[8u] RFR: JDK-8220786: Create new switch to redirect error reporting output to stdout or stderr

[Hohensee, Paul]

Also looks to me like the test in vmError.cpp should be "> 2" rather than "> 3". The original review thread

https://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2019-March/033293.html

has no discussion of why it's 3 instead of 2, but, since "> 3" is in tip, I'd rather keep "> 3" in this backport, fix it in tip, then backport the fix to 11u and 8u. It needs to be fixed in tip and 11u anyway, and doing it the formal way will keep things organized.

Otherwise lgtm.

Thanks,
Paul

-----Original Message-----
From: jdk8u-dev <jdk8u-dev-retn at openjdk.java.net> on behalf of Volker Simonis <volker.simonis at gmail.com>
Date: Tuesday, June 1, 2021 at 12:37 PM
To: jdk8u-dev <jdk8u-dev at openjdk.java.net>
Subject: [8u] RFR: JDK-8220786: Create new switch to redirect error reporting output to stdout or stderr

Hi,

can I please get a review for this backport?

This change initially went into jdk 13 and has already been downported
to jdk 11u more than a year ago. But as jdk8u is still used a lot and
increasingly in containerized environments I think it still makes a
lot of sense to downport it to jdk 8u as well.

If the JVM crashes in a containerized environment with its ephemeral
file system it becomes impossible to do any post mortem analysis of
the problem. In such situations the ability to dump the hs_err file to
stdout/stderr is very useful, because many container environments log
the stdout/stderr stream by default.

Original issue: https://bugs.openjdk.java.net/browse/JDK-8220786
Original CSR: https://bugs.openjdk.java.net/browse/JDK-8220787
Original change: http://hg.openjdk.java.net/jdk/jdk/rev/cf75ea6af695

jdk11 backport: https://bugs.openjdk.java.net/browse/JDK-8238531
jdk11 CSR: https://bugs.openjdk.java.net/browse/JDK-8238532
jdk11 change: https://hg.openjdk.java.net/jdk-updates/jdk11u/rev/783a56f3ac1f

jdk8 backport: https://bugs.openjdk.java.net/browse/JDK-8268055
jdk8 CSR: https://bugs.openjdk.java.net/browse/JDK-8268058
jdk8 webrev: http://cr.openjdk.java.net/~simonis/webrevs/2021/8220786-jdk8u/

I had to do quite some, but trivial changes to the jdk 11 backport
(which I started with) to fit it into jdk 8u:

arguments.cpp
-------------------
In jdk 11 "FLAG_SET_CMDLINE(boolean, ...)" expands to "JVMFlag::Error
boolAtPut(JVMFlagsWithType flag, bool value, JVMFlag::Flags origin)"
which returns a "JVMFlag::Error" and can be checked for success. In
jdk 8,  "FLAG_SET_CMDLINE(boolean, ...)" expands to "void
boolAtPut(CommandLineFlagWithType flag, bool value, Flag::Flags
origin)" which returns void, so there's nothing to check for...

vmError.cpp
----------------
I think the initial implementation has a bug in the following code:

-    if (fd_log != -1) {
+    if (fd_log > 3) {
       close(fd_log);

I think the intention is to close the log stream if it was not stdout
(i.e. "1") or stderr (i.e. "2") but it checks for "fd_log > 3".

I've fixed this in the downport but I'm happy to revert the fix if
somebody has a good explanation for the original code:

-    if (log.fd() != defaultStream::output_fd()) {
+    if (log.fd() > 2) {

ErrorFileRedirectTest.java
---------------------------------
- path/package shuffling for the test library
- use "Platform.isDebugBuild()" instead of "@requires (vm.debug ==
true)" which is not supported in jdk8
- remove "-XX:-CreateCoredumpOnCrash" option because it doesn't exist in jdk 8
- use "-XX:ErrorHandlerTest=12" instead of "-XX:ErrorHandlerTest=14"
because "14" is not available in jdk 8. But "12" still generates a
SIGSEV by reading from memory address 0.
- check for "T H R E A D" in the output because jdk 8 has no "S U M M
A R Y" section.

The jdk 8 CSR (https://bugs.openjdk.java.net/browse/JDK-8268058) has
been reviewed and waits for approval.

Thank you and best regards,
Volker