Non disruptive application core dump infrastructure

[Janani Venkataraman <jananive@linux.vnet.ibm.com>]

Hi,

We have developed a tool called "gencore" which captures the core of an 
application without
disrupting its process. The dump is collected non-disruptively and this 
tool currently supports
s390, x86 and power systems.

THE TOOL:

The tool can perform non-disruptive third party dumps. The tool also 
contains a library "libgencore"
which helps applicationsto trigger self dumps.

The tool can perform:

1) Third party dump: The pid of the process to dumped is given along 
with name of the core-file to
be created.

eg.

[janani@localhost]:gencore 6616 core.test

2) Self dump: The programs can request a self-dump using gencore() API, 
provided throughlibgencore. This
is implemented through a daemon which listens on a UNIX Filesocket for 
such requests. The daemon is started
immediately post installation. The program which requires the dump makes 
use of the gencore() API and provides
the name of the core-file as a parameter.

eg.

/* Opening the library, in this case the library is present in the 
/usr/lib64 */
lib = dlopen("libgencore.so", RTLD_LAZY);

gencore = dlsym(lib, "gencore");

Call the API:
gencore("/home/janani/core_test").

BASIC IDEA:

The basic idea is that the threads of the process are held using ptrace 
calls and the dump is generated in the
ELF format using the /proc/pid filesystem.

PATCH SET:
We have designed this tool based on the discussions with linux kernel 
community. The patches have been posted
at: https://lkml.org/lkml/2014/3/20/138

Do you think this can be part of the util-linux bundle? We can tweak it 
to make it work as a package in util-linux.

Let us know your reviews and comments.

Thanks.
Janani