtlTryAcquireSRWLockShared(RTL_SRWLOCK *);
 NTSYSAPI BOOL      WINAPI RtlTryEnterCriticalSection(RTL_CRITICAL_SECTION *);
 NTSYSAPI NTSTATUS  WINAPI RtlUTF8ToUnicodeN(WCHAR*,DWORD,DWORD*,const char*,DWORD);
-NTSYSAPI ULONGLONG __cdecl RtlUlonglongByteSwap(ULONGLONG);
 NTSYSAPI DWORD     WINAPI RtlUnicodeStringToAnsiSize(const UNICODE_STRING*);
 NTSYSAPI NTSTATUS  WINAPI RtlUnicodeStringToAnsiString(PANSI_STRING,PCUNICODE_STRING,BOOLEAN);
 NTSYSAPI NTSTATUS  WINAPI RtlUnicodeStringToInteger(const UNICODE_STRING *,ULONG,ULONG *);
@@ -4733,20 +4732,20 @@ static inline BOOLEAN RtlCheckBit(PCRTL_BITMAP lpBits, ULONG ulBit)
     return FALSE;
 }
 
-/* These are implemented as __fastcall, so we can't let Winelib apps link with them */
+/* These are implemented as __fastcall, so we can't let Winelib apps link with them.
+ * Moreover, they're always inlined and not exported on 64bit systems.
+ */
 static inline USHORT RtlUshortByteSwap(USHORT s)
 {
     return (s >> 8) | (s << 8);
 }
 static inline ULONG RtlUlongByteSwap(ULONG i)
 {
-#if defined(__i386__) && defined(__GNUC__)
-    ULONG ret;
-    __asm__("bswap %0" : "=r" (ret) : "0" (i) );
-    return ret;
-#else
     return ((ULONG)RtlUshortByteSwap((USHORT)i) << 16) | RtlUshortByteSwap((USHORT)(i >> 16));
-#endif
+}
+static inline ULONGLONG RtlUlonglongByteSwap(ULONGLONG i)
+{
+    return ((ULONGLONG)RtlUlongByteSwap((ULONG)i) << 32) | RtlUlongByteSwap((ULONG)(i >> 32));
 }
 
 /* list manipulation macros */