Manually checking build id in elf files

[Alex Bennee <kernel-hacker@bennee.com>]

Hi,

I'm trying to track down a weird failure in oprofile due to bad CRC's
in debug files [1]. As has
been noted in the bug report gdb should complain. However I'm able to
load the symbol-file
with nary a harsh word from gdb. The manual says gdb uses one of two
methods to verify
a symbol file is the correct one. The second method mentions "Build
Id" and the ld man page
seems to imply I should see a "note" section in the library to
indicate the build id.

I'd like to manually check it but readelf doesn't show any such notes:

vnms@vnms:~$ readelf -n /usr/lib/libcairo.so.2.17.3
vnms@vnms:~$ readelf -n /usr/lib/debug/usr/lib/libcairo.so.2.17.3
vnms@vnms:~$

Am I missing something? Is there a way to use readelf to read this information?

[1] https://bugs.launchpad.net/ubuntu/+source/cairo/+bug/415424
-- 
Alex, homepage: http://www.bennee.com/~alex/
http://www.half-llama.co.uk