On Wed, 11 Jan 2023 13:19:32 GMT, Jaikiran Pai <j...@openjdk.org> wrote:
> Can I please get a review for this change which proposes to fix the issue > reported in https://bugs.openjdk.org/browse/JDK-8206890? > > The `jlink` command allows a `--endian` option to specify the byte order in > the generated image. Before this change, when such a image was being > launched, the code would assume the byte order in the image to be the native > order of the host where the image is being launched. That would result in > failure to launch java, as noted in the linked issue. > > The commit in this PR, changes relevant places to not assume native order and > instead determine the byte order by reading the magic bytes in the image > file's header content. > > A new jtreg test has been added which reproduces the issue and verifies the > fix. Changes requested by jlaskey (Reviewer). src/java.base/share/classes/jdk/internal/jimage/ImageHeader.java line 222: > 220: if (bb.getInt() == MAGIC) { > 221: return bb.order(); > 222: } I would have just added `public static final int REVERSE_MAGIC = 0xDADAFECA;` and add an else clause. to compare to REVERSE_MAGIC. Much simpler. src/java.base/share/classes/jdk/internal/jimage/ImageHeader.java line 226: > 224: ByteOrder altByteOrder = bb.order() == ByteOrder.BIG_ENDIAN > 225: ? ByteOrder.LITTLE_ENDIAN : ByteOrder.BIG_ENDIAN; > 226: bb.flip(); Don't you just want to rewind here? src/java.base/share/native/libjimage/imageFile.cpp line 284: > 282: if (reader == NULL || !reader->open()) { > 283: // Failed to open. > 284: if (reader != NULL && reader->_invalid_magic) { Similar here. Flip the byte order if matches IMAGE_REVERSE_MAGIC. ------------- PR: https://git.openjdk.org/jdk/pull/11943
