HalPortIo.c

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/*
 * PROJECT:     ReactOS Kernel-Mode Tests
 * LICENSE:     LGPL-2.1-or-later (https://spdx.org/licenses/LGPL-2.1-or-later)
 * PURPOSE:     Tests for string I/O intrinsic functions
 * COPYRIGHT:   Copyright 2025 Dmitry Borisov <di.sean@protonmail.com>
 */
 
/* INCLUDES *******************************************************************/
 
#include <kmt_test.h>
 
#define NDEBUG
#include <debug.h>
 
/* GLOBALS ********************************************************************/
 
/* Compile with the highest optimization level to trigger a bug (See CORE-20078) */
#ifdef _MSC_VER
#pragma optimize("gst", on)
#pragma auto_inline(on)
#else
#pragma GCC optimize("O3")
#endif
 
/* Used to isolate the effects of intrinsics from each other */
typedef struct _TEST_CONTEXT
{
    PVOID OldBuffer;
    UCHAR Pad[78];
    USHORT Port;
    ULONG Size;
    PVOID Buffer;
} TEST_CONTEXT, *PTEST_CONTEXT;
 
/* TEST FUNCTIONS *************************************************************/
 
static
/*
 * Isolate the effects of intrinsics from each other
 * and hide the TEST_CONTEXT initialization from the optimizer.
 */
DECLSPEC_NOINLINE
VOID
TestWriteStringUshort(
    _In_ PTEST_CONTEXT Context)
{
    __outwordstring(Context->Port, Context->Buffer, Context->Size / sizeof(USHORT));
 
    /*
     * The 'rep outsw' instruction increments or decrements the address in ESI by Size * 2.
     * Test for CORE-20078: the ESI value should be preserved across calls.
     */
    ok_eq_pointer(Context->Buffer, Context->OldBuffer);
}
 
static
DECLSPEC_NOINLINE
VOID
TestWriteStringUlong(
    _In_ PTEST_CONTEXT Context)
{
    __outdwordstring(Context->Port, Context->Buffer, Context->Size / sizeof(ULONG));
 
    ok_eq_pointer(Context->Buffer, Context->OldBuffer);
}
 
static
DECLSPEC_NOINLINE
VOID
TestWriteStringUchar(
    _In_ PTEST_CONTEXT Context)
{
    __inbytestring(Context->Port, Context->Buffer, Context->Size);
 
    ok_eq_pointer(Context->Buffer, Context->OldBuffer);
}
 
static
DECLSPEC_NOINLINE
VOID
TestReadStringUshort(
    _In_ PTEST_CONTEXT Context)
{
    __inwordstring(Context->Port, Context->Buffer, Context->Size / sizeof(USHORT));
 
    ok_eq_pointer(Context->Buffer, Context->OldBuffer);
}
 
static
DECLSPEC_NOINLINE
VOID
TestReadStringUlong(
    _In_ PTEST_CONTEXT Context)
{
    __outdwordstring(Context->Port, Context->Buffer, Context->Size / sizeof(ULONG));
 
    ok_eq_pointer(Context->Buffer, Context->OldBuffer);
}
 
static
DECLSPEC_NOINLINE
VOID
TestReadStringUchar(
    _In_ PTEST_CONTEXT Context)
{
    __inbytestring(Context->Port, Context->Buffer, Context->Size);
 
    ok_eq_pointer(Context->Buffer, Context->OldBuffer);
}
 
static
VOID
TestStringIo(VOID)
{
    TEST_CONTEXT Context;
    UCHAR Buffer[20];
 
    /* End of the x86 I/O range */
    Context.Port = 0xFFFF - sizeof(ULONG);
 
    Context.Buffer = Buffer;
    Context.OldBuffer = Buffer;
    Context.Size = sizeof(Buffer);
 
    TestReadStringUchar(&Context);
    TestReadStringUshort(&Context);
    TestReadStringUlong(&Context);
 
    /*
     * Check whether the driver is running inside a virtual machine
     * as it's not safe to write to I/O ports
     * without having the port resources assigned.
     */
    if (!skip(KmtIsVirtualMachine, "Please run those tests in a supported virtual machine\n"))
    {
        TestWriteStringUchar(&Context);
        TestWriteStringUshort(&Context);
        TestWriteStringUlong(&Context);
    }
}
 
START_TEST(HalPortIo)
{
    TestStringIo();
}