Bug ID: JDK-8026300 VM warning: increase O_BUFLEN in ostream.hpp -- output truncated occurs with fastdebug VM when printing flags

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JDK 7	JDK 8	JDK 9
7u80Resolved	8u20Fixed	9 b02Fixed

As of jdk8-b111 (hs25-b53) we have a regression trying to print the final flags values:

 /java/re/jdk/8/promoted/all/b111/binaries/linux-i586/fastdebug/bin/java -XX:+PrintFlagsFinal -version 2>&1 | more
[Global flags]
    ccstr AbortVMOnException                        =                 Java HotSpot(TM) Server VM warning: increase O_BUFLEN
in ostream.hpp -- output truncated
{notproduct}
    ccstr AbortVMOnExceptionMessage                 =                 Java HotSpot(TM) Server VM warning: increase O_BUFLEN
in ostream.hpp -- output truncated
{notproduct}
    uintx AdaptiveSizeDecrementScaleFactor          = 4               Java HotSpot(TM) Server VM warning: increase O_BUFLEN
in ostream.hpp -- output truncated
{product}
    uintx AdaptiveSizeMajorGCDecayTimeScale         = 10              Java HotSpot(TM) Server VM warning: increase O_BUFLEN
in ostream.hpp -- output truncated
{product}
    uintx AdaptiveSizePausePolicy                   = 0               Java HotSpot(TM) Server VM warning: increase O_BUFLEN
in ostream.hpp -- output truncated
{product}
    uintx AdaptiveSizePolicyCollectionCostMargin    = 50              Java HotSpot(TM) Server VM warning: increase O_BUFLEN
in ostream.hpp -- output truncated
{product}

Somehow we get a ostream buffer overflow printing each flag - though the buffer should be 2000 characters and so of ample size.

Only affects fastdebug.

Can we please backport this everywhere it applies.

03-04-2014

A simple fix when repo is reopen: diff --git a/src/share/vm/runtime/globals.cpp b/src/share/vm/runtime/globals.cpp --- a/src/share/vm/runtime/globals.cpp +++ b/src/share/vm/runtime/globals.cpp @@ -295,7 +295,7 @@ else st->print("%-16s", ""); } - st->print("%-20"); + st->print("%-20s", " "); print_kind(st); if (withComments) {

02-12-2013

ILW LHM = P4 I: Low, Warnings when printing flags L: High, Happens every time with -XX:+PrintFlagsFinal when running on debug builds W: Medium, Don't use this flag on debug builds

11-10-2013

Duplicate :	JDK-6967948 - "OpenJDK 64-Bit Server VM warning: increase O_BUFLEN in ostream.hpp -- output truncated" on Windows
Relates :	JDK-6967948 - "OpenJDK 64-Bit Server VM warning: increase O_BUFLEN in ostream.hpp -- output truncated" on Windows