kernel32: Don't allocate FLS index 0.

dlls/kernel32/fiber.c

@@ -230,7 +230,7 @@ DWORD WINAPI FlsAlloc( PFLS_CALLBACK_FUNCTION callback )
     }
     else
     {
-        index = RtlFindClearBitsAndSet( peb->FlsBitmap, 1, 0 );
+        index = RtlFindClearBitsAndSet( peb->FlsBitmap, 1, 1 );
         if (index != ~0U)
         {
             if (!NtCurrentTeb()->FlsSlots &&
@@ -279,7 +279,7 @@ BOOL WINAPI FlsFree( DWORD index )
  */
 PVOID WINAPI FlsGetValue( DWORD index )
 {
-    if (index >= 8 * sizeof(NtCurrentTeb()->Peb->FlsBitmapBits) || !NtCurrentTeb()->FlsSlots)
+    if (!index || index >= 8 * sizeof(NtCurrentTeb()->Peb->FlsBitmapBits) || !NtCurrentTeb()->FlsSlots)
     {
         SetLastError( ERROR_INVALID_PARAMETER );
         return NULL;
@@ -293,7 +293,7 @@ PVOID WINAPI FlsGetValue( DWORD index )
  */
 BOOL WINAPI FlsSetValue( DWORD index, PVOID data )
 {
-    if (index >= 8 * sizeof(NtCurrentTeb()->Peb->FlsBitmapBits))
+    if (!index || index >= 8 * sizeof(NtCurrentTeb()->Peb->FlsBitmapBits))
     {
         SetLastError( ERROR_INVALID_PARAMETER );
         return FALSE;

dlls/kernel32/process.c

@@ -2768,7 +2768,7 @@ DWORD WINAPI TlsAlloc( void )
     PEB * const peb = NtCurrentTeb()->Peb;
 
     RtlAcquirePebLock();
-    index = RtlFindClearBitsAndSet( peb->TlsBitmap, 1, 0 );
+    index = RtlFindClearBitsAndSet( peb->TlsBitmap, 1, 1 );
     if (index != ~0U) NtCurrentTeb()->TlsSlots[index] = 0; /* clear the value */
     else
     {

dlls/kernel32/tests/fiber.c

@@ -181,6 +181,35 @@ static void test_FiberLocalStorage(PFLS_CALLBACK_FUNCTION cbfunc)
     ok(ret, "FlsFree failed\n");
     if (cbfunc)
         todo_wine ok(cbCount == 1, "Wrong callback count: %d\n", cbCount);
+
+    /* test index 0 */
+    SetLastError( 0xdeadbeef );
+    val = pFlsGetValue( 0 );
+    ok( !val, "fls index 0 set to %p\n", val );
+    ok( GetLastError() == ERROR_INVALID_PARAMETER, "setting fls index wrong error %u\n", GetLastError() );
+    SetLastError( 0xdeadbeef );
+    ret = pFlsSetValue( 0, (void *)0xdeadbeef );
+    ok( !ret, "setting fls index 0 succeeded\n" );
+    ok( GetLastError() == ERROR_INVALID_PARAMETER, "setting fls index wrong error %u\n", GetLastError() );
+    SetLastError( 0xdeadbeef );
+    val = pFlsGetValue( 0 );
+    ok( !val, "fls index 0 wrong value %p\n", val );
+    ok( GetLastError() == ERROR_INVALID_PARAMETER, "setting fls index wrong error %u\n", GetLastError() );
+
+    fls = pFlsAlloc( NULL );
+    ok( fls != FLS_OUT_OF_INDEXES, "FlsAlloc failed\n" );
+    ok( fls != 0, "fls index 0 allocated\n" );
+    val = pFlsGetValue( fls );
+    ok( !val, "fls index %u wrong value %p\n", fls, val );
+    ret = pFlsSetValue( fls, (void *)0xdeadbeef );
+    ok( ret, "setting fls index %u failed\n", fls );
+    val = pFlsGetValue( fls );
+    ok( val == (void *)0xdeadbeef, "fls index %u wrong value %p\n", fls, val );
+    pFlsFree( fls );
+    ret = pFlsSetValue( fls, (void *)0xdeadbabe );
+    ok( ret, "setting fls index %u failed\n", fls );
+    val = pFlsGetValue( fls );
+    ok( val == (void *)0xdeadbabe, "fls index %u wrong value %p\n", fls, val );
 }
 
 START_TEST(fiber)

dlls/ntdll/thread.c

@@ -257,6 +257,7 @@ HANDLE thread_init(void)
                          sizeof(peb->TlsExpansionBitmapBits) * 8 );
     RtlInitializeBitMap( &fls_bitmap, peb->FlsBitmapBits, sizeof(peb->FlsBitmapBits) * 8 );
     RtlSetBits( peb->TlsBitmap, 0, 1 ); /* TLS index 0 is reserved and should be initialized to NULL. */
+    RtlSetBits( peb->FlsBitmap, 0, 1 );
     InitializeListHead( &peb->FlsListHead );
     InitializeListHead( &ldr.InLoadOrderModuleList );
     InitializeListHead( &ldr.InMemoryOrderModuleList );