8287101: CDS should check for file truncation for all regions

Reviewed-by: iklam, coleenp

Author: calvinccheung

src/hotspot/share/cds/filemap.cpp

@@ -1370,12 +1370,10 @@ bool FileMapInfo::init_from_file(int fd) {
 
   _file_offset = header()->header_size(); // accounts for the size of _base_archive_name
 
-  if (is_static()) {
-    // just checking the last region is sufficient since the archive is written
-    // in sequential order
-    size_t len = os::lseek(fd, 0, SEEK_END);
-    FileMapRegion* si = space_at(MetaspaceShared::last_valid_region);
-    // The last space might be empty
+  size_t len = os::lseek(fd, 0, SEEK_END);
+
+  for (int i = 0; i <= MetaspaceShared::last_valid_region; i++) {
+    FileMapRegion* si = space_at(i);
     if (si->file_offset() > len || len - si->file_offset() < si->used()) {
       fail_continue("The shared archive file has been truncated.");
       return false;

test/hotspot/jtreg/runtime/cds/appcds/SharedArchiveConsistency.java

@@ -76,7 +76,7 @@ public static String startNewArchive(String testName) {
         return newArchiveName;
     }
 
-    public static void testAndCheck(String[] execArgs) throws Exception {
+    public static void testAndCheck(String[] execArgs, String... expectedMessages) throws Exception {
         OutputAnalyzer output = shareAuto ? TestCommon.execAuto(execArgs) : TestCommon.execCommon(execArgs);
         String stdtxt = output.getOutput();
         System.out.println("Note: this test may fail in very rare occasions due to CRC32 checksum collision");
@@ -88,6 +88,9 @@ public static void testAndCheck(String[] execArgs) throws Exception {
             output.shouldNotContain("A fatal error has been detected by the Java Runtime Environment");
           }
         }
+        for (int i = 0; i < expectedMessages.length; i++) {
+            output.shouldContain(expectedMessages[i]);
+        }
         for (String message : matchMessages) {
             if (stdtxt.contains(message)) {
                 // match any to return
@@ -236,11 +239,17 @@ public static void main(String... args) throws Exception {
         testAndCheck(verifyExecArgs);
 
         // delete bytes in data section forward
-        System.out.println("\n6. Delete bytes at beginning of data section, should fail\n");
+        System.out.println("\n6a. Delete bytes at beginning of data section, should fail\n");
         String deleteBytes = startNewArchive("delete-bytes");
         CDSArchiveUtils.deleteBytesAtRandomPositionAfterHeader(orgJsaFile, deleteBytes, 4096 /*bytes*/);
         testAndCheck(verifyExecArgs);
 
+        // delete bytes at the end
+        System.out.println("\n6b. Delete bytes at the end, should fail\n");
+        deleteBytes = startNewArchive("delete-bytes-end");
+        CDSArchiveUtils.deleteBytesAtTheEnd(orgJsaFile, deleteBytes);
+        testAndCheck(verifyExecArgs, "The shared archive file has been truncated.");
+
         // modify contents in random area
         System.out.println("\n7. modify Content in random areas, should fail\n");
         String randomAreas = startNewArchive("random-areas");

test/lib/jdk/test/lib/cds/CDSArchiveUtils.java

@@ -461,6 +461,35 @@ public static File deleteBytesAtRandomPositionAfterHeader(File orgFile, String n
         return dstFile;
     }
 
+    // returns the size of the last region with used bytes > 0.
+    private static long getLastUsedRegionSize(File jsaFile) throws Exception {
+        int i = num_regions - 1;
+        long regionSize = 0;
+        while (i >= 0) {
+            regionSize = usedRegionSizeAligned(jsaFile, i);
+            if (regionSize > 0) {
+                break;
+            }
+            i--;
+        }
+        return regionSize;
+    }
+
+    // delete last regions's used bytes at the end, so new file will be smaller than the original
+    public static File deleteBytesAtTheEnd(File orgFile, String newFileName) throws Exception {
+        long offset = fileHeaderSize(orgFile);
+        long bytesToDelete = getLastUsedRegionSize(orgFile);
+        File dstFile = new File(newFileName);
+        try (FileChannel inputChannel = new FileInputStream(orgFile).getChannel();
+             FileChannel outputChannel = new FileOutputStream(dstFile).getChannel()) {
+            long orgSize = inputChannel.size();
+            transferFrom(inputChannel, outputChannel, 0, offset);
+            inputChannel.position(offset);
+            transferFrom(inputChannel, outputChannel, offset, orgSize - bytesToDelete);
+        }
+        return dstFile;
+    }
+
     // used region size
     public static long usedRegionSizeAligned(File archiveFile, int region) throws Exception {
         long offset = spOffset + cdsFileMapRegionSize * region + spUsedOffset;