Hi Thomas , thanks for looking into it . I suggest to handle the read issue in another bug because this one just deals with “jexec fails to execute simple helloworld.jar” .
( there seem to be a few other read(…) calls in the jdk code base to consider as well ) Can we push the existing change ? Regards, Matthias From: Thomas Stüfe [mailto:thomas.stu...@gmail.com] Sent: Mittwoch, 1. März 2017 12:47 To: Baesken, Matthias <matthias.baes...@sap.com> Cc: core-libs-dev@openjdk.java.net; Simonis, Volker <volker.simo...@sap.com> Subject: Re: RFR [XS] : 8175000 : jexec fails to execute simple helloworld.jar Hi Matthias, the fix makes sense, this is very clearly a bug. I'd suggest a simpler fix though: end -= 4; // make sure there are 4 bytes to read at start - while (start < end) { + while (start <= end) { Note that the code has a diffent bug too, very unlikely but not impossible to hit: 321 ssize_t count = read(fd, buf, CHUNK_SIZE); 322 if (count >= MIN_SIZE) { We attempt to read CHUNK_SIZE bytes and require the read to have returned at least MIN_SIZE (something like 30ish bytes). If not, jexec fails. read may have been interrupted (EINTR) or may have returned less bytes than MIN_SIZE, so it should read in a loop til eof or CHUNK_SIZE bytes are read. Kind Regards, Thomas On Wed, Mar 1, 2017 at 10:23 AM, Baesken, Matthias <matthias.baes...@sap.com<mailto:matthias.baes...@sap.com>> wrote: Ping ... Can I get a review please for the change ? Thanks, Matthias From: Baesken, Matthias Sent: Donnerstag, 23. Februar 2017 12:28 To: 'core-libs-dev@openjdk.java.net<mailto:core-libs-dev@openjdk.java.net>' <core-libs-dev@openjdk.java.net<mailto:core-libs-dev@openjdk.java.net>> Cc: Langer, Christoph <christoph.lan...@sap.com<mailto:christoph.lan...@sap.com>>; Erik Joelsson (erik.joels...@oracle.com<mailto:erik.joels...@oracle.com>) <erik.joels...@oracle.com<mailto:erik.joels...@oracle.com>>; 'Michel Trudeau' <michel.trud...@oracle.com<mailto:michel.trud...@oracle.com>> Subject: RE: RFR [XS] : 8175000 : jexec fails to execute simple helloworld.jar Here is the webrev for jdk9 : http://cr.openjdk.java.net/~mbaesken/webrevs/8175000/ ? And btw I really wonder - is jexec still needed in future jdk's like jdk10 ? Seems it is not used much . ? In case jexec will stay in the jdk I might add a test for the tool as well, if there is interest ( could not really find one that tests execution of a simple jar-file with jexec). Best regards, Matthias From: Baesken, Matthias Sent: Donnerstag, 23. Februar 2017 07:39 To: 'core-libs-dev@openjdk.java.net<mailto:core-libs-dev@openjdk.java.net>' <core-libs-dev@openjdk.java.net<mailto:core-libs-dev@openjdk.java.net><mailto:core-libs-dev@openjdk.java.net<mailto:core-libs-dev@openjdk.java.net>>> Cc: Langer, Christoph <christoph.lan...@sap.com<mailto:christoph.lan...@sap.com><mailto:christoph.lan...@sap.com<mailto:christoph.lan...@sap.com>>>; Erik Joelsson (erik.joels...@oracle.com<mailto:erik.joels...@oracle.com><mailto:erik.joels...@oracle.com<mailto:erik.joels...@oracle.com>>) <erik.joels...@oracle.com<mailto:erik.joels...@oracle.com><mailto:erik.joels...@oracle.com<mailto:erik.joels...@oracle.com>>> Subject: RE: RFR [XS] : 8175000 : jexec fails to execute simple helloworld.jar Hello, probably I should add the info that the fix is needed in jdk9 as well , not only jdk10 . Without the fix jdk9/10 show this error when executing a small example jar : /myjdk9/images/jdk/lib/jexec /java_test/hellojar/helloworld.jar invalid file (bad magic number): Exec format error with the fix : jdk/lib/jexec /java_test/hellojar/helloworld.jar Hello world from a jar file And btw I really wonder - is jexec still needed in future jdk's like jdk10 ? Seems it is not used much . Best regards, Matthias From: Baesken, Matthias Sent: Mittwoch, 22. Februar 2017 18:16 To: core-libs-dev@openjdk.java.net<mailto:core-libs-dev@openjdk.java.net><mailto:core-libs-dev@openjdk.java.net<mailto:core-libs-dev@openjdk.java.net>> Cc: Langer, Christoph <christoph.lan...@sap.com<mailto:christoph.lan...@sap.com><mailto:christoph.lan...@sap.com<mailto:christoph.lan...@sap.com>>>; Erik Joelsson (erik.joels...@oracle.com<mailto:erik.joels...@oracle.com><mailto:erik.joels...@oracle.com<mailto:erik.joels...@oracle.com>>) <erik.joels...@oracle.com<mailto:erik.joels...@oracle.com><mailto:erik.joels...@oracle.com<mailto:erik.joels...@oracle.com>>> Subject: RFR [XS] : 8175000 : jexec fails to execute simple helloworld.jar Hello , when looking into the jexec build I noticed that execution of a simple helloworld.jar with jexec does not work any more. I did a little patch for this which adjusted the addition done with CR 8156478: 3 Buffer overrun defect groups in jexec.c<https://javapartner.oracle.com/mproxy/repository/technology/java2/jdk9/jdk/rev/4f96129b45ee> . Could I have a review ( just a diff this time is provided because of infrastructure issues) for it ? Thanks, Matthias Bug : https://bugs.openjdk.java.net/browse/JDK-8175000 Diff for jdk10 : # HG changeset patch # User mbaesken # Date 1487782485 -3600 # Wed Feb 22 17:54:45 2017 +0100 # Node ID 93d55a711f3b1c3f282e6889c24d13f16d4a4548 # Parent 884872263accabd4ab68d005abd4e5393144aa4f 8175000: jexec fails to execute simple helloworld.jar diff --git a/src/java.base/unix/native/launcher/jexec.c b/src/java.base/unix/native/launcher/jexec.c --- a/src/java.base/unix/native/launcher/jexec.c +++ b/src/java.base/unix/native/launcher/jexec.c @@ -331,8 +331,9 @@ off_t end = start + xlen; if (end <= count) { - end -= 4; // make sure there are 4 bytes to read at start - while (start < end) { + // make sure there are 4 bytes to read at start + end -= 3; + while ((start < end) && (start < count-3)) { off_t xhid = SH(buf, start); off_t xdlen = SH(buf, start + 2);
