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3.2.1.1.5 Ensure Permissions Allow Core Files
Some Java processes run setuid; that is, a process where the effective uid or gid differs from the
real uid or gid. On HP–UX 11.11 and later versions a kernel security feature prevents core file
creation for these processes. Use the following command when you are logged in as the root
user to enable core dumps of setuid Java processes:
$ echo "dump_all/W 1" | adb -w /stand/vmunix /dev/kmem
This capability is turned on only for the current boot.
3.2.1.2 Generating a Core File
Analyzing the core file is essential for troubleshooting problems. Core files are automatically
generated for application aborts. For hung processes and performance issues, you need to generate
them using gdb's dumpcore command.
The gdb dumpcore command forces the generation of a core file without killing a running
process. This command causes a core file named core.<pid> to be created. The current process
state is not modified when this command is issued.
Following is an example for a Java application running on an Integrity system:
$ echo "dumpcore\nq" > gdb_cmds
$ ps -u myuser | grep java
12290 pts/6 12:58 java
$ gdb --command=gdb_cmds -batch /opt/java1.4/bin/IA64N/java 12290
This generates a core file in the current directory with the name core.12290.
On HP-UX 11.31, another way to generate a core file is by using the gcore command. Following
is an example invocation of gcore to dump the core image of process 11050. The core image
will be written to file core.11050 by default:
$ gcore 11050
3.2.1.3 Verifying a Core File
Once you have successfully collected your core file, you should verify that it is complete and
valid with the following two steps.
First, open the core file in gdb and check the error and warning messages. If the message
“<corefilename> is not a core dump: File format not recognized“ is displayed when you open
the file, your core file is invalid. Following is an example of verifying a core file produced by a
32-bit application on a PA-RISC. In this example, the core file is valid.
$ gdb /opt/java1.4/jre/lib/PA_RISC2.0/server/libjunwind.sl core
HP gdb 5.5.7 for PA-RISC 1.1 or 2.0 (narrow), HP-UX 11.00 and target hppa1.1-hp-hpux11.00.
Copyright 1986 - 2001 Free Software Foundation, Inc.
Hewlett-Packard Wildebeest 5.5.7 (based on GDB) is covered by the GNU General Public License. Type "show copying"
to see the conditions to change it and/or distribute copies. Type "show warranty" for warranty/support.
..
Core was generated by `java'.
Program terminated with signal 6, Aborted.
#0 0xc0214db0 in kill+0x10 () from ./libc.2
Second, check to make sure that the core file was not trucated by issuing the “what core”
command. If you do not see the dld.sl version at the bottom of the what output, then the core
file is truncated and is not usable. In the following example, the dld.sl version exists at the
bottom of the what output, so you know the core file is not truncated:
$ what core
core:
some other library names and version information ...
92453-07 dld dld dld.sl B.11.48 EXP 051121
3.2.2 Collecting Fatal Error Log Information
When a Java application aborts, the fatal error log file (hs_err_pid<pid>.log) is generated.
The contents of this file vary depending on the architecture and the Java version (for example,
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