user space probe in ubuntu 14.04

[Frank Ch. Eigler]

academicgareth wrote:

> http://paste.openstack.org/show/462471/
> [...]
>>>    probe process("/usr/sbin/mysqld").mark("query__start")

These ubuntu 14 builds of mysql did not include the sys/sdt.h markers
necessary for use of the .mark() probes.  "readelf -n /usr/sbin/mysqld"
fails to show any NT_STAPSDT notes.

If you installed mysql-{client,server}-5.5-dbgsym, you should be
able to use .function() etc. probes ... but something's broken in the
ubuntu build system:

% dpkg -l 'mysql-server-5.5*'
ii  mysql-server-5.5                           5.5.44-0ubuntu0.14.04.1    amd64                      MySQL database server binaries and system database setup
ii  mysql-server-5.5-dbgsym                    5.5.44-0ubuntu0.14.04.1    amd64                      debug symbols for package mysql-server-5.5

% stap -L 'process("/usr/sbin/mysqld").function("*")'
[empty!]

% readelf -n /usr/sbin/mysqld
[...]
    Build ID: 7c5b991d6ba0d7722a41f9a39e2915f6a354a1c7

% dpkg -L mysql-server-5.5-dbgsym | grep 5b99
[empty!]

So the dbgsym package doesn't contain debuginfo for that actual build,
despite the identical version numbers.  Please raise this problem with
ubuntu.


The mysql-client-5.5{-dbgsym} peers appears less broken:

% stap -L 'process("/usr/bin/mysqldump").function("*")'
[... lots of delicious stuff ...]


- FChE