RFR (S): JDK-8129855: -XX:+IgnoreUnrecognizedVMOptions hides out of range VM options. (original) (raw)

gerard ziemski gerard.ziemski at oracle.com
Thu Oct 15 21:45:06 UTC 2015

hi Dan,

Thank you for the review, and please see my answers in-line:

From: Daniel D. Daugherty <daniel.daugherty at oracle.com> Reply-To: daniel.daugherty at oracle.com To: gerard ziemski <gerard.ziemski at oracle.com>, hotspot-dev at openjdk.java.net Developers <hotspot-dev at openjdk.java.net>, Dmitry Dmitriev <dmitry.dmitriev at oracle.com> On 9/29/15 12:09 PM, gerard ziemski wrote:

Here is a webrev1 updated with fixes based on Dmitry's feedback (ie. changes to the java test only):

http://cr.openjdk.java.net/~gziemski/8129855rev1 src/share/vm/runtime/arguments.cpp It took a couple of reading attempts (L893-899), but I'm good with this file. src/share/vm/runtime/globals.cpp L336: getlockedmessageext(buf, buflen); L337: return Flag::NONE; Seems a bit strange for Flag::NONE to be returned after we've called out to getlockedmessageext(buf, buflen). Looks like the protocol is to check buf[0]. If it's non-NULL: (buf[0] != '\0'), then we've gotten a message from the extension…

There are currently no cases from get_locked_message_ext() that we are interested in, so I didn’t bother to extend Flag::MsgType with more types and code there.

src/share/vm/runtime/globals.hpp No comments. test/runtime/CommandLine/IgnoreUnrecognizedVMOptions.java L29 * @summary -XX:+IgnoreUnrecognizedVMOptions should work according to the spec from https:... Is this URL persistent and will it survive the test of time (and DB changes)?

I honestly don’t know, but since there are no other places anywhere else where we link in such matter, I took it away and replaced with:

@summary -XX:+IgnoreUnrecognizedVMOptions should work according to the spec from JDK-8129855

L84: runJavaAndCheckExitValue(false, "-XX:-IgnoreUnrecognizedVMOptions", "-XX:-UnlockDiagnosticVMOptions", "-XX:+AlwaysSafeConstructors", "-version"); Should this be '-XX:-UnlockExperimentalVMOptions’?

Yes, fixed.

L85: runJavaAndCheckExitValue(false, "-XX:-IgnoreUnrecognizedVMOptions", "-XX:-UnlockDiagnosticVMOptions", "-XX:+FlightRecorder", "-version"); Should this be '-XX:-UnlockCommercialFeatures’?

Yes, fixed.

L87: runJavaAndCheckExitValue(false, "-XX:+IgnoreUnrecognizedVMOptions", "-XX:-UnlockDiagnosticVMOptions", "-XX:+AlwaysSafeConstructors", "-version"); Should this be '-XX:-UnlockExperimentalVMOptions’?

Yes, fixed.

L88: runJavaAndCheckExitValue(false, "-XX:+IgnoreUnrecognizedVMOptions", "-XX:-UnlockDiagnosticVMOptions", "-XX:+FlightRecorder", "-version"); Should this be '-XX:-UnlockCommercialFeatures’?

Yes, fixed.

L126-131: seems like you should narrow down the use of "-XX:-IgnoreUnrecognizedVMOptions" and "-XX:-UnlockDiagnosticVMOptions" to just the options to which they apply.

Actually the problem here is similar to line L84-L88 fixes that you pointed out above. Fixed.

I took the opportunity here when fixing these cases to add another section, "malformed unlocked flags”, which next to the already existing "locked flags” and "malformed locked flags” should give the test better coverage.

Thank you for the review!

I will re-test and post rev 1 soon.

cheers

cheers On 09/28/2015 04:55 PM, gerard ziemski wrote: hi all, We are fixing how IgnoreUnrecognizedVMOptions treats those flags whose values are out of range. Before the fix, the VM would continue even if flag’s value was out of range, ex: javaold -XX:+IgnoreUnrecognizedVMOptions -XX:MinTLABSize=0 -version sizet MinTLABSize=0 is outside the allowed range [ 1 ... 4294967295 ] java version "1.9.0-internal-fastdebug" Java(TM) SE Runtime Environment (build 1.9.0-internal-fastdebug-20150624183527.jesper.main2rt-b00) Java HotSpot(TM) Server VM (build 1.9.0-internal-fastdebug-20150624183527.jesper.main2rt-b00, mixed mode) now, we correctly exit the VM with an error, ex: javanew -XX:+IgnoreUnrecognizedVMOptions -XX:MinTLABSize=0 -version sizet MinTLABSize=0 is outside the allowed range [ 1 ... 18446744073709551615 ] Improperly specified VM option 'MinTLABSize=0' Error: Could not create the Java Virtual Machine. Error: A fatal exception has occurred. Program will exit. In addition IgnoreUnrecognizedVMOptions nows strictly follows the spec as outlined in JDK-8129855. The behavior changes depending on whether the build is product or debug. We also introduce a new test that verifies all known use cases that we care about. References: bugid: https://bugs.openjdk.java.net/browse/JDK-8129855 webrev: http://cr.openjdk.java.net/~gziemski/8129855rev0 discussion: http://mail.openjdk.java.net/pipermail/hotspot-dev/2015-June/019213.html Passes "JPRT hotspot" and "RBT testlist,noncolo.testlist quick"

cheers

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