1 files changed, 126 insertions, 0 deletions
diff --git a/src/VBox/Additions/linux/sharedfolders/testcase/tstmmap.c b/src/VBox/Additions/linux/sharedfolders/testcase/tstmmap.c
new file mode 100644
index 00000000..9af2b4e4
--- /dev/null
+++ b/src/VBox/Additions/linux/sharedfolders/testcase/tstmmap.c
@@ -0,0 +1,126 @@
+/* $Id: tstmmap.c $ */
+/** @file
+ * vboxsf - Simple writable mmap testcase.
+ */
+
+/*
+ * Copyright (C) 2019-2023 Oracle and/or its affiliates.
+ *
+ * This file is part of VirtualBox base platform packages, as
+ * available from https://www.virtualbox.org.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, in version 3 of the
+ * License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+
+int main(int argc, char **argv)
+{
+    uint8_t     abBuf[4096];
+    int         fd;
+    size_t      cErrors = 0;
+    size_t      cbFile;
+    size_t      offFile;
+    uint8_t    *pbMapping;
+    const char *pszFile = "tstmmap-file1";
+    if (argc > 1)
+        pszFile = argv[1];
+
+    fd = open(pszFile, O_CREAT | O_TRUNC | O_RDWR, 0660);
+    if (fd < 0)
+    {
+        fprintf(stderr, "error creating file: %s\n", pszFile);
+        return 1;
+    }
+
+    /* write 64 KB to the file: */
+    memset(abBuf, 0xf6, sizeof(abBuf));
+    for (cbFile = 0; cbFile < 0x10000; cbFile += sizeof(abBuf))
+        if (write(fd, abBuf, sizeof(abBuf)) != sizeof(abBuf))
+        {
+            fprintf(stderr, "error writing file: %s\n", pszFile);
+            return 1;
+        }
+    fsync(fd);
+
+    /* Map the file: */
+    pbMapping = (uint8_t *)mmap(NULL, cbFile, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+    if (pbMapping == (void *)-1)
+    {
+        fprintf(stderr, "error mapping file: %s\n", pszFile);
+        return 1;
+    }
+
+    /* Modify the mapping and sync it: */
+    memset(pbMapping, 0xf7, cbFile);
+    if (msync(pbMapping, cbFile, MS_SYNC) != 0)
+    {
+        fprintf(stderr, "error msync'ing file: %s\n", pszFile);
+        return 1;
+    }
+
+    /* Unmap and close it: */
+    if (munmap(pbMapping, cbFile) != 0)
+        fprintf(stderr, "error munmap'ing file: %s\n", pszFile);
+    close(fd);
+
+    /*
+     * Open it again and check the content.
+     */
+    fd = open(pszFile, O_RDWR, 0);
+    if (fd < 0)
+    {
+        fprintf(stderr, "error reopening file: %s\n", pszFile);
+        return 1;
+    }
+
+    while (offFile < cbFile && cErrors < 42)
+    {
+        size_t offBuf;
+        ssize_t cbRead = read(fd, abBuf, sizeof(abBuf));
+        if (cbRead != (ssize_t)sizeof(abBuf))
+        {
+            fprintf(stderr, "error reading file: %zd, off %#zx (%s)\n", cbRead, offFile, pszFile);
+            return 1;
+        }
+
+        for (offBuf = 0; offBuf < sizeof(abBuf); offBuf++)
+            if (abBuf[offBuf] != 0xf7)
+            {
+                fprintf(stderr, "mismatch at %#zx: %#x, expected %#x\n", offFile + offBuf, abBuf[offBuf], 0xf7);
+                cErrors++;
+                if (cErrors > 42)
+                    break;
+            }
+
+        offFile += sizeof(abBuf);
+    }
+
+    close(fd);
+
+    return cErrors == 0 ? 0 : 1;
+}
+