ntdll: Add helpers to lock the user output buffer during file reads.

dlls/kernel32/tests/virtual.c

@@ -1840,13 +1840,10 @@ static DWORD CALLBACK read_pipe( void *arg )
         "%u: ConnectNamedPipe failed %u\n", args->index, GetLastError() );
 
     success = ReadFile( args->pipe, args->base, args->size, &num_bytes, NULL );
-    todo_wine_if (!args->index)
-    {
     ok( success, "%u: ReadFile failed %u\n", args->index, GetLastError() );
     ok( num_bytes == sizeof(testdata), "%u: wrong number of bytes read %u\n", args->index, num_bytes );
     ok( !memcmp( args->base, testdata, sizeof(testdata)),
         "%u: didn't receive expected data\n", args->index );
-    }
     return 0;
 }
 
@@ -2056,22 +2053,16 @@ static void test_write_watch(void)
 
         num_bytes = 0;
         success = GetOverlappedResult( readpipe, &overlapped, &num_bytes, TRUE );
-        todo_wine_if (!i)
-        {
         ok( success, "%u: GetOverlappedResult failed %u\n", i, GetLastError() );
         ok( num_bytes == sizeof(testdata), "%u: wrong number of bytes read %u\n", i, num_bytes );
         ok( !memcmp( base, testdata, sizeof(testdata)), "%u: didn't receive expected data\n", i );
-        }
 
         count = 64;
         memset( results, 0, sizeof(results) );
         ret = pGetWriteWatch( WRITE_WATCH_FLAG_RESET, base, size, results, &count, &pagesize );
         ok( !ret, "%u: GetWriteWatch failed %u\n", i, GetLastError() );
-        todo_wine_if (!i)
-        {
         ok( count == 1, "%u: wrong count %lu\n", i, count );
         ok( results[0] == base, "%u: wrong result %p\n", i, results[0] );
-        }
 
         CloseHandle( readpipe );
         CloseHandle( writepipe );
@@ -2120,11 +2111,8 @@ static void test_write_watch(void)
         memset( results, 0, sizeof(results) );
         ret = pGetWriteWatch( WRITE_WATCH_FLAG_RESET, base, size, results, &count, &pagesize );
         ok( !ret, "%u: GetWriteWatch failed %u\n", i, GetLastError() );
-        todo_wine_if (!i)
-        {
         ok( count == 1, "%u: wrong count %lu\n", i, count );
         ok( results[0] == base, "%u: wrong result %p\n", i, results[0] );
-        }
 
         CloseHandle( readpipe );
         CloseHandle( writepipe );

dlls/ntdll/file.c

@@ -517,7 +517,7 @@ static NTSTATUS FILE_AsyncReadService( void *user, IO_STATUS_BLOCK *iosb, NTSTAT
                                           &needs_close, NULL, NULL )))
             break;
 
-        result = read(fd, &fileio->buffer[fileio->already], fileio->count - fileio->already);
+        result = virtual_locked_read(fd, &fileio->buffer[fileio->already], fileio->count-fileio->already);
         if (needs_close) close( fd );
 
         if (result < 0)
@@ -869,7 +869,7 @@ NTSTATUS WINAPI NtReadFile(HANDLE hFile, HANDLE hEvent,
         if (offset && offset->QuadPart != FILE_USE_FILE_POINTER_POSITION)
         {
             /* async I/O doesn't make sense on regular files */
-            while ((result = pread( unix_handle, buffer, length, offset->QuadPart )) == -1)
+            while ((result = virtual_locked_pread( unix_handle, buffer, length, offset->QuadPart )) == -1)
             {
                 if (errno != EINTR)
                 {
@@ -911,7 +911,7 @@ NTSTATUS WINAPI NtReadFile(HANDLE hFile, HANDLE hEvent,
 
     for (;;)
     {
-        if ((result = read( unix_handle, (char *)buffer + total, length - total )) >= 0)
+        if ((result = virtual_locked_read( unix_handle, (char *)buffer + total, length - total )) >= 0)
         {
             total += result;
             if (!result || total == length)

dlls/ntdll/ntdll_misc.h

@@ -171,6 +171,8 @@ extern BOOL virtual_handle_stack_fault( void *addr ) DECLSPEC_HIDDEN;
 extern BOOL virtual_is_valid_code_address( const void *addr, SIZE_T size ) DECLSPEC_HIDDEN;
 extern NTSTATUS virtual_handle_fault( LPCVOID addr, DWORD err, BOOL on_signal_stack ) DECLSPEC_HIDDEN;
 extern unsigned int virtual_locked_server_call( void *req_ptr ) DECLSPEC_HIDDEN;
+extern ssize_t virtual_locked_read( int fd, void *addr, size_t size ) DECLSPEC_HIDDEN;
+extern ssize_t virtual_locked_pread( int fd, void *addr, size_t size, off_t offset ) DECLSPEC_HIDDEN;
 extern BOOL virtual_check_buffer_for_read( const void *ptr, SIZE_T size ) DECLSPEC_HIDDEN;
 extern BOOL virtual_check_buffer_for_write( void *ptr, SIZE_T size ) DECLSPEC_HIDDEN;
 extern SIZE_T virtual_uninterrupted_read_memory( const void *addr, void *buffer, SIZE_T size ) DECLSPEC_HIDDEN;

dlls/ntdll/virtual.c

@@ -1863,6 +1863,56 @@ unsigned int virtual_locked_server_call( void *req_ptr )
 }
 
 
+/***********************************************************************
+ *           virtual_locked_read
+ */
+ssize_t virtual_locked_read( int fd, void *addr, size_t size )
+{
+    sigset_t sigset;
+    BOOL has_write_watch = FALSE;
+    int err = EFAULT;
+
+    ssize_t ret = read( fd, addr, size );
+    if (ret != -1 || errno != EFAULT) return ret;
+
+    server_enter_uninterrupted_section( &csVirtual, &sigset );
+    if (!check_write_access( addr, size, &has_write_watch ))
+    {
+        ret = read( fd, addr, size );
+        err = errno;
+        if (has_write_watch) update_write_watches( addr, size, max( 0, ret ));
+    }
+    server_leave_uninterrupted_section( &csVirtual, &sigset );
+    errno = err;
+    return ret;
+}
+
+
+/***********************************************************************
+ *           virtual_locked_pread
+ */
+ssize_t virtual_locked_pread( int fd, void *addr, size_t size, off_t offset )
+{
+    sigset_t sigset;
+    BOOL has_write_watch = FALSE;
+    int err = EFAULT;
+
+    ssize_t ret = pread( fd, addr, size, offset );
+    if (ret != -1 || errno != EFAULT) return ret;
+
+    server_enter_uninterrupted_section( &csVirtual, &sigset );
+    if (!check_write_access( addr, size, &has_write_watch ))
+    {
+        ret = pread( fd, addr, size, offset );
+        err = errno;
+        if (has_write_watch) update_write_watches( addr, size, max( 0, ret ));
+    }
+    server_leave_uninterrupted_section( &csVirtual, &sigset );
+    errno = err;
+    return ret;
+}
+
+
 
 /***********************************************************************
  *           virtual_is_valid_code_address